Merge pull request #921 from mathuo/883-tab-overflow-dropdown-doesnt-collide-with-edge-of-screen

883 tab overflow dropdown doesnt collide with edge of screen

.codesandbox/ci.json

@@ -0,0 +1,46 @@
+{
+  "packages": [
+    "packages/dockview-core",
+    "packages/dockview-vue",
+    "packages/dockview-react",
+    "packages/dockview"
+  ],
+  "sandboxes": [
+    "/packages/docs/sandboxes/constraints-dockview",
+    "/packages/docs/sandboxes/customheader-dockview",
+    "/packages/docs/sandboxes/demo-dockview",
+    "/packages/docs/sandboxes/dnd-dockview",
+    "/packages/docs/sandboxes/dockview-app",
+    "/packages/docs/sandboxes/editor-gridview",
+    "/packages/docs/sandboxes/events-dockview",
+    "/packages/docs/sandboxes/externaldnd-dockview",
+    "/packages/docs/sandboxes/floatinggroup-dockview",
+    "/packages/docs/sandboxes/fullwidthtab-dockview",
+    "/packages/docs/sandboxes/headeractions-dockview",
+    "/packages/docs/sandboxes/groupcontol-dockview",
+    "/packages/docs/sandboxes/iframe-dockview",
+    "/packages/docs/sandboxes/keyboard-dockview",
+    "/packages/docs/sandboxes/layout-dockview",
+    "/packages/docs/sandboxes/lockedgroup-dockview",
+    "/packages/docs/sandboxes/maximizegroup-dockview",
+    "/packages/docs/sandboxes/nativeapp-dockview",
+    "/packages/docs/sandboxes/nested-dockview",
+    "/packages/docs/sandboxes/popoutgroup-dockview",
+    "/packages/docs/sandboxes/rendering-dockview",
+    "/packages/docs/sandboxes/rendermode-dockview",
+    "/packages/docs/sandboxes/resize-dockview",
+    "/packages/docs/sandboxes/resizecontainer-dockview",
+    "/packages/docs/sandboxes/scrollbars-dockview",
+    "/packages/docs/sandboxes/simple-dockview",
+    "/packages/docs/sandboxes/simple-gridview",
+    "/packages/docs/sandboxes/simple-paneview",
+    "/packages/docs/sandboxes/tabheight-dockview",
+    "/packages/docs/sandboxes/updatetitle-dockview",
+    "/packages/docs/sandboxes/watermark-dockview",
+    "/packages/docs/sandboxes/javascript/fullwidthtab-dockview",
+    "/packages/docs/sandboxes/javascript/simple-dockview",
+    "/packages/docs/sandboxes/javascript/tabheight-dockview",
+    "/packages/docs/sandboxes/javascript/vanilla-dockview"
+  ],
+  "node": "18"
+}

.editorconfig

@@ -0,0 +1,10 @@
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+quote_type = single

.eslintrc

@@ -1,21 +0,0 @@
-{
-    "parser": "@typescript-eslint/parser",
-    "plugins": [
-      "@typescript-eslint"
-    ],
-    "extends": [
-      "eslint:recommended",
-      "plugin:@typescript-eslint/eslint-recommended",
-      "plugin:@typescript-eslint/recommended"
-    ],
-    "rules": {
-      "no-case-declarations":"off",
-      "@typescript-eslint/no-namespace": "off",
-      "@typescript-eslint/explicit-module-boundary-types": "off",
-      "@typescript-eslint/no-explicit-any": "off",
-      "@typescript-eslint/no-unused-vars": "off",
-      "@typescript-eslint/ban-types": "off",
-      "@typescript-eslint/no-empty-interface": "off",
-      "@typescript-eslint/no-non-null-assertion":"off"
-    }
-  }

.eslintrc.js

@@ -0,0 +1,19 @@
+module.exports = {
+    root: true,
+    parserOptions: {
+        sourceType: 'module',
+        project: ['./tsconfig.eslint.json', './packages/*/tsconfig.json'],
+        tsconfigRootDir: __dirname,
+    },
+    plugins: ['@typescript-eslint'],
+    extends: ['eslint:recommended', 'plugin:@typescript-eslint/recommended'],
+    rules: {
+        'no-case-declarations': 'off',
+        '@typescript-eslint/no-namespace': 'off',
+        '@typescript-eslint/explicit-module-boundary-types': 'off',
+        '@typescript-eslint/no-explicit-any': 'off',
+        '@typescript-eslint/no-unused-vars': 'off',
+        '@typescript-eslint/ban-types': 'off',
+        '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+};

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,33 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+[dockview.dev](https://dockview.dev) provides a number of examples with Code Sandbox templates. Are you able to produce the bug by forking one of those templates? Sharing a link to the forked sandbox with the bug would be extremely helpful.
+
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Desktop (please complete the following information):**
+ - Browser [e.g. chrome, safari]
+ - Version [e.g. 22]
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/workflows/codeql-analysis.yml

@@ -3,60 +3,60 @@
 #
 # You may wish to alter this file to override the set of languages analyzed,
 # or to provide custom queries or build logic.
-name: "CodeQL"
+name: 'CodeQL'
 
 on:
-  push:
-    branches: [master]
-  pull_request:
-    # The branches below must be a subset of the branches above
-    branches: [master]
-  schedule:
-    - cron: '0 4 * * 1'
+    # push:
+    #   branches: [master]
+    # pull_request:
+    #   # The branches below must be a subset of the branches above
+    #   branches: [master]
+    schedule:
+        - cron: '0 4 * * *'
 
 jobs:
-  analyze:
-    name: Analyze
-    runs-on: ubuntu-latest
+    analyze:
+        name: Analyze
+        runs-on: ubuntu-latest
 
-    strategy:
-      fail-fast: false
-      matrix:
-        # Override automatic language detection by changing the below list
-        # Supported options are ['csharp', 'cpp', 'go', 'java', 'javascript', 'python']
-        language: ['javascript']
-        # Learn more...
-        # https://docs.github.com/en/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#overriding-automatic-language-detection
+        strategy:
+            fail-fast: false
+            matrix:
+                # Override automatic language detection by changing the below list
+                # Supported options are ['csharp', 'cpp', 'go', 'java', 'javascript', 'python']
+                language: ['javascript']
+                # Learn more...
+                # https://docs.github.com/en/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#overriding-automatic-language-detection
 
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v4
 
-    # Initializes the CodeQL tools for scanning.
-    - name: Initialize CodeQL
-      uses: github/codeql-action/init@v1
-      with:
-        languages: ${{ matrix.language }}
-        # If you wish to specify custom queries, you can do so here or in a config file.
-        # By default, queries listed here will override any specified in a config file.
-        # Prefix the list here with "+" to use these queries and those in the config file.
-        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+            # Initializes the CodeQL tools for scanning.
+            - name: Initialize CodeQL
+              uses: github/codeql-action/init@v3
+              with:
+                  languages: ${{ matrix.language }}
+                  # If you wish to specify custom queries, you can do so here or in a config file.
+                  # By default, queries listed here will override any specified in a config file.
+                  # Prefix the list here with "+" to use these queries and those in the config file.
+                  # queries: ./path/to/local/query, your-org/your-repo/queries@main
 
-    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
-    # If this step fails, then you should remove it and run the build manually (see below)
-    - name: Autobuild
-      uses: github/codeql-action/autobuild@v1
+            # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+            # If this step fails, then you should remove it and run the build manually (see below)
+            - name: Autobuild
+              uses: github/codeql-action/autobuild@v3
 
-    # ℹ️ Command-line programs to run using the OS shell.
-    # 📚 https://git.io/JvXDl
+            # ℹ️ Command-line programs to run using the OS shell.
+            # 📚 https://git.io/JvXDl
 
-    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
-    #    and modify them (or add more) to build your code if your project
-    #    uses a compiled language
+            # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+            #    and modify them (or add more) to build your code if your project
+            #    uses a compiled language
 
-    #- run: |
-    #   make bootstrap
-    #   make release
+            #- run: |
+            #   make bootstrap
+            #   make release
 
-    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
+            - name: Perform CodeQL Analysis
+              uses: github/codeql-action/analyze@v3

.github/workflows/deploy-docs.yml

@@ -0,0 +1,46 @@
+name: Deploy Docs
+
+on:
+    workflow_dispatch:
+
+jobs:
+    deploy-nightly-demo-app:
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout 🛎️
+              uses: actions/checkout@v4
+            - name: Use Node.js
+              uses: actions/setup-node@v4
+              with:
+                  node-version: '20.x'
+
+            - uses: actions/cache@v4
+              with:
+                  path: ~/.npm
+                  key: ${{ runner.os }}-node-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-node-
+
+            - run: yarn install
+            - run: npm run build
+              working-directory: packages/dockview-core
+            - run: npm run build
+              working-directory: packages/dockview
+            - run: npm run build
+              working-directory: packages/dockview-vue
+            - run: npm run build
+              working-directory: packages/dockview-react
+            - run: npm run build
+              working-directory: packages/docs
+            - run: npm run docs
+              working-directory: .
+            - run: npm run package-docs
+              working-directory: .
+            - name: Deploy 🚀
+              uses: JamesIves/github-pages-deploy-action@3.7.1
+              with:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+                  BRANCH: gh-pages # The branch the action should deploy to.
+                  FOLDER: build # The folder the action should deploy.
+                  TARGET_FOLDER: .
+                  CLEAN: true # Automatically remove deleted files from the deploy branch

.github/workflows/deploy_nightly.yml

@@ -1,40 +0,0 @@
-name: Deploy Nightly Demo App
-
-on:
-  schedule:
-    - cron:  '0 3 * * *' # every day at 3 am UTC
-
-jobs:
-  deploy-nightly-demo-app:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout 🛎️
-        uses: actions/checkout@v2.3.1 # If you're using actions/checkout@v2 you must set persist-credentials to false in most cases for the deployment to work correctly.
-        with:
-          persist-credentials: false
-
-      - name: Use Node.js
-        uses: actions/setup-node@v1
-        with:
-            node-version: '12.x'
-
-      - uses: actions/cache@v2
-        with:
-          path: ~/.npm
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-              ${{ runner.os }}-node-
-              
-      - run: npm ci
-      - run: npm run bootstrap-no-hoist
-      - run: npm run build
-      - run: npm run test
-      - run: npm run package-all
-      - name: Deploy 🚀
-        uses: JamesIves/github-pages-deploy-action@3.7.1
-        with:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          BRANCH: gh-pages # The branch the action should deploy to.
-          FOLDER: output # The folder the action should deploy.
-          TARGET_FOLDER: output
-          CLEAN: true # Automatically remove deleted files from the deploy branch

.github/workflows/main.yml

@@ -7,25 +7,27 @@ jobs:
         runs-on: ubuntu-latest
 
         steps:
-            - uses: actions/checkout@v2
-
+            - uses: actions/checkout@v4
+              # might be required for sonar to work correctly
+              with:
+                  fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of analysis
             - name: Use Node.js
-              uses: actions/setup-node@v1
+              uses: actions/setup-node@v4
               with:
-                  node-version: '12.x'
+                  node-version: '20.x'
 
-            - uses: actions/cache@v2
+            - uses: actions/cache@v4
               with:
-                path: ~/.npm
-                key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-                restore-keys: |
-                    ${{ runner.os }}-node-
-                    
-            - run: npm ci
-            - run: npm run bootstrap
+                  path: ~/.npm
+                  key: ${{ runner.os }}-node-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-node-
+
+            - run: yarn
             - run: npm run build
-            - run: npm run test-cov
-            - run: npm run codecov-publish
+            - run: npm run test:cov
+            - name: SonarCloud Scan
+              uses: sonarsource/sonarqube-scan-action@v5
               env:
-                  CI: true
-                  CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # Needed to get PR information, if any
+                  SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}

.github/workflows/publish.yml

@@ -0,0 +1,78 @@
+name: Publish to npm
+
+env:
+    NPM_CONFIG_PROVENANCE: true
+on:
+    workflow_dispatch:
+    release:
+        types: [published]
+jobs:
+    publish:
+        if: github.event_name == 'release'
+        runs-on: ubuntu-latest
+        env:
+            NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        permissions:
+            id-token: write
+        steps:
+            - uses: actions/checkout@v4
+            - uses: actions/setup-node@v4
+              with:
+                  node-version: '20.x'
+                  registry-url: 'https://registry.npmjs.org'
+
+            - uses: actions/cache@v4
+              with:
+                  path: ~/.npm
+                  key: ${{ runner.os }}-node-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-node-
+
+            - run: yarn
+            - name: Publish dockview-core
+              run: npm publish --provenance
+              working-directory: packages/dockview-core
+            - name: Publish dockview
+              run: npm publish --provenance
+              working-directory: packages/dockview
+            - name: Publish dockview-vue
+              run: npm publish --provenance
+              working-directory: packages/dockview-vue
+            - name: Publish dockview-react
+              run: npm publish --provenance
+              working-directory: packages/dockview-react
+    publish-experimental:
+        if: github.event_name == 'workflow_dispatch'
+        runs-on: ubuntu-latest
+        env:
+            NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        permissions:
+            id-token: write
+        steps:
+            - uses: actions/checkout@v4
+            - uses: actions/setup-node@v4
+              with:
+                  node-version: '20.x'
+                  registry-url: 'https://registry.npmjs.org'
+
+            - uses: actions/cache@v4
+              with:
+                  path: ~/.npm
+                  key: ${{ runner.os }}-node-${{ hashFiles('**/yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-node-
+
+            - run: yarn
+            - run: npm run set-experimental-versions
+            - name: Publish dockview-core
+              run: npm publish --provenance --tag experimental
+              working-directory: packages/dockview-core
+            - name: Publish dockview
+              run: npm publish --provenance --tag experimental
+              working-directory: packages/dockview
+            - name: Publish dockview-vue
+              run: npm publish --provenance --tag experimental
+              working-directory: packages/dockview-vue
+            - name: Publish dockview-react
+              run: npm publish --provenance --tag experimental
+              working-directory: packages/dockview-react

.gitignore

@@ -7,4 +7,11 @@ typedocs/
 .DS_Store
 *-debug.log
 .build
-storybook-static/
+storybook-static/
+.rollup.cache/
+test-report.xml
+*.code-workspace
+yarn-error.log
+/build
+/docs/
+/generated/

.vscode/extensions.json

@@ -3,7 +3,13 @@
     // Extension identifier format: ${publisher}.${name}. Example: vscode.csharp
 
     // List of extensions which should be recommended for users of this workspace.
-    "recommendations": ["esbenp.prettier-vscode", "redhat.vscode-yaml"],
+    "recommendations": [
+        "esbenp.prettier-vscode",
+        "redhat.vscode-yaml",
+        "dbaeumer.vscode-eslint",
+        "editorconfig.editorconfig",
+        "vue.volar"
+    ],
     // List of extensions recommended by VS Code that should not be recommended for users of this workspace.
     "unwantedRecommendations": []
 }

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 mathuo
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,97 +1,38 @@
 <div align="center">
 <h1>dockview</h1>
 
-<p>Zero dependency layout manager supporting tabs, grids and splitviews with ReactJS support</p>
+<p>Zero dependency layout manager supporting tabs, groups, grids and splitviews. Supports React, Vue and Vanilla TypeScript</p>
 
 </div>
 
 ---
 
-![stability-experimental](https://img.shields.io/badge/stability-experimental-orange.svg)
-[![npm version](https://badge.fury.io/js/dockview.svg)](https://www.npmjs.com/package/dockview)
+[![npm version](https://badge.fury.io/js/dockview-core.svg)](https://www.npmjs.com/package/dockview-core)
+[![npm](https://img.shields.io/npm/dm/dockview-core)](https://www.npmjs.com/package/dockview-core)
 [![CI Build](https://github.com/mathuo/dockview/workflows/CI/badge.svg)](https://github.com/mathuo/dockview/actions?query=workflow%3ACI)
-[![codecov](https://codecov.io/gh/mathuo/dockview/branch/master/graph/badge.svg?token=BF083TK64H)](https://codecov.io/gh/mathuo/dockview/branch/master)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=coverage)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=alert_status)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Bundle Phobia](https://badgen.net/bundlephobia/minzip/dockview-core)](https://bundlephobia.com/result?p=dockview-core)
 
 ##
 
-A zero dependency layout manager based on the layering of split-view components with ReactJS support.
-- View the live demo [here](https://mathuo.github.io/dockview/). 
-- Storybook demo [here](https://mathuo.github.io/dockview/output/storybook-static).
-- Automatically generated TypeDocs can be found [here](https://mathuo.github.io/dockview/output/docs/index.html).
+![](packages/docs/static/img/splashscreen.gif)
 
-## Installation
-You can install the project from [npm](https://www.npmjs.com/package/dockview). The project comes with TypeScript typings.
+Please see the website: https://dockview.dev
 
-```bash
-npm install --save dockview
-```
+## Features
 
-## Configuration
+-   Serialization / deserialization with full layout management
+-   Support for split-views, grid-views and 'dockable' views
+-   Themeable and customizable
+-   Tab and Group docking / Drag n' Drop
+-   Popout Windows
+-   Floating Groups
+-   Extensive API
+-   Supports Shadow DOMs
+-   High test coverage
+-   Documentation website with live examples
+-   Transparent builds and Code Analysis
+-   Security at mind - verifed publishing and builds through GitHub Actions
 
-You must import the core css stylesheet but you are free to supply your own theming in addition to the core stylesheet. The location to reference for the stylesheet is
-
-```
-dockview/dist/styles.css
-```
-
-By default the seperator between panels is `transparent` but this can be set through the CSS varibable `--separator-border`. Alternatively, or if you require the `DockviewReact` you should attach the classname of an included theme; either `dockview-theme-dark` or `dockview-theme-light`.
-
-
-### Sandbox examples
-- [Dockview](https://codesandbox.io/s/simple-dockview-t6491)
-- [Gridview](https://codesandbox.io/s/simple-gridview-jrp0n)
-- [Splitview](https://codesandbox.io/s/simple-splitview-l53nn)
-- [Paneview](https://codesandbox.io/s/simple-paneview-v8qvb)
-
-## React
-
-### Splitview
-
-```javascript
-import { 
-    ISplitviewPanelProps, 
-    Orientation, 
-    SplitviewReact,
-    SplitviewReadyEvent
-} from "dockview";
-
-const components = {
-    "my-component": (props: ISplitviewPanelProps) => {
-        return (
-            <div>
-                <span>This is a panel</span>
-                <span>{props.arbitraryProp}</span>
-            </div>
-        )
-    }
-}
-
-const Example = () => {
-    const onReady = (event: SplitviewReadyEvent) => {
-        event.addPanel({
-            id: "panel-1",
-            component: "my-component",
-            params: {
-                arbitraryProp: "Hello World"
-            }
-        });
-        event.addPanel({
-            id: "panel-2",
-            component: "my-component",
-            params: {
-                arbitraryProp: "World Hello"
-            }
-        });
-    }
-
-    return (
-        <SplitviewReact
-            components={components}
-            onReady={onReady}
-            orientation={Orientation.VERTICAL}
-        />
-    )
-}
-```
-
-## Run the demo locally
+Want to verify our builds? Go [here](https://www.npmjs.com/package/dockview#user-content-provenance).

SECURITY.md

@@ -0,0 +1,8 @@
+# Reporting a Vulnerability
+
+- Dockview is an entirely open source project.
+- All build and publication scripts use public Github Action files found [here](https://github.com/mathuo/dockview/tree/master/.github/workflows).
+- All npm publications are verified through the use of [provenance statements](https://docs.npmjs.com/generating-provenance-statements/).
+- All builds are scanned with SonarCube and outputs can be found [here](https://sonarcloud.io/summary/overall?id=mathuo_dockview).
+
+If you believe you have found a security or vulnerability issue please send a complete example to github.mathuo@gmail.com where it will be investigated.

jest-setup.ts

@@ -0,0 +1 @@
+import '@testing-library/jest-dom';

jest.config.base.js

@@ -1,20 +0,0 @@
-const {join, normalize} = require("path");
-
-const tsconfig = normalize(join(__dirname, "tsconfig.test.json"))
-
-module.exports = {
-    displayName: { name: "root" },
-    preset: "ts-jest",
-    projects: ["<rootDir>/packages/*/jest.config.js"],
-    transform: {
-        "^.+\\.tsx?$":"ts-jest"
-    },
-    moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json"],
-    globals: {
-        "ts-jest": {
-            tsconfig,
-            experimental: true,
-            compilerHost: true
-        }
-    }
-}

jest.config.js

@@ -1,16 +0,0 @@
-const baseConfig = require("./jest.config.base");
-
-module.exports = {
-    ...baseConfig,
-    displayName: { name: "root", color: "blue" },
-    projects: ["<rootDir>/packages/*/jest.config.js"],
-    collectCoverage: true,
-    collectCoverageFrom:[
-        "<rootDir>/packages/*/src/**/*.{js,jsx,ts,tsx}",
-    ],
-    coveragePathIgnorePatterns: [
-        "/node_modules/",
-        "<rootDir>packages/*/src/__tests__/",
-    ],
-    coverageDirectory: "coverage"
-};

jest.config.ts

@@ -0,0 +1,17 @@
+import { JestConfigWithTsJest } from 'ts-jest';
+
+const config: JestConfigWithTsJest = {
+    preset: 'ts-jest',
+    displayName: { name: 'root', color: 'blue' },
+    projects: ['<rootDir>/packages/*/jest.config.ts'],
+    collectCoverage: true,
+    collectCoverageFrom: ['<rootDir>/packages/*/src/**/*.{js,jsx,ts,tsx}'],
+    coveragePathIgnorePatterns: [
+        '/node_modules/',
+        '<rootDir>/packages/*/src/__tests__/',
+    ],
+    coverageDirectory: 'coverage',
+    testResultsProcessor: 'jest-sonar-reporter',
+};
+
+export default config;

lerna.json

@@ -1,6 +1,12 @@
 {
-    "packages": [
-        "packages/*"
-    ],
-    "version": "0.0.5"
-}
+  "packages": [
+    "packages/*"
+  ],
+  "version": "4.2.4",
+  "npmClient": "yarn",
+  "command": {
+    "publish": {
+      "message": "chore(release): publish %s"
+    }
+  }
+}

module-build/tsconfig.es6.json

@@ -1,30 +0,0 @@
-{
-    "compilerOptions": {
-        "module": "es6",
-        "declaration": true,
-        "target": "es5",
-        "moduleResolution": "node",
-        "esModuleInterop": true,
-        "downlevelIteration": true,
-        "incremental": true,
-        "noImplicitReturns": true,
-        "noImplicitAny": true,
-        "allowUnreachableCode": false,
-        "forceConsistentCasingInFileNames": true,
-        // "strict": true,
-        "strictBindCallApply": true, // pass
-        "alwaysStrict": true, // pass
-        "noImplicitThis": true, // pass
-        "strictFunctionTypes": true, // pass
-        "strictNullChecks": false,
-        "strictPropertyInitialization": false,
-        "lib": [
-			"ES2015",
-			"ES2016.Array.Include",
-			"ES2017.String",
-			"ES2018.Promise",
-			"DOM",
-		]
-        
-    }
-}

module-build/tsconfig.json

@@ -1,29 +0,0 @@
-{
-    "compilerOptions": {
-        "module": "commonjs",
-        "declaration": true,
-        "target": "es5",
-        "esModuleInterop": true,
-        "downlevelIteration": true,
-        "incremental": true,
-        "sourceMap": true,
-        "noImplicitReturns": true,
-        "noImplicitAny": true,
-        "allowUnreachableCode": false,
-        "forceConsistentCasingInFileNames": true, 
-        // "strict": true,
-        "strictBindCallApply": true, // pass
-        "alwaysStrict": true, // pass
-        "noImplicitThis": true, // pass
-        "strictFunctionTypes": true, // pass
-        "strictNullChecks": false,
-        "strictPropertyInitialization": false,
-        "lib": [
-			"ES2015",
-			"ES2016.Array.Include",
-			"ES2017.String",
-			"ES2018.Promise",
-			"DOM",
-		]
-    }
-}

package.json

@@ -1,61 +1,81 @@
 {
-    "name": "splitview-root",
-    "private": true,
-    "description": "",
-    "main": "index.js",
-    "scripts": {
-        "test": "jest",
-        "lint": "eslint packages/**/src/** --ext .ts,.tsx,.js,.jsx",
-        "package": "node scripts/package.js",
-        "package-all": "npm run build-demo && npm run docs && node scripts/package.js",
-        "build": "lerna run build --ignore splitview-demo",
-        "build-demo": "lerna run build --scope splitview-demo",
-        "docs": "lerna run docs --scope dockview",
-        "clean": "lerna run clean",
-        "bootstrap": "lerna bootstrap --hoist",
-        "bootstrap-no-hoist": "lerna bootstrap",
-        "test-cov": "jest --coverage",
-        "codecov-publish": "codecov",
-        "version-beta-build": "lerna version prerelease --preid beta",
-        "publish-app": "lerna publish"
-    },
-    "repository": {
-        "type": "git",
-        "url": "git+https://github.com/mathuo/dockview.git"
-    },
-    "author": "",
-    "license": "ISC",
-    "bugs": {
-        "url": "https://github.com/mathuo/dockview/issues"
-    },
-    "homepage": "https://github.com/mathuo/dockview#readme",
-    "devDependencies": {
-        "@testing-library/dom": "^7.28.1",
-        "@types/jest": "^26.0.15",
-        "@typescript-eslint/eslint-plugin": "^4.8.1",
-        "@typescript-eslint/parser": "^4.8.1",
-        "codecov": "^3.8.1",
-        "cross-env": "^7.0.2",
-        "css-loader": "^3.6.0",
-        "eslint": "^7.14.0",
-        "fs-extra": "^9.0.1",
-        "gulp": "^4.0.2",
-        "gulp-concat": "^2.6.1",
-        "gulp-sass": "^4.1.0",
-        "jest": "^26.6.3",
-        "jsdom": "^16.4.0",
-        "lerna": "^3.22.1",
-        "merge2": "^1.4.1",
-        "node-sass": "^4.14.1",
-        "rimraf": "^3.0.2",
-        "sass-loader": "^8.0.2",
-        "style-loader": "^1.3.0",
-        "ts-jest": "^26.4.4",
-        "ts-loader": "^7.0.5",
-        "typescript": "^4.1.2",
-        "webpack": "^5.6.0",
-        "webpack-cli": "^4.2.0",
-        "webpack-dev-server": "^3.11.0"
-    },
-    "dependencies": {}
+  "name": "dockview-monorepo-root",
+  "private": true,
+  "description": "Monorepo for https://github.com/mathuo/dockview",
+  "homepage": "https://github.com/mathuo/dockview#readme",
+  "bugs": {
+    "url": "https://github.com/mathuo/dockview/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/mathuo/dockview.git"
+  },
+  "license": "MIT",
+  "author": "https://github.com/mathuo",
+  "workspaces": [
+    "packages/*"
+  ],
+  "scripts": {
+    "build": "lerna run build --scope '{dockview-core,dockview,dockview-vue,dockview-react}'",
+    "clean": "lerna run clean",
+    "docs": "typedoc",
+    "generate-docs": "node scripts/docs.mjs",
+    "lint": "eslint packages/**/src/** --ext .ts,.tsx,.js,.jsx",
+    "package": "node scripts/package.js",
+    "package-docs": "node scripts/package-docs.js",
+    "set-experimental-versions": "node scripts/set-experimental-versions",
+    "test": "jest",
+    "test:cov": "jest --coverage",
+    "version": "lerna version"
+  },
+  "resolutions": {
+    "@types/react": "^18.2.46",
+    "@types/react-dom": "^18.2.18"
+  },
+  "devDependencies": {
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "@rollup/plugin-terser": "^0.4.4",
+    "@rollup/plugin-typescript": "^11.1.5",
+    "@testing-library/dom": "^9.3.3",
+    "@testing-library/jest-dom": "^6.1.6",
+    "@testing-library/react": "^14.1.2",
+    "@total-typescript/shoehorn": "^0.1.1",
+    "@types/jest": "^29.5.11",
+    "@types/react": "^18.2.46",
+    "@types/react-dom": "^18.2.18",
+    "@typescript-eslint/eslint-plugin": "^6.17.0",
+    "@typescript-eslint/parser": "^6.17.0",
+    "@vitejs/plugin-vue": "^5.0.4",
+    "@vue/tsconfig": "^0.5.1",
+    "concurrently": "^8.2.2",
+    "cross-env": "^7.0.3",
+    "eslint": "^8.56.0",
+    "fs-extra": "^11.2.0",
+    "gulp": "^4.0.2",
+    "gulp-concat": "^2.6.1",
+    "gulp-dart-sass": "^1.1.0",
+    "jest": "^29.7.0",
+    "jest-environment-jsdom": "^29.7.0",
+    "jest-sonar-reporter": "^2.0.0",
+    "jsdom": "^23.0.1",
+    "lerna": "^8.2.1",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "rimraf": "^5.0.5",
+    "rollup": "^4.9.2",
+    "rollup-plugin-postcss": "^4.0.2",
+    "ts-jest": "^29.1.1",
+    "ts-loader": "^9.5.1",
+    "ts-node": "^10.9.2",
+    "tslib": "^2.6.2",
+    "typedoc": "^0.25.6",
+    "typescript": "^5.3.3",
+    "vite": "^5.1.5",
+    "vue": "^3.4.21",
+    "vue-sfc-loader": "^0.1.0",
+    "vue-tsc": "^2.0.5"
+  },
+  "engines": {
+    "node": ">=18.0"
+  }
 }

packages/README.md

@@ -0,0 +1,18 @@
+# Project Structure
+
+This mono-repository has a number of packages containing the code for the [dockview](https://www.npmjs.com/package/dockview) library and the documentation website [dockview.dev](dockview.dev).
+
+## dockview-core
+
+-   Contains the core logic for the dockview library.
+-   Written entirely in vanilla JavaScript/TypeScript.
+
+## dockview
+
+-   Depends on `dockview-core`.
+-   Exports a `React` wrapper.
+-   Published as [dockview](https://www.npmjs.com/package/dockview) on npm.
+
+## docs
+
+-   Code for [dockview.dev](dockview.dev).

packages/dockview-angular/README.md

@@ -0,0 +1,56 @@
+<div align="center">
+<h1>dockview</h1>
+
+<p>Zero dependency layout manager supporting tabs, groups, grids and splitviews with ReactJS support written in TypeScript</p>
+
+</div>
+
+---
+
+[![npm version](https://badge.fury.io/js/dockview.svg)](https://www.npmjs.com/package/dockview)
+[![npm](https://img.shields.io/npm/dm/dockview)](https://www.npmjs.com/package/dockview)
+[![CI Build](https://github.com/mathuo/dockview/workflows/CI/badge.svg)](https://github.com/mathuo/dockview/actions?query=workflow%3ACI)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=coverage)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=alert_status)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Bundle Phobia](https://badgen.net/bundlephobia/minzip/dockview)](https://bundlephobia.com/result?p=dockview)
+
+##
+
+Please see the website: https://dockview.dev
+
+## Features
+
+-   Serialization / deserialization with full layout management
+-   Support for split-views, grid-views and 'dockable' views
+-   Themeable and customizable
+-   Tab and Group docking / Drag n' Drop
+-   Popout Windows
+-   Floating Groups
+-   Extensive API
+-   Supports Shadow DOMs
+-   High test coverage
+-   Documentation website with live examples
+-   Transparent builds and Code Analysis
+-   Security at mind - verifed publishing and builds through GitHub Actions
+
+Want to verify our builds? Go [here](https://www.npmjs.com/package/dockview#Provenance).
+
+## Quick start
+
+Dockview has a peer dependency on `react >= 16.8.0` and `react-dom >= 16.8.0`. You can install dockview from [npm](https://www.npmjs.com/package/dockview).
+
+```
+npm install --save dockview
+```
+
+Within your project you must import or reference the stylesheet at `dockview/dist/styles/dockview.css` and attach a theme.
+
+```css
+@import '~dockview/dist/styles/dockview.css';
+```
+
+You should also attach a dockview theme to an element containing your components. For example:
+
+```html
+<body classname="dockview-theme-dark"></body>
+```

packages/dockview-angular/jest.config.ts

@@ -0,0 +1,34 @@
+import { JestConfigWithTsJest } from 'ts-jest';
+
+const config: JestConfigWithTsJest = {
+    preset: 'ts-jest',
+    roots: ['<rootDir>/packages/dockview-angular'],
+    modulePaths: ['<rootDir>/packages/dockview-angular/src'],
+    displayName: { name: 'dockview-angular', color: 'blue' },
+    rootDir: '../../',
+    collectCoverageFrom: [
+        '<rootDir>/packages/dockview-angular/src/**/*.{js,jsx,ts,tsx}',
+    ],
+    setupFiles: [
+        // '<rootDir>/packages/dockview-angular/src/__tests__/__mocks__/resizeObserver.js',
+    ],
+    setupFilesAfterEnv: ['<rootDir>/jest-setup.ts'],
+    coveragePathIgnorePatterns: ['/node_modules/'],
+    modulePathIgnorePatterns: [
+        // '<rootDir>/packages/dockview-angular/src/__tests__/__mocks__',
+        // '<rootDir>/packages/dockview-angular/src/__tests__/__test_utils__',
+    ],
+    coverageDirectory: '<rootDir>/packages/dockview-angular/coverage/',
+    testResultsProcessor: 'jest-sonar-reporter',
+    testEnvironment: 'jsdom',
+    transform: {
+        '^.+\\.tsx?$': [
+            'ts-jest',
+            {
+                tsconfig: '<rootDir>/tsconfig.test.json',
+            },
+        ],
+    },
+};
+
+export default config;

packages/dockview-angular/package.json

@@ -0,0 +1,59 @@
+{
+  "name": "dockview-angular",
+  "version": "4.2.4",
+  "description": "Zero dependency layout manager supporting tabs, grids and splitviews",
+  "keywords": [
+    "splitview",
+    "split-view",
+    "gridview",
+    "grid-view",
+    "dockview",
+    "dock-view",
+    "grid",
+    "tabs",
+    "layout",
+    "layout manager",
+    "dock layout",
+    "dock",
+    "docking",
+    "splitter",
+    "drag-and-drop",
+    "drag",
+    "drop",
+    "react",
+    "react-component"
+  ],
+  "homepage": "https://github.com/mathuo/dockview",
+  "bugs": {
+    "url": "https://github.com/mathuo/dockview/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mathuo/dockview.git"
+  },
+  "license": "MIT",
+  "author": "https://github.com/mathuo",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "types": "./dist/cjs/index.d.ts",
+  "files": [
+    "dist",
+    "README.md"
+  ],
+  "scripts": {
+    "build": "npm run build:package && npm run build:bundles",
+    "build:bundles": "rollup -c",
+    "build:cjs": "cross-env ../../node_modules/.bin/tsc --build ./tsconfig.json --verbose --extendedDiagnostics",
+    "build:css": "gulp sass",
+    "build:esm": "cross-env ../../node_modules/.bin/tsc --build ./tsconfig.esm.json --verbose --extendedDiagnostics",
+    "build:package": "npm run build:cjs && npm run build:esm && npm run build:css",
+    "clean": "rimraf dist/ .build/ .rollup.cache/",
+    "prepublishOnly": "npm run rebuild && npm run test",
+    "rebuild": "npm run clean && npm run build",
+    "test": "cross-env ../../node_modules/.bin/jest --selectProjects dockview",
+    "test:cov": "cross-env ../../node_modules/.bin/jest --selectProjects dockview --coverage"
+  },
+  "dependencies": {
+    "dockview-core": "^4.2.4"
+  }
+}

packages/dockview-angular/rollup.config.js

@@ -0,0 +1,113 @@
+/* eslint-disable */
+
+const { join } = require('path');
+const typescript = require('@rollup/plugin-typescript');
+const terser = require('@rollup/plugin-terser');
+const postcss = require('rollup-plugin-postcss');
+const nodeResolve = require('@rollup/plugin-node-resolve');
+
+const { name, version, homepage, license } = require('./package.json');
+const main = join(__dirname, './scripts/rollupEntryTarget.ts');
+const mainNoStyles = join(__dirname, './src/index.ts');
+const outputDir = join(__dirname, 'dist');
+
+function outputFile(format, isMinified, withStyles) {
+    let filename = join(outputDir, name);
+
+    if (format !== 'umd') {
+        filename += `.${format}`;
+    }
+    if (isMinified) {
+        filename += '.min';
+    }
+    if (!withStyles) {
+        filename += '.noStyle';
+    }
+
+    return `${filename}.js`;
+}
+
+function getInput(options) {
+    const { withStyles } = options;
+
+    if (withStyles) {
+        return main;
+    }
+
+    return mainNoStyles;
+}
+
+function createBundle(format, options) {
+    const { withStyles, isMinified } = options;
+    const input = getInput(options);
+    const file = outputFile(format, isMinified, withStyles);
+
+    const external = [];
+
+    const output = {
+        file,
+        format,
+        sourcemap: true,
+        globals: {},
+        banner: [
+            `/**`,
+            ` * ${name}`,
+            ` * @version ${version}`,
+            ` * @link ${homepage}`,
+            ` * @license ${license}`,
+            ` */`,
+        ].join('\n'),
+    };
+
+    const plugins = [
+        nodeResolve({
+            include: ['node_modules/dockview-core/**'],
+        }),
+        typescript({
+            tsconfig: 'tsconfig.esm.json',
+        }),
+    ];
+
+    if (isMinified) {
+        plugins.push(terser());
+    }
+    if (withStyles) {
+        plugins.push(postcss());
+    }
+
+    if (format === 'umd') {
+        output['name'] = name;
+    }
+
+    external.push('react', 'react-dom');
+
+    if (format === 'umd') {
+        output.globals['react'] = 'React';
+        output.globals['react-dom'] = 'ReactDOM';
+    }
+
+    return {
+        input,
+        output,
+        plugins,
+        external,
+    };
+}
+
+module.exports = [
+    // amd
+    createBundle('amd', { withStyles: false, isMinified: false }),
+    createBundle('amd', { withStyles: true, isMinified: false }),
+    createBundle('amd', { withStyles: false, isMinified: true }),
+    createBundle('amd', { withStyles: true, isMinified: true }),
+    // umd
+    createBundle('umd', { withStyles: false, isMinified: false }),
+    createBundle('umd', { withStyles: true, isMinified: false }),
+    createBundle('umd', { withStyles: false, isMinified: true }),
+    createBundle('umd', { withStyles: true, isMinified: true }),
+    // cjs
+    createBundle('cjs', { withStyles: true, isMinified: false }),
+    // esm
+    createBundle('esm', { withStyles: true, isMinified: false }),
+    createBundle('esm', { withStyles: true, isMinified: true }),
+];

packages/dockview-angular/scripts/rollupEntryTarget.ts

@@ -0,0 +1,2 @@
+import '../dist/styles/dockview.css';
+export * from '../src/index';

packages/dockview-angular/src/__tests__/empty.spec.ts

@@ -0,0 +1,5 @@
+describe('empty', () => {
+    test('that passes', () => {
+        expect(true).toBeTruthy();
+    });
+});

packages/dockview-angular/src/index.ts

@@ -0,0 +1 @@
+export * from 'dockview-core';

packages/dockview-angular/tsconfig.esm.json

@@ -0,0 +1,14 @@
+{
+    "extends": "../../tsconfig.base.json",
+    "compilerOptions": {
+        "module": "ES2020",
+        "moduleResolution": "node",
+        "target": "es6",
+        "outDir": "dist/esm",
+        "tsBuildInfoFile": ".build/tsconfig.tsbuildinfo.esm",
+        "jsx": "react",
+        "rootDir": "src"
+    },
+    "include": ["src"],
+    "exclude": ["**/node_modules", "src/__tests__"]
+}

packages/dockview-angular/tsconfig.json

@@ -1,5 +1,5 @@
 {
-    "extends": "../../module-build/tsconfig.json",
+    "extends": "../../tsconfig.base.json",
     "compilerOptions": {
         "outDir": "dist/cjs",
         "tsBuildInfoFile": ".build/tsconfig.tsbuildinfo.cjs",
@@ -8,4 +8,4 @@
     },
     "include": ["src"],
     "exclude": ["**/node_modules", "src/__tests__"]
-}
+}

packages/dockview-angular/typedoc.json

@@ -0,0 +1,5 @@
+{
+    "extends": ["../../typedoc.base.json"],
+    "entryPoints": ["src/index.ts"],
+    "exclude": ["**/dist/**"]
+}

packages/dockview-core/README.md

@@ -0,0 +1,38 @@
+<div align="center">
+<h1>dockview</h1>
+
+<p>Zero dependency layout manager supporting tabs, groups, grids and splitviews. Supports React, Vue and Vanilla TypeScript</p>
+
+</div>
+
+---
+
+[![npm version](https://badge.fury.io/js/dockview.svg)](https://www.npmjs.com/package/dockview)
+[![npm](https://img.shields.io/npm/dm/dockview)](https://www.npmjs.com/package/dockview)
+[![CI Build](https://github.com/mathuo/dockview/workflows/CI/badge.svg)](https://github.com/mathuo/dockview/actions?query=workflow%3ACI)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=coverage)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=mathuo_dockview&metric=alert_status)](https://sonarcloud.io/summary/overall?id=mathuo_dockview)
+[![Bundle Phobia](https://badgen.net/bundlephobia/minzip/dockview)](https://bundlephobia.com/result?p=dockview)
+
+##
+
+![](packages/docs/static/img/splashscreen.gif)
+
+Please see the website: https://dockview.dev
+
+## Features
+
+-   Serialization / deserialization with full layout management
+-   Support for split-views, grid-views and 'dockable' views
+-   Themeable and customizable
+-   Tab and Group docking / Drag n' Drop
+-   Popout Windows
+-   Floating Groups
+-   Extensive API
+-   Supports Shadow DOMs
+-   High test coverage
+-   Documentation website with live examples
+-   Transparent builds and Code Analysis
+-   Security at mind - verifed publishing and builds through GitHub Actions
+
+Want to verify our builds? Go [here](https://www.npmjs.com/package/dockview#Provenance).

packages/dockview-core/gulpfile.js

@@ -0,0 +1,13 @@
+const gulp = require('gulp');
+const gulpSass = require('gulp-dart-sass');
+const concat = require('gulp-concat');
+
+gulp.task('sass', () => {
+    return gulp
+        .src('./src/**/*.scss')
+        .pipe(gulpSass().on('error', gulpSass.logError))
+        .pipe(concat('dockview.css'))
+        .pipe(gulp.dest('./dist/styles/'));
+});
+
+gulp.task('run', gulp.series(['sass']));

packages/dockview-core/jest.config.ts

@@ -0,0 +1,34 @@
+import { JestConfigWithTsJest } from 'ts-jest';
+
+const config: JestConfigWithTsJest = {
+    preset: 'ts-jest',
+    roots: ['<rootDir>/packages/dockview-core'],
+    modulePaths: ['<rootDir>/packages/dockview-core/src'],
+    displayName: { name: 'dockview-core', color: 'blue' },
+    rootDir: '../../',
+    collectCoverageFrom: [
+        '<rootDir>/packages/dockview-core/src/**/*.{js,jsx,ts,tsx}',
+    ],
+    setupFiles: [
+        '<rootDir>/packages/dockview-core/src/__tests__/__mocks__/resizeObserver.js',
+    ],
+    setupFilesAfterEnv: ['<rootDir>/jest-setup.ts'],
+    coveragePathIgnorePatterns: ['/node_modules/'],
+    modulePathIgnorePatterns: [
+        '<rootDir>/packages/dockview-core/src/__tests__/__mocks__',
+        '<rootDir>/packages/dockview-core/src/__tests__/__test_utils__',
+    ],
+    coverageDirectory: '<rootDir>/packages/dockview-core/coverage/',
+    testResultsProcessor: 'jest-sonar-reporter',
+    testEnvironment: 'jsdom',
+    transform: {
+        '^.+\\.tsx?$': [
+            'ts-jest',
+            {
+                tsconfig: '<rootDir>/tsconfig.test.json',
+            },
+        ],
+    },
+};
+
+export default config;

packages/dockview-core/package.json

@@ -0,0 +1,56 @@
+{
+  "name": "dockview-core",
+  "version": "4.2.4",
+  "description": "Zero dependency layout manager supporting tabs, grids and splitviews",
+  "keywords": [
+    "splitview",
+    "split-view",
+    "gridview",
+    "grid-view",
+    "dockview",
+    "dock-view",
+    "grid",
+    "tabs",
+    "layout",
+    "layout manager",
+    "dock layout",
+    "dock",
+    "docking",
+    "splitter",
+    "drag-and-drop",
+    "drag",
+    "drop",
+    "react",
+    "react-component"
+  ],
+  "homepage": "https://github.com/mathuo/dockview",
+  "bugs": {
+    "url": "https://github.com/mathuo/dockview/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mathuo/dockview.git"
+  },
+  "license": "MIT",
+  "author": "https://github.com/mathuo",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "types": "./dist/cjs/index.d.ts",
+  "files": [
+    "dist",
+    "README.md"
+  ],
+  "scripts": {
+    "build": "npm run build:package && npm run build:bundles",
+    "build:bundles": "rollup -c",
+    "build:cjs": "cross-env ../../node_modules/.bin/tsc --build ./tsconfig.json --verbose --extendedDiagnostics",
+    "build:css": "gulp sass",
+    "build:esm": "cross-env ../../node_modules/.bin/tsc --build ./tsconfig.esm.json --verbose --extendedDiagnostics",
+    "build:package": "npm run build:cjs && npm run build:esm && npm run build:css",
+    "clean": "rimraf dist/ .build/ .rollup.cache/",
+    "prepublishOnly": "npm run rebuild && npm run test",
+    "rebuild": "npm run clean && npm run build",
+    "test": "cross-env ../../node_modules/.bin/jest --selectProjects dockview-core",
+    "test:cov": "cross-env ../../node_modules/.bin/jest --selectProjects dockview-core --coverage"
+  }
+}

packages/dockview-core/rollup.config.js

@@ -0,0 +1,102 @@
+/* eslint-disable */
+
+const { join } = require('path');
+const typescript = require('@rollup/plugin-typescript');
+const terser = require('@rollup/plugin-terser');
+const postcss = require('rollup-plugin-postcss');
+
+const { name, version, homepage, license } = require('./package.json');
+const main = join(__dirname, './scripts/rollupEntryTarget.ts');
+const mainNoStyles = join(__dirname, './src/index.ts');
+const outputDir = join(__dirname, 'dist');
+
+function outputFile(format, isMinified, withStyles) {
+    let filename = join(outputDir, name);
+
+    if (format !== 'umd') {
+        filename += `.${format}`;
+    }
+    if (isMinified) {
+        filename += '.min';
+    }
+    if (!withStyles) {
+        filename += '.noStyle';
+    }
+
+    return `${filename}.js`;
+}
+
+function getInput(options) {
+    const { withStyles } = options;
+
+    if (withStyles) {
+        return main;
+    }
+
+    return mainNoStyles;
+}
+
+function createBundle(format, options) {
+    const { withStyles, isMinified, isReact } = options;
+    const input = getInput(options);
+    const file = outputFile(format, isMinified, withStyles, isReact);
+
+    const external = [];
+
+    const output = {
+        file,
+        format,
+        sourcemap: true,
+        globals: {},
+        banner: [
+            `/**`,
+            ` * ${name}`,
+            ` * @version ${version}`,
+            ` * @link ${homepage}`,
+            ` * @license ${license}`,
+            ` */`,
+        ].join('\n'),
+    };
+
+    const plugins = [
+        typescript({
+            tsconfig: 'tsconfig.esm.json',
+        }),
+    ];
+
+    if (isMinified) {
+        plugins.push(terser());
+    }
+    if (withStyles) {
+        plugins.push(postcss());
+    }
+
+    if (format === 'umd') {
+        output['name'] = name;
+    }
+
+    return {
+        input,
+        output,
+        plugins,
+        external,
+    };
+}
+
+module.exports = [
+    // amd
+    createBundle('amd', { withStyles: false, isMinified: false }),
+    createBundle('amd', { withStyles: true, isMinified: false }),
+    createBundle('amd', { withStyles: false, isMinified: true }),
+    createBundle('amd', { withStyles: true, isMinified: true }),
+    // umd
+    createBundle('umd', { withStyles: false, isMinified: false }),
+    createBundle('umd', { withStyles: true, isMinified: false }),
+    createBundle('umd', { withStyles: false, isMinified: true }),
+    createBundle('umd', { withStyles: true, isMinified: true }),
+    // cjs
+    createBundle('cjs', { withStyles: true, isMinified: false }),
+    // esm
+    createBundle('esm', { withStyles: true, isMinified: false }),
+    createBundle('esm', { withStyles: true, isMinified: true }),
+];

packages/dockview-core/scripts/rollupEntryTarget.ts

@@ -0,0 +1,2 @@
+import '../dist/styles/dockview.css';
+export * from '../src/index';

packages/dockview-core/src/__tests__/__mocks__/mockDockviewPanelModel.ts

@@ -0,0 +1,47 @@
+import { IDockviewPanelModel } from '../../dockview/dockviewPanelModel';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import {
+    TabPartInitParameters,
+    IContentRenderer,
+    ITabRenderer,
+} from '../../dockview/types';
+import { PanelUpdateEvent } from '../../panel/types';
+import { TabLocation } from '../../dockview/framework';
+
+export class DockviewPanelModelMock implements IDockviewPanelModel {
+    constructor(
+        readonly contentComponent: string,
+        readonly content: IContentRenderer,
+        readonly tabComponent: string,
+        readonly tab: ITabRenderer
+    ) {
+        //
+    }
+
+    createTabRenderer(tabLocation: TabLocation): ITabRenderer {
+        return this.tab;
+    }
+
+    init(params: TabPartInitParameters): void {
+        //
+    }
+
+    updateParentGroup(
+        group: DockviewGroupPanel,
+        isPanelVisible: boolean
+    ): void {
+        //
+    }
+
+    update(event: PanelUpdateEvent): void {
+        //
+    }
+
+    layout(width: number, height: number): void {
+        //
+    }
+
+    dispose(): void {
+        //
+    }
+}

packages/dockview-core/src/__tests__/__mocks__/mockWindow.ts

@@ -0,0 +1,45 @@
+import { fromPartial } from '@total-typescript/shoehorn';
+
+export function setupMockWindow() {
+    const listeners: Record<string, (() => void)[]> = {};
+
+    let width = 1000;
+    let height = 2000;
+
+    return fromPartial<Window>({
+        addEventListener: (type: string, listener: () => void) => {
+            if (!listeners[type]) {
+                listeners[type] = [];
+            }
+            listeners[type].push(listener);
+            if (type === 'load') {
+                listener();
+            }
+        },
+        removeEventListener: (type: string, listener: () => void) => {
+            if (listeners[type]) {
+                const index = listeners[type].indexOf(listener);
+                if (index > -1) {
+                    listeners[type].splice(index, 1);
+                }
+            }
+        },
+        dispatchEvent: (event: Event) => {
+            const items = listeners[event.type];
+            if (!items) {
+                return;
+            }
+            items.forEach((item) => item());
+        },
+        document: document,
+        close: () => {
+            listeners['beforeunload']?.forEach((f) => f());
+        },
+        get innerWidth() {
+            return width++;
+        },
+        get innerHeight() {
+            return height++;
+        },
+    });
+}

packages/dockview-core/src/__tests__/__mocks__/resizeObserver.js

@@ -0,0 +1,13 @@
+class ResizeObserver {
+    observe() {
+        // do nothing
+    }
+    unobserve() {
+        // do nothing
+    }
+    disconnect() {
+      // do nothing
+    }
+}
+
+window.ResizeObserver = ResizeObserver;

packages/dockview-core/src/__tests__/__test_utils__/utils.ts

@@ -0,0 +1,73 @@
+import React from 'react';
+
+/**
+ * useful utility type to erase readonly signatures for testing purposes
+ *
+ * @see https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-4.html#readonly-mapped-type-modifiers-and-readonly-arrays
+ */
+export type Writable<T> = T extends object
+    ? { -readonly [K in keyof T]: Writable<T[K]> }
+    : T;
+
+export function setMockRefElement(node: Partial<HTMLElement>): void {
+    const mockRef = {
+        get current() {
+            return node;
+        },
+        set current(_value) {
+            //noop
+        },
+    };
+
+    jest.spyOn(React, 'useRef').mockReturnValueOnce(mockRef);
+}
+
+export function createOffsetDragOverEvent(params: {
+    clientX: number;
+    clientY: number;
+}): Event {
+    const event = new Event('dragover', {
+        bubbles: true,
+        cancelable: true,
+    });
+    Object.defineProperty(event, 'clientX', { get: () => params.clientX });
+    Object.defineProperty(event, 'clientY', { get: () => params.clientY });
+    return event;
+}
+
+/**
+ * `jest.runAllTicks` doesn't seem to exhaust all events in the micro-task queue so
+ * as a **hacky** alternative we'll wait for an empty Promise to complete which runs
+ * on the micro-task queue so will force a run-to-completion emptying the queue
+ * of any pending micro-task
+ */
+export function exhaustMicrotaskQueue(): Promise<void> {
+    return new Promise<void>((resolve) => resolve());
+}
+
+export const mockGetBoundingClientRect = ({
+    left,
+    top,
+    height,
+    width,
+}: {
+    left: number;
+    top: number;
+    height: number;
+    width: number;
+}) => {
+    const result = {
+        left,
+        top,
+        height,
+        width,
+        right: left + width,
+        bottom: top + height,
+        x: left,
+        y: top,
+    };
+    return {
+        ...result,
+        toJSON: () => result,
+    };
+};

packages/dockview-core/src/__tests__/api/api.spec.ts

@@ -0,0 +1,69 @@
+import { PanelApiImpl } from '../../api/panelApi';
+import { IPanel } from '../../panel/types';
+
+describe('api', () => {
+    let api: PanelApiImpl;
+
+    beforeEach(() => {
+        api = new PanelApiImpl('dummy_id', 'fake-component');
+    });
+
+    test('updateParameters', () => {
+        const panel = {
+            update: jest.fn(),
+        } as Partial<IPanel>;
+
+        api.initialize(panel as IPanel);
+
+        expect(panel.update).toHaveBeenCalledTimes(0);
+
+        api.updateParameters({ keyA: 'valueA' });
+        expect(panel.update).toHaveBeenCalledTimes(1);
+        expect(panel.update).toHaveBeenCalledWith({
+            params: { keyA: 'valueA' },
+        });
+    });
+
+    test('should update isFcoused getter', () => {
+        expect(api.isFocused).toBeFalsy();
+
+        api._onDidChangeFocus.fire({ isFocused: true });
+        expect(api.isFocused).toBeTruthy();
+
+        api._onDidChangeFocus.fire({ isFocused: false });
+        expect(api.isFocused).toBeFalsy();
+    });
+
+    test('should update isActive getter', () => {
+        expect(api.isFocused).toBeFalsy();
+
+        api._onDidActiveChange.fire({ isActive: true });
+        expect(api.isActive).toBeTruthy();
+
+        api._onDidActiveChange.fire({ isActive: false });
+        expect(api.isActive).toBeFalsy();
+    });
+
+    test('should update isActive getter', () => {
+        expect(api.isVisible).toBeTruthy();
+
+        api._onDidVisibilityChange.fire({ isVisible: false });
+        expect(api.isVisible).toBeFalsy();
+
+        api._onDidVisibilityChange.fire({ isVisible: true });
+        expect(api.isVisible).toBeTruthy();
+    });
+
+    test('should update width and height getter', () => {
+        expect(api.height).toBe(0);
+        expect(api.width).toBe(0);
+
+        api._onDidDimensionChange.fire({ height: 10, width: 20 });
+        expect(api.height).toBe(10);
+        expect(api.width).toBe(20);
+
+        api._onDidDimensionChange.fire({ height: 20, width: 10 });
+        expect(api.height).toBe(20);
+        expect(api.width).toBe(10);
+    });
+});

packages/dockview-core/src/__tests__/api/component.api.spec.ts

@@ -0,0 +1,155 @@
+import {
+    SplitviewApi,
+    PaneviewApi,
+    GridviewApi,
+    DockviewApi,
+} from '../../api/component.api';
+import { GridviewComponent } from '../../gridview/gridviewComponent';
+import { PaneviewComponent } from '../../paneview/paneviewComponent';
+import { SplitviewComponent } from '../../splitview/splitviewComponent';
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+
+describe('component.api', () => {
+    describe('splitview', () => {
+        test('splitviewapi', () => {
+            const list: (keyof SplitviewComponent)[] = [
+                'minimumSize',
+                'maximumSize',
+                'height',
+                'width',
+                'length',
+                'orientation',
+                'onDidLayoutChange',
+                'onDidAddView',
+                'onDidRemoveView',
+                'panels',
+                'focus',
+                'toJSON',
+            ];
+
+            for (const _ of list) {
+                const f = jest.fn();
+
+                const component: Partial<SplitviewComponent> = {
+                    [_]: f(),
+                };
+
+                const cut = new SplitviewApi(<SplitviewComponent>component);
+
+                (cut as any)[_];
+
+                expect(f).toBeCalledTimes(1);
+            }
+        });
+    });
+
+    describe('paneview', () => {
+        test('panviewapi', () => {
+            const list: (keyof PaneviewComponent)[] = [
+                'minimumSize',
+                'maximumSize',
+                'height',
+                'width',
+                'onDidLayoutChange',
+                'onDidAddView',
+                'onDidRemoveView',
+                'panels',
+                'focus',
+                'toJSON',
+            ];
+
+            for (const _ of list) {
+                const f = jest.fn();
+
+                const component: Partial<PaneviewComponent> = {
+                    [_]: f(),
+                };
+
+                const cut = new PaneviewApi(<PaneviewComponent>component);
+
+                (cut as any)[_];
+
+                expect(f).toBeCalledTimes(1);
+            }
+        });
+    });
+
+    describe('gridview', () => {
+        test('gridviewapi', () => {
+            const list: (keyof GridviewComponent)[] = [
+                'minimumHeight',
+                'maximumHeight',
+                'minimumWidth',
+                'maximumWidth',
+                'width',
+                'height',
+                'onDidLayoutChange',
+                'orientation',
+                'focus',
+                'toJSON',
+                'onDidActiveGroupChange',
+                'onDidAddGroup',
+                'onDidRemoveGroup',
+                'onDidLayoutFromJSON',
+            ];
+
+            for (const _ of list) {
+                const f = jest.fn();
+
+                const component: Partial<GridviewComponent> = {
+                    [_]: f(),
+                };
+
+                const cut = new GridviewApi(<GridviewComponent>component);
+
+                (cut as any)[_];
+
+                expect(f).toBeCalledTimes(1);
+            }
+        });
+    });
+
+    describe('dockview', () => {
+        test('dockviewapi', () => {
+            const list: (keyof DockviewComponent)[] = [
+                'minimumHeight',
+                'maximumHeight',
+                'minimumWidth',
+                'maximumWidth',
+                'width',
+                'height',
+                'size',
+                'totalPanels',
+                'onDidLayoutChange',
+                'panels',
+                'groups',
+                'activeGroup',
+                'activePanel',
+                'focus',
+                'closeAllGroups',
+                'toJSON',
+                'onDidActiveGroupChange',
+                'onDidAddGroup',
+                'onDidRemoveGroup',
+                'onDidActivePanelChange',
+                'onDidAddPanel',
+                'onDidRemovePanel',
+                'onDidLayoutFromJSON',
+            ];
+
+            for (const _ of list) {
+                const f = jest.fn();
+
+                const component: Partial<DockviewComponent> = {
+                    [_]: f(),
+                };
+
+                const cut = new DockviewApi(<DockviewComponent>component);
+
+                (cut as any)[_];
+
+                expect(f).toBeCalledTimes(1);
+            }
+        });
+    });
+});

packages/dockview-core/src/__tests__/api/dockviewPanelApi.spec.ts

@@ -0,0 +1,123 @@
+import { DockviewPanelApiImpl } from '../../api/dockviewPanelApi';
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewPanel } from '../../dockview/dockviewPanel';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import { fromPartial } from '@total-typescript/shoehorn';
+
+describe('groupPanelApi', () => {
+    test('title', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const panelMock = jest.fn<DockviewPanel, []>(() => {
+            return {
+                update: jest.fn(),
+                setTitle: jest.fn(),
+            } as any;
+        });
+
+        const panel = new panelMock();
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+            },
+        });
+
+        const cut = new DockviewPanelApiImpl(
+            panel,
+            group,
+            <DockviewComponent>accessor,
+            'fake-component'
+        );
+
+        cut.setTitle('test_title');
+        expect(panel.setTitle).toBeCalledTimes(1);
+        expect(panel.setTitle).toBeCalledWith('test_title');
+    });
+
+    test('updateParameters', () => {
+        const groupPanel: Partial<DockviewPanel> = {
+            id: 'test_id',
+            update: jest.fn(),
+        };
+
+        const accessor = fromPartial<DockviewComponent>({
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupViewPanel = new DockviewGroupPanel(
+            <DockviewComponent>accessor,
+            '',
+            {}
+        );
+
+        const cut = new DockviewPanelApiImpl(
+            <DockviewPanel>groupPanel,
+            <DockviewGroupPanel>groupViewPanel,
+            <DockviewComponent>accessor,
+            'fake-component'
+        );
+
+        cut.updateParameters({ keyA: 'valueA' });
+
+        expect(groupPanel.update).toHaveBeenCalledWith({
+            params: { keyA: 'valueA' },
+        });
+        expect(groupPanel.update).toHaveBeenCalledTimes(1);
+    });
+
+    test('onDidGroupChange', () => {
+        const groupPanel: Partial<DockviewPanel> = {
+            id: 'test_id',
+        };
+
+        const accessor = fromPartial<DockviewComponent>({
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupViewPanel = new DockviewGroupPanel(
+            <DockviewComponent>accessor,
+            '',
+            {}
+        );
+
+        const cut = new DockviewPanelApiImpl(
+            <DockviewPanel>groupPanel,
+            <DockviewGroupPanel>groupViewPanel,
+            <DockviewComponent>accessor,
+            'fake-component'
+        );
+
+        let events = 0;
+
+        const disposable = cut.onDidGroupChange(() => {
+            events++;
+        });
+
+        expect(events).toBe(0);
+        expect(cut.group).toBe(groupViewPanel);
+
+        const groupViewPanel2 = new DockviewGroupPanel(
+            <DockviewComponent>accessor,
+            '',
+            {}
+        );
+        cut.group = groupViewPanel2;
+        expect(events).toBe(1);
+        expect(cut.group).toBe(groupViewPanel2);
+
+        disposable.dispose();
+    });
+});

packages/dockview-core/src/__tests__/array.spec.ts

@@ -3,24 +3,25 @@ import {
     last,
     pushToEnd,
     pushToStart,
-    range,
+    remove,
     sequenceEquals,
     tail,
 } from '../array';
 
 describe('array', () => {
-    it('tail', () => {
+    test('tail', () => {
         expect(tail([1, 2, 3, 4, 5])).toEqual([[1, 2, 3, 4], 5]);
         expect(tail([1, 2])).toEqual([[1], 2]);
         expect(tail([1])).toEqual([[], 1]);
+        expect(() => tail([])).toThrow('Invalid tail call');
     });
 
-    it('last', () => {
+    test('last', () => {
         expect(last([1, 2, 3, 4])).toBe(4);
         expect(last([])).toBeUndefined();
     });
 
-    it('pushToEnd', () => {
+    test('pushToEnd', () => {
         const arr1 = [1, 2, 3, 4];
         pushToEnd(arr1, 3);
         expect(arr1).toEqual([1, 2, 4, 3]);
@@ -28,7 +29,7 @@ describe('array', () => {
         expect(arr1).toEqual([1, 2, 4, 3]);
     });
 
-    it('pushToStart', () => {
+    test('pushToStart', () => {
         const arr1 = [1, 2, 3, 4];
         pushToStart(arr1, 3);
         expect(arr1).toEqual([3, 1, 2, 4]);
@@ -36,21 +37,33 @@ describe('array', () => {
         expect(arr1).toEqual([3, 1, 2, 4]);
     });
 
-    it('range', () => {
-        expect(range(0, 5)).toEqual([0, 1, 2, 3, 4]);
-        expect(range(5, 0)).toEqual([5, 4, 3, 2, 1]);
-        expect(range(5)).toEqual([0, 1, 2, 3, 4]);
-    });
-
-    it('firstIndex', () => {
+    test('firstIndex', () => {
         expect(firstIndex([1, 2, 3, 4, 3], (item) => item === 3)).toBe(2);
         expect(firstIndex([1, 2, 3, 4, 3], (item) => item === 5)).toBe(-1);
     });
 
-    it('firstIndex', () => {
+    test('firstIndex', () => {
         expect(sequenceEquals([1, 2, 3, 4], [1, 2, 3, 4])).toBeTruthy();
         expect(sequenceEquals([1, 2, 3, 4], [4, 3, 2, 1])).toBeFalsy();
         expect(sequenceEquals([1, 2, 3, 4], [1, 2, 3])).toBeFalsy();
         expect(sequenceEquals([1, 2, 3, 4], [1, 2, 3, 4, 5])).toBeFalsy();
     });
+
+    test('remove', () => {
+        const arr1 = [1, 2, 3, 4];
+        remove(arr1, 2);
+        expect(arr1).toEqual([1, 3, 4]);
+
+        const arr2 = [1, 2, 2, 3, 4];
+        remove(arr2, 2);
+        expect(arr2).toEqual([1, 2, 3, 4]);
+
+        const arr3 = [1];
+        remove(arr3, 2);
+        expect(arr3).toEqual([1]);
+        remove(arr3, 1);
+        expect(arr3).toEqual([]);
+        remove(arr3, 1);
+        expect(arr3).toEqual([]);
+    });
 });

packages/dockview-core/src/__tests__/dnd/abstractDragHandler.spec.ts

@@ -0,0 +1,179 @@
+import { fireEvent } from '@testing-library/dom';
+import { DragHandler } from '../../dnd/abstractDragHandler';
+import { IDisposable } from '../../lifecycle';
+
+describe('abstractDragHandler', () => {
+    test('that className dv-dragged is added to element after dragstart event', () => {
+        jest.useFakeTimers();
+
+        const element = document.createElement('div');
+
+        const handler = new (class TestClass extends DragHandler {
+            constructor(el: HTMLElement) {
+                super(el);
+            }
+
+            getData(): IDisposable {
+                return {
+                    dispose: () => {
+                        // /
+                    },
+                };
+            }
+        })(element);
+
+        expect(element.classList.contains('dv-dragged')).toBeFalsy();
+
+        fireEvent.dragStart(element);
+        expect(element.classList.contains('dv-dragged')).toBeTruthy();
+
+        jest.runAllTimers();
+        expect(element.classList.contains('dv-dragged')).toBeFalsy();
+
+        handler.dispose();
+    });
+
+    test('that iframes and webviews have pointerEvents=none set whilst drag action is in process', () => {
+        jest.useFakeTimers();
+
+        const element = document.createElement('div');
+        const iframe = document.createElement('iframe');
+        const webview = document.createElement('webview');
+        const span = document.createElement('span');
+
+        document.body.appendChild(element);
+        document.body.appendChild(iframe);
+        document.body.appendChild(webview);
+        document.body.appendChild(span);
+
+        const handler = new (class TestClass extends DragHandler {
+            constructor(el: HTMLElement) {
+                super(el);
+            }
+
+            getData(): IDisposable {
+                return {
+                    dispose: () => {
+                        // /
+                    },
+                };
+            }
+        })(element);
+
+        expect(iframe.style.pointerEvents).toBeFalsy();
+        expect(webview.style.pointerEvents).toBeFalsy();
+        expect(span.style.pointerEvents).toBeFalsy();
+
+        fireEvent.dragStart(element);
+        expect(iframe.style.pointerEvents).toBe('none');
+        expect(webview.style.pointerEvents).toBe('none');
+        expect(span.style.pointerEvents).toBeFalsy();
+
+        fireEvent.dragEnd(element);
+        expect(iframe.style.pointerEvents).toBe('');
+        expect(webview.style.pointerEvents).toBe('');
+        expect(span.style.pointerEvents).toBeFalsy();
+
+        handler.dispose();
+    });
+
+    test('that the disabling of pointerEvents is restored on a premature disposal of the handler', () => {
+        jest.useFakeTimers();
+
+        const element = document.createElement('div');
+        const iframe = document.createElement('iframe');
+        const webview = document.createElement('webview');
+        const span = document.createElement('span');
+
+        document.body.appendChild(element);
+        document.body.appendChild(iframe);
+        document.body.appendChild(webview);
+        document.body.appendChild(span);
+
+        const handler = new (class TestClass extends DragHandler {
+            constructor(el: HTMLElement) {
+                super(el);
+            }
+
+            getData(): IDisposable {
+                return {
+                    dispose: () => {
+                        // /
+                    },
+                };
+            }
+        })(element);
+
+        expect(iframe.style.pointerEvents).toBeFalsy();
+        expect(webview.style.pointerEvents).toBeFalsy();
+        expect(span.style.pointerEvents).toBeFalsy();
+
+        fireEvent.dragStart(element);
+        expect(iframe.style.pointerEvents).toBe('none');
+        expect(webview.style.pointerEvents).toBe('none');
+        expect(span.style.pointerEvents).toBeFalsy();
+
+        handler.dispose();
+        expect(iframe.style.pointerEvents).toBe('');
+        expect(webview.style.pointerEvents).toBe('');
+        expect(span.style.pointerEvents).toBeFalsy();
+    });
+
+    test('that .preventDefault() is called for cancelled events', () => {
+        const element = document.createElement('div');
+
+        const handler = new (class TestClass extends DragHandler {
+            constructor(el: HTMLElement) {
+                super(el);
+            }
+
+            protected isCancelled(_event: DragEvent): boolean {
+                return true;
+            }
+
+            getData(): IDisposable {
+                return {
+                    dispose: () => {
+                        // /
+                    },
+                };
+            }
+        })(element);
+
+        const event = new Event('dragstart');
+        const spy = jest.spyOn(event, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy).toBeCalledTimes(1);
+
+        handler.dispose();
+    });
+
+    test('that .preventDefault() is not called for non-cancelled events', () => {
+        const element = document.createElement('div');
+
+        const handler = new (class TestClass extends DragHandler {
+            constructor(el: HTMLElement) {
+                super(el);
+            }
+
+            protected isCancelled(_event: DragEvent): boolean {
+                return false;
+            }
+
+            getData(): IDisposable {
+                return {
+                    dispose: () => {
+                        // /
+                    },
+                };
+            }
+        })(element);
+
+        const event = new Event('dragstart');
+        const spy = jest.spyOn(event, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy).toHaveBeenCalledTimes(0);
+
+        handler.dispose();
+    });
+});

packages/dockview-core/src/__tests__/dnd/dataTransfer.spec.ts

@@ -0,0 +1,101 @@
+import {
+    getPaneData,
+    getPanelData,
+    LocalSelectionTransfer,
+    PanelTransfer,
+    PaneTransfer,
+} from '../../dnd/dataTransfer';
+
+describe('dataTransfer', () => {
+    describe('getPanelData', () => {
+        test('should be undefined when there is no local transfer object', () => {
+            expect(getPanelData()).toBeUndefined();
+        });
+
+        test('should be undefined when there is a local transfer object that is not a PanelTransfer', () => {
+            LocalSelectionTransfer.getInstance<PaneTransfer>().setData(
+                [new PaneTransfer('viewId', 'groupId')],
+                PaneTransfer.prototype
+            );
+
+            expect(getPanelData()).toBeUndefined();
+        });
+
+        test('should retrieve the PanelTransfer object when transfer is active', () => {
+            const transferObject = new PanelTransfer(
+                'viewId',
+                'groupId',
+                'panelId'
+            );
+            LocalSelectionTransfer.getInstance<PanelTransfer>().setData(
+                [transferObject],
+                PanelTransfer.prototype
+            );
+
+            expect(getPanelData()).toBe(transferObject);
+        });
+
+        test('should retrieve the PanelTransfer when a new transfer overrides an existing one', () => {
+            LocalSelectionTransfer.getInstance<PaneTransfer>().setData(
+                [new PaneTransfer('viewId', 'groupId')],
+                PaneTransfer.prototype
+            );
+
+            expect(getPanelData()).toBeUndefined();
+
+            const transferObject = new PanelTransfer(
+                'viewId',
+                'groupId',
+                'panelId'
+            );
+            LocalSelectionTransfer.getInstance<PanelTransfer>().setData(
+                [transferObject],
+                PanelTransfer.prototype
+            );
+
+            expect(getPanelData()).toBe(transferObject);
+        });
+    });
+
+    describe('getPaneData', () => {
+        test('should be undefined when there is no local transfer object', () => {
+            expect(getPaneData()).toBeUndefined();
+        });
+
+        test('should be undefined when there is a local transfer object that is not a PaneTransfer', () => {
+            LocalSelectionTransfer.getInstance<PanelTransfer>().setData(
+                [new PanelTransfer('viewId', 'groupId', 'panelId')],
+                PanelTransfer.prototype
+            );
+
+            expect(getPaneData()).toBeUndefined();
+        });
+
+        test('should retrieve the PaneTransfer object when transfer is active', () => {
+            const transferObject = new PaneTransfer('viewId', 'groupId');
+            LocalSelectionTransfer.getInstance<PaneTransfer>().setData(
+                [transferObject],
+                PaneTransfer.prototype
+            );
+
+            expect(getPaneData()).toBe(transferObject);
+        });
+
+        test('should retrieve the PanelTransfer when a new transfer overrides an existing one', () => {
+            LocalSelectionTransfer.getInstance<PanelTransfer>().setData(
+                [new PanelTransfer('viewId', 'groupId', 'panelId')],
+                PanelTransfer.prototype
+            );
+
+            expect(getPaneData()).toBeUndefined();
+
+            const transferObject = new PaneTransfer('viewId', 'groupId');
+            LocalSelectionTransfer.getInstance<PaneTransfer>().setData(
+                [transferObject],
+                PaneTransfer.prototype
+            );
+
+            expect(getPaneData()).toBe(transferObject);
+        });
+    });
+});

packages/dockview-core/src/__tests__/dnd/droptarget.spec.ts

@@ -0,0 +1,401 @@
+import {
+    calculateQuadrantAsPercentage,
+    calculateQuadrantAsPixels,
+    directionToPosition,
+    Droptarget,
+    Position,
+    positionToDirection,
+} from '../../dnd/droptarget';
+import { fireEvent } from '@testing-library/dom';
+import { createOffsetDragOverEvent } from '../__test_utils__/utils';
+
+describe('droptarget', () => {
+    let element: HTMLElement;
+    let droptarget: Droptarget;
+
+    beforeEach(() => {
+        element = document.createElement('div');
+
+        jest.spyOn(element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(element, 'offsetWidth', 'get').mockImplementation(() => 200);
+    });
+
+    test('that dragover events are marked', () => {
+        droptarget = new Droptarget(element, {
+            canDisplayOverlay: () => true,
+            acceptedTargetZones: ['center'],
+        });
+
+        fireEvent.dragEnter(element);
+        const event = new Event('dragover');
+        fireEvent(element, event);
+
+        expect(
+            (event as any)['__dockview_droptarget_event_is_used__']
+        ).toBeTruthy();
+    });
+
+    test('that the drop target is removed when receiving a marked dragover event', () => {
+        let position: Position | undefined = undefined;
+
+        droptarget = new Droptarget(element, {
+            canDisplayOverlay: () => true,
+            acceptedTargetZones: ['center'],
+        });
+
+        droptarget.onDrop((event) => {
+            position = event.position;
+        });
+
+        fireEvent.dragEnter(element);
+        fireEvent.dragOver(element);
+
+        const target = element.querySelector(
+            '.dv-drop-target-dropzone'
+        ) as HTMLElement;
+        fireEvent.drop(target);
+        expect(position).toBe('center');
+
+        const event = new Event('dragover');
+        (event as any)['__dockview_droptarget_event_is_used__'] = true;
+        fireEvent(element, event);
+        expect(element.querySelector('.dv-drop-target-dropzone')).toBeNull();
+    });
+
+    test('directionToPosition', () => {
+        expect(directionToPosition('above')).toBe('top');
+        expect(directionToPosition('below')).toBe('bottom');
+        expect(directionToPosition('left')).toBe('left');
+        expect(directionToPosition('right')).toBe('right');
+        expect(directionToPosition('within')).toBe('center');
+        expect(() => directionToPosition('bad_input' as any)).toThrow(
+            "invalid direction 'bad_input'"
+        );
+    });
+
+    test('positionToDirection', () => {
+        expect(positionToDirection('top')).toBe('above');
+        expect(positionToDirection('bottom')).toBe('below');
+        expect(positionToDirection('left')).toBe('left');
+        expect(positionToDirection('right')).toBe('right');
+        expect(positionToDirection('center')).toBe('within');
+        expect(() => positionToDirection('bad_input' as any)).toThrow(
+            "invalid position 'bad_input'"
+        );
+    });
+
+    test('non-directional', () => {
+        let position: Position | undefined = undefined;
+
+        droptarget = new Droptarget(element, {
+            canDisplayOverlay: () => true,
+            acceptedTargetZones: ['center'],
+        });
+
+        droptarget.onDrop((event) => {
+            position = event.position;
+        });
+
+        fireEvent.dragEnter(element);
+        fireEvent.dragOver(element);
+
+        const target = element.querySelector(
+            '.dv-drop-target-dropzone'
+        ) as HTMLElement;
+        fireEvent.drop(target);
+        expect(position).toBe('center');
+    });
+
+    test('drop', () => {
+        let position: Position | undefined = undefined;
+
+        droptarget = new Droptarget(element, {
+            canDisplayOverlay: () => true,
+            acceptedTargetZones: ['top', 'left', 'right', 'bottom', 'center'],
+        });
+
+        droptarget.onDrop((event) => {
+            position = event.position;
+        });
+
+        fireEvent.dragEnter(element);
+        fireEvent.dragOver(element);
+
+        const target = element.querySelector(
+            '.dv-drop-target-dropzone'
+        ) as HTMLElement;
+
+        jest.spyOn(target, 'clientHeight', 'get').mockImplementation(() => 100);
+        jest.spyOn(target, 'clientWidth', 'get').mockImplementation(() => 200);
+
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({
+                clientX: 19,
+                clientY: 0,
+            })
+        );
+
+        expect(position).toBeUndefined();
+        fireEvent.drop(target);
+        expect(position).toBe('left');
+    });
+
+    test('default', () => {
+        droptarget = new Droptarget(element, {
+            canDisplayOverlay: () => true,
+            acceptedTargetZones: ['top', 'left', 'right', 'bottom', 'center'],
+        });
+
+        expect(droptarget.state).toBeUndefined();
+
+        fireEvent.dragEnter(element);
+        fireEvent.dragOver(element);
+
+        let viewQuery = element.querySelectorAll(
+            '.dv-drop-target > .dv-drop-target-dropzone > .dv-drop-target-selection'
+        );
+        expect(viewQuery.length).toBe(1);
+
+        const target = element.querySelector(
+            '.dv-drop-target-dropzone'
+        ) as HTMLElement;
+
+        jest.spyOn(target, 'clientHeight', 'get').mockImplementation(() => 100);
+        jest.spyOn(target, 'clientWidth', 'get').mockImplementation(() => 200);
+
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({ clientX: 19, clientY: 0 })
+        );
+
+        function check(
+            element: HTMLElement,
+            box: {
+                left: string;
+                top: string;
+                width: string;
+                height: string;
+            }
+        ) {
+            expect(element.style.top).toBe(box.top);
+            expect(element.style.left).toBe(box.left);
+            expect(element.style.width).toBe(box.width);
+            expect(element.style.height).toBe(box.height);
+        }
+
+        viewQuery = element.querySelectorAll(
+            '.dv-drop-target > .dv-drop-target-dropzone > .dv-drop-target-selection'
+        );
+        expect(viewQuery.length).toBe(1);
+        expect(droptarget.state).toBe('left');
+        check(
+            element
+                .getElementsByClassName('dv-drop-target-selection')
+                .item(0) as HTMLDivElement,
+            {
+                top: '0px',
+                left: '0px',
+                width: '50%',
+                height: '100%',
+            }
+        );
+
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({ clientX: 40, clientY: 19 })
+        );
+
+        viewQuery = element.querySelectorAll(
+            '.dv-drop-target > .dv-drop-target-dropzone > .dv-drop-target-selection'
+        );
+        expect(viewQuery.length).toBe(1);
+        expect(droptarget.state).toBe('top');
+        check(
+            element
+                .getElementsByClassName('dv-drop-target-selection')
+                .item(0) as HTMLDivElement,
+            {
+                top: '0px',
+                left: '0px',
+                width: '100%',
+                height: '50%',
+            }
+        );
+
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({ clientX: 160, clientY: 81 })
+        );
+
+        viewQuery = element.querySelectorAll(
+            '.dv-drop-target > .dv-drop-target-dropzone > .dv-drop-target-selection'
+        );
+        expect(viewQuery.length).toBe(1);
+        expect(droptarget.state).toBe('bottom');
+        check(
+            element
+                .getElementsByClassName('dv-drop-target-selection')
+                .item(0) as HTMLDivElement,
+            {
+                top: '50%',
+                left: '0px',
+                width: '100%',
+                height: '50%',
+            }
+        );
+
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({ clientX: 161, clientY: 0 })
+        );
+
+        viewQuery = element.querySelectorAll(
+            '.dv-drop-target > .dv-drop-target-dropzone > .dv-drop-target-selection'
+        );
+        expect(viewQuery.length).toBe(1);
+        expect(droptarget.state).toBe('right');
+        check(
+            element
+                .getElementsByClassName('dv-drop-target-selection')
+                .item(0) as HTMLDivElement,
+            {
+                top: '0px',
+                left: '50%',
+                width: '50%',
+                height: '100%',
+            }
+        );
+        fireEvent(
+            target,
+            createOffsetDragOverEvent({ clientX: 100, clientY: 50 })
+        );
+        expect(droptarget.state).toBe('center');
+        expect(
+            (
+                element
+                    .getElementsByClassName('dv-drop-target-selection')
+                    .item(0) as HTMLDivElement
+            ).style.transform
+        ).toBe('');
+
+        fireEvent.dragLeave(target);
+        expect(droptarget.state).toBe('center');
+        viewQuery = element.querySelectorAll('.dv-drop-target');
+        expect(viewQuery.length).toBe(0);
+    });
+
+    describe('calculateQuadrantAsPercentage', () => {
+        test('variety of cases', () => {
+            const inputs: Array<{
+                directions: Position[];
+                x: number;
+                y: number;
+                result: Position | null;
+            }> = [
+                { directions: ['left', 'right'], x: 19, y: 50, result: 'left' },
+                {
+                    directions: ['left', 'right'],
+                    x: 81,
+                    y: 50,
+                    result: 'right',
+                },
+                {
+                    directions: ['top', 'bottom'],
+                    x: 50,
+                    y: 19,
+                    result: 'top',
+                },
+                {
+                    directions: ['top', 'bottom'],
+                    x: 50,
+                    y: 81,
+                    result: 'bottom',
+                },
+                {
+                    directions: ['left', 'right', 'top', 'bottom', 'center'],
+                    x: 50,
+                    y: 50,
+                    result: 'center',
+                },
+                {
+                    directions: ['left', 'right', 'top', 'bottom'],
+                    x: 50,
+                    y: 50,
+                    result: null,
+                },
+            ];
+
+            for (const input of inputs) {
+                expect(
+                    calculateQuadrantAsPercentage(
+                        new Set(input.directions),
+                        input.x,
+                        input.y,
+                        100,
+                        100,
+                        20
+                    )
+                ).toBe(input.result);
+            }
+        });
+    });
+
+    describe('calculateQuadrantAsPixels', () => {
+        test('variety of cases', () => {
+            const inputs: Array<{
+                directions: Position[];
+                x: number;
+                y: number;
+                result: Position | null;
+            }> = [
+                { directions: ['left', 'right'], x: 19, y: 50, result: 'left' },
+                {
+                    directions: ['left', 'right'],
+                    x: 81,
+                    y: 50,
+                    result: 'right',
+                },
+                {
+                    directions: ['top', 'bottom'],
+                    x: 50,
+                    y: 19,
+                    result: 'top',
+                },
+                {
+                    directions: ['top', 'bottom'],
+                    x: 50,
+                    y: 81,
+                    result: 'bottom',
+                },
+                {
+                    directions: ['left', 'right', 'top', 'bottom', 'center'],
+                    x: 50,
+                    y: 50,
+                    result: 'center',
+                },
+                {
+                    directions: ['left', 'right', 'top', 'bottom'],
+                    x: 50,
+                    y: 50,
+                    result: null,
+                },
+            ];
+
+            for (const input of inputs) {
+                expect(
+                    calculateQuadrantAsPixels(
+                        new Set(input.directions),
+                        input.x,
+                        input.y,
+                        100,
+                        100,
+                        20
+                    )
+                ).toBe(input.result);
+            }
+        });
+    });
+});

packages/dockview-core/src/__tests__/dnd/ghost.spec.ts

@@ -0,0 +1,31 @@
+import { addGhostImage } from '../../dnd/ghost';
+
+describe('ghost', () => {
+    beforeEach(() => {
+        jest.useFakeTimers();
+        jest.clearAllTimers();
+    });
+
+    test('that a custom class is added, the element is added to the document and all is removed afterwards', () => {
+        const dataTransferMock = jest.fn<Partial<DataTransfer>, []>(() => {
+            return {
+                setDragImage: jest.fn(),
+            };
+        });
+
+        const element = document.createElement('div');
+        const dataTransfer = <DataTransfer>new dataTransferMock();
+
+        addGhostImage(dataTransfer, element);
+
+        expect(element.className).toBe('dv-dragged');
+        expect(element.parentElement).toBe(document.body);
+        expect(dataTransfer.setDragImage).toBeCalledTimes(1);
+        expect(dataTransfer.setDragImage).toBeCalledWith(element, 0, 0);
+
+        jest.runAllTimers();
+
+        expect(element.className).toBe('');
+        expect(element.parentElement).toBe(null);
+    });
+});

packages/dockview-core/src/__tests__/dnd/groupDragHandler.spec.ts

@@ -0,0 +1,114 @@
+import { fireEvent } from '@testing-library/dom';
+import { GroupDragHandler } from '../../dnd/groupDragHandler';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import { LocalSelectionTransfer, PanelTransfer } from '../../dnd/dataTransfer';
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+
+describe('groupDragHandler', () => {
+    test('that the dnd transfer object is setup and torndown', () => {
+        const element = document.createElement('div');
+
+        const groupMock = jest.fn<DockviewGroupPanel, []>(() => {
+            const partial: Partial<DockviewGroupPanel> = {
+                id: 'test_group_id',
+                api: { location: { type: 'grid' } } as any,
+            };
+            return partial as DockviewGroupPanel;
+        });
+        const group = new groupMock();
+
+        const cut = new GroupDragHandler(
+            element,
+            { id: 'test_accessor_id' } as DockviewComponent,
+            group
+        );
+
+        fireEvent.dragStart(element, new Event('dragstart'));
+
+        expect(
+            LocalSelectionTransfer.getInstance<PanelTransfer>().hasData(
+                PanelTransfer.prototype
+            )
+        ).toBeTruthy();
+        const transferObject =
+            LocalSelectionTransfer.getInstance<PanelTransfer>().getData(
+                PanelTransfer.prototype
+            )![0];
+        expect(transferObject).toBeTruthy();
+        expect(transferObject.viewId).toBe('test_accessor_id');
+        expect(transferObject.groupId).toBe('test_group_id');
+        expect(transferObject.panelId).toBeNull();
+
+        fireEvent.dragStart(element, new Event('dragend'));
+        expect(
+            LocalSelectionTransfer.getInstance<PanelTransfer>().hasData(
+                PanelTransfer.prototype
+            )
+        ).toBeFalsy();
+
+        cut.dispose();
+    });
+    test('that the event is cancelled when floating and shiftKey=true', () => {
+        const element = document.createElement('div');
+
+        const groupMock = jest.fn<DockviewGroupPanel, []>(() => {
+            const partial: Partial<DockviewGroupPanel> = {
+                api: { location: { type: 'floating' } } as any,
+            };
+            return partial as DockviewGroupPanel;
+        });
+        const group = new groupMock();
+
+        const cut = new GroupDragHandler(
+            element,
+            { id: 'accessor_id' } as DockviewComponent,
+            group
+        );
+
+        const event = new KeyboardEvent('dragstart', { shiftKey: false });
+
+        const spy = jest.spyOn(event, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy).toBeCalledTimes(1);
+
+        const event2 = new KeyboardEvent('dragstart', { shiftKey: true });
+
+        const spy2 = jest.spyOn(event2, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy2).toBeCalledTimes(0);
+
+        cut.dispose();
+    });
+
+    test('that the event is never cancelled when the group is not floating', () => {
+        const element = document.createElement('div');
+
+        const groupMock = jest.fn<DockviewGroupPanel, []>(() => {
+            const partial: Partial<DockviewGroupPanel> = {
+                api: { location: { type: 'grid' } } as any,
+            };
+            return partial as DockviewGroupPanel;
+        });
+        const group = new groupMock();
+
+        const cut = new GroupDragHandler(
+            element,
+            { id: 'accessor_id' } as DockviewComponent,
+            group
+        );
+
+        const event = new KeyboardEvent('dragstart', { shiftKey: false });
+
+        const spy = jest.spyOn(event, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy).toBeCalledTimes(0);
+
+        const event2 = new KeyboardEvent('dragstart', { shiftKey: true });
+
+        const spy2 = jest.spyOn(event2, 'preventDefault');
+        fireEvent(element, event);
+        expect(spy2).toBeCalledTimes(0);
+
+        cut.dispose();
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/panel/content.spec.ts

@@ -0,0 +1,174 @@
+import { fireEvent } from '@testing-library/dom';
+import { ContentContainer } from '../../../../dockview/components/panel/content';
+import {
+    GroupPanelPartInitParameters,
+    IContentRenderer,
+} from '../../../../dockview/types';
+import { CompositeDisposable } from '../../../../lifecycle';
+import { PanelUpdateEvent } from '../../../../panel/types';
+import { IDockviewPanel } from '../../../../dockview/dockviewPanel';
+import { IDockviewPanelModel } from '../../../../dockview/dockviewPanelModel';
+import { DockviewComponent } from '../../../../dockview/dockviewComponent';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { DockviewGroupPanelModel } from '../../../../dockview/dockviewGroupPanelModel';
+import { OverlayRenderContainer } from '../../../../overlay/overlayRenderContainer';
+
+class TestContentRenderer
+    extends CompositeDisposable
+    implements IContentRenderer
+{
+    readonly element: HTMLElement;
+
+    constructor(public id: string) {
+        super();
+        this.element = document.createElement('div');
+        this.element.id = id;
+    }
+
+    init(parameters: GroupPanelPartInitParameters): void {
+        //
+    }
+
+    layout(width: number, height: number): void {
+        //
+    }
+    update(event: PanelUpdateEvent): void {
+        //
+    }
+
+    toJSON(): object {
+        return {};
+    }
+
+    focus(): void {
+        //
+    }
+}
+
+describe('contentContainer', () => {
+    beforeEach(() => {
+        jest.useFakeTimers();
+    });
+
+    test('basic focus test', () => {
+        let focus = 0;
+        let blur = 0;
+
+        const disposable = new CompositeDisposable();
+
+        const overlayRenderContainer = new OverlayRenderContainer(
+            document.createElement('div'),
+            fromPartial<DockviewComponent>({})
+        );
+
+        const cut = new ContentContainer(
+            fromPartial<DockviewComponent>({
+                renderer: 'onlyWhenVisible',
+                overlayRenderContainer,
+            }),
+            fromPartial<DockviewGroupPanelModel>({
+                renderContainer: overlayRenderContainer,
+            })
+        );
+
+        disposable.addDisposables(
+            cut.onDidFocus(() => {
+                focus++;
+            }),
+            cut.onDidBlur(() => {
+                blur++;
+            })
+        );
+
+        const contentRenderer = new TestContentRenderer('id-1');
+
+        const panel = fromPartial<IDockviewPanel>({
+            view: {
+                content: contentRenderer,
+            },
+            api: { renderer: 'onlyWhenVisible' },
+        });
+
+        cut.openPanel(panel as IDockviewPanel);
+
+        expect(focus).toBe(0);
+        expect(blur).toBe(0);
+
+        // container has focus within
+        fireEvent.focus(contentRenderer.element);
+        expect(focus).toBe(1);
+        expect(blur).toBe(0);
+
+        // container looses focus
+        fireEvent.blur(contentRenderer.element);
+        jest.runAllTimers();
+        expect(focus).toBe(1);
+        expect(blur).toBe(1);
+
+        const contentRenderer2 = new TestContentRenderer('id-2');
+
+        const panel2 = {
+            view: {
+                content: contentRenderer2,
+            } as Partial<IDockviewPanelModel>,
+            api: { renderer: 'onlyWhenVisible' },
+        } as Partial<IDockviewPanel>;
+
+        cut.openPanel(panel2 as IDockviewPanel);
+        // expect(focus).toBe(2);
+        // expect(blur).toBe(1);
+
+        // new panel recieves focus
+        fireEvent.focus(contentRenderer2.element);
+        expect(focus).toBe(2);
+        expect(blur).toBe(1);
+
+        // new panel looses focus
+        fireEvent.blur(contentRenderer2.element);
+        jest.runAllTimers();
+        expect(focus).toBe(2);
+        expect(blur).toBe(2);
+
+        disposable.dispose();
+    });
+
+    test("that panels renderered as 'onlyWhenVisible' are removed when closed", () => {
+        const overlayRenderContainer = fromPartial<OverlayRenderContainer>({
+            detatch: jest.fn(),
+        });
+
+        const cut = new ContentContainer(
+            fromPartial<DockviewComponent>({
+                overlayRenderContainer,
+            }),
+            fromPartial<DockviewGroupPanelModel>({
+                renderContainer: overlayRenderContainer,
+            })
+        );
+
+        const panel1 = fromPartial<IDockviewPanel>({
+            api: {
+                renderer: 'onlyWhenVisible',
+            },
+            view: { content: new TestContentRenderer('panel_1') },
+        });
+
+        const panel2 = fromPartial<IDockviewPanel>({
+            api: {
+                renderer: 'onlyWhenVisible',
+            },
+            view: { content: new TestContentRenderer('panel_2') },
+        });
+
+        cut.openPanel(panel1);
+
+        expect(panel1.view.content.element.parentElement).toBe(cut.element);
+        expect(cut.element.childNodes.length).toBe(1);
+
+        cut.openPanel(panel2);
+
+        expect(panel1.view.content.element.parentElement).toBeNull();
+        expect(panel2.view.content.element.parentElement).toBe(cut.element);
+        expect(cut.element.childNodes.length).toBe(1);
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/tab.spec.ts

@@ -0,0 +1,310 @@
+import { fireEvent } from '@testing-library/dom';
+import {
+    LocalSelectionTransfer,
+    PanelTransfer,
+} from '../../../dnd/dataTransfer';
+import { DockviewComponent } from '../../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../../dockview/dockviewGroupPanel';
+import { DockviewGroupPanelModel } from '../../../dockview/dockviewGroupPanelModel';
+import { Tab } from '../../../dockview/components/tab/tab';
+import { IDockviewPanel } from '../../../dockview/dockviewPanel';
+import { fromPartial } from '@total-typescript/shoehorn';
+
+describe('tab', () => {
+    test('that empty tab has inactive-tab class', () => {
+        const accessorMock = jest.fn();
+        const groupMock = jest.fn();
+
+        const cut = new Tab(
+            { id: 'panelId' } as IDockviewPanel,
+            new accessorMock(),
+            new groupMock()
+        );
+
+        expect(cut.element.className).toBe('dv-tab dv-inactive-tab');
+    });
+
+    test('that active tab has active-tab class', () => {
+        const accessorMock = jest.fn();
+        const groupMock = jest.fn();
+
+        const cut = new Tab(
+            { id: 'panelId' } as IDockviewPanel,
+            new accessorMock(),
+            new groupMock()
+        );
+
+        cut.setActive(true);
+        expect(cut.element.className).toBe('dv-tab dv-active-tab');
+
+        cut.setActive(false);
+        expect(cut.element.className).toBe('dv-tab dv-inactive-tab');
+    });
+
+    test('that an external event does not render a drop target and calls through to the group model', () => {
+        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
+            return {
+                id: 'testcomponentid',
+            };
+        });
+
+        const groupView = fromPartial<DockviewGroupPanelModel>({
+            canDisplayOverlay: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const accessor = new accessorMock() as DockviewComponent;
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new Tab(
+            { id: 'panelId' } as IDockviewPanel,
+            accessor,
+            groupPanel
+        );
+
+        jest.spyOn(cut.element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(cut.element, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        fireEvent.dragEnter(cut.element);
+        fireEvent.dragOver(cut.element);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalled();
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(0);
+    });
+
+    test('that if you drag over yourself a drop target is shown', () => {
+        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
+            return {
+                id: 'testcomponentid',
+            };
+        });
+
+        const groupView = fromPartial<DockviewGroupPanelModel>({
+            canDisplayOverlay: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const accessor = new accessorMock() as DockviewComponent;
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new Tab(
+            { id: 'panel1' } as IDockviewPanel,
+            accessor,
+            groupPanel
+        );
+
+        jest.spyOn(cut.element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(cut.element, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [new PanelTransfer('testcomponentid', 'anothergroupid', 'panel1')],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(cut.element);
+        fireEvent.dragOver(cut.element);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalledTimes(0);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(1);
+    });
+
+    test('that if you drag over another tab a drop target is shown', () => {
+        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
+            return {
+                id: 'testcomponentid',
+            };
+        });
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const accessor = new accessorMock() as DockviewComponent;
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new Tab(
+            { id: 'panel1' } as IDockviewPanel,
+            accessor,
+            groupPanel
+        );
+
+        jest.spyOn(cut.element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(cut.element, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [new PanelTransfer('testcomponentid', 'anothergroupid', 'panel2')],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(cut.element);
+        fireEvent.dragOver(cut.element);
+
+        expect(groupView.canDisplayOverlay).toBeCalledTimes(0);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(1);
+    });
+
+    test('that dropping on a tab with the same id but from a different component should not render a drop over and call through to the group model', () => {
+        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
+            return {
+                id: 'testcomponentid',
+            };
+        });
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const accessor = new accessorMock() as DockviewComponent;
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new Tab(
+            { id: 'panel1' } as IDockviewPanel,
+            accessor,
+            groupPanel
+        );
+
+        jest.spyOn(cut.element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(cut.element, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [
+                new PanelTransfer(
+                    'anothercomponentid',
+                    'anothergroupid',
+                    'panel1'
+                ),
+            ],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(cut.element);
+        fireEvent.dragOver(cut.element);
+
+        expect(groupView.canDisplayOverlay).toBeCalledTimes(1);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(0);
+    });
+
+    test('that dropping on a tab from a different component should not render a drop over and call through to the group model', () => {
+        const accessorMock = jest.fn<Partial<DockviewComponent>, []>(() => {
+            return {
+                id: 'testcomponentid',
+            };
+        });
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const accessor = new accessorMock() as DockviewComponent;
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new Tab(
+            { id: 'panel1' } as IDockviewPanel,
+            accessor,
+            groupPanel
+        );
+
+        jest.spyOn(cut.element, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(cut.element, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [
+                new PanelTransfer(
+                    'anothercomponentid',
+                    'anothergroupid',
+                    'panel2'
+                ),
+            ],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(cut.element);
+        fireEvent.dragOver(cut.element);
+
+        expect(groupView.canDisplayOverlay).toBeCalledTimes(1);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(0);
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/tab/defaultTab.spec.ts

@@ -0,0 +1,63 @@
+import { DockviewApi } from '../../../../api/component.api';
+import { DockviewPanelApi, TitleEvent } from '../../../../api/dockviewPanelApi';
+import { DefaultTab } from '../../../../dockview/components/tab/defaultTab';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { Emitter } from '../../../../events';
+import { fireEvent } from '@testing-library/dom';
+
+describe('defaultTab', () => {
+    test('that title updates', () => {
+        const cut = new DefaultTab();
+
+        let el = cut.element.querySelector('.dv-default-tab-content');
+        expect(el).toBeTruthy();
+        expect(el!.textContent).toBe('');
+
+        const onDidTitleChange = new Emitter<TitleEvent>();
+
+        const api = fromPartial<DockviewPanelApi>({
+            onDidTitleChange: onDidTitleChange.event,
+        });
+        const containerApi = fromPartial<DockviewApi>({});
+
+        cut.init({
+            api,
+            containerApi,
+            params: {},
+            title: 'title_abc',
+        });
+
+        el = cut.element.querySelector('.dv-default-tab-content');
+        expect(el).toBeTruthy();
+        expect(el!.textContent).toBe('title_abc');
+
+        onDidTitleChange.fire({ title: 'title_def' });
+
+        expect(el!.textContent).toBe('title_def');
+    });
+
+    test('that click closes tab', () => {
+        const cut = new DefaultTab();
+
+        const api = fromPartial<DockviewPanelApi>({
+            onDidTitleChange: jest.fn(),
+            close: jest.fn(),
+        });
+        const containerApi = fromPartial<DockviewApi>({});
+
+        cut.init({
+            api,
+            containerApi,
+            params: {},
+            title: 'title_abc',
+        });
+
+        let el = cut.element.querySelector('.dv-default-tab-action');
+
+        fireEvent.pointerDown(el!);
+        expect(api.close).toHaveBeenCalledTimes(0);
+
+        fireEvent.click(el!);
+        expect(api.close).toHaveBeenCalledTimes(1);
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/titlebar/tabs.spec.ts

@@ -0,0 +1,66 @@
+import { Tabs } from '../../../../dockview/components/titlebar/tabs';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { DockviewGroupPanel } from '../../../../dockview/dockviewGroupPanel';
+import { DockviewComponent } from '../../../../dockview/dockviewComponent';
+
+describe('tabs', () => {
+    describe('disableCustomScrollbars', () => {
+        test('enabled by default', () => {
+            const cut = new Tabs(
+                fromPartial<DockviewGroupPanel>({}),
+                fromPartial<DockviewComponent>({
+                    options: {},
+                }),
+                {
+                    showTabsOverflowControl: true,
+                }
+            );
+
+            expect(
+                cut.element.querySelectorAll(
+                    '.dv-scrollable > .dv-tabs-container'
+                ).length
+            ).toBe(1);
+        });
+
+        test('enabled when disabled flag is false', () => {
+            const cut = new Tabs(
+                fromPartial<DockviewGroupPanel>({}),
+                fromPartial<DockviewComponent>({
+                    options: {
+                        scrollbars: 'custom',
+                    },
+                }),
+                {
+                    showTabsOverflowControl: true,
+                }
+            );
+
+            expect(
+                cut.element.querySelectorAll(
+                    '.dv-scrollable > .dv-tabs-container'
+                ).length
+            ).toBe(1);
+        });
+
+        test('disabled when disabled flag is true', () => {
+            const cut = new Tabs(
+                fromPartial<DockviewGroupPanel>({}),
+                fromPartial<DockviewComponent>({
+                    options: {
+                        scrollbars: 'native',
+                    },
+                }),
+                {
+                    showTabsOverflowControl: true,
+                }
+            );
+
+            expect(
+                cut.element.querySelectorAll(
+                    '.dv-scrollable > .dv-tabs-container'
+                ).length
+            ).toBe(0);
+        });
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/titlebar/tabsContainer.spec.ts

@@ -0,0 +1,867 @@
+import {
+    LocalSelectionTransfer,
+    PanelTransfer,
+} from '../../../../dnd/dataTransfer';
+import { TabsContainer } from '../../../../dockview/components/titlebar/tabsContainer';
+import { DockviewComponent } from '../../../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../../../dockview/dockviewGroupPanel';
+import { DockviewGroupPanelModel } from '../../../../dockview/dockviewGroupPanelModel';
+import { fireEvent } from '@testing-library/dom';
+import { TestPanel } from '../../dockviewGroupPanelModel.spec';
+import { IDockviewPanel } from '../../../../dockview/dockviewPanel';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { DockviewPanelApi } from '../../../../api/dockviewPanelApi';
+
+describe('tabsContainer', () => {
+    test('that an external event does not render a drop target and calls through to the group mode', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                model: groupView,
+            };
+        });
+
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const emptySpace = cut.element
+            .getElementsByClassName('dv-void-container')
+            .item(0) as HTMLElement;
+
+        if (!emptySpace!) {
+            fail('element not found');
+        }
+
+        jest.spyOn(emptySpace!, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(emptySpace!, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        fireEvent.dragEnter(emptySpace!);
+        fireEvent.dragOver(emptySpace!);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalled();
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(0);
+    });
+
+    test('that a drag over event from another tab should render a drop target', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const dropTargetContainer = document.createElement('div');
+
+        const groupView = fromPartial<DockviewGroupPanelModel>({
+            canDisplayOverlay: jest.fn(),
+            // dropTargetContainer: new DropTargetAnchorContainer(
+            //     dropTargetContainer
+            // ),
+        });
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+                panels: [],
+            };
+        });
+
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const emptySpace = cut.element
+            .getElementsByClassName('dv-void-container')
+            .item(0) as HTMLElement;
+
+        if (!emptySpace!) {
+            fail('element not found');
+        }
+
+        jest.spyOn(emptySpace!, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(emptySpace!, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [
+                new PanelTransfer(
+                    'testcomponentid',
+                    'anothergroupid',
+                    'anotherpanelid'
+                ),
+            ],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(emptySpace!);
+        fireEvent.dragOver(emptySpace!);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalledTimes(0);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(1);
+        // expect(
+        //     dropTargetContainer.getElementsByClassName('dv-drop-target-anchor')
+        //         .length
+        // ).toBe(1);
+    });
+
+    test('that dropping over the empty space should render a drop target', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+                panels: [],
+            };
+        });
+
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        cut.openPanel(new TestPanel('panel1', jest.fn() as any));
+        cut.openPanel(new TestPanel('panel2', jest.fn() as any));
+
+        const emptySpace = cut.element
+            .getElementsByClassName('dv-void-container')
+            .item(0) as HTMLElement;
+
+        if (!emptySpace!) {
+            fail('element not found');
+        }
+
+        jest.spyOn(emptySpace!, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(emptySpace!, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [new PanelTransfer('testcomponentid', 'anothergroupid', 'panel2')],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(emptySpace!);
+        fireEvent.dragOver(emptySpace!);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalledTimes(0);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(1);
+    });
+
+    test('that dropping the first tab should render a drop target', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+                panels: [],
+            };
+        });
+
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        cut.openPanel(new TestPanel('panel1', jest.fn() as any));
+        cut.openPanel(new TestPanel('panel2', jest.fn() as any));
+
+        const emptySpace = cut.element
+            .getElementsByClassName('dv-void-container')
+            .item(0) as HTMLElement;
+
+        if (!emptySpace!) {
+            fail('element not found');
+        }
+
+        jest.spyOn(emptySpace!, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(emptySpace!, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [new PanelTransfer('testcomponentid', 'anothergroupid', 'panel1')],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(emptySpace!);
+        fireEvent.dragOver(emptySpace!);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalledTimes(0);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(1);
+    });
+
+    test('that dropping a tab from another component should not render a drop target', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupviewMock = jest.fn<Partial<DockviewGroupPanelModel>, []>(
+            () => {
+                return {
+                    canDisplayOverlay: jest.fn(),
+                };
+            }
+        );
+
+        const groupView = new groupviewMock() as DockviewGroupPanelModel;
+
+        const groupPanelMock = jest.fn<Partial<DockviewGroupPanel>, []>(() => {
+            return {
+                id: 'testgroupid',
+                model: groupView,
+            };
+        });
+
+        const groupPanel = new groupPanelMock() as DockviewGroupPanel;
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        cut.openPanel(new TestPanel('panel1', jest.fn() as any));
+        cut.openPanel(new TestPanel('panel2', jest.fn() as any));
+
+        const emptySpace = cut.element
+            .getElementsByClassName('dv-void-container')
+            .item(0) as HTMLElement;
+
+        if (!emptySpace!) {
+            fail('element not found');
+        }
+
+        jest.spyOn(emptySpace!, 'offsetHeight', 'get').mockImplementation(
+            () => 100
+        );
+        jest.spyOn(emptySpace!, 'offsetWidth', 'get').mockImplementation(
+            () => 100
+        );
+
+        LocalSelectionTransfer.getInstance().setData(
+            [
+                new PanelTransfer(
+                    'anothercomponentid',
+                    'anothergroupid',
+                    'panel1'
+                ),
+            ],
+            PanelTransfer.prototype
+        );
+
+        fireEvent.dragEnter(emptySpace!);
+        fireEvent.dragOver(emptySpace!);
+
+        expect(groupView.canDisplayOverlay).toHaveBeenCalledTimes(1);
+
+        expect(
+            cut.element.getElementsByClassName('dv-drop-target-dropzone').length
+        ).toBe(0);
+    });
+
+    test('left actions', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{}) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        let query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-left-actions-container'
+        );
+
+        expect(query.length).toBe(1);
+        expect(query[0].children.length).toBe(0);
+
+        // add left action
+
+        const left = document.createElement('div');
+        left.className = 'test-left-actions-element';
+        cut.setLeftActionsElement(left);
+
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-left-actions-container'
+        );
+        expect(query.length).toBe(1);
+        expect(query[0].children.item(0)?.className).toBe(
+            'test-left-actions-element'
+        );
+        expect(query[0].children.length).toBe(1);
+
+        // add left action
+
+        const left2 = document.createElement('div');
+        left2.className = 'test-left-actions-element-2';
+        cut.setLeftActionsElement(left2);
+
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-left-actions-container'
+        );
+        expect(query.length).toBe(1);
+        expect(query[0].children.item(0)?.className).toBe(
+            'test-left-actions-element-2'
+        );
+        expect(query[0].children.length).toBe(1);
+
+        // remove left action
+
+        cut.setLeftActionsElement(undefined);
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-left-actions-container'
+        );
+
+        expect(query.length).toBe(1);
+        expect(query[0].children.length).toBe(0);
+    });
+
+    test('right actions', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            id: 'testcomponentid',
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{}) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        let query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-right-actions-container'
+        );
+
+        expect(query.length).toBe(1);
+        expect(query[0].children.length).toBe(0);
+
+        // add right action
+
+        const right = document.createElement('div');
+        right.className = 'test-right-actions-element';
+        cut.setRightActionsElement(right);
+
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-right-actions-container'
+        );
+        expect(query.length).toBe(1);
+        expect(query[0].children.item(0)?.className).toBe(
+            'test-right-actions-element'
+        );
+        expect(query[0].children.length).toBe(1);
+
+        // add right action
+
+        const right2 = document.createElement('div');
+        right2.className = 'test-right-actions-element-2';
+        cut.setRightActionsElement(right2);
+
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-right-actions-container'
+        );
+        expect(query.length).toBe(1);
+        expect(query[0].children.item(0)?.className).toBe(
+            'test-right-actions-element-2'
+        );
+        expect(query[0].children.length).toBe(1);
+
+        // remove right action
+
+        cut.setRightActionsElement(undefined);
+        query = cut.element.querySelectorAll(
+            '.dv-tabs-and-actions-container > .dv-right-actions-container'
+        );
+
+        expect(query.length).toBe(1);
+        expect(query[0].children.length).toBe(0);
+    });
+
+    test('that a tab will become floating when clicked if not floating and shift is selected', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            doSetGroupActive: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'grid' } } as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const container = cut.element.querySelector('.dv-void-container')!;
+        expect(container).toBeTruthy();
+
+        jest.spyOn(cut.element, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return { top: 50, left: 100, width: 0, height: 0 } as any;
+            }
+        );
+        jest.spyOn(
+            accessor.element,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return { top: 10, left: 20, width: 0, height: 0 } as any;
+        });
+
+        const event = new KeyboardEvent('pointerdown', { shiftKey: true });
+        const eventPreventDefaultSpy = jest.spyOn(event, 'preventDefault');
+        fireEvent(container, event);
+
+        expect(accessor.doSetGroupActive).toHaveBeenCalledWith(groupPanel);
+        expect(accessor.addFloatingGroup).toHaveBeenCalledWith(groupPanel, {
+            x: 100,
+            y: 60,
+            inDragMode: true,
+        });
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(1);
+        expect(eventPreventDefaultSpy).toHaveBeenCalledTimes(1);
+
+        const event2 = new KeyboardEvent('pointerdown', { shiftKey: false });
+        const eventPreventDefaultSpy2 = jest.spyOn(event2, 'preventDefault');
+        fireEvent(container, event2);
+
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(1);
+        expect(eventPreventDefaultSpy2).toHaveBeenCalledTimes(0);
+    });
+
+    test('that a tab that is already floating cannot be floated again', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            doSetGroupActive: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'floating' } } as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const container = cut.element.querySelector('.dv-void-container')!;
+        expect(container).toBeTruthy();
+
+        jest.spyOn(cut.element, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return { top: 50, left: 100, width: 0, height: 0 } as any;
+            }
+        );
+        jest.spyOn(
+            accessor.element,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return { top: 10, left: 20, width: 0, height: 0 } as any;
+        });
+
+        const event = new KeyboardEvent('pointerdown', { shiftKey: true });
+        const eventPreventDefaultSpy = jest.spyOn(event, 'preventDefault');
+        fireEvent(container, event);
+
+        expect(accessor.doSetGroupActive).toHaveBeenCalledWith(groupPanel);
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(0);
+        expect(eventPreventDefaultSpy).toHaveBeenCalledTimes(0);
+
+        const event2 = new KeyboardEvent('pointerdown', { shiftKey: false });
+        const eventPreventDefaultSpy2 = jest.spyOn(event2, 'preventDefault');
+        fireEvent(container, event2);
+
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(0);
+        expect(eventPreventDefaultSpy2).toHaveBeenCalledTimes(0);
+    });
+
+    test('that selecting a tab with shift down will move that tab into a new floating group', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            getGroupPanel: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'floating' } } as any,
+                model: {} as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const createPanel = (id: string) =>
+            fromPartial<IDockviewPanel>({
+                id,
+                view: {
+                    tab: {
+                        element: document.createElement('div'),
+                    },
+                    content: {
+                        element: document.createElement('div'),
+                    },
+                },
+            });
+
+        const panel = createPanel('test_id');
+        cut.openPanel(panel);
+
+        const el = cut.element.querySelector('.dv-tab')!;
+        expect(el).toBeTruthy();
+
+        const event = new KeyboardEvent('pointerdown', { shiftKey: true });
+        const preventDefaultSpy = jest.spyOn(event, 'preventDefault');
+        fireEvent(el, event);
+
+        // a floating group with a single tab shouldn't be eligible
+        expect(preventDefaultSpy).toHaveBeenCalledTimes(0);
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(0);
+
+        const panel2 = createPanel('test_id_2');
+        cut.openPanel(panel2);
+        fireEvent(el, event);
+
+        expect(preventDefaultSpy).toHaveBeenCalledTimes(1);
+        expect(accessor.addFloatingGroup).toHaveBeenCalledTimes(1);
+    });
+
+    test('pre header actions', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            getGroupPanel: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'grid' } } as any,
+                model: {} as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const panelMock = jest.fn<IDockviewPanel, [string]>((id: string) => {
+            const partial: Partial<IDockviewPanel> = {
+                id,
+
+                view: {
+                    tab: {
+                        element: document.createElement('div'),
+                    } as any,
+                    content: {
+                        element: document.createElement('div'),
+                    } as any,
+                } as any,
+            };
+            return partial as IDockviewPanel;
+        });
+
+        const panel = new panelMock('test_id');
+        cut.openPanel(panel);
+
+        let result = cut.element.querySelector('.dv-pre-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+
+        const actions = document.createElement('div');
+        cut.setPrefixActionsElement(actions);
+
+        result = cut.element.querySelector('.dv-pre-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(actions);
+
+        const updatedActions = document.createElement('div');
+        cut.setPrefixActionsElement(updatedActions);
+
+        result = cut.element.querySelector('.dv-pre-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(updatedActions);
+
+        cut.setPrefixActionsElement(undefined);
+
+        result = cut.element.querySelector('.dv-pre-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+    });
+
+    test('left header actions', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            getGroupPanel: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'grid' } } as any,
+                model: {} as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const panelMock = jest.fn<IDockviewPanel, [string]>((id: string) => {
+            const partial: Partial<IDockviewPanel> = {
+                id,
+
+                view: {
+                    tab: {
+                        element: document.createElement('div'),
+                    } as any,
+                    content: {
+                        element: document.createElement('div'),
+                    } as any,
+                } as any,
+            };
+            return partial as IDockviewPanel;
+        });
+
+        const panel = new panelMock('test_id');
+        cut.openPanel(panel);
+
+        let result = cut.element.querySelector('.dv-left-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+
+        const actions = document.createElement('div');
+        cut.setLeftActionsElement(actions);
+
+        result = cut.element.querySelector('.dv-left-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(actions);
+
+        const updatedActions = document.createElement('div');
+        cut.setLeftActionsElement(updatedActions);
+
+        result = cut.element.querySelector('.dv-left-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(updatedActions);
+
+        cut.setLeftActionsElement(undefined);
+
+        result = cut.element.querySelector('.dv-left-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+    });
+
+    test('right header actions', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            options: {},
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            element: document.createElement('div'),
+            addFloatingGroup: jest.fn(),
+            getGroupPanel: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+
+        const groupPanelMock = jest.fn<DockviewGroupPanel, []>(() => {
+            return (<Partial<DockviewGroupPanel>>{
+                api: { location: { type: 'grid' } } as any,
+                model: {} as any,
+            }) as DockviewGroupPanel;
+        });
+
+        const groupPanel = new groupPanelMock();
+
+        const cut = new TabsContainer(accessor, groupPanel);
+
+        const panelMock = jest.fn<IDockviewPanel, [string]>((id: string) => {
+            const partial: Partial<IDockviewPanel> = {
+                id,
+
+                view: {
+                    tab: {
+                        element: document.createElement('div'),
+                    } as any,
+                    content: {
+                        element: document.createElement('div'),
+                    } as any,
+                } as any,
+            };
+            return partial as IDockviewPanel;
+        });
+
+        const panel = new panelMock('test_id');
+        cut.openPanel(panel);
+
+        let result = cut.element.querySelector('.dv-right-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+
+        const actions = document.createElement('div');
+        cut.setRightActionsElement(actions);
+
+        result = cut.element.querySelector('.dv-right-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(actions);
+
+        const updatedActions = document.createElement('div');
+        cut.setRightActionsElement(updatedActions);
+
+        result = cut.element.querySelector('.dv-right-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(1);
+        expect(result!.childNodes.item(0)).toBe(updatedActions);
+
+        cut.setRightActionsElement(undefined);
+
+        result = cut.element.querySelector('.dv-right-actions-container');
+        expect(result).toBeTruthy();
+        expect(result!.childNodes.length).toBe(0);
+    });
+
+    test('class dv-single-tab is present when only one tab exists`', () => {
+        const cut = new TabsContainer(
+            fromPartial<DockviewComponent>({
+                options: {},
+                onDidOptionsChange: jest.fn(),
+            }),
+            fromPartial<DockviewGroupPanel>({})
+        );
+
+        expect(cut.element.classList.contains('dv-single-tab')).toBeFalsy();
+
+        const panel1 = new TestPanel(
+            'panel_1',
+            fromPartial<DockviewPanelApi>({})
+        );
+        cut.openPanel(panel1);
+        expect(cut.element.classList.contains('dv-single-tab')).toBeTruthy();
+
+        const panel2 = new TestPanel(
+            'panel_2',
+            fromPartial<DockviewPanelApi>({})
+        );
+        cut.openPanel(panel2);
+        expect(cut.element.classList.contains('dv-single-tab')).toBeFalsy();
+
+        cut.closePanel(panel1);
+        expect(cut.element.classList.contains('dv-single-tab')).toBeTruthy();
+
+        cut.closePanel(panel2);
+        expect(cut.element.classList.contains('dv-single-tab')).toBeFalsy();
+    });
+});

packages/dockview-core/src/__tests__/dockview/components/titlebar/voidContainer.spec.ts

@@ -0,0 +1,20 @@
+import { VoidContainer } from '../../../../dockview/components/titlebar/voidContainer';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { DockviewComponent } from '../../../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../../../dockview/dockviewGroupPanel';
+import { fireEvent } from '@testing-library/dom';
+
+describe('voidContainer', () => {
+    test('that `pointerDown` triggers activation', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            doSetGroupActive: jest.fn(),
+        });
+        const group = fromPartial<DockviewGroupPanel>({});
+        const cut = new VoidContainer(accessor, group);
+
+        expect(accessor.doSetGroupActive).not.toHaveBeenCalled();
+
+        fireEvent.pointerDown(cut.element);
+        expect(accessor.doSetGroupActive).toHaveBeenCalledWith(group);
+    });
+});

packages/dockview-core/src/__tests__/dockview/dockviewGroupPanel.spec.ts

@@ -0,0 +1,190 @@
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { GroupOptions } from '../../dockview/dockviewGroupPanelModel';
+import { DockviewPanel, IDockviewPanel } from '../../dockview/dockviewPanel';
+import { DockviewPanelModelMock } from '../__mocks__/mockDockviewPanelModel';
+import { IContentRenderer, ITabRenderer } from '../../dockview/types';
+import { OverlayRenderContainer } from '../../overlay/overlayRenderContainer';
+import { IDockviewPanelModel } from '../../dockview/dockviewPanelModel';
+import { ContentContainer } from '../../dockview/components/panel/content';
+
+describe('dockviewGroupPanel', () => {
+    test('default minimum/maximium width/height', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            onDidActivePanelChange: jest.fn(),
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+        const options = fromPartial<GroupOptions>({});
+        const cut = new DockviewGroupPanel(accessor, 'test_id', options);
+
+        expect(cut.minimumWidth).toBe(100);
+        expect(cut.minimumHeight).toBe(100);
+        expect(cut.maximumHeight).toBe(Number.MAX_SAFE_INTEGER);
+        expect(cut.maximumWidth).toBe(Number.MAX_SAFE_INTEGER);
+    });
+
+    test('that onDidActivePanelChange is configured at inline', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            onDidActivePanelChange: jest.fn(),
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            options: {},
+            api: {},
+            renderer: 'always',
+            overlayRenderContainer: {
+                attach: jest.fn(),
+                detatch: jest.fn(),
+            },
+            doSetGroupActive: jest.fn(),
+            onDidOptionsChange: jest.fn(),
+        });
+        const options = fromPartial<GroupOptions>({});
+
+        const cut = new DockviewGroupPanel(accessor, 'test_id', options);
+
+        let counter = 0;
+
+        cut.api.onDidActivePanelChange((event) => {
+            counter++;
+        });
+
+        cut.model.openPanel(
+            fromPartial<IDockviewPanel>({
+                updateParentGroup: jest.fn(),
+                view: {
+                    tab: { element: document.createElement('div') },
+                    content: new ContentContainer(accessor, cut.model),
+                },
+                api: {
+                    renderer: 'onlyWhenVisible',
+                    onDidTitleChange: jest.fn(),
+                    onDidParametersChange: jest.fn(),
+                },
+                layout: jest.fn(),
+                runEvents: jest.fn(),
+            })
+        );
+
+        expect(counter).toBe(1);
+    });
+
+    test('group constraints', () => {
+        const accessor = fromPartial<DockviewComponent>({
+            onDidActivePanelChange: jest.fn(),
+            onDidAddPanel: jest.fn(),
+            onDidRemovePanel: jest.fn(),
+            doSetGroupActive: jest.fn(),
+            overlayRenderContainer: fromPartial<OverlayRenderContainer>({
+                attach: jest.fn(),
+                detatch: jest.fn(),
+            }),
+            options: {},
+            onDidOptionsChange: jest.fn(),
+        });
+        const options = fromPartial<GroupOptions>({});
+        const cut = new DockviewGroupPanel(accessor, 'test_id', options);
+
+        cut.api.setConstraints({
+            minimumHeight: 10,
+            maximumHeight: 100,
+            minimumWidth: 20,
+            maximumWidth: 200,
+        });
+
+        // initial constraints
+
+        expect(cut.minimumWidth).toBe(20);
+        expect(cut.minimumHeight).toBe(10);
+        expect(cut.maximumHeight).toBe(100);
+        expect(cut.maximumWidth).toBe(200);
+
+        const panelModel = new DockviewPanelModelMock(
+            'content_component',
+            fromPartial<IContentRenderer>({
+                element: document.createElement('div'),
+            }),
+            'tab_component',
+            fromPartial<ITabRenderer>({
+                element: document.createElement('div'),
+            })
+        );
+
+        const panel = new DockviewPanel(
+            'panel_id',
+            'component_id',
+            undefined,
+            accessor,
+            accessor.api,
+            cut,
+            panelModel,
+            {
+                renderer: 'onlyWhenVisible',
+                minimumWidth: 21,
+                minimumHeight: 11,
+                maximumHeight: 101,
+                maximumWidth: 201,
+            }
+        );
+
+        cut.model.openPanel(panel);
+
+        // active panel constraints
+
+        expect(cut.minimumWidth).toBe(21);
+        expect(cut.minimumHeight).toBe(11);
+        expect(cut.maximumHeight).toBe(101);
+        expect(cut.maximumWidth).toBe(201);
+
+        const panel2 = new DockviewPanel(
+            'panel_id',
+            'component_id',
+            undefined,
+            accessor,
+            accessor.api,
+            cut,
+            panelModel,
+            {
+                renderer: 'onlyWhenVisible',
+                minimumWidth: 22,
+                minimumHeight: 12,
+                maximumHeight: 102,
+                maximumWidth: 202,
+            }
+        );
+
+        cut.model.openPanel(panel2);
+
+        // active panel constraints
+
+        expect(cut.minimumWidth).toBe(22);
+        expect(cut.minimumHeight).toBe(12);
+        expect(cut.maximumHeight).toBe(102);
+        expect(cut.maximumWidth).toBe(202);
+
+        const panel3 = new DockviewPanel(
+            'panel_id',
+            'component_id',
+            undefined,
+            accessor,
+            accessor.api,
+            cut,
+            panelModel,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        cut.model.openPanel(panel3);
+
+        // active panel without specified constraints so falls back to group constraints
+
+        expect(cut.minimumWidth).toBe(20);
+        expect(cut.minimumHeight).toBe(10);
+        expect(cut.maximumHeight).toBe(100);
+        expect(cut.maximumWidth).toBe(200);
+    });
+});

packages/dockview-core/src/__tests__/dockview/dockviewPanel.spec.ts

@@ -0,0 +1,287 @@
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewApi } from '../../api/component.api';
+import { DockviewPanel } from '../../dockview/dockviewPanel';
+import { IDockviewPanelModel } from '../../dockview/dockviewPanelModel';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+import { fromPartial } from '@total-typescript/shoehorn';
+
+describe('dockviewPanel', () => {
+    test('update title', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+            dispose: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        let latestTitle: string | undefined = undefined;
+
+        const disposable = cut.api.onDidTitleChange((event) => {
+            latestTitle = event.title;
+        });
+
+        expect(cut.title).toBeUndefined();
+
+        cut.init({ title: 'new title', params: {} });
+        expect(latestTitle).toBe('new title');
+        expect(cut.title).toBe('new title');
+
+        cut.setTitle('another title');
+        expect(latestTitle).toBe('another title');
+        expect(cut.title).toBe('another title');
+
+        disposable.dispose();
+    });
+
+    test('that .setTitle updates the title', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        cut.init({ title: 'myTitle', params: {} });
+        expect(cut.title).toBe('myTitle');
+
+        cut.setTitle('newTitle');
+        expect(cut.title).toBe('newTitle');
+
+        cut.api.setTitle('new title 2');
+        expect(cut.title).toBe('new title 2');
+    });
+
+    test('dispose cleanup', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest
+                    .fn()
+                    .mockReturnValue({ dispose: jest.fn() }),
+                onDidLocationChange: jest
+                    .fn()
+                    .mockReturnValue({ dispose: jest.fn() }),
+                onDidActiveChange: jest
+                    .fn()
+                    .mockReturnValue({ dispose: jest.fn() }),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+            dispose: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        cut.init({ params: {}, title: 'title' });
+
+        cut.dispose();
+
+        expect(model.dispose).toHaveBeenCalled();
+    });
+
+    test('get params', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+            dispose: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        expect(cut.params).toEqual(undefined);
+
+        cut.update({ params: { variableA: 'A', variableB: 'B' } });
+
+        expect(cut.params).toEqual({ variableA: 'A', variableB: 'B' });
+    });
+
+    test('setSize propagates to underlying group', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+                setSize: jest.fn(),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+            dispose: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        cut.api.setSize({ height: 123, width: 456 });
+
+        expect(group.api.setSize).toHaveBeenCalledWith({
+            height: 123,
+            width: 456,
+        });
+        expect(group.api.setSize).toHaveBeenCalledTimes(1);
+    });
+
+    test('updateParameter', () => {
+        const api = fromPartial<DockviewApi>({});
+        const accessor = fromPartial<DockviewComponent>({});
+        const group = fromPartial<DockviewGroupPanel>({
+            api: {
+                onDidVisibilityChange: jest.fn(),
+                onDidLocationChange: jest.fn(),
+                onDidActiveChange: jest.fn(),
+            },
+        });
+        const model = fromPartial<IDockviewPanelModel>({
+            update: jest.fn(),
+            init: jest.fn(),
+            dispose: jest.fn(),
+        });
+
+        const cut = new DockviewPanel(
+            'fake-id',
+            'fake-component',
+            undefined,
+            accessor,
+            api,
+            group,
+            model,
+            {
+                renderer: 'onlyWhenVisible',
+            }
+        );
+
+        cut.init({ params: { a: '1', b: '2' }, title: 'A title' });
+        expect(cut.params).toEqual({ a: '1', b: '2' });
+
+        // update 'a' and add 'c'
+        cut.update({ params: { a: '-1', c: '3' } });
+        expect(cut.params).toEqual({ a: '-1', b: '2', c: '3' });
+        expect(model.update).toHaveBeenCalledWith({
+            params: { a: '-1', b: '2', c: '3' },
+        });
+
+        cut.update({ params: { d: '4', e: '5', f: '6' } });
+        expect(cut.params).toEqual({
+            a: '-1',
+            b: '2',
+            c: '3',
+            d: '4',
+            e: '5',
+            f: '6',
+        });
+        expect(model.update).toHaveBeenCalledWith({
+            params: { a: '-1', b: '2', c: '3', d: '4', e: '5', f: '6' },
+        });
+
+        cut.update({
+            params: {
+                d: '',
+                e: null,
+                f: undefined,
+                g: '',
+                h: null,
+                i: undefined,
+            },
+        });
+        expect(cut.params).toEqual({
+            a: '-1',
+            b: '2',
+            c: '3',
+            d: '',
+            e: null,
+            g: '',
+            h: null,
+        });
+        expect(model.update).toHaveBeenCalledWith({
+            params: { a: '-1', b: '2', c: '3', d: '', e: null, g: '', h: null },
+        });
+    });
+});

packages/dockview-core/src/__tests__/dockview/dockviewPanelModel.spec.ts

@@ -0,0 +1,200 @@
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewPanelModel } from '../../dockview/dockviewPanelModel';
+import { IContentRenderer, ITabRenderer } from '../../dockview/types';
+import { DefaultTab } from '../../dockview/components/tab/defaultTab';
+import { fromPartial } from '@total-typescript/shoehorn';
+
+describe('dockviewGroupPanel', () => {
+    let contentMock: jest.Mock<IContentRenderer>;
+    let tabMock: jest.Mock<ITabRenderer>;
+    let accessorMock: DockviewComponent;
+
+    beforeEach(() => {
+        contentMock = jest.fn<IContentRenderer, []>(() => {
+            const partial: Partial<IContentRenderer> = {
+                element: document.createElement('div'),
+                dispose: jest.fn(),
+                update: jest.fn(),
+            };
+            return partial as IContentRenderer;
+        });
+
+        tabMock = jest.fn<ITabRenderer, []>(() => {
+            const partial: Partial<IContentRenderer> = {
+                element: document.createElement('div'),
+                dispose: jest.fn(),
+                update: jest.fn(),
+            };
+            return partial as IContentRenderer;
+        });
+
+        accessorMock = fromPartial<DockviewComponent>({
+            options: {
+                createComponent(options) {
+                    switch (options.name) {
+                        case 'contentComponent':
+                            return new contentMock(options.id, options.name);
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+                createTabComponent(options) {
+                    switch (options.name) {
+                        case 'tabComponent':
+                            return new tabMock(options.id, options.name);
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+            },
+        });
+    });
+
+    test('that dispose is called on content and tab renderers when present', () => {
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent',
+            'tabComponent'
+        );
+
+        cut.dispose();
+
+        expect(cut.content.dispose).toHaveBeenCalled();
+        expect(cut.tab.dispose).toHaveBeenCalled();
+    });
+
+    test('that update is called on content and tab renderers when present', () => {
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent',
+            'tabComponent'
+        );
+
+        cut.update({
+            params: {},
+        });
+
+        expect(cut.content.update).toHaveBeenCalled();
+        expect(cut.tab.update).toHaveBeenCalled();
+    });
+
+    test('that the default tab is created', () => {
+        accessorMock = fromPartial<DockviewComponent>({
+            options: {
+                createComponent(options) {
+                    switch (options.name) {
+                        case 'contentComponent':
+                            return new contentMock(options.id, options.name);
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+                createTabComponent(options) {
+                    switch (options.name) {
+                        case 'tabComponent':
+                            return tabMock;
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+            },
+        });
+
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent',
+            'tabComponent'
+        );
+
+        expect(cut.tab).toEqual(tabMock);
+    });
+
+    test('that the provided default tab is chosen when no implementation is provided', () => {
+        accessorMock = fromPartial<DockviewComponent>({
+            options: {
+                defaultTabComponent: 'tabComponent',
+                createComponent(options) {
+                    switch (options.name) {
+                        case 'contentComponent':
+                            return new contentMock(options.id, options.name);
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+                createTabComponent(options) {
+                    switch (options.name) {
+                        case 'tabComponent':
+                            return tabMock;
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+            },
+        });
+
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.tab).toEqual(tabMock);
+    });
+
+    test('that is library default tab instance is created when no alternative exists', () => {
+        accessorMock = fromPartial<DockviewComponent>({
+            options: {
+                createComponent(options) {
+                    switch (options.name) {
+                        case 'contentComponent':
+                            return new contentMock(options.id, options.name);
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+            },
+        });
+
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.tab instanceof DefaultTab).toBeTruthy();
+    });
+
+    test('that the default content is created', () => {
+        accessorMock = fromPartial<DockviewComponent>({
+            options: {
+                createComponent(options) {
+                    switch (options.name) {
+                        case 'contentComponent':
+                            return contentMock;
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+                createTabComponent(options) {
+                    switch (options.name) {
+                        case 'tabComponent':
+                            return tabMock;
+                        default:
+                            throw new Error(`unsupported`);
+                    }
+                },
+            },
+        });
+
+        const cut = new DockviewPanelModel(
+            accessorMock,
+            'id',
+            'contentComponent'
+        );
+
+        expect(cut.content).toEqual(contentMock);
+    });
+});

packages/dockview-core/src/__tests__/dom.spec.ts

@@ -0,0 +1,83 @@
+import {
+    disableIframePointEvents,
+    isInDocument,
+    quasiDefaultPrevented,
+    quasiPreventDefault,
+} from '../dom';
+
+describe('dom', () => {
+    test('quasiPreventDefault', () => {
+        const event = new Event('myevent');
+        expect((event as any)['dv-quasiPreventDefault']).toBeUndefined();
+        quasiPreventDefault(event);
+        expect((event as any)['dv-quasiPreventDefault']).toBe(true);
+    });
+
+    test('quasiDefaultPrevented', () => {
+        const event = new Event('myevent');
+        expect(quasiDefaultPrevented(event)).toBeFalsy();
+
+        (event as any)['dv-quasiPreventDefault'] = false;
+        expect(quasiDefaultPrevented(event)).toBeFalsy();
+
+        (event as any)['dv-quasiPreventDefault'] = true;
+        expect(quasiDefaultPrevented(event)).toBeTruthy();
+    });
+
+    test('isInDocument: DOM element', () => {
+        const el = document.createElement('div');
+
+        expect(isInDocument(el)).toBeFalsy();
+
+        document.body.appendChild(el);
+        expect(isInDocument(el)).toBeTruthy();
+    });
+
+    test('isInDocument: Shadow DOM element', () => {
+        const el = document.createElement('div');
+        document.body.appendChild(el);
+
+        const shadow = el.attachShadow({ mode: 'open' });
+
+        const el2 = document.createElement('div');
+        expect(isInDocument(el2)).toBeFalsy();
+
+        shadow.appendChild(el2);
+
+        expect(isInDocument(el2)).toBeTruthy();
+    });
+
+    test('disableIframePointEvents', () => {
+        const el1 = document.createElement('iframe');
+        const el2 = document.createElement('iframe');
+        const el3 = document.createElement('webview');
+        const el4 = document.createElement('webview');
+
+        document.body.appendChild(el1);
+        document.body.appendChild(el2);
+        document.body.appendChild(el3);
+        document.body.appendChild(el4);
+
+        el1.style.pointerEvents = 'inherit';
+        el3.style.pointerEvents = 'inherit';
+
+        expect(el1.style.pointerEvents).toBe('inherit');
+        expect(el2.style.pointerEvents).toBe('');
+        expect(el3.style.pointerEvents).toBe('inherit');
+        expect(el4.style.pointerEvents).toBe('');
+
+        const f = disableIframePointEvents();
+
+        expect(el1.style.pointerEvents).toBe('none');
+        expect(el2.style.pointerEvents).toBe('none');
+        expect(el3.style.pointerEvents).toBe('none');
+        expect(el4.style.pointerEvents).toBe('none');
+
+        f.release();
+
+        expect(el1.style.pointerEvents).toBe('inherit');
+        expect(el2.style.pointerEvents).toBe('');
+        expect(el3.style.pointerEvents).toBe('inherit');
+        expect(el4.style.pointerEvents).toBe('');
+    });
+});

packages/dockview-core/src/__tests__/events.spec.ts

@@ -0,0 +1,278 @@
+import {
+    AsapEvent,
+    Emitter,
+    Event,
+    addDisposableListener,
+} from '../events';
+
+describe('events', () => {
+    describe('emitter', () => {
+        it('debug mode is off', () => {
+            expect(Emitter.ENABLE_TRACKING).toBeFalsy();
+        });
+
+        it('should emit values', () => {
+            const emitter = new Emitter<number>();
+            let value: number | undefined = undefined;
+
+            emitter.fire(-1);
+            expect(value).toBeUndefined();
+
+            const stream = emitter.event((x) => {
+                value = x;
+            });
+
+            emitter.fire(0);
+            expect(value).toBe(0);
+
+            emitter.fire(1);
+            expect(value).toBe(1);
+
+            stream.dispose();
+        });
+
+        it('should stop emitting after dispose', () => {
+            const emitter = new Emitter<number>();
+            let value: number | undefined = undefined;
+
+            const stream = emitter.event((x) => {
+                value = x;
+            });
+
+            emitter.fire(0);
+            expect(value).toBe(0);
+
+            stream.dispose();
+
+            value = undefined;
+            emitter.fire(1);
+            expect(value).toBeUndefined();
+        });
+
+        it('should stop emitting after dispose', () => {
+            const emitter = new Emitter<number>();
+            let value: number | undefined = undefined;
+
+            const stream = emitter.event((x) => {
+                value = x;
+            });
+
+            emitter.fire(0);
+            expect(value).toBe(0);
+
+            stream.dispose();
+
+            value = undefined;
+            emitter.fire(1);
+            expect(value).toBeUndefined();
+        });
+
+        it('should relay last value in replay mode', () => {
+            const emitter = new Emitter<number>({ replay: true });
+            let value: number | undefined = undefined;
+
+            emitter.fire(1);
+
+            const stream = emitter.event((x) => {
+                value = x;
+            });
+            expect(value).toBe(1);
+
+            stream.dispose();
+        });
+    });
+
+    describe('asapEvent', () => {
+        test('that asapEvents fire once per event-loop-cycle', () => {
+            jest.useFakeTimers();
+
+            const event = new AsapEvent();
+
+            let preFireCount = 0;
+            let postFireCount = 0;
+
+            event.onEvent(() => {
+                preFireCount++;
+            });
+
+            for (let i = 0; i < 100; i++) {
+                event.fire();
+            }
+
+            /**
+             * check that subscribing after the events have fired but before the event-loop cycle completes
+             * results in no event fires.
+             */
+            event.onEvent((e) => {
+                postFireCount++;
+            });
+
+            expect(preFireCount).toBe(0);
+            expect(postFireCount).toBe(0);
+
+            jest.runAllTimers();
+
+            expect(preFireCount).toBe(1);
+            expect(postFireCount).toBe(0);
+        });
+    });
+
+    it('should emit a value when any event fires', () => {
+        const emitter1 = new Emitter<number>();
+        const emitter2 = new Emitter<number>();
+        const emitter3 = new Emitter<number>();
+
+        let value: number | undefined = 0;
+
+        const stream = Event.any(
+            emitter1.event,
+            emitter2.event,
+            emitter3.event
+        )((x) => {
+            value = x;
+        });
+
+        emitter2.fire(2);
+        expect(value).toBe(2);
+
+        emitter1.fire(1);
+        expect(value).toBe(1);
+
+        emitter3.fire(3);
+        expect(value).toBe(3);
+    });
+
+    it('addDisposableListener with capture options', () => {
+        const element = {
+            addEventListener: jest.fn(),
+            removeEventListener: jest.fn(),
+        };
+
+        const handler = jest.fn();
+
+        const disposable = addDisposableListener(
+            element as any,
+            'pointerdown',
+            handler,
+            true
+        );
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.addEventListener).toHaveBeenCalledWith(
+            'pointerdown',
+            handler,
+            true
+        );
+        expect(element.removeEventListener).toBeCalledTimes(0);
+
+        disposable.dispose();
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledWith(
+            'pointerdown',
+            handler,
+            true
+        );
+    });
+
+    it('addDisposableListener without capture options', () => {
+        const element = {
+            addEventListener: jest.fn(),
+            removeEventListener: jest.fn(),
+        };
+
+        const handler = jest.fn();
+
+        const disposable = addDisposableListener(
+            element as any,
+            'pointerdown',
+            handler
+        );
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.addEventListener).toHaveBeenCalledWith(
+            'pointerdown',
+            handler,
+            undefined
+        );
+        expect(element.removeEventListener).toBeCalledTimes(0);
+
+        disposable.dispose();
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledWith(
+            'pointerdown',
+            handler,
+            undefined
+        );
+    });
+
+    it('addDisposableListener with capture options', () => {
+        const element = {
+            addEventListener: jest.fn(),
+            removeEventListener: jest.fn(),
+        };
+
+        const handler = jest.fn();
+
+        const disposable = addDisposableListener(
+            element as any,
+            'pointerdown',
+            handler,
+            true
+        );
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.addEventListener).toHaveBeenCalledWith(
+            'pointerdown',
+            handler,
+            true
+        );
+        expect(element.removeEventListener).toBeCalledTimes(0);
+
+        disposable.dispose();
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledWith(
+            'pointerdown',
+            handler,
+            true
+        );
+    });
+
+    it('addDisposableListener without capture options', () => {
+        const element = {
+            addEventListener: jest.fn(),
+            removeEventListener: jest.fn(),
+        };
+
+        const handler = jest.fn();
+
+        const disposable = addDisposableListener(
+            element as any,
+            'pointerdown',
+            handler
+        );
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.addEventListener).toHaveBeenCalledWith(
+            'pointerdown',
+            handler,
+            undefined
+        );
+        expect(element.removeEventListener).toBeCalledTimes(0);
+
+        disposable.dispose();
+
+        expect(element.addEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledTimes(1);
+        expect(element.removeEventListener).toBeCalledWith(
+            'pointerdown',
+            handler,
+            undefined
+        );
+    });
+});

packages/dockview-core/src/__tests__/gridview/baseComponentGridview.spec.ts

@@ -0,0 +1,206 @@
+import { Emitter } from '../../events';
+import {
+    BaseGrid,
+    IGridPanelView,
+    BaseGridOptions,
+} from '../../gridview/baseComponentGridview';
+import { IViewSize } from '../../gridview/gridview';
+import { CompositeDisposable } from '../../lifecycle';
+import {
+    PanelInitParameters,
+    PanelUpdateEvent,
+    Parameters,
+} from '../../panel/types';
+import { LayoutPriority, Orientation } from '../../splitview/splitview';
+
+class TestPanel implements IGridPanelView {
+    _onDidChange = new Emitter<IViewSize | undefined>();
+    readonly onDidChange = this._onDidChange.event;
+
+    isVisible: boolean = true;
+    isActive: boolean = true;
+    params: Parameters = {};
+
+    constructor(
+        public readonly id: string,
+        public readonly element: HTMLElement,
+        public readonly minimumWidth: number,
+        public readonly maximumWidth: number,
+        public readonly minimumHeight: number,
+        public readonly maximumHeight: number,
+        public priority: LayoutPriority,
+        public snap: boolean
+    ) {}
+
+    init(params: PanelInitParameters): void {
+        //
+    }
+
+    setActive(isActive: boolean): void {
+        //
+    }
+
+    toJSON(): object {
+        return {};
+    }
+
+    layout(width: number, height: number): void {
+        //
+    }
+
+    update(event: PanelUpdateEvent<Parameters>): void {
+        //
+    }
+
+    focus(): void {
+        //
+    }
+
+    fromJSON(json: object): void {
+        //
+    }
+
+    dispose(): void {
+        //
+    }
+}
+
+class ClassUnderTest extends BaseGrid<TestPanel> {
+    readonly gridview = this.gridview;
+
+    constructor(parentElement: HTMLElement, options: BaseGridOptions) {
+        super(parentElement, options);
+    }
+
+    doRemoveGroup(
+        group: TestPanel,
+        options?: { skipActive?: boolean; skipDispose?: boolean }
+    ): TestPanel {
+        return super.doRemoveGroup(group, options);
+    }
+
+    doAddGroup(group: TestPanel, location?: number[], size?: number): void {
+        this._groups.set(group.id, {
+            value: group,
+            disposable: {
+                dispose: () => {
+                    //
+                },
+            },
+        });
+        super.doAddGroup(group, location, size);
+    }
+
+    public fromJSON(data: any): void {
+        //
+    }
+
+    public toJSON(): object {
+        return {};
+    }
+
+    public clear(): void {
+        //
+    }
+}
+
+describe('baseComponentGridview', () => {
+    test('that the container is not removed when grid is disposed', () => {
+        const root = document.createElement('div');
+        const container = document.createElement('div');
+        root.appendChild(container);
+
+        const cut = new ClassUnderTest(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: true,
+        });
+
+        cut.dispose();
+
+        expect(container.parentElement).toBe(root);
+    });
+
+    test('that .layout(...) force flag works', () => {
+        const cut = new ClassUnderTest(document.createElement('div'), {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: true,
+        });
+
+        const spy = jest.spyOn(cut.gridview, 'layout');
+
+        cut.layout(100, 100);
+        expect(spy).toHaveBeenCalledTimes(1);
+
+        cut.layout(100, 100, false);
+        expect(spy).toHaveBeenCalledTimes(1);
+
+        cut.layout(100, 100, true);
+        expect(spy).toHaveBeenCalledTimes(2);
+
+        cut.layout(150, 150, false);
+        expect(spy).toHaveBeenCalledTimes(3);
+
+        cut.layout(150, 150, true);
+        expect(spy).toHaveBeenCalledTimes(4);
+    });
+
+    test('can add group', () => {
+        const cut = new ClassUnderTest(document.createElement('div'), {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: true,
+        });
+
+        const events: { type: string; panel: TestPanel | undefined }[] = [];
+
+        const disposable = new CompositeDisposable(
+            cut.onDidAdd((event) => {
+                events.push({ type: 'add', panel: event });
+            }),
+            cut.onDidRemove((event) => {
+                events.push({ type: 'remove', panel: event });
+            }),
+            cut.onDidActiveChange((event) => {
+                events.push({ type: 'active', panel: event });
+            })
+        );
+
+        const panel1 = new TestPanel(
+            'id',
+            document.createElement('div'),
+            0,
+            100,
+            0,
+            100,
+            LayoutPriority.Normal,
+            false
+        );
+
+        cut.doAddGroup(panel1);
+
+        expect(events.length).toBe(1);
+        expect(events[0]).toEqual({ type: 'add', panel: panel1 });
+
+        const panel2 = new TestPanel(
+            'id',
+            document.createElement('div'),
+            0,
+            100,
+            0,
+            100,
+            LayoutPriority.Normal,
+            false
+        );
+
+        cut.doAddGroup(panel2);
+
+        expect(events.length).toBe(2);
+        expect(events[1]).toEqual({ type: 'add', panel: panel2 });
+
+        cut.doRemoveGroup(panel1);
+        expect(events.length).toBe(3);
+        expect(events[2]).toEqual({ type: 'remove', panel: panel1 });
+
+        disposable.dispose();
+        cut.dispose();
+    });
+});

packages/dockview-core/src/__tests__/gridview/gridviewPanel.spec.ts

@@ -0,0 +1,25 @@
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+
+describe('gridviewPanel', () => {
+    test('get panel', () => {
+        const accessorMock = jest.fn<DockviewComponent, []>(() => {
+            return {
+                onDidAddPanel: jest.fn(),
+                onDidRemovePanel: jest.fn(),
+                options: {},
+                onDidOptionsChange: jest.fn(),
+            } as any;
+        });
+
+        const accessor = new accessorMock();
+
+        const cut = new DockviewGroupPanel(accessor, 'id', {});
+
+        expect(cut.params).toEqual(undefined);
+
+        cut.update({ params: { variableA: 'A', variableB: 'B' } });
+
+        expect(cut.params).toEqual({ variableA: 'A', variableB: 'B' });
+    });
+});

packages/dockview-core/src/__tests__/lifecycle.spec.ts

@@ -0,0 +1,83 @@
+import {
+    CompositeDisposable,
+    Disposable,
+    MutableDisposable,
+} from '../lifecycle';
+
+describe('lifecycle', () => {
+    test('mutable disposable', () => {
+        const mutableDisposable = new MutableDisposable();
+
+        let disposed = 0;
+
+        const disposable = () => ({
+            dispose: () => {
+                disposed++;
+            },
+        });
+
+        mutableDisposable.value = disposable();
+        expect(disposed).toBe(0);
+
+        mutableDisposable.value = disposable();
+        expect(disposed).toBe(1);
+
+        mutableDisposable.dispose();
+        expect(disposed).toBe(2);
+
+        mutableDisposable.dispose();
+    });
+
+    test('composite disposable', () => {
+        const d1 = {
+            dispose: jest.fn(),
+        };
+        const d2 = {
+            dispose: jest.fn(),
+        };
+        const d3 = {
+            dispose: jest.fn(),
+        };
+        const d4 = {
+            dispose: jest.fn(),
+        };
+
+        const cut = new CompositeDisposable(d1, d2);
+        cut.addDisposables(d3, d4);
+
+        cut.dispose();
+
+        expect(d1.dispose).toHaveBeenCalledTimes(1);
+        expect(d2.dispose).toHaveBeenCalledTimes(1);
+        expect(d3.dispose).toHaveBeenCalledTimes(1);
+        expect(d4.dispose).toHaveBeenCalledTimes(1);
+    });
+
+    test('that isDisposed=true once CompositeDisposable is disposed', () => {
+        class Test extends CompositeDisposable {
+            checkIsDisposed(): boolean {
+                return this.isDisposed;
+            }
+        }
+
+        const cut = new Test();
+
+        expect(cut.checkIsDisposed()).toBeFalsy();
+
+        cut.dispose();
+
+        expect(cut.checkIsDisposed()).toBeTruthy();
+    });
+
+    test('Disposable.from(...)', () => {
+        const func = jest.fn();
+
+        const disposable = Disposable.from(func);
+
+        expect(func).not.toHaveBeenCalled();
+
+        disposable.dispose();
+
+        expect(func).toHaveBeenCalledTimes(1);
+    });
+});

packages/dockview-core/src/__tests__/math.spec.ts

@@ -0,0 +1,21 @@
+import { clamp, range } from '../math';
+
+describe('math', () => {
+    describe('clamp', () => {
+        it('should clamp between a minimum and maximum value', () => {
+            expect(clamp(45, 40, 50)).toBe(45);
+            expect(clamp(35, 40, 50)).toBe(40);
+            expect(clamp(55, 40, 50)).toBe(50);
+        });
+
+        it('if min > max return min', () => {
+            expect(clamp(55, 50, 40)).toBe(50);
+        });
+    });
+
+    test('range', () => {
+        expect(range(0, 5)).toEqual([0, 1, 2, 3, 4]);
+        expect(range(5, 0)).toEqual([5, 4, 3, 2, 1]);
+        expect(range(5)).toEqual([0, 1, 2, 3, 4]);
+    });
+});

packages/dockview-core/src/__tests__/overlay/overlay.spec.ts

@@ -0,0 +1,418 @@
+import { Overlay } from '../../overlay/overlay';
+import { mockGetBoundingClientRect } from '../__test_utils__/utils';
+
+describe('overlay', () => {
+    test('toJSON, top left', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 200,
+            width: 100,
+            left: 10,
+            top: 20,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        jest.spyOn(
+            container.childNodes.item(0) as HTMLElement,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 80,
+                top: 100,
+                width: 40,
+                height: 50,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 20,
+                    top: 30,
+                    width: 100,
+                    height: 100,
+                });
+            }
+        );
+
+        cut.setBounds();
+
+        expect(cut.toJSON()).toEqual({
+            top: 70,
+            left: 60,
+            width: 40,
+            height: 50,
+        });
+
+        cut.dispose();
+    });
+
+    test('toJSON, bottom right', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 200,
+            width: 100,
+            right: 10,
+            bottom: 20,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        jest.spyOn(
+            container.childNodes.item(0) as HTMLElement,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 80,
+                top: 100,
+                width: 40,
+                height: 50,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 20,
+                    top: 30,
+                    width: 100,
+                    height: 100,
+                });
+            }
+        );
+
+        cut.setBounds();
+
+        expect(cut.toJSON()).toEqual({
+            bottom: -20,
+            right: 0,
+            width: 40,
+            height: 50,
+        });
+
+        cut.dispose();
+    });
+
+    test('that out-of-bounds dimensions are fixed, top left', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 200,
+            width: 100,
+            left: -1000,
+            top: -1000,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        jest.spyOn(
+            container.childNodes.item(0) as HTMLElement,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 80,
+                top: 100,
+                width: 40,
+                height: 50,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 20,
+                    top: 30,
+                    width: 100,
+                    height: 100,
+                });
+            }
+        );
+
+        cut.setBounds();
+
+        expect(cut.toJSON()).toEqual({
+            top: 70,
+            left: 60,
+            width: 40,
+            height: 50,
+        });
+
+        cut.dispose();
+    });
+
+    test('that out-of-bounds dimensions are fixed, bottom right', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 200,
+            width: 100,
+            bottom: -1000,
+            right: -1000,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        jest.spyOn(
+            container.childNodes.item(0) as HTMLElement,
+            'getBoundingClientRect'
+        ).mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 80,
+                top: 100,
+                width: 40,
+                height: 50,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 20,
+                    top: 30,
+                    width: 100,
+                    height: 100,
+                });
+            }
+        );
+
+        cut.setBounds();
+
+        expect(cut.toJSON()).toEqual({
+            bottom: -20,
+            right: 0,
+            width: 40,
+            height: 50,
+        });
+
+        cut.dispose();
+    });
+
+    test('setBounds, top left', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 1000,
+            width: 1000,
+            left: 0,
+            top: 0,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        const element: HTMLElement = container.querySelector(
+            '.dv-resize-container'
+        )!;
+        expect(element).toBeTruthy();
+
+        jest.spyOn(element, 'getBoundingClientRect').mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 300,
+                top: 400,
+                width: 200,
+                height: 100,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 0,
+                    top: 0,
+                    width: 1000,
+                    height: 1000,
+                });
+            }
+        );
+
+        cut.setBounds({ height: 100, width: 200, left: 300, top: 400 });
+
+        expect(element.style.height).toBe('100px');
+        expect(element.style.width).toBe('200px');
+        expect(element.style.left).toBe('300px');
+        expect(element.style.top).toBe('400px');
+
+        cut.dispose();
+    });
+
+    test('setBounds, bottom right', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        document.body.appendChild(container);
+        container.appendChild(content);
+
+        const cut = new Overlay({
+            height: 1000,
+            width: 1000,
+            right: 0,
+            bottom: 0,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        const element: HTMLElement = container.querySelector(
+            '.dv-resize-container'
+        )!;
+        expect(element).toBeTruthy();
+
+        jest.spyOn(element, 'getBoundingClientRect').mockImplementation(() => {
+            return mockGetBoundingClientRect({
+                left: 500,
+                top: 500,
+                width: 200,
+                height: 100,
+            });
+        });
+        jest.spyOn(container, 'getBoundingClientRect').mockImplementation(
+            () => {
+                return mockGetBoundingClientRect({
+                    left: 0,
+                    top: 0,
+                    width: 1000,
+                    height: 1000,
+                });
+            }
+        );
+
+        cut.setBounds({ height: 100, width: 200, right: 300, bottom: 400 });
+
+        expect(element.style.height).toBe('100px');
+        expect(element.style.width).toBe('200px');
+        expect(element.style.right).toBe('300px');
+        expect(element.style.bottom).toBe('400px');
+
+        cut.dispose();
+    });
+
+    test('that the resize handles are added', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        const cut = new Overlay({
+            height: 500,
+            width: 500,
+            left: 100,
+            top: 200,
+            minimumInViewportWidth: 0,
+            minimumInViewportHeight: 0,
+            container,
+            content,
+        });
+
+        expect(container.querySelector('.dv-resize-handle-top')).toBeTruthy();
+        expect(
+            container.querySelector('.dv-resize-handle-bottom')
+        ).toBeTruthy();
+        expect(container.querySelector('.dv-resize-handle-left')).toBeTruthy();
+        expect(container.querySelector('.dv-resize-handle-right')).toBeTruthy();
+        expect(
+            container.querySelector('.dv-resize-handle-topleft')
+        ).toBeTruthy();
+        expect(
+            container.querySelector('.dv-resize-handle-topright')
+        ).toBeTruthy();
+        expect(
+            container.querySelector('.dv-resize-handle-bottomleft')
+        ).toBeTruthy();
+        expect(
+            container.querySelector('.dv-resize-handle-bottomright')
+        ).toBeTruthy();
+
+        cut.dispose();
+    });
+
+    test('aria-level attributes and corresponding z-index', () => {
+        const container = document.createElement('div');
+        const content = document.createElement('div');
+
+        const createOverlay = () =>
+            new Overlay({
+                height: 500,
+                width: 500,
+                left: 100,
+                top: 200,
+                minimumInViewportWidth: 0,
+                minimumInViewportHeight: 0,
+                container,
+                content,
+            });
+
+        const overlay1 = createOverlay();
+
+        const zIndexValue = (delta: number) =>
+            `calc(var(--dv-overlay-z-index, 999) + ${delta})`;
+
+        expect(overlay1.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay1.element.style.zIndex).toBe(zIndexValue(0));
+
+        const overlay2 = createOverlay();
+        const overlay3 = createOverlay();
+
+        expect(overlay1.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay2.element.getAttribute('aria-level')).toBe('1');
+        expect(overlay3.element.getAttribute('aria-level')).toBe('2');
+        expect(overlay1.element.style.zIndex).toBe(zIndexValue(0));
+        expect(overlay2.element.style.zIndex).toBe(zIndexValue(2));
+        expect(overlay3.element.style.zIndex).toBe(zIndexValue(4));
+
+        overlay2.bringToFront();
+
+        expect(overlay1.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay2.element.getAttribute('aria-level')).toBe('2');
+        expect(overlay3.element.getAttribute('aria-level')).toBe('1');
+        expect(overlay1.element.style.zIndex).toBe(zIndexValue(0));
+        expect(overlay2.element.style.zIndex).toBe(zIndexValue(4));
+        expect(overlay3.element.style.zIndex).toBe(zIndexValue(2));
+
+        overlay1.bringToFront();
+
+        expect(overlay1.element.getAttribute('aria-level')).toBe('2');
+        expect(overlay2.element.getAttribute('aria-level')).toBe('1');
+        expect(overlay3.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay1.element.style.zIndex).toBe(zIndexValue(4));
+        expect(overlay2.element.style.zIndex).toBe(zIndexValue(2));
+        expect(overlay3.element.style.zIndex).toBe(zIndexValue(0));
+
+        overlay2.dispose();
+
+        expect(overlay1.element.getAttribute('aria-level')).toBe('1');
+        expect(overlay3.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay1.element.style.zIndex).toBe(zIndexValue(2));
+        expect(overlay3.element.style.zIndex).toBe(zIndexValue(0));
+
+        overlay1.dispose();
+
+        expect(overlay3.element.getAttribute('aria-level')).toBe('0');
+        expect(overlay3.element.style.zIndex).toBe(zIndexValue(0));
+    });
+});

packages/dockview-core/src/__tests__/overlay/overlayRenderContainer.spec.ts

@@ -0,0 +1,265 @@
+import { Droptarget } from '../../dnd/droptarget';
+import { IDockviewPanel } from '../../dockview/dockviewPanel';
+import { Emitter } from '../../events';
+import {
+    IRenderable,
+    OverlayRenderContainer,
+} from '../../overlay/overlayRenderContainer';
+import { fromPartial } from '@total-typescript/shoehorn';
+import { Writable, exhaustMicrotaskQueue } from '../__test_utils__/utils';
+import { DockviewComponent } from '../../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../../dockview/dockviewGroupPanel';
+
+describe('overlayRenderContainer', () => {
+    let referenceContainer: IRenderable;
+    let parentContainer: HTMLElement;
+
+    beforeEach(() => {
+        parentContainer = document.createElement('div');
+
+        referenceContainer = {
+            element: document.createElement('div'),
+            dropTarget: fromPartial<Droptarget>({}),
+        };
+    });
+
+    test('that attach(...) and detach(...) mutate the DOM as expected', () => {
+        const cut = new OverlayRenderContainer(
+            parentContainer,
+            fromPartial<DockviewComponent>({})
+        );
+
+        const panelContentEl = document.createElement('div');
+
+        const onDidVisibilityChange = new Emitter<any>();
+        const onDidDimensionsChange = new Emitter<any>();
+        const onDidLocationChange = new Emitter<any>();
+
+        const panel = fromPartial<IDockviewPanel>({
+            api: {
+                id: 'test_panel_id',
+                onDidVisibilityChange: onDidVisibilityChange.event,
+                onDidDimensionsChange: onDidDimensionsChange.event,
+                onDidLocationChange: onDidLocationChange.event,
+                isVisible: true,
+                location: { type: 'grid' },
+            },
+            view: {
+                content: {
+                    element: panelContentEl,
+                },
+            },
+            group: {
+                api: {
+                    location: { type: 'grid' },
+                },
+            },
+        });
+
+        cut.attach({ panel, referenceContainer });
+
+        expect(panelContentEl.parentElement?.parentElement).toBe(
+            parentContainer
+        );
+
+        cut.detatch(panel);
+
+        expect(panelContentEl.parentElement?.parentElement).toBeUndefined();
+    });
+
+    test('add a view that is not currently in the DOM', async () => {
+        const cut = new OverlayRenderContainer(
+            parentContainer,
+            fromPartial<DockviewComponent>({})
+        );
+
+        const panelContentEl = document.createElement('div');
+
+        const onDidVisibilityChange = new Emitter<any>();
+        const onDidDimensionsChange = new Emitter<any>();
+        const onDidLocationChange = new Emitter<any>();
+
+        const panel = fromPartial<IDockviewPanel>({
+            api: {
+                id: 'test_panel_id',
+                onDidVisibilityChange: onDidVisibilityChange.event,
+                onDidDimensionsChange: onDidDimensionsChange.event,
+                onDidLocationChange: onDidLocationChange.event,
+                isVisible: true,
+                location: { type: 'grid' },
+            },
+            view: {
+                content: {
+                    element: panelContentEl,
+                },
+            },
+            group: {
+                api: {
+                    location: { type: 'grid' },
+                },
+            },
+        });
+
+        (parentContainer as jest.Mocked<HTMLDivElement>).getBoundingClientRect =
+            jest
+                .fn<DOMRect, []>()
+                .mockReturnValueOnce(
+                    fromPartial<DOMRect>({
+                        left: 100,
+                        top: 200,
+                        width: 1000,
+                        height: 500,
+                    })
+                )
+                .mockReturnValueOnce(
+                    fromPartial<DOMRect>({
+                        left: 101,
+                        top: 201,
+                        width: 1000,
+                        height: 500,
+                    })
+                )
+                .mockReturnValueOnce(
+                    fromPartial<DOMRect>({
+                        left: 100,
+                        top: 200,
+                        width: 1000,
+                        height: 500,
+                    })
+                );
+
+        (
+            referenceContainer.element as jest.Mocked<HTMLDivElement>
+        ).getBoundingClientRect = jest
+            .fn<DOMRect, []>()
+            .mockReturnValueOnce(
+                fromPartial<DOMRect>({
+                    left: 150,
+                    top: 300,
+                    width: 100,
+                    height: 200,
+                })
+            )
+            .mockReturnValueOnce(
+                fromPartial<DOMRect>({
+                    left: 150,
+                    top: 300,
+                    width: 101,
+                    height: 201,
+                })
+            )
+            .mockReturnValueOnce(
+                fromPartial<DOMRect>({
+                    left: 150,
+                    top: 300,
+                    width: 100,
+                    height: 200,
+                })
+            );
+
+        const container = cut.attach({ panel, referenceContainer });
+
+        await exhaustMicrotaskQueue();
+
+        expect(panelContentEl.parentElement).toBe(container);
+        expect(container.parentElement).toBe(parentContainer);
+
+        expect(container.style.display).toBe('');
+
+        expect(container.style.left).toBe('50px');
+        expect(container.style.top).toBe('100px');
+        expect(container.style.width).toBe('100px');
+        expect(container.style.height).toBe('200px');
+        expect(
+            referenceContainer.element.getBoundingClientRect
+        ).toHaveBeenCalledTimes(1);
+
+        onDidDimensionsChange.fire({});
+        expect(container.style.display).toBe('');
+
+        expect(container.style.left).toBe('49px');
+        expect(container.style.top).toBe('99px');
+        expect(container.style.width).toBe('101px');
+        expect(container.style.height).toBe('201px');
+        expect(
+            referenceContainer.element.getBoundingClientRect
+        ).toHaveBeenCalledTimes(2);
+
+        (panel as Writable<IDockviewPanel>).api.isVisible = false;
+        onDidVisibilityChange.fire({});
+        expect(container.style.display).toBe('none');
+        expect(
+            referenceContainer.element.getBoundingClientRect
+        ).toHaveBeenCalledTimes(2);
+
+        (panel as Writable<IDockviewPanel>).api.isVisible = true;
+        onDidVisibilityChange.fire({});
+        expect(container.style.display).toBe('');
+
+        expect(container.style.left).toBe('50px');
+        expect(container.style.top).toBe('100px');
+        expect(container.style.width).toBe('100px');
+        expect(container.style.height).toBe('200px');
+        expect(
+            referenceContainer.element.getBoundingClientRect
+        ).toHaveBeenCalledTimes(3);
+    });
+
+    test('related z-index from `aria-level` set on floating panels', async () => {
+        const group = fromPartial<DockviewGroupPanel>({});
+
+        const element = document.createElement('div');
+        element.setAttribute('aria-level', '2');
+        const spy = jest.spyOn(element, 'getAttribute');
+
+        const accessor = fromPartial<DockviewComponent>({
+            floatingGroups: [
+                {
+                    group,
+                    overlay: {
+                        element,
+                    },
+                },
+            ],
+        });
+
+        const cut = new OverlayRenderContainer(parentContainer, accessor);
+
+        const panelContentEl = document.createElement('div');
+
+        const onDidVisibilityChange = new Emitter<any>();
+        const onDidDimensionsChange = new Emitter<any>();
+        const onDidLocationChange = new Emitter<any>();
+
+        const panel = fromPartial<IDockviewPanel>({
+            api: {
+                id: 'test_panel_id',
+                onDidVisibilityChange: onDidVisibilityChange.event,
+                onDidDimensionsChange: onDidDimensionsChange.event,
+                onDidLocationChange: onDidLocationChange.event,
+                isVisible: true,
+                group,
+                location: { type: 'floating' },
+            },
+            view: {
+                content: {
+                    element: panelContentEl,
+                },
+            },
+            group: {
+                api: {
+                    location: { type: 'floating' },
+                },
+            },
+        });
+
+        cut.attach({ panel, referenceContainer });
+
+        await exhaustMicrotaskQueue();
+
+        expect(spy).toHaveBeenCalledWith('aria-level');
+        expect(panelContentEl.parentElement!.style.zIndex).toBe(
+            'calc(var(--dv-overlay-z-index, 999) + 5)'
+        );
+    });
+});

packages/dockview-core/src/__tests__/paneview/paneview.spec.ts

@@ -0,0 +1,147 @@
+import { CompositeDisposable } from '../../lifecycle';
+import { Paneview } from '../../paneview/paneview';
+import { IPanePart, PaneviewPanel } from '../../paneview/paneviewPanel';
+import { Orientation } from '../../splitview/splitview';
+
+class TestPanel extends PaneviewPanel {
+    protected getBodyComponent(): IPanePart {
+        return {
+            element: document.createElement('div'),
+            update: () => {
+                //
+            },
+            dispose: () => {
+                //
+            },
+            init: () => {
+                // /
+            },
+        };
+    }
+
+    protected getHeaderComponent(): IPanePart {
+        return {
+            element: document.createElement('div'),
+            update: () => {
+                //
+            },
+            dispose: () => {
+                //
+            },
+            init: () => {
+                // /
+            },
+        };
+    }
+}
+
+describe('paneview', () => {
+    let container: HTMLElement;
+
+    beforeEach(() => {
+        container = document.createElement('div');
+        container.className = 'container';
+    });
+
+    test('onDidAddView and onDidRemoveView events', () => {
+        const paneview = new Paneview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        const added: PaneviewPanel[] = [];
+        const removed: PaneviewPanel[] = [];
+
+        const disposable = new CompositeDisposable(
+            paneview.onDidAddView((view) => added.push(view)),
+            paneview.onDidRemoveView((view) => removed.push(view))
+        );
+
+        const view1 = new TestPanel({
+            id: 'id',
+            component: 'component',
+            headerComponent: 'headerComponent',
+            orientation: Orientation.VERTICAL,
+            isExpanded: true,
+            isHeaderVisible: true,
+            headerSize: 22,
+            minimumBodySize: 0,
+            maximumBodySize: Number.MAX_SAFE_INTEGER,
+        });
+        const view2 = new TestPanel({
+            id: 'id2',
+            component: 'component',
+            headerComponent: 'headerComponent',
+            orientation: Orientation.VERTICAL,
+            isExpanded: true,
+            isHeaderVisible: true,
+            headerSize: 22,
+            minimumBodySize: 0,
+            maximumBodySize: Number.MAX_SAFE_INTEGER,
+        });
+
+        expect(added.length).toBe(0);
+        expect(removed.length).toBe(0);
+
+        paneview.addPane(view1);
+        expect(added.length).toBe(1);
+        expect(removed.length).toBe(0);
+        expect(added[0]).toBe(view1);
+
+        paneview.addPane(view2);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(0);
+        expect(added[1]).toBe(view2);
+
+        paneview.removePane(0);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(1);
+        expect(removed[0]).toBe(view1);
+
+        paneview.removePane(0);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(2);
+        expect(removed[1]).toBe(view2);
+
+        disposable.dispose();
+    });
+
+    test('dispose of paneview', () => {
+        expect(container.childNodes.length).toBe(0);
+
+        const paneview = new Paneview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        const view1 = new TestPanel({
+            id: 'id',
+            component: 'component',
+            headerComponent: 'headerComponent',
+            orientation: Orientation.VERTICAL,
+            isExpanded: true,
+            isHeaderVisible: true,
+            headerSize: 22,
+            minimumBodySize: 0,
+            maximumBodySize: Number.MAX_SAFE_INTEGER,
+        });
+        const view2 = new TestPanel({
+            id: 'id2',
+            component: 'component',
+            headerComponent: 'headerComponent',
+            orientation: Orientation.VERTICAL,
+            isExpanded: true,
+            isHeaderVisible: true,
+            headerSize: 22,
+            minimumBodySize: 0,
+            maximumBodySize: Number.MAX_SAFE_INTEGER,
+        });
+
+        paneview.addPane(view1);
+        paneview.addPane(view2);
+
+        expect(container.childNodes.length).toBeGreaterThan(0);
+
+        paneview.dispose();
+
+        expect(container.childNodes.length).toBe(0);
+    });
+});

packages/dockview-core/src/__tests__/paneview/paneviewComponent.spec.ts

@@ -0,0 +1,619 @@
+import { PanelDimensionChangeEvent } from '../../api/panelApi';
+import { CompositeDisposable } from '../../lifecycle';
+import { PanelUpdateEvent } from '../../panel/types';
+import { PaneviewComponent } from '../../paneview/paneviewComponent';
+import {
+    PaneviewPanel,
+    IPanePart,
+    PanePanelComponentInitParameter,
+} from '../../paneview/paneviewPanel';
+import { Orientation } from '../../splitview/splitview';
+
+class TestPanel extends PaneviewPanel {
+    constructor(id: string, component: string) {
+        super({
+            id,
+            component,
+            headerComponent: 'header',
+            orientation: Orientation.VERTICAL,
+            isExpanded: false,
+            isHeaderVisible: true,
+            headerSize: 22,
+            minimumBodySize: 0,
+            maximumBodySize: Number.MAX_SAFE_INTEGER,
+        });
+    }
+
+    getHeaderComponent() {
+        return new (class Header implements IPanePart {
+            private _element: HTMLElement = document.createElement('div');
+
+            get element() {
+                return this._element;
+            }
+
+            init(params: PanePanelComponentInitParameter) {
+                //
+            }
+
+            update(params: PanelUpdateEvent) {
+                //
+            }
+
+            dispose() {
+                //
+            }
+        })();
+    }
+
+    getBodyComponent() {
+        return new (class Header implements IPanePart {
+            private _element: HTMLElement = document.createElement('div');
+
+            get element() {
+                return this._element;
+            }
+
+            init(params: PanePanelComponentInitParameter) {
+                //
+            }
+
+            update(params: PanelUpdateEvent) {
+                //
+            }
+
+            dispose() {
+                //
+            }
+        })();
+    }
+}
+
+describe('paneviewComponent', () => {
+    let container: HTMLElement;
+
+    beforeEach(() => {
+        container = document.createElement('div');
+        container.className = 'container';
+    });
+
+    test('that the container is not removed when grid is disposed', () => {
+        const root = document.createElement('div');
+        const container = document.createElement('div');
+        root.appendChild(container);
+
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.dispose();
+
+        expect(container.parentElement).toBe(root);
+        expect(container.children.length).toBe(0);
+    });
+
+    test('vertical panels', () => {
+        const disposables = new CompositeDisposable();
+
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.layout(300, 200);
+
+        paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'Panel 1',
+        });
+        paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'Panel2',
+        });
+
+        const panel1 = paneview.getPanel('panel1') as PaneviewPanel;
+        const panel2 = paneview.getPanel('panel2') as PaneviewPanel;
+
+        let panel1Dimensions: PanelDimensionChangeEvent | undefined = undefined;
+        disposables.addDisposables(
+            panel1.api.onDidDimensionsChange((event) => {
+                panel1Dimensions = event;
+            })
+        );
+
+        let panel2Dimensions: PanelDimensionChangeEvent | undefined = undefined;
+        disposables.addDisposables(
+            panel2.api.onDidDimensionsChange((event) => {
+                panel2Dimensions = event;
+            })
+        );
+
+        paneview.layout(600, 400);
+
+        expect(panel1Dimensions).toEqual({ width: 600, height: 22 });
+        expect(panel2Dimensions).toEqual({ width: 600, height: 22 });
+
+        panel1.api.setSize({ size: 300 });
+
+        expect(panel1Dimensions).toEqual({ width: 600, height: 22 });
+        expect(panel2Dimensions).toEqual({ width: 600, height: 22 });
+
+        paneview.layout(200, 600);
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 22 });
+        expect(panel2Dimensions).toEqual({ width: 200, height: 22 });
+
+        panel1.api.setExpanded(true);
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 578 });
+        expect(panel2Dimensions).toEqual({ width: 200, height: 22 });
+
+        panel2.api.setExpanded(true);
+        panel1.api.setSize({ size: 300 });
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 300 });
+        expect(panel2Dimensions).toEqual({ width: 200, height: 300 });
+
+        panel1.api.setSize({ size: 200 });
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 200 });
+        expect(panel2Dimensions).toEqual({ width: 200, height: 400 });
+
+        disposables.dispose();
+        paneview.dispose();
+    });
+
+    test('serialization', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        expect(container.querySelectorAll('.dv-pane-container').length).toBe(1);
+
+        paneview.fromJSON({
+            size: 6,
+            views: [
+                {
+                    size: 1,
+                    data: {
+                        id: 'panel1',
+                        component: 'default',
+                        title: 'Panel 1',
+                    },
+                    expanded: true,
+                },
+                {
+                    size: 2,
+                    data: {
+                        id: 'panel2',
+                        component: 'default',
+                        title: 'Panel 2',
+                    },
+                    expanded: false,
+                },
+                {
+                    size: 3,
+                    data: {
+                        id: 'panel3',
+                        component: 'default',
+                        title: 'Panel 3',
+                    },
+                },
+            ],
+        });
+
+        expect(container.querySelectorAll('.dv-pane-container').length).toBe(1);
+
+        paneview.layout(400, 800);
+
+        const panel1 = paneview.getPanel('panel1');
+
+        expect(panel1!.api.height).toBe(756);
+        expect(panel1!.api.width).toBe(400);
+        expect(panel1!.api.id).toBe('panel1');
+        // expect(panel1!.api.isActive).toBeTruthy();
+        // expect(panel1?.api.isFocused).toBeFalsy();
+        expect(panel1!.api.isVisible).toBeTruthy();
+        expect(panel1!.api.isExpanded).toBeTruthy();
+
+        const panel2 = paneview.getPanel('panel2');
+
+        expect(panel2!.api.height).toBe(22);
+        expect(panel2!.api.width).toBe(400);
+        expect(panel2!.api.id).toBe('panel2');
+        // expect(panel2!.api.isActive).toBeTruthy();
+        // expect(panel2?.api.isFocused).toBeFalsy();
+        expect(panel2!.api.isVisible).toBeTruthy();
+        expect(panel2!.api.isExpanded).toBeFalsy();
+
+        const panel3 = paneview.getPanel('panel3');
+
+        expect(panel3!.api.height).toBe(22);
+        expect(panel3!.api.width).toBe(400);
+        expect(panel3!.api.id).toBe('panel3');
+        // expect(panel3!.api.isActive).toBeTruthy();
+        // expect(panel3?.api.isFocused).toBeFalsy();
+        expect(panel3!.api.isVisible).toBeTruthy();
+        expect(panel3!.api.isExpanded).toBeFalsy();
+
+        expect(JSON.parse(JSON.stringify(paneview.toJSON()))).toEqual({
+            size: 800,
+            views: [
+                {
+                    size: 756,
+                    data: {
+                        id: 'panel1',
+                        component: 'default',
+                        title: 'Panel 1',
+                    },
+                    expanded: true,
+                    headerSize: 22,
+                },
+                {
+                    size: 22,
+                    data: {
+                        id: 'panel2',
+                        component: 'default',
+                        title: 'Panel 2',
+                    },
+                    expanded: false,
+                    headerSize: 22,
+                },
+                {
+                    size: 22,
+                    data: {
+                        id: 'panel3',
+                        component: 'default',
+                        title: 'Panel 3',
+                    },
+                    expanded: false,
+                    headerSize: 22,
+                },
+            ],
+        });
+    });
+
+    test('toJSON shouldnt fire any layout events', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        paneview.layout(1000, 1000);
+
+        paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'Panel 1',
+        });
+        paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'Panel 2',
+        });
+
+        const disposable = paneview.onDidLayoutChange(() => {
+            fail('onDidLayoutChange shouldnt have been called');
+        });
+
+        const result = paneview.toJSON();
+        expect(result).toBeTruthy();
+
+        disposable.dispose();
+    });
+
+    test('panel is disposed of when component is disposed', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.layout(1000, 1000);
+
+        paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'Panel 1',
+        });
+        paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'Panel 2',
+        });
+
+        const panel1 = paneview.getPanel('panel1')!;
+        const panel2 = paneview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        paneview.dispose();
+
+        expect(panel1Spy).toHaveBeenCalledTimes(1);
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('panel is disposed of when removed', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.layout(1000, 1000);
+
+        paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'Panel 1',
+        });
+        paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'Panel 2',
+        });
+
+        const panel1 = paneview.getPanel('panel1')!;
+        const panel2 = paneview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        paneview.removePanel(panel2);
+
+        expect(panel1Spy).not.toHaveBeenCalled();
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('panel is disposed of when fromJSON is called', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.layout(1000, 1000);
+
+        paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'Panel 1',
+        });
+        paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'Panel 2',
+        });
+
+        const panel1 = paneview.getPanel('panel1')!;
+        const panel2 = paneview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        paneview.fromJSON({ views: [], size: 0 });
+
+        expect(panel1Spy).toHaveBeenCalledTimes(1);
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('that fromJSON layouts are resized to the current dimensions', async () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        paneview.layout(400, 600);
+
+        paneview.fromJSON({
+            size: 6,
+            views: [
+                {
+                    size: 1,
+                    data: {
+                        id: 'panel1',
+                        component: 'default',
+                        title: 'Panel 1',
+                    },
+                    minimumSize: 100,
+                    expanded: true,
+                },
+                {
+                    size: 2,
+                    data: {
+                        id: 'panel2',
+                        component: 'default',
+                        title: 'Panel 2',
+                    },
+                    expanded: true,
+                },
+                {
+                    size: 3,
+                    data: {
+                        id: 'panel3',
+                        component: 'default',
+                        title: 'Panel 3',
+                    },
+                    expanded: true,
+                },
+            ],
+        });
+
+        // heights slightly differ because header height isn't accounted for
+        expect(JSON.parse(JSON.stringify(paneview.toJSON()))).toEqual({
+            size: 600,
+            views: [
+                {
+                    size: 122,
+                    data: {
+                        id: 'panel1',
+                        component: 'default',
+                        title: 'Panel 1',
+                    },
+                    expanded: true,
+                    minimumSize: 100,
+                    headerSize: 22,
+                },
+                {
+                    size: 22,
+                    data: {
+                        id: 'panel2',
+                        component: 'default',
+                        title: 'Panel 2',
+                    },
+                    expanded: true,
+                    headerSize: 22,
+                },
+                {
+                    size: 456,
+                    data: {
+                        id: 'panel3',
+                        component: 'default',
+                        title: 'Panel 3',
+                    },
+                    expanded: true,
+                    headerSize: 22,
+                },
+            ],
+        });
+    });
+
+    test('that disableAutoResizing is false by default', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        expect(paneview.disableResizing).toBeFalsy();
+    });
+
+    test('that disableAutoResizing can be enabled', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+            disableAutoResizing: true,
+        });
+
+        expect(paneview.disableResizing).toBeTruthy();
+    });
+
+    test('that setVisible toggles visiblity', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+            disableAutoResizing: true,
+        });
+
+        paneview.layout(1000, 1000);
+
+        const panel1 = paneview.addPanel({
+            id: 'panel1',
+            component: 'default',
+            title: 'panel1',
+        });
+        const panel2 = paneview.addPanel({
+            id: 'panel2',
+            component: 'default',
+            title: 'panel2',
+        });
+
+        expect(panel1.api.isVisible).toBeTruthy();
+        expect(panel2.api.isVisible).toBeTruthy();
+
+        panel1.api.setVisible(false);
+        expect(panel1.api.isVisible).toBeFalsy();
+        expect(panel2.api.isVisible).toBeTruthy();
+
+        panel1.api.setVisible(true);
+        expect(panel1.api.isVisible).toBeTruthy();
+        expect(panel2.api.isVisible).toBeTruthy();
+    });
+
+    test('update className', () => {
+        const paneview = new PaneviewComponent(container, {
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+            disableAutoResizing: true,
+            className: 'test-a test-b',
+        });
+
+        expect(paneview.element.className).toBe('test-a test-b');
+
+        paneview.updateOptions({ className: 'test-b test-c' });
+
+        expect(paneview.element.className).toBe('test-b test-c');
+    });
+});

packages/dockview-core/src/__tests__/splitview/splitview.spec.ts

@@ -0,0 +1,901 @@
+import { Emitter } from '../../events';
+import { CompositeDisposable } from '../../lifecycle';
+import {
+    IView,
+    LayoutPriority,
+    Orientation,
+    Sizing,
+    Splitview,
+} from '../../splitview/splitview';
+import { fireEvent } from '@testing-library/dom';
+class Testview implements IView {
+    private _element: HTMLElement = document.createElement('div');
+    private _size = 0;
+    private _orthogonalSize = 0;
+    private _priority: LayoutPriority | undefined;
+
+    private readonly _onDidChange = new Emitter<{
+        size?: number;
+        orthogonalSize?: number;
+    }>();
+    readonly onDidChange = this._onDidChange.event;
+
+    private readonly _onLayoutCalled = new Emitter<void>();
+    readonly onLayoutCalled = this._onLayoutCalled.event;
+
+    private readonly _onRendered = new Emitter<void>();
+    readonly onRenderered = this._onRendered.event;
+
+    get minimumSize() {
+        return this._minimumSize;
+    }
+
+    get maximumSize() {
+        return this._maxiumSize;
+    }
+
+    get element() {
+        this._onRendered.fire();
+        return this._element;
+    }
+
+    get size() {
+        return this._size;
+    }
+
+    get orthogonalSize() {
+        return this._orthogonalSize;
+    }
+
+    get priority() {
+        return this._priority;
+    }
+
+    constructor(
+        private _minimumSize: number,
+        private _maxiumSize: number,
+        priority?: LayoutPriority
+    ) {
+        this._priority = priority;
+    }
+
+    layout(size: number, orthogonalSize: number) {
+        this._size = size;
+        this._orthogonalSize = orthogonalSize;
+        this._onLayoutCalled.fire();
+    }
+
+    fireChangeEvent(value: { size?: number; orthogonalSize?: number }) {
+        this._onDidChange.fire(value);
+    }
+
+    setVisible(isVisible: boolean) {
+        //
+    }
+
+    dispose() {
+        this._onDidChange.dispose();
+    }
+}
+
+describe('splitview', () => {
+    let container: HTMLElement;
+
+    beforeEach(() => {
+        container = document.createElement('div');
+        container.className = 'container';
+
+        jest.clearAllMocks();
+    });
+
+    test('vertical splitview', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        expect(splitview.orientation).toBe(Orientation.HORIZONTAL);
+
+        const viewQuery = container.querySelectorAll(
+            '.dv-split-view-container dv-horizontal'
+        );
+        expect(viewQuery).toBeTruthy();
+
+        splitview.dispose();
+    });
+
+    test('horiziontal splitview', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.VERTICAL,
+        });
+
+        expect(splitview.orientation).toBe(Orientation.VERTICAL);
+
+        const viewQuery = container.querySelectorAll(
+            '.dv-split-view-container dv-vertical'
+        );
+        expect(viewQuery).toBeTruthy();
+
+        splitview.dispose();
+    });
+
+    test('has views and sashes', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.addView(new Testview(50, 50));
+        splitview.addView(new Testview(50, 50));
+        splitview.addView(new Testview(50, 50));
+
+        let viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view'
+        );
+        expect(viewQuery.length).toBe(3);
+
+        let sashQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-sash-container > .dv-sash'
+        );
+        expect(sashQuery.length).toBe(2);
+
+        splitview.removeView(2);
+
+        viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view'
+        );
+        expect(viewQuery.length).toBe(2);
+
+        sashQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-sash-container > .dv-sash'
+        );
+        expect(sashQuery.length).toBe(1);
+
+        splitview.removeView(0);
+
+        viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view'
+        );
+        expect(viewQuery.length).toBe(1);
+
+        sashQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-sash-container > .dv-sash'
+        );
+        expect(sashQuery.length).toBe(0);
+
+        splitview.removeView(0);
+
+        viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view'
+        );
+        expect(viewQuery.length).toBe(0);
+
+        sashQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-sash-container > .dv-sash'
+        );
+        expect(sashQuery.length).toBe(0);
+
+        splitview.dispose();
+    });
+
+    test('visiblity classnames', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        const view1 = new Testview(50, 50);
+        const view2 = new Testview(50, 50);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        let viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view.visible'
+        );
+        expect(viewQuery.length).toBe(2);
+
+        splitview.setViewVisible(1, false);
+
+        viewQuery = container.querySelectorAll(
+            '.dv-split-view-container > .dv-view-container > .dv-view.visible'
+        );
+        expect(viewQuery.length).toBe(1);
+
+        splitview.dispose();
+    });
+
+    test('calls lifecycle methods on view', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        let rendered = false;
+        let layout = false;
+
+        const view = new Testview(50, Number.POSITIVE_INFINITY);
+        const layoutDisposable = view.onLayoutCalled(() => {
+            layout = true;
+        });
+        const renderDisposable = view.onRenderered(() => {
+            rendered = true;
+        });
+
+        splitview.addView(view);
+
+        splitview.layout(100, 100);
+
+        expect(rendered).toBeTruthy();
+        expect(layout).toBeTruthy();
+
+        layoutDisposable.dispose();
+        renderDisposable.dispose();
+        splitview.dispose();
+    });
+
+    test('add view at specified index', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(50, 200);
+        const view2 = new Testview(50, 200);
+        const view3 = new Testview(50, 200);
+
+        splitview.addView(view1);
+        splitview.addView(view2, Sizing.Distribute, 0);
+        splitview.addView(view3, Sizing.Distribute, 1);
+
+        expect(splitview.getViews()).toEqual([view2, view3, view1]);
+    });
+
+    test('streches to viewport', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view = new Testview(50, Number.POSITIVE_INFINITY);
+
+        splitview.addView(view);
+        expect(view.size).toBe(200);
+
+        splitview.layout(100, 500);
+        expect(view.size).toBe(100);
+
+        splitview.layout(50, 500);
+        expect(view.size).toBe(50);
+
+        splitview.layout(30, 500);
+        expect(view.size).toBe(50);
+
+        splitview.layout(100, 500);
+        expect(view.size).toBe(100);
+
+        splitview.dispose();
+    });
+
+    test('can resize views 1', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(50, 200);
+        const view2 = new Testview(50, 200);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        expect(view1.size).toBe(100);
+        expect(view2.size).toBe(100);
+
+        view1.fireChangeEvent({ size: 65 });
+
+        expect(view1.size).toBe(65);
+        expect(view2.size).toBe(135);
+
+        view2.fireChangeEvent({ size: 75 });
+
+        expect(view1.size).toBe(125);
+        expect(view2.size).toBe(75);
+
+        view2.fireChangeEvent({});
+
+        expect(view1.size).toBe(125);
+        expect(view2.size).toBe(75);
+
+        splitview.dispose();
+    });
+
+    test('can resize views 2', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(50, 200);
+        const view2 = new Testview(50, 200);
+        const view3 = new Testview(50, 200);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([66, 66, 68]);
+
+        splitview.resizeView(1, 100);
+        expect([view1.size, view2.size, view3.size]).toEqual([50, 100, 50]);
+
+        splitview.resizeView(2, 60);
+        expect([view1.size, view2.size, view3.size]).toEqual([50, 90, 60]);
+
+        expect([
+            splitview.getViewSize(0),
+            splitview.getViewSize(1),
+            splitview.getViewSize(2),
+            splitview.getViewSize(3),
+        ]).toEqual([50, 90, 60, -1]);
+
+        splitview.dispose();
+    });
+
+    test('move view', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(50, 200);
+        const view2 = new Testview(50, 200);
+        const view3 = new Testview(50, 200);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([66, 66, 68]);
+
+        splitview.moveView(2, 0);
+        expect(splitview.getViews()).toEqual([view3, view1, view2]);
+        expect([view1.size, view2.size, view3.size]).toEqual([66, 66, 68]);
+
+        splitview.moveView(0, 2);
+        expect(splitview.getViews()).toEqual([view1, view2, view3]);
+        expect([view1.size, view2.size, view3.size]).toEqual([66, 66, 68]);
+
+        splitview.dispose();
+    });
+
+    test('layout called after views added', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        const view1 = new Testview(50, 200);
+        const view2 = new Testview(50, 200);
+        const view3 = new Testview(50, 200);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        splitview.layout(200, 500);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([67, 67, 66]);
+
+        splitview.dispose();
+    });
+
+    test('proportional layout', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(20, Number.POSITIVE_INFINITY);
+        const view2 = new Testview(20, Number.POSITIVE_INFINITY);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        expect([view1.size, view2.size]).toEqual([100, 100]);
+
+        splitview.layout(100, 500);
+
+        expect([view1.size, view2.size]).toEqual([50, 50]);
+
+        splitview.dispose();
+    });
+
+    test('disable proportional layout', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+
+        splitview.layout(200, 500);
+
+        const view1 = new Testview(20, Number.POSITIVE_INFINITY);
+        const view2 = new Testview(20, Number.POSITIVE_INFINITY);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        expect([view1.size, view2.size]).toEqual([100, 100]);
+
+        splitview.layout(100, 500);
+
+        expect([view1.size, view2.size]).toEqual([80, 20]);
+
+        splitview.dispose();
+    });
+
+    test('high priority', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+
+        splitview.layout(300, 500);
+
+        const view1 = new Testview(50, Number.POSITIVE_INFINITY);
+        const view2 = new Testview(
+            50,
+            Number.POSITIVE_INFINITY,
+            LayoutPriority.High
+        );
+        const view3 = new Testview(50, Number.POSITIVE_INFINITY);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([100, 100, 100]);
+
+        splitview.layout(400, 500);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([100, 200, 100]);
+
+        splitview.dispose();
+    });
+
+    test('low priority', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+
+        splitview.layout(300, 500);
+
+        const view1 = new Testview(
+            50,
+            Number.POSITIVE_INFINITY,
+            LayoutPriority.Low
+        );
+        const view2 = new Testview(50, Number.POSITIVE_INFINITY);
+        const view3 = new Testview(50, Number.POSITIVE_INFINITY);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([100, 100, 100]);
+
+        splitview.layout(400, 500);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([100, 100, 200]);
+
+        splitview.dispose();
+    });
+
+    test('from descriptor', () => {
+        const descriptor = {
+            size: 300,
+            views: [
+                {
+                    size: 80,
+                    view: new Testview(0, Number.POSITIVE_INFINITY),
+                },
+                {
+                    size: 100,
+                    view: new Testview(0, Number.POSITIVE_INFINITY),
+                },
+                {
+                    size: 120,
+                    view: new Testview(0, Number.POSITIVE_INFINITY),
+                },
+            ],
+        };
+
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+            descriptor,
+        });
+
+        expect([
+            descriptor.views[0].size,
+            descriptor.views[1].size,
+            descriptor.views[2].size,
+        ]).toEqual([80, 100, 120]);
+        expect(splitview.size).toBe(300);
+    });
+
+    test('onDidAddView and onDidRemoveView events', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+
+        const added: IView[] = [];
+        const removed: IView[] = [];
+
+        const disposable = new CompositeDisposable(
+            splitview.onDidAddView((view) => added.push(view)),
+            splitview.onDidRemoveView((view) => removed.push(view))
+        );
+
+        const view1 = new Testview(0, 100);
+        const view2 = new Testview(0, 100);
+
+        expect(added.length).toBe(0);
+        expect(removed.length).toBe(0);
+
+        splitview.addView(view1);
+        expect(added.length).toBe(1);
+        expect(removed.length).toBe(0);
+        expect(added[0]).toBe(view1);
+
+        splitview.addView(view2);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(0);
+        expect(added[1]).toBe(view2);
+
+        splitview.removeView(0);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(1);
+        expect(removed[0]).toBe(view1);
+
+        splitview.removeView(0);
+        expect(added.length).toBe(2);
+        expect(removed.length).toBe(2);
+        expect(removed[1]).toBe(view2);
+
+        disposable.dispose();
+    });
+
+    test('dispose of splitview', () => {
+        expect(container.childNodes.length).toBe(0);
+
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+
+        const view1 = new Testview(0, 100);
+        const view2 = new Testview(0, 100);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        expect(container.childNodes.length).toBeGreaterThan(0);
+
+        let anyEvents = false;
+        const listener = splitview.onDidRemoveView((e) => {
+            anyEvents = true; // disposing of the splitview shouldn't fire onDidRemoveView events
+        });
+
+        splitview.dispose();
+        listener.dispose();
+
+        expect(anyEvents).toBeFalsy();
+        expect(container.childNodes.length).toBe(0);
+    });
+
+    test('dnd: pointer events to move sash', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+        splitview.layout(400, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+
+        const addEventListenerSpy = jest.spyOn(document, 'addEventListener');
+        const removeEventListenerSpy = jest.spyOn(
+            document,
+            'removeEventListener'
+        );
+
+        const sashElement = container
+            .getElementsByClassName('dv-sash')
+            .item(0) as HTMLElement;
+
+        // validate the expected state before drag
+        expect([view1.size, view2.size]).toEqual([200, 200]);
+        expect(sashElement).toBeTruthy();
+        expect(view1.element.parentElement!.style.pointerEvents).toBe('');
+        expect(view2.element.parentElement!.style.pointerEvents).toBe('');
+
+        // start the drag event
+        fireEvent(
+            sashElement,
+            new MouseEvent('pointerdown', { clientX: 50, clientY: 100 })
+        );
+
+        expect(addEventListenerSpy).toBeCalledTimes(3);
+
+        // during a sash drag the views should have pointer-events disabled
+        expect(view1.element.parentElement!.style.pointerEvents).toBe('none');
+        expect(view2.element.parentElement!.style.pointerEvents).toBe('none');
+
+        // expect a delta move of 70 - 50 = 20
+        fireEvent(
+            document,
+            new MouseEvent('pointermove', { clientX: 70, clientY: 110 })
+        );
+        expect([view1.size, view2.size]).toEqual([220, 180]);
+
+        // expect a delta move of 75 - 70 = 5
+        fireEvent(
+            document,
+            new MouseEvent('pointermove', { clientX: 75, clientY: 110 })
+        );
+        expect([view1.size, view2.size]).toEqual([225, 175]);
+
+        // end the drag event
+        fireEvent(
+            document,
+            new MouseEvent('pointerup', { clientX: 70, clientY: 110 })
+        );
+
+        expect(removeEventListenerSpy).toBeCalledTimes(3);
+
+        // expect pointer-eventes on views to be restored
+        expect(view1.element.parentElement!.style.pointerEvents).toBe('');
+        expect(view2.element.parentElement!.style.pointerEvents).toBe('');
+
+        fireEvent(
+            document,
+            new MouseEvent('pointermove', { clientX: 100, clientY: 100 })
+        );
+        // expect no additional resizes
+        expect([view1.size, view2.size]).toEqual([225, 175]);
+        // expect no additional document listeners
+        expect(addEventListenerSpy).toBeCalledTimes(3);
+        expect(removeEventListenerSpy).toBeCalledTimes(3);
+    });
+
+    test('setViewVisible', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+        splitview.layout(900, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000);
+        const view3 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+
+        splitview.setViewVisible(0, false);
+        expect([view1.size, view2.size, view3.size]).toEqual([0, 300, 600]);
+
+        splitview.setViewVisible(0, true);
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+    });
+
+    test('setViewVisible with one view having high layout priority', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+        splitview.layout(900, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000, LayoutPriority.High);
+        const view3 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+
+        splitview.setViewVisible(0, false);
+        expect([view1.size, view2.size, view3.size]).toEqual([0, 600, 300]);
+
+        splitview.setViewVisible(0, true);
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+    });
+
+    test('set view size', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+        splitview.layout(900, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000);
+        const view3 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+
+        view1.fireChangeEvent({ size: 0 });
+        expect([view1.size, view2.size, view3.size]).toEqual([0, 300, 600]);
+
+        view1.fireChangeEvent({ size: 300 });
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+    });
+
+    test('set view size with one view having high layout priority', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+        });
+        splitview.layout(900, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000, LayoutPriority.High);
+        const view3 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        splitview.addView(view2);
+        splitview.addView(view3);
+
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+
+        view1.fireChangeEvent({ size: 0 });
+        expect([view1.size, view2.size, view3.size]).toEqual([0, 600, 300]);
+
+        view1.fireChangeEvent({ size: 300 });
+        expect([view1.size, view2.size, view3.size]).toEqual([300, 300, 300]);
+    });
+
+    test('that margins are applied to view sizing', () => {
+        const splitview = new Splitview(container, {
+            orientation: Orientation.HORIZONTAL,
+            proportionalLayout: false,
+            margin: 24,
+        });
+        splitview.layout(924, 500);
+
+        const view1 = new Testview(0, 1000);
+        const view2 = new Testview(0, 1000);
+        const view3 = new Testview(0, 1000);
+        const view4 = new Testview(0, 1000);
+
+        splitview.addView(view1);
+        expect([view1.size]).toEqual([924]);
+
+        splitview.addView(view2);
+        expect([view1.size, view2.size]).toEqual([450, 450]); // 450 + 24 + 450  = 924
+
+        splitview.addView(view3);
+        expect([view1.size, view2.size, view3.size]).toEqual([292, 292, 292]); // 292 + 24 + 292 + 24 + 292 = 924
+
+        splitview.addView(view4);
+        expect([view1.size, view2.size, view3.size, view4.size]).toEqual([
+            213, 213, 213, 213,
+        ]); // 213 + 24 + 213 + 24 + 213 + 24 + 213 = 924
+
+        let viewQuery = Array.from(
+            container
+                .querySelectorAll(
+                    '.dv-split-view-container > .dv-view-container > .dv-view'
+                )
+                .entries()
+        )
+            .map(([i, e]) => e as HTMLElement)
+            .map((e) => ({
+                left: e.style.left,
+                top: e.style.top,
+                height: e.style.height,
+                width: e.style.width,
+            }));
+
+        let sashQuery = Array.from(
+            container
+                .querySelectorAll(
+                    '.dv-split-view-container > .dv-sash-container > .dv-sash'
+                )
+                .entries()
+        )
+            .map(([i, e]) => e as HTMLElement)
+            .map((e) => ({
+                left: e.style.left,
+                top: e.style.top,
+            }));
+
+        // check HTMLElement positions since these are the ones that really matter
+
+        expect(viewQuery).toEqual([
+            { left: '0px', top: '', width: '213px', height: '' },
+            // 213 + 24 = 237
+            { left: '237px', top: '', width: '213px', height: '' },
+            // 237 + 213 + 24 = 474
+            { left: '474px', top: '', width: '213px', height: '' },
+            // 474 + 213 + 24 = 474
+            { left: '711px', top: '', width: '213px', height: '' },
+            // 711 + 213 = 924
+        ]);
+
+        // 924 / 4 = 231 view size
+        // 231 - (24*3/4) = 213 margin adjusted view size
+        // 213 - 4/2 + 24/2 = 223
+        expect(sashQuery).toEqual([
+            // 213 - 4/2 + 24/2 = 223
+            { left: '223px', top: '0px' },
+            // 213 + 24 + 213 = 450
+            // 450 - 4/2 + 24/2 = 460
+            { left: '460px', top: '0px' },
+            // 213 + 24 + 213 + 24 + 213 = 687
+            // 687 - 4/2 + 24/2 = 697
+            { left: '697px', top: '0px' },
+        ]);
+
+        splitview.setViewVisible(0, false);
+
+        viewQuery = Array.from(
+            container
+                .querySelectorAll(
+                    '.dv-split-view-container > .dv-view-container > .dv-view'
+                )
+                .entries()
+        )
+            .map(([i, e]) => e as HTMLElement)
+            .map((e) => ({
+                left: e.style.left,
+                top: e.style.top,
+                height: e.style.height,
+                width: e.style.width,
+            }));
+
+        sashQuery = Array.from(
+            container
+                .querySelectorAll(
+                    '.dv-split-view-container > .dv-sash-container > .dv-sash'
+                )
+                .entries()
+        )
+            .map(([i, e]) => e as HTMLElement)
+            .map((e) => ({
+                left: e.style.left,
+                top: e.style.top,
+            }));
+
+        expect(viewQuery).toEqual([
+            { left: '0px', top: '', width: '0px', height: '' },
+            { left: '0px', top: '', width: '215px', height: '' },
+            { left: '239px', top: '', width: '215px', height: '' },
+            { left: '478px', top: '', width: '446px', height: '' },
+        ]);
+
+        expect(sashQuery).toEqual([
+            { left: '0px', top: '0px' },
+            { left: '225px', top: '0px' },
+            { left: '464px', top: '0px' },
+        ]);
+    });
+});

packages/dockview-core/src/__tests__/splitview/splitviewComponent.spec.ts

@@ -0,0 +1,743 @@
+import { PanelDimensionChangeEvent } from '../../api/panelApi';
+import { Emitter } from '../../events';
+import { CompositeDisposable } from '../../lifecycle';
+import { Orientation } from '../../splitview/splitview';
+import { SplitviewComponent } from '../../splitview/splitviewComponent';
+import { SplitviewPanel } from '../../splitview/splitviewPanel';
+
+class TestPanel extends SplitviewPanel {
+    getComponent() {
+        return {
+            update: () => {
+                //
+            },
+            dispose: () => {
+                //
+            },
+        };
+    }
+}
+
+describe('componentSplitview', () => {
+    let container: HTMLElement;
+
+    beforeEach(() => {
+        container = document.createElement('div');
+        container.className = 'container';
+    });
+
+    test('that the container is not removed when grid is disposed', () => {
+        const root = document.createElement('div');
+        const container = document.createElement('div');
+        root.appendChild(container);
+
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.dispose();
+
+        expect(container.parentElement).toBe(root);
+        expect(container.children.length).toBe(0);
+    });
+
+    test('event leakage', () => {
+        Emitter.setLeakageMonitorEnabled(true);
+
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(600, 400);
+
+        const panel1 = splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        const panel2 = splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        splitview.movePanel(0, 1);
+
+        splitview.removePanel(panel1);
+
+        splitview.dispose();
+
+        if (Emitter.MEMORY_LEAK_WATCHER.size > 0) {
+            for (const entry of Array.from(
+                Emitter.MEMORY_LEAK_WATCHER.events
+            )) {
+                console.log(entry[1]);
+            }
+            throw new Error('not all listeners disposed');
+        }
+
+        Emitter.setLeakageMonitorEnabled(false);
+    });
+
+    test('remove panel', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(600, 400);
+
+        splitview.addPanel({ id: 'panel1', component: 'default' });
+        splitview.addPanel({ id: 'panel2', component: 'default' });
+        splitview.addPanel({ id: 'panel3', component: 'default' });
+
+        const panel1 = splitview.getPanel('panel1')!;
+        const panel2 = splitview.getPanel('panel2')!;
+        const panel3 = splitview.getPanel('panel3')!;
+
+        expect(panel1.api.isActive).toBeFalsy();
+        expect(panel2.api.isActive).toBeFalsy();
+        expect(panel3.api.isActive).toBeTruthy();
+
+        splitview.removePanel(panel3);
+
+        expect(panel1.api.isActive).toBeFalsy();
+        expect(panel2.api.isActive).toBeTruthy();
+        expect(splitview.length).toBe(2);
+
+        splitview.removePanel(panel1);
+        expect(panel2.api.isActive).toBeTruthy();
+        expect(splitview.length).toBe(1);
+
+        splitview.removePanel(panel2);
+        expect(splitview.length).toBe(0);
+    });
+
+    test('horizontal dimensions', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(600, 400);
+
+        expect(splitview.height).toBe(400);
+        expect(splitview.width).toBe(600);
+    });
+
+    test('vertical dimensions', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(600, 400);
+
+        expect(splitview.height).toBe(400);
+        expect(splitview.width).toBe(600);
+    });
+
+    test('api resize', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(400, 600);
+        splitview.addPanel({ id: 'panel1', component: 'default' });
+        splitview.addPanel({ id: 'panel2', component: 'default' });
+        splitview.addPanel({ id: 'panel3', component: 'default' });
+
+        const panel1 = splitview.getPanel('panel1')!;
+        const panel2 = splitview.getPanel('panel2')!;
+        const panel3 = splitview.getPanel('panel3')!;
+
+        expect(panel1.width).toBe(400);
+        expect(panel1.height).toBe(200);
+        expect(panel2.width).toBe(400);
+        expect(panel2.height).toBe(200);
+        expect(panel3.width).toBe(400);
+        expect(panel3.height).toBe(200);
+
+        panel1.api.setSize({ size: 100 });
+
+        expect(panel1.width).toBe(400);
+        expect(panel1.height).toBe(100);
+        expect(panel2.width).toBe(400);
+        expect(panel2.height).toBe(200);
+        expect(panel3.width).toBe(400);
+        expect(panel3.height).toBe(300);
+
+        panel2.api.setSize({ size: 100 });
+
+        expect(panel1.width).toBe(400);
+        expect(panel1.height).toBe(100);
+        expect(panel2.width).toBe(400);
+        expect(panel2.height).toBe(100);
+        expect(panel3.width).toBe(400);
+        expect(panel3.height).toBe(400);
+
+        panel3.api.setSize({ size: 100 });
+
+        expect(panel1.width).toBe(400);
+        expect(panel1.height).toBe(100);
+        expect(panel2.width).toBe(400);
+        expect(panel2.height).toBe(400);
+        expect(panel3.width).toBe(400);
+        expect(panel3.height).toBe(100);
+    });
+
+    test('api', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(600, 400);
+        splitview.addPanel({ id: 'panel1', component: 'default' });
+
+        const panel1 = splitview.getPanel('panel1');
+
+        expect(panel1!.api.height).toBe(400);
+        expect(panel1!.api.width).toBe(600);
+        expect(panel1!.api.id).toBe('panel1');
+        expect(panel1!.api.isActive).toBeTruthy();
+        // expect(panel1?.api.isFocused).toBeFalsy();
+        expect(panel1!.api.isVisible).toBeTruthy();
+
+        splitview.addPanel({ id: 'panel2', component: 'default' });
+
+        const panel2 = splitview.getPanel('panel2');
+
+        expect(panel1!.api.isActive).toBeFalsy();
+
+        expect(panel2!.api.height).toBe(400);
+        expect(panel2!.api.width).toBe(300);
+        expect(panel2!.api.id).toBe('panel2');
+        expect(panel2!.api.isActive).toBeTruthy();
+        // expect(panel2!.api.isFocused).toBeFalsy();
+        expect(panel2!.api.isVisible).toBeTruthy();
+
+        panel1?.api.setActive();
+
+        expect(panel1!.api.isActive).toBeTruthy();
+        expect(panel2!.api.isActive).toBeFalsy();
+    });
+
+    test('vertical panels', () => {
+        const disposables = new CompositeDisposable();
+
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(300, 200);
+
+        splitview.addPanel({ id: 'panel1', component: 'default' });
+        splitview.addPanel({ id: 'panel2', component: 'default' });
+
+        const panel1 = splitview.getPanel('panel1') as SplitviewPanel;
+        const panel2 = splitview.getPanel('panel2') as SplitviewPanel;
+
+        let panel1Dimensions: PanelDimensionChangeEvent | undefined;
+        disposables.addDisposables(
+            panel1.api.onDidDimensionsChange((event) => {
+                panel1Dimensions = event;
+            })
+        );
+
+        let panel2Dimensions: PanelDimensionChangeEvent | undefined;
+        disposables.addDisposables(
+            panel2.api.onDidDimensionsChange((event) => {
+                panel2Dimensions = event;
+            })
+        );
+
+        splitview.layout(600, 400);
+
+        expect(panel1Dimensions).toEqual({ width: 600, height: 200 });
+        expect(panel2Dimensions).toEqual({ width: 600, height: 200 });
+
+        panel1.api.setSize({ size: 300 });
+
+        expect(panel1Dimensions).toEqual({ width: 600, height: 300 });
+        expect(panel2Dimensions).toEqual({ width: 600, height: 100 });
+
+        splitview.layout(200, 600);
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 450 });
+        expect(panel2Dimensions).toEqual({ width: 200, height: 150 });
+
+        disposables.dispose();
+        splitview.dispose();
+    });
+
+    test('horizontal panels', () => {
+        const disposables = new CompositeDisposable();
+
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(300, 200);
+
+        splitview.addPanel({ id: 'panel1', component: 'default' });
+        splitview.addPanel({ id: 'panel2', component: 'default' });
+
+        const panel1 = splitview.getPanel('panel1') as SplitviewPanel;
+        const panel2 = splitview.getPanel('panel2') as SplitviewPanel;
+
+        let panel1Dimensions: PanelDimensionChangeEvent | undefined;
+        disposables.addDisposables(
+            panel1.api.onDidDimensionsChange((event) => {
+                panel1Dimensions = event;
+            })
+        );
+
+        let panel2Dimensions: PanelDimensionChangeEvent | undefined;
+        disposables.addDisposables(
+            panel2.api.onDidDimensionsChange((event) => {
+                panel2Dimensions = event;
+            })
+        );
+
+        splitview.layout(600, 400);
+
+        expect(panel1Dimensions).toEqual({ width: 300, height: 400 });
+        expect(panel2Dimensions).toEqual({ width: 300, height: 400 });
+
+        panel1.api.setSize({ size: 200 });
+
+        expect(panel1Dimensions).toEqual({ width: 200, height: 400 });
+        expect(panel2Dimensions).toEqual({ width: 400, height: 400 });
+
+        splitview.layout(200, 600);
+
+        expect(panel1Dimensions).toEqual({ width: 67, height: 600 });
+        expect(panel2Dimensions).toEqual({ width: 133, height: 600 });
+
+        disposables.dispose();
+        splitview.dispose();
+    });
+
+    test('serialization', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(400, 6);
+
+        expect(
+            container.querySelectorAll('.dv-split-view-container').length
+        ).toBe(1);
+
+        splitview.fromJSON({
+            views: [
+                {
+                    size: 1,
+                    data: { id: 'panel1', component: 'default' },
+                    snap: false,
+                },
+                {
+                    size: 2,
+                    data: { id: 'panel2', component: 'default' },
+                    snap: true,
+                },
+                { size: 3, data: { id: 'panel3', component: 'default' } },
+            ],
+            size: 6,
+            orientation: Orientation.VERTICAL,
+            activeView: 'panel1',
+        });
+
+        expect(
+            container.querySelectorAll('.dv-split-view-container').length
+        ).toBe(1);
+
+        expect(splitview.length).toBe(3);
+
+        expect(JSON.parse(JSON.stringify(splitview.toJSON()))).toEqual({
+            views: [
+                {
+                    size: 1,
+                    data: { id: 'panel1', component: 'default' },
+                    snap: false,
+                },
+                {
+                    size: 2,
+                    data: { id: 'panel2', component: 'default' },
+                    snap: true,
+                },
+                {
+                    size: 3,
+                    data: { id: 'panel3', component: 'default' },
+                    snap: false,
+                },
+            ],
+            size: 6,
+            orientation: Orientation.VERTICAL,
+            activeView: 'panel1',
+        });
+    });
+
+    test('toJSON shouldnt fire any layout events', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(1000, 1000);
+
+        splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        const disposable = splitview.onDidLayoutChange(() => {
+            fail('onDidLayoutChange shouldnt have been called');
+        });
+
+        const result = splitview.toJSON();
+        expect(result).toBeTruthy();
+
+        disposable.dispose();
+    });
+
+    test('panel is disposed of when component is disposed', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(1000, 1000);
+
+        splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        const panel1 = splitview.getPanel('panel1')!;
+        const panel2 = splitview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        splitview.dispose();
+
+        expect(panel1Spy).toHaveBeenCalledTimes(1);
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('panel is disposed of when removed', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(1000, 1000);
+
+        splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        const panel1 = splitview.getPanel('panel1')!;
+        const panel2 = splitview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        splitview.removePanel(panel2);
+
+        expect(panel1Spy).not.toHaveBeenCalled();
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('panel is disposed of when fromJSON is called', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(1000, 1000);
+
+        splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        const panel1 = splitview.getPanel('panel1')!;
+        const panel2 = splitview.getPanel('panel2')!;
+
+        const panel1Spy = jest.spyOn(panel1, 'dispose');
+        const panel2Spy = jest.spyOn(panel2, 'dispose');
+
+        splitview.fromJSON({
+            orientation: Orientation.HORIZONTAL,
+            size: 0,
+            views: [],
+        });
+
+        expect(panel1Spy).toHaveBeenCalledTimes(1);
+        expect(panel2Spy).toHaveBeenCalledTimes(1);
+    });
+
+    test('that fromJSON layouts are resized to the current dimensions', async () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+        splitview.layout(400, 600);
+
+        splitview.fromJSON({
+            views: [
+                {
+                    size: 1,
+                    data: { id: 'panel1', component: 'default' },
+                    snap: false,
+                },
+                {
+                    size: 2,
+                    data: { id: 'panel2', component: 'default' },
+                    snap: true,
+                },
+                { size: 3, data: { id: 'panel3', component: 'default' } },
+            ],
+            size: 6,
+            orientation: Orientation.VERTICAL,
+            activeView: 'panel1',
+        });
+
+        expect(JSON.parse(JSON.stringify(splitview.toJSON()))).toEqual({
+            views: [
+                {
+                    size: 100,
+                    data: { id: 'panel1', component: 'default' },
+                    snap: false,
+                },
+                {
+                    size: 200,
+                    data: { id: 'panel2', component: 'default' },
+                    snap: true,
+                },
+                {
+                    size: 300,
+                    data: { id: 'panel3', component: 'default' },
+                    snap: false,
+                },
+            ],
+            size: 600,
+            orientation: Orientation.VERTICAL,
+            activeView: 'panel1',
+        });
+    });
+
+    test('that disableAutoResizing is false by default', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        expect(splitview.disableResizing).toBeFalsy();
+    });
+
+    test('that disableAutoResizing can be enabled', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.VERTICAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+            disableAutoResizing: true,
+        });
+
+        expect(splitview.disableResizing).toBeTruthy();
+    });
+
+    test('that setVisible toggles visiblity', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+        });
+
+        splitview.layout(1000, 1000);
+
+        const panel1 = splitview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+        const panel2 = splitview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        expect(panel1.api.isVisible).toBeTruthy();
+        expect(panel2.api.isVisible).toBeTruthy();
+
+        panel1.api.setVisible(false);
+        expect(panel1.api.isVisible).toBeFalsy();
+        expect(panel2.api.isVisible).toBeTruthy();
+
+        panel1.api.setVisible(true);
+        expect(panel1.api.isVisible).toBeTruthy();
+        expect(panel2.api.isVisible).toBeTruthy();
+    });
+
+    test('update className', () => {
+        const splitview = new SplitviewComponent(container, {
+            orientation: Orientation.HORIZONTAL,
+            createComponent: (options) => {
+                switch (options.name) {
+                    case 'default':
+                        return new TestPanel(options.id, options.name);
+                    default:
+                        throw new Error('unsupported');
+                }
+            },
+            className: 'test-a test-b',
+        });
+
+        expect(splitview.element.className).toBe('test-a test-b');
+
+        splitview.updateOptions({ className: 'test-b test-c' });
+
+        expect(splitview.element.className).toBe('test-b test-c');
+    });
+});

packages/dockview-core/src/api/component.api.ts

@@ -0,0 +1,933 @@
+import {
+    DockviewMaximizedGroupChanged,
+    FloatingGroupOptions,
+    IDockviewComponent,
+    MovePanelEvent,
+    PopoutGroupChangePositionEvent,
+    PopoutGroupChangeSizeEvent,
+    SerializedDockview,
+} from '../dockview/dockviewComponent';
+import {
+    AddGroupOptions,
+    AddPanelOptions,
+    DockviewComponentOptions,
+    DockviewDndOverlayEvent,
+    MovementOptions,
+} from '../dockview/options';
+import { Parameters } from '../panel/types';
+import { Direction } from '../gridview/baseComponentGridview';
+import {
+    AddComponentOptions,
+    IGridviewComponent,
+    SerializedGridviewComponent,
+} from '../gridview/gridviewComponent';
+import { IGridviewPanel } from '../gridview/gridviewPanel';
+
+import {
+    AddPaneviewComponentOptions,
+    SerializedPaneview,
+    IPaneviewComponent,
+} from '../paneview/paneviewComponent';
+import { IPaneviewPanel } from '../paneview/paneviewPanel';
+import {
+    AddSplitviewComponentOptions,
+    ISplitviewComponent,
+    SerializedSplitview,
+} from '../splitview/splitviewComponent';
+import { IView, Orientation, Sizing } from '../splitview/splitview';
+import { ISplitviewPanel } from '../splitview/splitviewPanel';
+import {
+    DockviewGroupPanel,
+    IDockviewGroupPanel,
+} from '../dockview/dockviewGroupPanel';
+import { Event } from '../events';
+import { IDockviewPanel } from '../dockview/dockviewPanel';
+import { PaneviewDidDropEvent } from '../paneview/draggablePaneviewPanel';
+import {
+    GroupDragEvent,
+    TabDragEvent,
+} from '../dockview/components/titlebar/tabsContainer';
+import { Box } from '../types';
+import {
+    DockviewDidDropEvent,
+    DockviewWillDropEvent,
+    WillShowOverlayLocationEvent,
+} from '../dockview/dockviewGroupPanelModel';
+import {
+    PaneviewComponentOptions,
+    PaneviewDndOverlayEvent,
+} from '../paneview/options';
+import { SplitviewComponentOptions } from '../splitview/options';
+import { GridviewComponentOptions } from '../gridview/options';
+
+export interface CommonApi<T = any> {
+    readonly height: number;
+    readonly width: number;
+    readonly onDidLayoutChange: Event<void>;
+    readonly onDidLayoutFromJSON: Event<void>;
+    focus(): void;
+    layout(width: number, height: number): void;
+    fromJSON(data: T): void;
+    toJSON(): T;
+    clear(): void;
+    dispose(): void;
+}
+
+export class SplitviewApi implements CommonApi<SerializedSplitview> {
+    /**
+     * The minimum size  the component can reach where size is measured in the direction of orientation provided.
+     */
+    get minimumSize(): number {
+        return this.component.minimumSize;
+    }
+
+    /**
+     * The maximum size the component can reach where size is measured in the direction of orientation provided.
+     */
+    get maximumSize(): number {
+        return this.component.maximumSize;
+    }
+
+    /**
+     * Width of the component.
+     */
+    get width(): number {
+        return this.component.width;
+    }
+
+    /**
+     * Height of the component.
+     */
+    get height(): number {
+        return this.component.height;
+    }
+    /**
+     * The current number of panels.
+     */
+    get length(): number {
+        return this.component.length;
+    }
+
+    /**
+     * The current orientation of the component.
+     */
+    get orientation(): Orientation {
+        return this.component.orientation;
+    }
+
+    /**
+     * The list of current panels.
+     */
+    get panels(): ISplitviewPanel[] {
+        return this.component.panels;
+    }
+
+    /**
+     * Invoked after a layout is loaded through the `fromJSON` method.
+     */
+    get onDidLayoutFromJSON(): Event<void> {
+        return this.component.onDidLayoutFromJSON;
+    }
+
+    /**
+     * Invoked whenever any aspect of the layout changes.
+     * If listening to this event it may be worth debouncing ouputs.
+     */
+    get onDidLayoutChange(): Event<void> {
+        return this.component.onDidLayoutChange;
+    }
+
+    /**
+     * Invoked when a view is added.
+     */
+    get onDidAddView(): Event<IView> {
+        return this.component.onDidAddView;
+    }
+
+    /**
+     * Invoked when a view is removed.
+     */
+    get onDidRemoveView(): Event<IView> {
+        return this.component.onDidRemoveView;
+    }
+
+    constructor(private readonly component: ISplitviewComponent) {}
+
+    /**
+     * Removes an existing panel and optionally provide a `Sizing` method
+     * for the subsequent resize.
+     */
+    removePanel(panel: ISplitviewPanel, sizing?: Sizing): void {
+        this.component.removePanel(panel, sizing);
+    }
+
+    /**
+     * Focus the component.
+     */
+    focus(): void {
+        this.component.focus();
+    }
+
+    /**
+     * Get the reference to a panel given it's `string` id.
+     */
+    getPanel(id: string): ISplitviewPanel | undefined {
+        return this.component.getPanel(id);
+    }
+
+    /**
+     * Layout the panel with a width and height.
+     */
+    layout(width: number, height: number): void {
+        return this.component.layout(width, height);
+    }
+
+    /**
+     * Add a new panel and return the created instance.
+     */
+    addPanel<T extends object = Parameters>(
+        options: AddSplitviewComponentOptions<T>
+    ): ISplitviewPanel {
+        return this.component.addPanel(options);
+    }
+
+    /**
+     * Move a panel given it's current and desired index.
+     */
+    movePanel(from: number, to: number): void {
+        this.component.movePanel(from, to);
+    }
+
+    /**
+     * Deserialize a layout to built a splitivew.
+     */
+    fromJSON(data: SerializedSplitview): void {
+        this.component.fromJSON(data);
+    }
+
+    /** Serialize a layout */
+    toJSON(): SerializedSplitview {
+        return this.component.toJSON();
+    }
+
+    /**
+     * Remove all panels and clear the component.
+     */
+    clear(): void {
+        this.component.clear();
+    }
+
+    /**
+     * Update configuratable options.
+     */
+    updateOptions(options: Partial<SplitviewComponentOptions>): void {
+        this.component.updateOptions(options);
+    }
+
+    /**
+     * Release resources and teardown component. Do not call when using framework versions of dockview.
+     */
+    dispose(): void {
+        this.component.dispose();
+    }
+}
+
+export class PaneviewApi implements CommonApi<SerializedPaneview> {
+    /**
+     * The minimum size  the component can reach where size is measured in the direction of orientation provided.
+     */
+    get minimumSize(): number {
+        return this.component.minimumSize;
+    }
+
+    /**
+     * The maximum size the component can reach where size is measured in the direction of orientation provided.
+     */
+    get maximumSize(): number {
+        return this.component.maximumSize;
+    }
+
+    /**
+     * Width of the component.
+     */
+    get width(): number {
+        return this.component.width;
+    }
+
+    /**
+     * Height of the component.
+     */
+    get height(): number {
+        return this.component.height;
+    }
+
+    /**
+     * All panel objects.
+     */
+    get panels(): IPaneviewPanel[] {
+        return this.component.panels;
+    }
+
+    /**
+     * Invoked when any layout change occures, an aggregation of many events.
+     */
+    get onDidLayoutChange(): Event<void> {
+        return this.component.onDidLayoutChange;
+    }
+
+    /**
+     * Invoked after a layout is deserialzied using the `fromJSON` method.
+     */
+    get onDidLayoutFromJSON(): Event<void> {
+        return this.component.onDidLayoutFromJSON;
+    }
+
+    /**
+     * Invoked when a panel is added. May be called multiple times when moving panels.
+     */
+    get onDidAddView(): Event<IPaneviewPanel> {
+        return this.component.onDidAddView;
+    }
+
+    /**
+     * Invoked when a panel is removed. May be called multiple times when moving panels.
+     */
+    get onDidRemoveView(): Event<IPaneviewPanel> {
+        return this.component.onDidRemoveView;
+    }
+
+    /**
+     * Invoked when a Drag'n'Drop event occurs that the component was unable to handle. Exposed for custom Drag'n'Drop functionality.
+     */
+    get onDidDrop(): Event<PaneviewDidDropEvent> {
+        return this.component.onDidDrop;
+    }
+
+    get onUnhandledDragOverEvent(): Event<PaneviewDndOverlayEvent> {
+        return this.component.onUnhandledDragOverEvent;
+    }
+
+    constructor(private readonly component: IPaneviewComponent) {}
+
+    /**
+     * Remove a panel given the panel object.
+     */
+    removePanel(panel: IPaneviewPanel): void {
+        this.component.removePanel(panel);
+    }
+
+    /**
+     * Get a panel object given a `string` id. May return `undefined`.
+     */
+    getPanel(id: string): IPaneviewPanel | undefined {
+        return this.component.getPanel(id);
+    }
+
+    /**
+     * Move a panel given it's current and desired index.
+     */
+    movePanel(from: number, to: number): void {
+        this.component.movePanel(from, to);
+    }
+
+    /**
+     *  Focus the component. Will try to focus an active panel if one exists.
+     */
+    focus(): void {
+        this.component.focus();
+    }
+
+    /**
+     * Force resize the component to an exact width and height. Read about auto-resizing before using.
+     */
+    layout(width: number, height: number): void {
+        this.component.layout(width, height);
+    }
+
+    /**
+     * Add a panel and return the created object.
+     */
+    addPanel<T extends object = Parameters>(
+        options: AddPaneviewComponentOptions<T>
+    ): IPaneviewPanel {
+        return this.component.addPanel(options);
+    }
+
+    /**
+     * Create a component from a serialized object.
+     */
+    fromJSON(data: SerializedPaneview): void {
+        this.component.fromJSON(data);
+    }
+
+    /**
+     * Create a serialized object of the current component.
+     */
+    toJSON(): SerializedPaneview {
+        return this.component.toJSON();
+    }
+
+    /**
+     * Reset the component back to an empty and default state.
+     */
+    clear(): void {
+        this.component.clear();
+    }
+
+    /**
+     * Update configuratable options.
+     */
+    updateOptions(options: Partial<PaneviewComponentOptions>): void {
+        this.component.updateOptions(options);
+    }
+
+    /**
+     * Release resources and teardown component. Do not call when using framework versions of dockview.
+     */
+    dispose(): void {
+        this.component.dispose();
+    }
+}
+
+export class GridviewApi implements CommonApi<SerializedGridviewComponent> {
+    /**
+     * Width of the component.
+     */
+    get width(): number {
+        return this.component.width;
+    }
+
+    /**
+     * Height of the component.
+     */
+    get height(): number {
+        return this.component.height;
+    }
+
+    /**
+     * Minimum height of the component.
+     */
+    get minimumHeight(): number {
+        return this.component.minimumHeight;
+    }
+
+    /**
+     * Maximum height of the component.
+     */
+    get maximumHeight(): number {
+        return this.component.maximumHeight;
+    }
+
+    /**
+     * Minimum width of the component.
+     */
+    get minimumWidth(): number {
+        return this.component.minimumWidth;
+    }
+
+    /**
+     * Maximum width of the component.
+     */
+    get maximumWidth(): number {
+        return this.component.maximumWidth;
+    }
+
+    /**
+     * Invoked when any layout change occures, an aggregation of many events.
+     */
+    get onDidLayoutChange(): Event<void> {
+        return this.component.onDidLayoutChange;
+    }
+
+    /**
+     * Invoked when a panel is added. May be called multiple times when moving panels.
+     */
+    get onDidAddPanel(): Event<IGridviewPanel> {
+        return this.component.onDidAddGroup;
+    }
+
+    /**
+     * Invoked when a panel is removed. May be called multiple times when moving panels.
+     */
+    get onDidRemovePanel(): Event<IGridviewPanel> {
+        return this.component.onDidRemoveGroup;
+    }
+
+    /**
+     * Invoked when the active panel changes. May be undefined if no panel is active.
+     */
+    get onDidActivePanelChange(): Event<IGridviewPanel | undefined> {
+        return this.component.onDidActiveGroupChange;
+    }
+
+    /**
+     * Invoked after a layout is deserialzied using the `fromJSON` method.
+     */
+    get onDidLayoutFromJSON(): Event<void> {
+        return this.component.onDidLayoutFromJSON;
+    }
+
+    /**
+     * All panel objects.
+     */
+    get panels(): IGridviewPanel[] {
+        return this.component.groups;
+    }
+
+    /**
+     * Current orientation. Can be changed after initialization.
+     */
+    get orientation(): Orientation {
+        return this.component.orientation;
+    }
+
+    set orientation(value: Orientation) {
+        this.component.updateOptions({ orientation: value });
+    }
+
+    constructor(private readonly component: IGridviewComponent) {}
+
+    /**
+     *  Focus the component. Will try to focus an active panel if one exists.
+     */
+    focus(): void {
+        this.component.focus();
+    }
+
+    /**
+     * Force resize the component to an exact width and height. Read about auto-resizing before using.
+     */
+    layout(width: number, height: number, force = false): void {
+        this.component.layout(width, height, force);
+    }
+
+    /**
+     * Add a panel and return the created object.
+     */
+    addPanel<T extends object = Parameters>(
+        options: AddComponentOptions<T>
+    ): IGridviewPanel {
+        return this.component.addPanel(options);
+    }
+
+    /**
+     * Remove a panel given the panel object.
+     */
+    removePanel(panel: IGridviewPanel, sizing?: Sizing): void {
+        this.component.removePanel(panel, sizing);
+    }
+
+    /**
+     * Move a panel in a particular direction relative to another panel.
+     */
+    movePanel(
+        panel: IGridviewPanel,
+        options: { direction: Direction; reference: string; size?: number }
+    ): void {
+        this.component.movePanel(panel, options);
+    }
+
+    /**
+     * Get a panel object given a `string` id. May return `undefined`.
+     */
+    getPanel(id: string): IGridviewPanel | undefined {
+        return this.component.getPanel(id);
+    }
+
+    /**
+     * Create a component from a serialized object.
+     */
+    fromJSON(data: SerializedGridviewComponent): void {
+        return this.component.fromJSON(data);
+    }
+
+    /**
+     * Create a serialized object of the current component.
+     */
+    toJSON(): SerializedGridviewComponent {
+        return this.component.toJSON();
+    }
+
+    /**
+     * Reset the component back to an empty and default state.
+     */
+    clear(): void {
+        this.component.clear();
+    }
+
+    updateOptions(options: Partial<GridviewComponentOptions>) {
+        this.component.updateOptions(options);
+    }
+
+    /**
+     * Release resources and teardown component. Do not call when using framework versions of dockview.
+     */
+    dispose(): void {
+        this.component.dispose();
+    }
+}
+
+export class DockviewApi implements CommonApi<SerializedDockview> {
+    /**
+     * The unique identifier for this instance. Used to manage scope of Drag'n'Drop events.
+     */
+    get id(): string {
+        return this.component.id;
+    }
+
+    /**
+     * Width of the component.
+     */
+    get width(): number {
+        return this.component.width;
+    }
+
+    /**
+     * Height of the component.
+     */
+    get height(): number {
+        return this.component.height;
+    }
+
+    /**
+     * Minimum height of the component.
+     */
+    get minimumHeight(): number {
+        return this.component.minimumHeight;
+    }
+
+    /**
+     * Maximum height of the component.
+     */
+    get maximumHeight(): number {
+        return this.component.maximumHeight;
+    }
+
+    /**
+     * Minimum width of the component.
+     */
+    get minimumWidth(): number {
+        return this.component.minimumWidth;
+    }
+
+    /**
+     * Maximum width of the component.
+     */
+    get maximumWidth(): number {
+        return this.component.maximumWidth;
+    }
+
+    /**
+     * Total number of groups.
+     */
+    get size(): number {
+        return this.component.size;
+    }
+
+    /**
+     * Total number of panels.
+     */
+    get totalPanels(): number {
+        return this.component.totalPanels;
+    }
+
+    /**
+     * Invoked when the active group changes. May be undefined if no group is active.
+     */
+    get onDidActiveGroupChange(): Event<DockviewGroupPanel | undefined> {
+        return this.component.onDidActiveGroupChange;
+    }
+
+    /**
+     * Invoked when a group is added. May be called multiple times when moving groups.
+     */
+    get onDidAddGroup(): Event<DockviewGroupPanel> {
+        return this.component.onDidAddGroup;
+    }
+
+    /**
+     * Invoked when a group is removed. May be called multiple times when moving groups.
+     */
+    get onDidRemoveGroup(): Event<DockviewGroupPanel> {
+        return this.component.onDidRemoveGroup;
+    }
+
+    /**
+     * Invoked when the active panel changes. May be undefined if no panel is active.
+     */
+    get onDidActivePanelChange(): Event<IDockviewPanel | undefined> {
+        return this.component.onDidActivePanelChange;
+    }
+
+    /**
+     * Invoked when a panel is added. May be called multiple times when moving panels.
+     */
+    get onDidAddPanel(): Event<IDockviewPanel> {
+        return this.component.onDidAddPanel;
+    }
+
+    /**
+     * Invoked when a panel is removed. May be called multiple times when moving panels.
+     */
+    get onDidRemovePanel(): Event<IDockviewPanel> {
+        return this.component.onDidRemovePanel;
+    }
+
+    get onDidMovePanel(): Event<MovePanelEvent> {
+        return this.component.onDidMovePanel;
+    }
+
+    /**
+     * Invoked after a layout is deserialzied using the `fromJSON` method.
+     */
+    get onDidLayoutFromJSON(): Event<void> {
+        return this.component.onDidLayoutFromJSON;
+    }
+
+    /**
+     * Invoked when any layout change occures, an aggregation of many events.
+     */
+    get onDidLayoutChange(): Event<void> {
+        return this.component.onDidLayoutChange;
+    }
+
+    /**
+     * Invoked when a Drag'n'Drop event occurs that the component was unable to handle. Exposed for custom Drag'n'Drop functionality.
+     */
+    get onDidDrop(): Event<DockviewDidDropEvent> {
+        return this.component.onDidDrop;
+    }
+
+    /**
+     * Invoked when a Drag'n'Drop event occurs but before dockview handles it giving the user an opportunity to intecept and
+     * prevent the event from occuring using the standard `preventDefault()` syntax.
+     *
+     * Preventing certain events may causes unexpected behaviours, use carefully.
+     */
+    get onWillDrop(): Event<DockviewWillDropEvent> {
+        return this.component.onWillDrop;
+    }
+
+    /**
+     * Invoked before an overlay is shown indicating a drop target.
+     *
+     * Calling `event.preventDefault()` will prevent the overlay being shown and prevent
+     * the any subsequent drop event.
+     */
+    get onWillShowOverlay(): Event<WillShowOverlayLocationEvent> {
+        return this.component.onWillShowOverlay;
+    }
+
+    /**
+     * Invoked before a group is dragged.
+     *
+     * Calling `event.nativeEvent.preventDefault()` will prevent the group drag starting.
+     *
+     */
+    get onWillDragGroup(): Event<GroupDragEvent> {
+        return this.component.onWillDragGroup;
+    }
+
+    /**
+     * Invoked before a panel is dragged.
+     *
+     * Calling `event.nativeEvent.preventDefault()` will prevent the panel drag starting.
+     */
+    get onWillDragPanel(): Event<TabDragEvent> {
+        return this.component.onWillDragPanel;
+    }
+
+    get onUnhandledDragOverEvent(): Event<DockviewDndOverlayEvent> {
+        return this.component.onUnhandledDragOverEvent;
+    }
+
+    get onDidPopoutGroupSizeChange(): Event<PopoutGroupChangeSizeEvent> {
+        return this.component.onDidPopoutGroupSizeChange;
+    }
+
+    get onDidPopoutGroupPositionChange(): Event<PopoutGroupChangePositionEvent> {
+        return this.component.onDidPopoutGroupPositionChange;
+    }
+
+    /**
+     * All panel objects.
+     */
+    get panels(): IDockviewPanel[] {
+        return this.component.panels;
+    }
+
+    /**
+     * All group objects.
+     */
+    get groups(): DockviewGroupPanel[] {
+        return this.component.groups;
+    }
+
+    /**
+     *  Active panel object.
+     */
+    get activePanel(): IDockviewPanel | undefined {
+        return this.component.activePanel;
+    }
+
+    /**
+     * Active group object.
+     */
+    get activeGroup(): DockviewGroupPanel | undefined {
+        return this.component.activeGroup;
+    }
+
+    constructor(private readonly component: IDockviewComponent) {}
+
+    /**
+     *  Focus the component. Will try to focus an active panel if one exists.
+     */
+    focus(): void {
+        this.component.focus();
+    }
+
+    /**
+     * Get a panel object given a `string` id. May return `undefined`.
+     */
+    getPanel(id: string): IDockviewPanel | undefined {
+        return this.component.getGroupPanel(id);
+    }
+
+    /**
+     * Force resize the component to an exact width and height. Read about auto-resizing before using.
+     */
+    layout(width: number, height: number, force = false): void {
+        this.component.layout(width, height, force);
+    }
+
+    /**
+     * Add a panel and return the created object.
+     */
+    addPanel<T extends object = Parameters>(
+        options: AddPanelOptions<T>
+    ): IDockviewPanel {
+        return this.component.addPanel(options);
+    }
+
+    /**
+     * Remove a panel given the panel object.
+     */
+    removePanel(panel: IDockviewPanel): void {
+        this.component.removePanel(panel);
+    }
+
+    /**
+     * Add a group and return the created object.
+     */
+    addGroup(options?: AddGroupOptions): DockviewGroupPanel {
+        return this.component.addGroup(options);
+    }
+
+    /**
+     * Close all groups and panels.
+     */
+    closeAllGroups(): void {
+        return this.component.closeAllGroups();
+    }
+
+    /**
+     * Remove a group and any panels within the group.
+     */
+    removeGroup(group: IDockviewGroupPanel): void {
+        this.component.removeGroup(<DockviewGroupPanel>group);
+    }
+
+    /**
+     * Get a group object given a `string` id. May return undefined.
+     */
+    getGroup(id: string): DockviewGroupPanel | undefined {
+        return this.component.getPanel(id);
+    }
+
+    /**
+     * Add a floating group
+     */
+    addFloatingGroup(
+        item: IDockviewPanel | DockviewGroupPanel,
+        options?: FloatingGroupOptions
+    ): void {
+        return this.component.addFloatingGroup(item, options);
+    }
+
+    /**
+     * Create a component from a serialized object.
+     */
+    fromJSON(data: SerializedDockview): void {
+        this.component.fromJSON(data);
+    }
+
+    /**
+     * Create a serialized object of the current component.
+     */
+    toJSON(): SerializedDockview {
+        return this.component.toJSON();
+    }
+
+    /**
+     * Reset the component back to an empty and default state.
+     */
+    clear(): void {
+        this.component.clear();
+    }
+
+    /**
+     * Move the focus progmatically to the next panel or group.
+     */
+    moveToNext(options?: MovementOptions): void {
+        this.component.moveToNext(options);
+    }
+
+    /**
+     * Move the focus progmatically to the previous panel or group.
+     */
+    moveToPrevious(options?: MovementOptions): void {
+        this.component.moveToPrevious(options);
+    }
+
+    maximizeGroup(panel: IDockviewPanel): void {
+        this.component.maximizeGroup(panel.group);
+    }
+
+    hasMaximizedGroup(): boolean {
+        return this.component.hasMaximizedGroup();
+    }
+
+    exitMaximizedGroup(): void {
+        this.component.exitMaximizedGroup();
+    }
+
+    get onDidMaximizedGroupChange(): Event<DockviewMaximizedGroupChanged> {
+        return this.component.onDidMaximizedGroupChange;
+    }
+
+    /**
+     * Add a popout group in a new Window
+     */
+    addPopoutGroup(
+        item: IDockviewPanel | DockviewGroupPanel,
+        options?: {
+            position?: Box;
+            popoutUrl?: string;
+            onDidOpen?: (event: { id: string; window: Window }) => void;
+            onWillClose?: (event: { id: string; window: Window }) => void;
+        }
+    ): Promise<boolean> {
+        return this.component.addPopoutGroup(item, options);
+    }
+
+    updateOptions(options: Partial<DockviewComponentOptions>) {
+        this.component.updateOptions(options);
+    }
+
+    /**
+     * Release resources and teardown component. Do not call when using framework versions of dockview.
+     */
+    dispose(): void {
+        this.component.dispose();
+    }
+}

packages/dockview-core/src/api/dockviewGroupPanelApi.ts

@@ -0,0 +1,140 @@
+import { Position, positionToDirection } from '../dnd/droptarget';
+import { DockviewComponent } from '../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../dockview/dockviewGroupPanel';
+import {
+    DockviewGroupChangeEvent,
+    DockviewGroupLocation,
+} from '../dockview/dockviewGroupPanelModel';
+import { Emitter, Event } from '../events';
+import { GridviewPanelApi, GridviewPanelApiImpl } from './gridviewPanelApi';
+
+export interface DockviewGroupMoveParams {
+    group?: DockviewGroupPanel;
+    position?: Position;
+    /**
+     * The index to place the panel within a group, only applicable if the placement is within an existing group
+     */
+    index?: number;
+}
+
+export interface DockviewGroupPanelApi extends GridviewPanelApi {
+    readonly onDidLocationChange: Event<DockviewGroupPanelFloatingChangeEvent>;
+    readonly onDidActivePanelChange: Event<DockviewGroupChangeEvent>;
+    readonly location: DockviewGroupLocation;
+    /**
+     * If you require the Window object
+     */
+    getWindow(): Window;
+    moveTo(options: DockviewGroupMoveParams): void;
+    maximize(): void;
+    isMaximized(): boolean;
+    exitMaximized(): void;
+    close(): void;
+}
+
+export interface DockviewGroupPanelFloatingChangeEvent {
+    readonly location: DockviewGroupLocation;
+}
+
+const NOT_INITIALIZED_MESSAGE =
+    'dockview: DockviewGroupPanelApiImpl not initialized';
+
+export class DockviewGroupPanelApiImpl extends GridviewPanelApiImpl {
+    private _group: DockviewGroupPanel | undefined;
+
+    readonly _onDidLocationChange =
+        new Emitter<DockviewGroupPanelFloatingChangeEvent>();
+    readonly onDidLocationChange: Event<DockviewGroupPanelFloatingChangeEvent> =
+        this._onDidLocationChange.event;
+
+    readonly _onDidActivePanelChange = new Emitter<DockviewGroupChangeEvent>();
+    readonly onDidActivePanelChange = this._onDidActivePanelChange.event;
+
+    get location(): DockviewGroupLocation {
+        if (!this._group) {
+            throw new Error(NOT_INITIALIZED_MESSAGE);
+        }
+        return this._group.model.location;
+    }
+
+    constructor(id: string, private readonly accessor: DockviewComponent) {
+        super(id, '__dockviewgroup__');
+
+        this.addDisposables(
+            this._onDidLocationChange,
+            this._onDidActivePanelChange
+        );
+    }
+
+    close(): void {
+        if (!this._group) {
+            return;
+        }
+        return this.accessor.removeGroup(this._group);
+    }
+
+    getWindow(): Window {
+        return this.location.type === 'popout'
+            ? this.location.getWindow()
+            : window;
+    }
+
+    moveTo(options: DockviewGroupMoveParams): void {
+        if (!this._group) {
+            throw new Error(NOT_INITIALIZED_MESSAGE);
+        }
+
+        const group =
+            options.group ??
+            this.accessor.addGroup({
+                direction: positionToDirection(options.position ?? 'right'),
+                skipSetActive: true,
+            });
+
+        this.accessor.moveGroupOrPanel({
+            from: { groupId: this._group.id },
+            to: {
+                group,
+                position: options.group
+                    ? options.position ?? 'center'
+                    : 'center',
+                index: options.index,
+            },
+        });
+    }
+
+    maximize(): void {
+        if (!this._group) {
+            throw new Error(NOT_INITIALIZED_MESSAGE);
+        }
+
+        if (this.location.type !== 'grid') {
+            // only grid groups can be maximized
+            return;
+        }
+
+        this.accessor.maximizeGroup(this._group);
+    }
+
+    isMaximized(): boolean {
+        if (!this._group) {
+            throw new Error(NOT_INITIALIZED_MESSAGE);
+        }
+
+        return this.accessor.isMaximizedGroup(this._group);
+    }
+
+    exitMaximized(): void {
+        if (!this._group) {
+            throw new Error(NOT_INITIALIZED_MESSAGE);
+        }
+
+        if (this.isMaximized()) {
+            this.accessor.exitMaximizedGroup();
+        }
+    }
+
+    initialize(group: DockviewGroupPanel): void {
+        this._group = group;
+    }
+}

packages/dockview-core/src/api/dockviewPanelApi.ts

@@ -0,0 +1,236 @@
+import { Emitter, Event } from '../events';
+import { GridviewPanelApiImpl, GridviewPanelApi } from './gridviewPanelApi';
+import { DockviewGroupPanel } from '../dockview/dockviewGroupPanel';
+import { CompositeDisposable, MutableDisposable } from '../lifecycle';
+import { DockviewPanel } from '../dockview/dockviewPanel';
+import { DockviewComponent } from '../dockview/dockviewComponent';
+import { DockviewPanelRenderer } from '../overlay/overlayRenderContainer';
+import {
+    DockviewGroupMoveParams,
+    DockviewGroupPanelFloatingChangeEvent,
+} from './dockviewGroupPanelApi';
+import { DockviewGroupLocation } from '../dockview/dockviewGroupPanelModel';
+
+export interface TitleEvent {
+    readonly title: string;
+}
+
+export interface RendererChangedEvent {
+    readonly renderer: DockviewPanelRenderer;
+}
+
+export interface ActiveGroupEvent {
+    readonly isActive: boolean;
+}
+
+export interface GroupChangedEvent {
+    // empty
+}
+
+export type DockviewPanelMoveParams = DockviewGroupMoveParams;
+
+export interface DockviewPanelApi
+    extends Omit<
+        GridviewPanelApi,
+        // omit properties that do not make sense here
+        'setVisible' | 'onDidConstraintsChange' | 'setConstraints'
+    > {
+    /**
+     * The id of the tab component renderer
+     *
+     * Undefined if no custom tab renderer is provided
+     */
+    readonly tabComponent: string | undefined;
+    readonly group: DockviewGroupPanel;
+    readonly isGroupActive: boolean;
+    readonly renderer: DockviewPanelRenderer;
+    readonly title: string | undefined;
+    readonly onDidActiveGroupChange: Event<ActiveGroupEvent>;
+    readonly onDidGroupChange: Event<GroupChangedEvent>;
+    readonly onDidTitleChange: Event<TitleEvent>;
+    readonly onDidRendererChange: Event<RendererChangedEvent>;
+    readonly location: DockviewGroupLocation;
+    readonly onDidLocationChange: Event<DockviewGroupPanelFloatingChangeEvent>;
+    close(): void;
+    setTitle(title: string): void;
+    setRenderer(renderer: DockviewPanelRenderer): void;
+    moveTo(options: DockviewPanelMoveParams): void;
+    maximize(): void;
+    isMaximized(): boolean;
+    exitMaximized(): void;
+    /**
+     * If you require the Window object
+     */
+    getWindow(): Window;
+}
+
+export class DockviewPanelApiImpl
+    extends GridviewPanelApiImpl
+    implements DockviewPanelApi
+{
+    private _group: DockviewGroupPanel;
+    private readonly _tabComponent: string | undefined;
+
+    readonly _onDidTitleChange = new Emitter<TitleEvent>();
+    readonly onDidTitleChange = this._onDidTitleChange.event;
+
+    private readonly _onDidActiveGroupChange = new Emitter<ActiveGroupEvent>();
+    readonly onDidActiveGroupChange = this._onDidActiveGroupChange.event;
+
+    private readonly _onDidGroupChange = new Emitter<GroupChangedEvent>();
+    readonly onDidGroupChange = this._onDidGroupChange.event;
+
+    readonly _onDidRendererChange = new Emitter<RendererChangedEvent>();
+    readonly onDidRendererChange = this._onDidRendererChange.event;
+
+    private readonly _onDidLocationChange =
+        new Emitter<DockviewGroupPanelFloatingChangeEvent>();
+    readonly onDidLocationChange: Event<DockviewGroupPanelFloatingChangeEvent> =
+        this._onDidLocationChange.event;
+
+    private readonly groupEventsDisposable = new MutableDisposable();
+
+    get location(): DockviewGroupLocation {
+        return this.group.api.location;
+    }
+
+    get title(): string | undefined {
+        return this.panel.title;
+    }
+
+    get isGroupActive(): boolean {
+        return this.group.isActive;
+    }
+
+    get renderer(): DockviewPanelRenderer {
+        return this.panel.renderer;
+    }
+
+    set group(value: DockviewGroupPanel) {
+        const oldGroup = this._group;
+
+        if (this._group !== value) {
+            this._group = value;
+
+            this._onDidGroupChange.fire({});
+
+            this.setupGroupEventListeners(oldGroup);
+
+            this._onDidLocationChange.fire({
+                location: this.group.api.location,
+            });
+        }
+    }
+
+    get group(): DockviewGroupPanel {
+        return this._group;
+    }
+
+    get tabComponent(): string | undefined {
+        return this._tabComponent;
+    }
+
+    constructor(
+        private readonly panel: DockviewPanel,
+        group: DockviewGroupPanel,
+        private readonly accessor: DockviewComponent,
+        component: string,
+        tabComponent?: string
+    ) {
+        super(panel.id, component);
+
+        this._tabComponent = tabComponent;
+
+        this.initialize(panel);
+
+        this._group = group;
+        this.setupGroupEventListeners();
+
+        this.addDisposables(
+            this.groupEventsDisposable,
+            this._onDidRendererChange,
+            this._onDidTitleChange,
+            this._onDidGroupChange,
+            this._onDidActiveGroupChange,
+            this._onDidLocationChange
+        );
+    }
+
+    getWindow(): Window {
+        return this.group.api.getWindow();
+    }
+
+    moveTo(options: DockviewPanelMoveParams): void {
+        this.accessor.moveGroupOrPanel({
+            from: { groupId: this._group.id, panelId: this.panel.id },
+            to: {
+                group: options.group ?? this._group,
+                position: options.group
+                    ? options.position ?? 'center'
+                    : 'center',
+                index: options.index,
+            },
+        });
+    }
+
+    setTitle(title: string): void {
+        this.panel.setTitle(title);
+    }
+
+    setRenderer(renderer: DockviewPanelRenderer): void {
+        this.panel.setRenderer(renderer);
+    }
+
+    close(): void {
+        this.group.model.closePanel(this.panel);
+    }
+
+    maximize(): void {
+        this.group.api.maximize();
+    }
+
+    isMaximized(): boolean {
+        return this.group.api.isMaximized();
+    }
+
+    exitMaximized(): void {
+        this.group.api.exitMaximized();
+    }
+
+    private setupGroupEventListeners(previousGroup?: DockviewGroupPanel) {
+        let _trackGroupActive = previousGroup?.isActive ?? false; // prevent duplicate events with same state
+
+        this.groupEventsDisposable.value = new CompositeDisposable(
+            this.group.api.onDidVisibilityChange((event) => {
+                const hasBecomeHidden = !event.isVisible && this.isVisible;
+                const hasBecomeVisible = event.isVisible && !this.isVisible;
+
+                const isActivePanel = this.group.model.isPanelActive(
+                    this.panel
+                );
+
+                if (hasBecomeHidden || (hasBecomeVisible && isActivePanel)) {
+                    this._onDidVisibilityChange.fire(event);
+                }
+            }),
+            this.group.api.onDidLocationChange((event) => {
+                if (this.group !== this.panel.group) {
+                    return;
+                }
+                this._onDidLocationChange.fire(event);
+            }),
+            this.group.api.onDidActiveChange(() => {
+                if (this.group !== this.panel.group) {
+                    return;
+                }
+
+                if (_trackGroupActive !== this.isGroupActive) {
+                    _trackGroupActive = this.isGroupActive;
+                    this._onDidActiveGroupChange.fire({
+                        isActive: this.isGroupActive,
+                    });
+                }
+            })
+        );
+    }
+}

packages/dockview-core/src/api/entryPoints.ts

@@ -0,0 +1,46 @@
+import {
+    DockviewApi,
+    GridviewApi,
+    PaneviewApi,
+    SplitviewApi,
+} from '../api/component.api';
+import { DockviewComponent } from '../dockview/dockviewComponent';
+import { DockviewComponentOptions } from '../dockview/options';
+import { GridviewComponent } from '../gridview/gridviewComponent';
+import { GridviewComponentOptions } from '../gridview/options';
+import { PaneviewComponentOptions } from '../paneview/options';
+import { PaneviewComponent } from '../paneview/paneviewComponent';
+import { SplitviewComponentOptions } from '../splitview/options';
+import { SplitviewComponent } from '../splitview/splitviewComponent';
+
+export function createDockview(
+    element: HTMLElement,
+    options: DockviewComponentOptions
+): DockviewApi {
+    const component = new DockviewComponent(element, options);
+    return component.api;
+}
+
+export function createSplitview(
+    element: HTMLElement,
+    options: SplitviewComponentOptions
+): SplitviewApi {
+    const component = new SplitviewComponent(element, options);
+    return new SplitviewApi(component);
+}
+
+export function createGridview(
+    element: HTMLElement,
+    options: GridviewComponentOptions
+): GridviewApi {
+    const component = new GridviewComponent(element, options);
+    return new GridviewApi(component);
+}
+
+export function createPaneview(
+    element: HTMLElement,
+    options: PaneviewComponentOptions
+): PaneviewApi {
+    const component = new PaneviewComponent(element, options);
+    return new PaneviewApi(component);
+}

packages/dockview-core/src/api/gridviewPanelApi.ts

@@ -0,0 +1,68 @@
+import { Emitter, Event } from '../events';
+import { IPanel } from '../panel/types';
+import { FunctionOrValue } from '../types';
+import { PanelApiImpl, PanelApi } from './panelApi';
+
+export interface GridConstraintChangeEvent {
+    readonly minimumWidth?: number;
+    readonly minimumHeight?: number;
+    readonly maximumWidth?: number;
+    readonly maximumHeight?: number;
+}
+
+interface GridConstraintChangeEvent2 {
+    readonly minimumWidth?: FunctionOrValue<number>;
+    readonly minimumHeight?: FunctionOrValue<number>;
+    readonly maximumWidth?: FunctionOrValue<number>;
+    readonly maximumHeight?: FunctionOrValue<number>;
+}
+
+export interface SizeEvent {
+    readonly width?: number;
+    readonly height?: number;
+}
+
+export interface GridviewPanelApi extends PanelApi {
+    readonly onDidConstraintsChange: Event<GridConstraintChangeEvent>;
+    setConstraints(value: GridConstraintChangeEvent2): void;
+    setSize(event: SizeEvent): void;
+}
+
+export class GridviewPanelApiImpl
+    extends PanelApiImpl
+    implements GridviewPanelApi
+{
+    private readonly _onDidConstraintsChangeInternal =
+        new Emitter<GridConstraintChangeEvent2>();
+    readonly onDidConstraintsChangeInternal: Event<GridConstraintChangeEvent2> =
+        this._onDidConstraintsChangeInternal.event;
+
+    readonly _onDidConstraintsChange = new Emitter<GridConstraintChangeEvent>();
+    readonly onDidConstraintsChange: Event<GridConstraintChangeEvent> =
+        this._onDidConstraintsChange.event;
+
+    private readonly _onDidSizeChange = new Emitter<SizeEvent>();
+    readonly onDidSizeChange: Event<SizeEvent> = this._onDidSizeChange.event;
+
+    constructor(id: string, component: string, panel?: IPanel) {
+        super(id, component);
+
+        this.addDisposables(
+            this._onDidConstraintsChangeInternal,
+            this._onDidConstraintsChange,
+            this._onDidSizeChange
+        );
+
+        if (panel) {
+            this.initialize(panel);
+        }
+    }
+
+    public setConstraints(value: GridConstraintChangeEvent): void {
+        this._onDidConstraintsChangeInternal.fire(value);
+    }
+
+    public setSize(event: SizeEvent): void {
+        this._onDidSizeChange.fire(event);
+    }
+}

packages/dockview-core/src/api/panelApi.ts

@@ -0,0 +1,188 @@
+import { DockviewEvent, Emitter, Event } from '../events';
+import { CompositeDisposable, MutableDisposable } from '../lifecycle';
+import { IPanel, Parameters } from '../panel/types';
+
+export interface FocusEvent {
+    readonly isFocused: boolean;
+}
+export interface PanelDimensionChangeEvent {
+    readonly width: number;
+    readonly height: number;
+}
+
+export interface VisibilityEvent {
+    readonly isVisible: boolean;
+}
+
+export interface ActiveEvent {
+    readonly isActive: boolean;
+}
+
+export interface PanelApi {
+    // events
+    readonly onDidDimensionsChange: Event<PanelDimensionChangeEvent>;
+    readonly onDidFocusChange: Event<FocusEvent>;
+    readonly onDidVisibilityChange: Event<VisibilityEvent>;
+    readonly onDidActiveChange: Event<ActiveEvent>;
+    readonly onDidParametersChange: Event<Parameters>;
+    setActive(): void;
+    setVisible(isVisible: boolean): void;
+    updateParameters(parameters: Parameters): void;
+    /**
+     * The id of the component renderer
+     */
+    readonly component: string;
+    /**
+     * The id of the panel that would have been assigned when the panel was created
+     */
+    readonly id: string;
+    /**
+     * Whether the panel holds the current focus
+     */
+    readonly isFocused: boolean;
+    /**
+     * Whether the panel is the actively selected panel
+     */
+    readonly isActive: boolean;
+    /**
+     * Whether the panel is visible
+     */
+    readonly isVisible: boolean;
+    /**
+     * The panel width in pixels
+     */
+    readonly width: number;
+    /**
+     * The panel height in pixels
+     */
+    readonly height: number;
+
+    readonly onWillFocus: Event<WillFocusEvent>;
+
+    getParameters<T extends Parameters = Parameters>(): T;
+}
+
+export class WillFocusEvent extends DockviewEvent {
+    constructor() {
+        super();
+    }
+}
+
+/**
+ * A core api implementation that should be used across all panel-like objects
+ */
+export class PanelApiImpl extends CompositeDisposable implements PanelApi {
+    private _isFocused = false;
+    private _isActive = false;
+    private _isVisible = true;
+    private _width = 0;
+    private _height = 0;
+    private _parameters: Parameters = {};
+
+    private readonly panelUpdatesDisposable = new MutableDisposable();
+
+    readonly _onDidDimensionChange = new Emitter<PanelDimensionChangeEvent>();
+    readonly onDidDimensionsChange = this._onDidDimensionChange.event;
+
+    readonly _onDidChangeFocus = new Emitter<FocusEvent>();
+    readonly onDidFocusChange: Event<FocusEvent> = this._onDidChangeFocus.event;
+    //
+    readonly _onWillFocus = new Emitter<WillFocusEvent>();
+    readonly onWillFocus: Event<WillFocusEvent> = this._onWillFocus.event;
+    //
+    readonly _onDidVisibilityChange = new Emitter<VisibilityEvent>();
+    readonly onDidVisibilityChange: Event<VisibilityEvent> =
+        this._onDidVisibilityChange.event;
+
+    readonly _onWillVisibilityChange = new Emitter<VisibilityEvent>();
+    readonly onWillVisibilityChange: Event<VisibilityEvent> =
+        this._onWillVisibilityChange.event;
+
+    readonly _onDidActiveChange = new Emitter<ActiveEvent>();
+    readonly onDidActiveChange: Event<ActiveEvent> =
+        this._onDidActiveChange.event;
+
+    readonly _onActiveChange = new Emitter<void>();
+    readonly onActiveChange: Event<void> = this._onActiveChange.event;
+
+    readonly _onDidParametersChange = new Emitter<Parameters>();
+    readonly onDidParametersChange: Event<Parameters> =
+        this._onDidParametersChange.event;
+
+    get isFocused(): boolean {
+        return this._isFocused;
+    }
+
+    get isActive(): boolean {
+        return this._isActive;
+    }
+
+    get isVisible(): boolean {
+        return this._isVisible;
+    }
+
+    get width(): number {
+        return this._width;
+    }
+
+    get height(): number {
+        return this._height;
+    }
+
+    constructor(readonly id: string, readonly component: string) {
+        super();
+
+        this.addDisposables(
+            this.onDidFocusChange((event) => {
+                this._isFocused = event.isFocused;
+            }),
+            this.onDidActiveChange((event) => {
+                this._isActive = event.isActive;
+            }),
+            this.onDidVisibilityChange((event) => {
+                this._isVisible = event.isVisible;
+            }),
+            this.onDidDimensionsChange((event) => {
+                this._width = event.width;
+                this._height = event.height;
+            }),
+            this.panelUpdatesDisposable,
+            this._onDidDimensionChange,
+            this._onDidChangeFocus,
+            this._onDidVisibilityChange,
+            this._onDidActiveChange,
+            this._onWillFocus,
+            this._onActiveChange,
+            this._onWillFocus,
+            this._onWillVisibilityChange,
+            this._onDidParametersChange
+        );
+    }
+
+    getParameters<T extends Parameters = Parameters>(): T {
+        return this._parameters as T;
+    }
+
+    public initialize(panel: IPanel): void {
+        this.panelUpdatesDisposable.value = this._onDidParametersChange.event(
+            (parameters) => {
+                this._parameters = parameters;
+                panel.update({
+                    params: parameters,
+                });
+            }
+        );
+    }
+
+    setVisible(isVisible: boolean): void {
+        this._onWillVisibilityChange.fire({ isVisible });
+    }
+
+    setActive(): void {
+        this._onActiveChange.fire();
+    }
+
+    updateParameters(parameters: Parameters): void {
+        this._onDidParametersChange.fire(parameters);
+    }
+}

packages/dockview-core/src/api/paneviewPanelApi.ts

@@ -0,0 +1,55 @@
+import { Emitter, Event } from '../events';
+import { PaneviewPanel } from '../paneview/paneviewPanel';
+import { SplitviewPanelApi, SplitviewPanelApiImpl } from './splitviewPanelApi';
+
+export interface ExpansionEvent {
+    readonly isExpanded: boolean;
+}
+
+export interface PaneviewPanelApi extends SplitviewPanelApi {
+    readonly isExpanded: boolean;
+    readonly onDidExpansionChange: Event<ExpansionEvent>;
+    readonly onMouseEnter: Event<MouseEvent>;
+    readonly onMouseLeave: Event<MouseEvent>;
+    setExpanded(isExpanded: boolean): void;
+}
+
+export class PaneviewPanelApiImpl
+    extends SplitviewPanelApiImpl
+    implements PaneviewPanelApi
+{
+    readonly _onDidExpansionChange = new Emitter<ExpansionEvent>({
+        replay: true,
+    });
+    readonly onDidExpansionChange: Event<ExpansionEvent> =
+        this._onDidExpansionChange.event;
+
+    readonly _onMouseEnter = new Emitter<MouseEvent>({});
+    readonly onMouseEnter: Event<MouseEvent> = this._onMouseEnter.event;
+    readonly _onMouseLeave = new Emitter<MouseEvent>({});
+    readonly onMouseLeave: Event<MouseEvent> = this._onMouseLeave.event;
+
+    private _pane: PaneviewPanel | undefined;
+
+    set pane(pane: PaneviewPanel) {
+        this._pane = pane;
+    }
+
+    constructor(id: string, component: string) {
+        super(id, component);
+
+        this.addDisposables(
+            this._onDidExpansionChange,
+            this._onMouseEnter,
+            this._onMouseLeave
+        );
+    }
+
+    setExpanded(isExpanded: boolean): void {
+        this._pane?.setExpanded(isExpanded);
+    }
+
+    get isExpanded(): boolean {
+        return !!this._pane?.isExpanded();
+    }
+}

packages/dockview-core/src/api/splitviewPanelApi.ts

@@ -0,0 +1,65 @@
+import { Emitter, Event } from '../events';
+import { IDisposable } from '../lifecycle';
+import { FunctionOrValue } from '../types';
+import { PanelApiImpl, PanelApi } from './panelApi';
+
+interface PanelConstraintChangeEvent2 {
+    readonly minimumSize?: FunctionOrValue<number>;
+    readonly maximumSize?: FunctionOrValue<number>;
+}
+
+export interface PanelConstraintChangeEvent {
+    readonly minimumSize?: number;
+    readonly maximumSize?: number;
+}
+
+export interface PanelSizeEvent {
+    readonly size: number;
+}
+
+export interface SplitviewPanelApi extends PanelApi {
+    readonly onDidConstraintsChange: Event<PanelConstraintChangeEvent>;
+    setConstraints(value: PanelConstraintChangeEvent2): void;
+    setSize(event: PanelSizeEvent): void;
+}
+
+export class SplitviewPanelApiImpl
+    extends PanelApiImpl
+    implements SplitviewPanelApi, IDisposable
+{
+    readonly _onDidConstraintsChangeInternal =
+        new Emitter<PanelConstraintChangeEvent2>();
+    readonly onDidConstraintsChangeInternal: Event<PanelConstraintChangeEvent2> =
+        this._onDidConstraintsChangeInternal.event;
+    //
+
+    readonly _onDidConstraintsChange = new Emitter<PanelConstraintChangeEvent>({
+        replay: true,
+    });
+    readonly onDidConstraintsChange: Event<PanelConstraintChangeEvent> =
+        this._onDidConstraintsChange.event;
+    //
+
+    readonly _onDidSizeChange = new Emitter<PanelSizeEvent>();
+    readonly onDidSizeChange: Event<PanelSizeEvent> =
+        this._onDidSizeChange.event;
+    //
+
+    constructor(id: string, component: string) {
+        super(id, component);
+
+        this.addDisposables(
+            this._onDidConstraintsChangeInternal,
+            this._onDidConstraintsChange,
+            this._onDidSizeChange
+        );
+    }
+
+    setConstraints(value: PanelConstraintChangeEvent2) {
+        this._onDidConstraintsChangeInternal.fire(value);
+    }
+
+    setSize(event: PanelSizeEvent) {
+        this._onDidSizeChange.fire(event);
+    }
+}

packages/dockview-core/src/array.ts

@@ -47,27 +47,6 @@ export function pushToEnd<T>(arr: T[], value: T): void {
     }
 }
 
-export const range = (from: number, to?: number): number[] => {
-    const result: number[] = [];
-
-    if (typeof to !== 'number') {
-        to = from;
-        from = 0;
-    }
-
-    if (from <= to) {
-        for (let i = from; i < to; i++) {
-            result.push(i);
-        }
-    } else {
-        for (let i = from; i > to; i--) {
-            result.push(i);
-        }
-    }
-
-    return result;
-};
-
 export function firstIndex<T>(
     array: T[] | ReadonlyArray<T>,
     fn: (item: T) => boolean
@@ -82,3 +61,13 @@ export function firstIndex<T>(
 
     return -1;
 }
+
+export function remove<T>(array: T[], value: T): boolean {
+    const index = array.findIndex((t) => t === value);
+
+    if (index > -1) {
+        array.splice(index, 1);
+        return true;
+    }
+    return false;
+}

packages/dockview-core/src/constants.ts

@@ -0,0 +1,3 @@
+export const DEFAULT_FLOATING_GROUP_OVERFLOW_SIZE = 100;
+
+export const DEFAULT_FLOATING_GROUP_POSITION = { left: 100, top: 100, width: 300, height: 300 };

packages/dockview-core/src/dnd/abstractDragHandler.ts

@@ -0,0 +1,84 @@
+import { disableIframePointEvents } from '../dom';
+import { addDisposableListener, Emitter } from '../events';
+import {
+    CompositeDisposable,
+    IDisposable,
+    MutableDisposable,
+} from '../lifecycle';
+
+export abstract class DragHandler extends CompositeDisposable {
+    private readonly dataDisposable = new MutableDisposable();
+    private readonly pointerEventsDisposable = new MutableDisposable();
+
+    private readonly _onDragStart = new Emitter<DragEvent>();
+    readonly onDragStart = this._onDragStart.event;
+
+    constructor(protected readonly el: HTMLElement) {
+        super();
+
+        this.addDisposables(
+            this._onDragStart,
+            this.dataDisposable,
+            this.pointerEventsDisposable
+        );
+
+        this.configure();
+    }
+
+    abstract getData(event: DragEvent): IDisposable;
+
+    protected isCancelled(_event: DragEvent): boolean {
+        return false;
+    }
+
+    private configure(): void {
+        this.addDisposables(
+            this._onDragStart,
+            addDisposableListener(this.el, 'dragstart', (event) => {
+                if (event.defaultPrevented || this.isCancelled(event)) {
+                    event.preventDefault();
+                    return;
+                }
+
+                const iframes = disableIframePointEvents();
+
+                this.pointerEventsDisposable.value = {
+                    dispose: () => {
+                        iframes.release();
+                    },
+                };
+
+                this.el.classList.add('dv-dragged');
+                setTimeout(() => this.el.classList.remove('dv-dragged'), 0);
+
+                this.dataDisposable.value = this.getData(event);
+                this._onDragStart.fire(event);
+
+                if (event.dataTransfer) {
+                    event.dataTransfer.effectAllowed = 'move';
+
+                    const hasData = event.dataTransfer.items.length > 0;
+
+                    if (!hasData) {
+                        /**
+                         * Although this is not used by dockview many third party dnd libraries will check
+                         * dataTransfer.types to determine valid drag events.
+                         *
+                         * For example: in react-dnd if dataTransfer.types is not set then the dragStart event will be cancelled
+                         * through .preventDefault(). Since this is applied globally to all drag events this would break dockviews
+                         * dnd logic. You can see the code at
+                     P    * https://github.com/react-dnd/react-dnd/blob/main/packages/backend-html5/src/HTML5BackendImpl.ts#L542
+                         */
+                        event.dataTransfer.setData('text/plain', '');
+                    }
+                }
+            }),
+            addDisposableListener(this.el, 'dragend', () => {
+                this.pointerEventsDisposable.dispose();
+                setTimeout(() => {
+                    this.dataDisposable.dispose(); // allow the data to be read by other handlers before disposing
+                }, 0);
+            })
+        );
+    }
+}

packages/dockview-core/src/dnd/dataTransfer.ts

@@ -0,0 +1,88 @@
+class TransferObject {
+    // intentionally empty class
+}
+
+export class PanelTransfer extends TransferObject {
+    constructor(
+        public readonly viewId: string,
+        public readonly groupId: string,
+        public readonly panelId: string | null
+    ) {
+        super();
+    }
+}
+
+export class PaneTransfer extends TransferObject {
+    constructor(
+        public readonly viewId: string,
+        public readonly paneId: string
+    ) {
+        super();
+    }
+}
+
+/**
+ * A singleton to store transfer data during drag & drop operations that are only valid within the application.
+ */
+export class LocalSelectionTransfer<T> {
+    private static readonly INSTANCE = new LocalSelectionTransfer();
+
+    private data?: T[];
+    private proto?: T;
+
+    private constructor() {
+        // protect against external instantiation
+    }
+
+    static getInstance<T>(): LocalSelectionTransfer<T> {
+        return LocalSelectionTransfer.INSTANCE as LocalSelectionTransfer<T>;
+    }
+
+    hasData(proto: T): boolean {
+        return proto && proto === this.proto;
+    }
+
+    clearData(proto: T): void {
+        if (this.hasData(proto)) {
+            this.proto = undefined;
+            this.data = undefined;
+        }
+    }
+
+    getData(proto: T): T[] | undefined {
+        if (this.hasData(proto)) {
+            return this.data;
+        }
+
+        return undefined;
+    }
+
+    setData(data: T[], proto: T): void {
+        if (proto) {
+            this.data = data;
+            this.proto = proto;
+        }
+    }
+}
+
+export function getPanelData(): PanelTransfer | undefined {
+    const panelTransfer = LocalSelectionTransfer.getInstance<PanelTransfer>();
+    const isPanelEvent = panelTransfer.hasData(PanelTransfer.prototype);
+
+    if (!isPanelEvent) {
+        return undefined;
+    }
+
+    return panelTransfer.getData(PanelTransfer.prototype)![0];
+}
+
+export function getPaneData(): PaneTransfer | undefined {
+    const paneTransfer = LocalSelectionTransfer.getInstance<PaneTransfer>();
+    const isPanelEvent = paneTransfer.hasData(PaneTransfer.prototype);
+
+    if (!isPanelEvent) {
+        return undefined;
+    }
+
+    return paneTransfer.getData(PaneTransfer.prototype)![0];
+}

packages/dockview-core/src/dnd/dnd.ts

@@ -0,0 +1,109 @@
+import { addDisposableListener } from '../events';
+import { CompositeDisposable } from '../lifecycle';
+
+export interface IDragAndDropObserverCallbacks {
+    onDragEnter: (e: DragEvent) => void;
+    onDragLeave: (e: DragEvent) => void;
+    onDrop: (e: DragEvent) => void;
+    onDragEnd: (e: DragEvent) => void;
+    onDragOver?: (e: DragEvent) => void;
+}
+
+export class DragAndDropObserver extends CompositeDisposable {
+    private target: EventTarget | null = null;
+
+    constructor(
+        private readonly element: HTMLElement,
+        private readonly callbacks: IDragAndDropObserverCallbacks
+    ) {
+        super();
+
+        this.registerListeners();
+    }
+
+    onDragEnter(e: DragEvent): void {
+        this.target = e.target;
+        this.callbacks.onDragEnter(e);
+    }
+
+    onDragOver(e: DragEvent): void {
+        e.preventDefault(); // needed so that the drop event fires (https://stackoverflow.com/questions/21339924/drop-event-not-firing-in-chrome)
+
+        if (this.callbacks.onDragOver) {
+            this.callbacks.onDragOver(e);
+        }
+    }
+
+    onDragLeave(e: DragEvent): void {
+        if (this.target === e.target) {
+            this.target = null;
+
+            this.callbacks.onDragLeave(e);
+        }
+    }
+
+    onDragEnd(e: DragEvent): void {
+        this.target = null;
+        this.callbacks.onDragEnd(e);
+    }
+
+    onDrop(e: DragEvent): void {
+        this.callbacks.onDrop(e);
+    }
+
+    private registerListeners(): void {
+        this.addDisposables(
+            addDisposableListener(
+                this.element,
+                'dragenter',
+                (e: DragEvent) => {
+                    this.onDragEnter(e);
+                },
+                true
+            )
+        );
+
+        this.addDisposables(
+            addDisposableListener(
+                this.element,
+                'dragover',
+                (e: DragEvent) => {
+                    this.onDragOver(e);
+                },
+                true
+            )
+        );
+
+        this.addDisposables(
+            addDisposableListener(this.element, 'dragleave', (e: DragEvent) => {
+                this.onDragLeave(e);
+            })
+        );
+
+        this.addDisposables(
+            addDisposableListener(this.element, 'dragend', (e: DragEvent) => {
+                this.onDragEnd(e);
+            })
+        );
+
+        this.addDisposables(
+            addDisposableListener(this.element, 'drop', (e: DragEvent) => {
+                this.onDrop(e);
+            })
+        );
+    }
+}
+
+export interface IDraggedCompositeData {
+    eventData: DragEvent;
+    dragAndDropData: any;
+}
+
+export interface ICompositeDragAndDropObserverCallbacks {
+    onDragEnter?: (e: IDraggedCompositeData) => void;
+    onDragLeave?: (e: IDraggedCompositeData) => void;
+    onDrop?: (e: IDraggedCompositeData) => void;
+    onDragOver?: (e: IDraggedCompositeData) => void;
+    onDragStart?: (e: IDraggedCompositeData) => void;
+    onDragEnd?: (e: IDraggedCompositeData) => void;
+}

packages/dockview-core/src/dnd/dropTargetAnchorContainer.scss

@@ -0,0 +1,23 @@
+.dv-drop-target-container {
+    position: absolute;
+    z-index: 9999;
+    top: 0px;
+    left: 0px;
+    height: 100%;
+    width: 100%;
+    pointer-events: none;
+    overflow: hidden;
+    --dv-transition-duration: 300ms;
+
+    .dv-drop-target-anchor {
+        position: relative;
+        border: var(--dv-drag-over-border);
+        transition: opacity var(--dv-transition-duration) ease-in,
+            top var(--dv-transition-duration) ease-out,
+            left var(--dv-transition-duration) ease-out,
+            width var(--dv-transition-duration) ease-out,
+            height var(--dv-transition-duration) ease-out;
+        background-color: var(--dv-drag-over-background-color);
+        opacity: 1;
+    }
+}

packages/dockview-core/src/dnd/dropTargetAnchorContainer.ts

@@ -0,0 +1,102 @@
+import { CompositeDisposable, Disposable } from '../lifecycle';
+import { DropTargetTargetModel } from './droptarget';
+
+export class DropTargetAnchorContainer extends CompositeDisposable {
+    private _model:
+        | { root: HTMLElement; overlay: HTMLElement; changed: boolean }
+        | undefined;
+
+    private _outline: HTMLElement | undefined;
+
+    private _disabled = false;
+
+    get disabled(): boolean {
+        return this._disabled;
+    }
+
+    set disabled(value: boolean) {
+        if (this.disabled === value) {
+            return;
+        }
+
+        this._disabled = value;
+
+        if (value) {
+            this.model?.clear();
+        }
+    }
+
+    get model(): DropTargetTargetModel | undefined {
+        if (this.disabled) {
+            return undefined;
+        }
+
+        return {
+            clear: () => {
+                if (this._model) {
+                    this._model.root.parentElement?.removeChild(
+                        this._model.root
+                    );
+                }
+                this._model = undefined;
+            },
+            exists: () => {
+                return !!this._model;
+            },
+            getElements: (event?: DragEvent, outline?: HTMLElement) => {
+                const changed = this._outline !== outline;
+                this._outline = outline;
+
+                if (this._model) {
+                    this._model.changed = changed;
+                    return this._model;
+                }
+
+                const container = this.createContainer();
+                const anchor = this.createAnchor();
+
+                this._model = { root: container, overlay: anchor, changed };
+
+                container.appendChild(anchor);
+                this.element.appendChild(container);
+
+                if (event?.target instanceof HTMLElement) {
+                    const targetBox = event.target.getBoundingClientRect();
+                    const box = this.element.getBoundingClientRect();
+
+                    anchor.style.left = `${targetBox.left - box.left}px`;
+                    anchor.style.top = `${targetBox.top - box.top}px`;
+                }
+
+                return this._model;
+            },
+        };
+    }
+
+    constructor(readonly element: HTMLElement, options: { disabled: boolean }) {
+        super();
+
+        this._disabled = options.disabled;
+
+        this.addDisposables(
+            Disposable.from(() => {
+                this.model?.clear();
+            })
+        );
+    }
+
+    private createContainer(): HTMLElement {
+        const el = document.createElement('div');
+        el.className = 'dv-drop-target-container';
+
+        return el;
+    }
+
+    private createAnchor(): HTMLElement {
+        const el = document.createElement('div');
+        el.className = 'dv-drop-target-anchor';
+        el.style.visibility = 'hidden';
+
+        return el;
+    }
+}

packages/dockview-core/src/dnd/droptarget.scss

@@ -0,0 +1,54 @@
+.dv-drop-target {
+    position: relative;
+    --dv-transition-duration: 70ms;
+
+    > .dv-drop-target-dropzone {
+        position: absolute;
+        left: 0px;
+        top: 0px;
+        height: 100%;
+        width: 100%;
+        z-index: 1000;
+        pointer-events: none;
+
+        > .dv-drop-target-selection {
+            position: relative;
+            box-sizing: border-box;
+            height: 100%;
+            width: 100%;
+            border: var(--dv-drag-over-border);
+            background-color: var(--dv-drag-over-background-color);
+            transition: top var(--dv-transition-duration) ease-out,
+                left var(--dv-transition-duration) ease-out,
+                width var(--dv-transition-duration) ease-out,
+                height var(--dv-transition-duration) ease-out,
+                opacity var(--dv-transition-duration) ease-out;
+            will-change: transform;
+            pointer-events: none;
+
+            &.dv-drop-target-top {
+                &.dv-drop-target-small-vertical {
+                    border-top: 1px solid var(--dv-drag-over-border-color);
+                }
+            }
+
+            &.dv-drop-target-bottom {
+                &.dv-drop-target-small-vertical {
+                    border-bottom: 1px solid var(--dv-drag-over-border-color);
+                }
+            }
+
+            &.dv-drop-target-left {
+                &.dv-drop-target-small-horizontal {
+                    border-left: 1px solid var(--dv-drag-over-border-color);
+                }
+            }
+
+            &.dv-drop-target-right {
+                &.dv-drop-target-small-horizontal {
+                    border-right: 1px solid var(--dv-drag-over-border-color);
+                }
+            }
+        }
+    }
+}

packages/dockview-core/src/dnd/droptarget.ts

@@ -0,0 +1,644 @@
+import { toggleClass } from '../dom';
+import { DockviewEvent, Emitter, Event } from '../events';
+import { CompositeDisposable } from '../lifecycle';
+import { DragAndDropObserver } from './dnd';
+import { clamp } from '../math';
+import { Direction } from '../gridview/baseComponentGridview';
+
+export interface DroptargetEvent {
+    readonly position: Position;
+    readonly nativeEvent: DragEvent;
+}
+
+export class WillShowOverlayEvent
+    extends DockviewEvent
+    implements DroptargetEvent
+{
+    get nativeEvent(): DragEvent {
+        return this.options.nativeEvent;
+    }
+
+    get position(): Position {
+        return this.options.position;
+    }
+
+    constructor(
+        private readonly options: {
+            nativeEvent: DragEvent;
+            position: Position;
+        }
+    ) {
+        super();
+    }
+}
+
+export function directionToPosition(direction: Direction): Position {
+    switch (direction) {
+        case 'above':
+            return 'top';
+        case 'below':
+            return 'bottom';
+        case 'left':
+            return 'left';
+        case 'right':
+            return 'right';
+        case 'within':
+            return 'center';
+        default:
+            throw new Error(`invalid direction '${direction}'`);
+    }
+}
+
+export function positionToDirection(position: Position): Direction {
+    switch (position) {
+        case 'top':
+            return 'above';
+        case 'bottom':
+            return 'below';
+        case 'left':
+            return 'left';
+        case 'right':
+            return 'right';
+        case 'center':
+            return 'within';
+        default:
+            throw new Error(`invalid position '${position}'`);
+    }
+}
+
+export type Position = 'top' | 'bottom' | 'left' | 'right' | 'center';
+
+export type CanDisplayOverlay = (
+    dragEvent: DragEvent,
+    state: Position
+) => boolean;
+
+export type MeasuredValue = { value: number; type: 'pixels' | 'percentage' };
+
+export type DroptargetOverlayModel = {
+    size?: MeasuredValue;
+    activationSize?: MeasuredValue;
+};
+
+const DEFAULT_ACTIVATION_SIZE: MeasuredValue = {
+    value: 20,
+    type: 'percentage',
+};
+
+const DEFAULT_SIZE: MeasuredValue = {
+    value: 50,
+    type: 'percentage',
+};
+
+const SMALL_WIDTH_BOUNDARY = 100;
+const SMALL_HEIGHT_BOUNDARY = 100;
+
+export interface DropTargetTargetModel {
+    getElements(
+        event?: DragEvent,
+        outline?: HTMLElement
+    ): {
+        root: HTMLElement;
+        overlay: HTMLElement;
+        changed: boolean;
+    };
+    exists(): boolean;
+    clear(): void;
+}
+
+export interface DroptargetOptions {
+    canDisplayOverlay: CanDisplayOverlay;
+    acceptedTargetZones: Position[];
+    overlayModel?: DroptargetOverlayModel;
+    getOverrideTarget?: () => DropTargetTargetModel | undefined;
+    className?: string;
+    getOverlayOutline?: () => HTMLElement | null;
+}
+
+export class Droptarget extends CompositeDisposable {
+    private targetElement: HTMLElement | undefined;
+    private overlayElement: HTMLElement | undefined;
+    private _state: Position | undefined;
+    private _acceptedTargetZonesSet: Set<Position>;
+
+    private readonly _onDrop = new Emitter<DroptargetEvent>();
+    readonly onDrop: Event<DroptargetEvent> = this._onDrop.event;
+
+    private readonly _onWillShowOverlay = new Emitter<WillShowOverlayEvent>();
+    readonly onWillShowOverlay: Event<WillShowOverlayEvent> =
+        this._onWillShowOverlay.event;
+
+    readonly dnd: DragAndDropObserver;
+
+    private static USED_EVENT_ID = '__dockview_droptarget_event_is_used__';
+
+    private static ACTUAL_TARGET: Droptarget | undefined;
+
+    private _disabled: boolean;
+
+    get disabled(): boolean {
+        return this._disabled;
+    }
+
+    set disabled(value: boolean) {
+        this._disabled = value;
+    }
+
+    get state(): Position | undefined {
+        return this._state;
+    }
+
+    constructor(
+        private readonly element: HTMLElement,
+        private readonly options: DroptargetOptions
+    ) {
+        super();
+
+        this._disabled = false;
+
+        // use a set to take advantage of #<set>.has
+        this._acceptedTargetZonesSet = new Set(
+            this.options.acceptedTargetZones
+        );
+
+        this.dnd = new DragAndDropObserver(this.element, {
+            onDragEnter: () => {
+                this.options.getOverrideTarget?.()?.getElements();
+            },
+            onDragOver: (e) => {
+                Droptarget.ACTUAL_TARGET = this;
+
+                const overrideTraget = this.options.getOverrideTarget?.();
+
+                if (this._acceptedTargetZonesSet.size === 0) {
+                    if (overrideTraget) {
+                        return;
+                    }
+                    this.removeDropTarget();
+                    return;
+                }
+
+                const target =
+                    this.options.getOverlayOutline?.() ?? this.element;
+
+                const width = target.offsetWidth;
+                const height = target.offsetHeight;
+
+                if (width === 0 || height === 0) {
+                    return; // avoid div!0
+                }
+
+                const rect = (
+                    e.currentTarget as HTMLElement
+                ).getBoundingClientRect();
+                const x = (e.clientX ?? 0) - rect.left;
+                const y = (e.clientY ?? 0) - rect.top;
+
+                const quadrant = this.calculateQuadrant(
+                    this._acceptedTargetZonesSet,
+                    x,
+                    y,
+                    width,
+                    height
+                );
+
+                /**
+                 * If the event has already been used by another DropTarget instance
+                 * then don't show a second drop target, only one target should be
+                 * active at any one time
+                 */
+                if (this.isAlreadyUsed(e) || quadrant === null) {
+                    // no drop target should be displayed
+                    this.removeDropTarget();
+                    return;
+                }
+
+                if (!this.options.canDisplayOverlay(e, quadrant)) {
+                    if (overrideTraget) {
+                        return;
+                    }
+                    this.removeDropTarget();
+                    return;
+                }
+
+                const willShowOverlayEvent = new WillShowOverlayEvent({
+                    nativeEvent: e,
+                    position: quadrant,
+                });
+
+                /**
+                 * Provide an opportunity to prevent the overlay appearing and in turn
+                 * any dnd behaviours
+                 */
+                this._onWillShowOverlay.fire(willShowOverlayEvent);
+
+                if (willShowOverlayEvent.defaultPrevented) {
+                    this.removeDropTarget();
+                    return;
+                }
+
+                this.markAsUsed(e);
+
+                if (overrideTraget) {
+                    //
+                } else if (!this.targetElement) {
+                    this.targetElement = document.createElement('div');
+                    this.targetElement.className = 'dv-drop-target-dropzone';
+                    this.overlayElement = document.createElement('div');
+                    this.overlayElement.className = 'dv-drop-target-selection';
+                    this._state = 'center';
+                    this.targetElement.appendChild(this.overlayElement);
+
+                    target.classList.add('dv-drop-target');
+                    target.append(this.targetElement);
+
+                    // this.overlayElement.style.opacity = '0';
+
+                    // requestAnimationFrame(() => {
+                    //     if (this.overlayElement) {
+                    //         this.overlayElement.style.opacity = '';
+                    //     }
+                    // });
+                }
+
+                this.toggleClasses(quadrant, width, height);
+
+                this._state = quadrant;
+            },
+            onDragLeave: () => {
+                const target = this.options.getOverrideTarget?.();
+
+                if (target) {
+                    return;
+                }
+
+                this.removeDropTarget();
+            },
+            onDragEnd: (e) => {
+                const target = this.options.getOverrideTarget?.();
+
+                if (target && Droptarget.ACTUAL_TARGET === this) {
+                    if (this._state) {
+                        // only stop the propagation of the event if we are dealing with it
+                        // which is only when the target has state
+                        e.stopPropagation();
+                        this._onDrop.fire({
+                            position: this._state,
+                            nativeEvent: e,
+                        });
+                    }
+                }
+
+                this.removeDropTarget();
+
+                target?.clear();
+            },
+            onDrop: (e) => {
+                e.preventDefault();
+
+                const state = this._state;
+
+                this.removeDropTarget();
+
+                this.options.getOverrideTarget?.()?.clear();
+
+                if (state) {
+                    // only stop the propagation of the event if we are dealing with it
+                    // which is only when the target has state
+                    e.stopPropagation();
+                    this._onDrop.fire({ position: state, nativeEvent: e });
+                }
+            },
+        });
+
+        this.addDisposables(this._onDrop, this._onWillShowOverlay, this.dnd);
+    }
+
+    setTargetZones(acceptedTargetZones: Position[]): void {
+        this._acceptedTargetZonesSet = new Set(acceptedTargetZones);
+    }
+
+    setOverlayModel(model: DroptargetOverlayModel): void {
+        this.options.overlayModel = model;
+    }
+
+    dispose(): void {
+        this.removeDropTarget();
+        super.dispose();
+    }
+
+    /**
+     * Add a property to the event object for other potential listeners to check
+     */
+    private markAsUsed(event: DragEvent): void {
+        (event as any)[Droptarget.USED_EVENT_ID] = true;
+    }
+
+    /**
+     * Check is the event has already been used by another instance of DropTarget
+     */
+    private isAlreadyUsed(event: DragEvent): boolean {
+        const value = (event as any)[Droptarget.USED_EVENT_ID];
+        return typeof value === 'boolean' && value;
+    }
+
+    private toggleClasses(
+        quadrant: Position,
+        width: number,
+        height: number
+    ): void {
+        const target = this.options.getOverrideTarget?.();
+
+        if (!target && !this.overlayElement) {
+            return;
+        }
+
+        const isSmallX = width < SMALL_WIDTH_BOUNDARY;
+        const isSmallY = height < SMALL_HEIGHT_BOUNDARY;
+
+        const isLeft = quadrant === 'left';
+        const isRight = quadrant === 'right';
+        const isTop = quadrant === 'top';
+        const isBottom = quadrant === 'bottom';
+
+        const rightClass = !isSmallX && isRight;
+        const leftClass = !isSmallX && isLeft;
+        const topClass = !isSmallY && isTop;
+        const bottomClass = !isSmallY && isBottom;
+
+        let size = 1;
+
+        const sizeOptions = this.options.overlayModel?.size ?? DEFAULT_SIZE;
+
+        if (sizeOptions.type === 'percentage') {
+            size = clamp(sizeOptions.value, 0, 100) / 100;
+        } else {
+            if (rightClass || leftClass) {
+                size = clamp(0, sizeOptions.value, width) / width;
+            }
+            if (topClass || bottomClass) {
+                size = clamp(0, sizeOptions.value, height) / height;
+            }
+        }
+
+        if (target) {
+            const outlineEl =
+                this.options.getOverlayOutline?.() ?? this.element;
+            const elBox = outlineEl.getBoundingClientRect();
+
+            const ta = target.getElements(undefined, outlineEl);
+            const el = ta.root;
+            const overlay = ta.overlay;
+
+            const bigbox = el.getBoundingClientRect();
+
+            const rootTop = elBox.top - bigbox.top;
+            const rootLeft = elBox.left - bigbox.left;
+
+            const box = {
+                top: rootTop,
+                left: rootLeft,
+                width: width,
+                height: height,
+            };
+
+            if (rightClass) {
+                box.left = rootLeft + width * (1 - size);
+                box.width = width * size;
+            } else if (leftClass) {
+                box.width = width * size;
+            } else if (topClass) {
+                box.height = height * size;
+            } else if (bottomClass) {
+                box.top = rootTop + height * (1 - size);
+                box.height = height * size;
+            }
+
+            if (isSmallX && isLeft) {
+                box.width = 4;
+            }
+            if (isSmallX && isRight) {
+                box.left = rootLeft + width - 4;
+                box.width = 4;
+            }
+
+            const topPx = `${Math.round(box.top)}px`;
+            const leftPx = `${Math.round(box.left)}px`;
+            const widthPx = `${Math.round(box.width)}px`;
+            const heightPx = `${Math.round(box.height)}px`;
+
+            if (
+                overlay.style.top === topPx &&
+                overlay.style.left === leftPx &&
+                overlay.style.width === widthPx &&
+                overlay.style.height === heightPx
+            ) {
+                return;
+            }
+
+            overlay.style.top = topPx;
+            overlay.style.left = leftPx;
+            overlay.style.width = widthPx;
+            overlay.style.height = heightPx;
+            overlay.style.visibility = 'visible';
+
+            overlay.className = `dv-drop-target-anchor${
+                this.options.className ? ` ${this.options.className}` : ''
+            }`;
+
+            toggleClass(overlay, 'dv-drop-target-left', isLeft);
+            toggleClass(overlay, 'dv-drop-target-right', isRight);
+            toggleClass(overlay, 'dv-drop-target-top', isTop);
+            toggleClass(overlay, 'dv-drop-target-bottom', isBottom);
+            toggleClass(
+                overlay,
+                'dv-drop-target-center',
+                quadrant === 'center'
+            );
+
+            if (ta.changed) {
+                toggleClass(
+                    overlay,
+                    'dv-drop-target-anchor-container-changed',
+                    true
+                );
+                setTimeout(() => {
+                    toggleClass(
+                        overlay,
+                        'dv-drop-target-anchor-container-changed',
+                        false
+                    );
+                }, 10);
+            }
+
+            return;
+        }
+
+        if (!this.overlayElement) {
+            return;
+        }
+
+        const box = { top: '0px', left: '0px', width: '100%', height: '100%' };
+
+        /**
+         * You can also achieve the overlay placement using the transform CSS property
+         * to translate and scale the element however this has the undesired effect of
+         * 'skewing' the element. Comment left here for anybody that ever revisits this.
+         *
+         * @see https://developer.mozilla.org/en-US/docs/Web/CSS/transform
+         *
+         * right
+         * translateX(${100 * (1 - size) / 2}%) scaleX(${scale})
+         *
+         * left
+         * translateX(-${100 * (1 - size) / 2}%) scaleX(${scale})
+         *
+         * top
+         * translateY(-${100 * (1 - size) / 2}%) scaleY(${scale})
+         *
+         * bottom
+         * translateY(${100 * (1 - size) / 2}%) scaleY(${scale})
+         */
+        if (rightClass) {
+            box.left = `${100 * (1 - size)}%`;
+            box.width = `${100 * size}%`;
+        } else if (leftClass) {
+            box.width = `${100 * size}%`;
+        } else if (topClass) {
+            box.height = `${100 * size}%`;
+        } else if (bottomClass) {
+            box.top = `${100 * (1 - size)}%`;
+            box.height = `${100 * size}%`;
+        }
+
+        this.overlayElement.style.top = box.top;
+        this.overlayElement.style.left = box.left;
+        this.overlayElement.style.width = box.width;
+        this.overlayElement.style.height = box.height;
+
+        toggleClass(
+            this.overlayElement,
+            'dv-drop-target-small-vertical',
+            isSmallY
+        );
+        toggleClass(
+            this.overlayElement,
+            'dv-drop-target-small-horizontal',
+            isSmallX
+        );
+        toggleClass(this.overlayElement, 'dv-drop-target-left', isLeft);
+        toggleClass(this.overlayElement, 'dv-drop-target-right', isRight);
+        toggleClass(this.overlayElement, 'dv-drop-target-top', isTop);
+        toggleClass(this.overlayElement, 'dv-drop-target-bottom', isBottom);
+        toggleClass(
+            this.overlayElement,
+            'dv-drop-target-center',
+            quadrant === 'center'
+        );
+    }
+
+    private calculateQuadrant(
+        overlayType: Set<Position>,
+        x: number,
+        y: number,
+        width: number,
+        height: number
+    ): Position | null {
+        const activationSizeOptions =
+            this.options.overlayModel?.activationSize ??
+            DEFAULT_ACTIVATION_SIZE;
+
+        const isPercentage = activationSizeOptions.type === 'percentage';
+
+        if (isPercentage) {
+            return calculateQuadrantAsPercentage(
+                overlayType,
+                x,
+                y,
+                width,
+                height,
+                activationSizeOptions.value
+            );
+        }
+
+        return calculateQuadrantAsPixels(
+            overlayType,
+            x,
+            y,
+            width,
+            height,
+            activationSizeOptions.value
+        );
+    }
+
+    private removeDropTarget(): void {
+        if (this.targetElement) {
+            this._state = undefined;
+            this.targetElement.parentElement?.classList.remove(
+                'dv-drop-target'
+            );
+            this.targetElement.remove();
+            this.targetElement = undefined;
+            this.overlayElement = undefined;
+        }
+    }
+}
+
+export function calculateQuadrantAsPercentage(
+    overlayType: Set<Position>,
+    x: number,
+    y: number,
+    width: number,
+    height: number,
+    threshold: number
+): Position | null {
+    const xp = (100 * x) / width;
+    const yp = (100 * y) / height;
+
+    if (overlayType.has('left') && xp < threshold) {
+        return 'left';
+    }
+    if (overlayType.has('right') && xp > 100 - threshold) {
+        return 'right';
+    }
+    if (overlayType.has('top') && yp < threshold) {
+        return 'top';
+    }
+    if (overlayType.has('bottom') && yp > 100 - threshold) {
+        return 'bottom';
+    }
+
+    if (!overlayType.has('center')) {
+        return null;
+    }
+
+    return 'center';
+}
+
+export function calculateQuadrantAsPixels(
+    overlayType: Set<Position>,
+    x: number,
+    y: number,
+    width: number,
+    height: number,
+    threshold: number
+): Position | null {
+    if (overlayType.has('left') && x < threshold) {
+        return 'left';
+    }
+    if (overlayType.has('right') && x > width - threshold) {
+        return 'right';
+    }
+    if (overlayType.has('top') && y < threshold) {
+        return 'top';
+    }
+    if (overlayType.has('bottom') && y > height - threshold) {
+        return 'bottom';
+    }
+
+    if (!overlayType.has('center')) {
+        return null;
+    }
+
+    return 'center';
+}

packages/dockview-core/src/dnd/ghost.ts

@@ -0,0 +1,21 @@
+import { addClasses, removeClasses } from '../dom';
+
+export function addGhostImage(
+    dataTransfer: DataTransfer,
+    ghostElement: HTMLElement,
+    options?: { x?: number; y?: number }
+): void {
+    // class dockview provides to force ghost image to be drawn on a different layer and prevent weird rendering issues
+    addClasses(ghostElement, 'dv-dragged');
+
+    // move the element off-screen initially otherwise it may in some cases be rendered at (0,0) momentarily
+    ghostElement.style.top = '-9999px';
+
+    document.body.appendChild(ghostElement);
+    dataTransfer.setDragImage(ghostElement, options?.x ?? 0, options?.y ?? 0);
+
+    setTimeout(() => {
+        removeClasses(ghostElement, 'dv-dragged');
+        ghostElement.remove();
+    }, 0);
+}

packages/dockview-core/src/dnd/groupDragHandler.ts

@@ -0,0 +1,88 @@
+import { DockviewComponent } from '../dockview/dockviewComponent';
+import { DockviewGroupPanel } from '../dockview/dockviewGroupPanel';
+import { quasiPreventDefault } from '../dom';
+import { addDisposableListener } from '../events';
+import { IDisposable } from '../lifecycle';
+import { DragHandler } from './abstractDragHandler';
+import { LocalSelectionTransfer, PanelTransfer } from './dataTransfer';
+import { addGhostImage } from './ghost';
+
+export class GroupDragHandler extends DragHandler {
+    private readonly panelTransfer =
+        LocalSelectionTransfer.getInstance<PanelTransfer>();
+
+    constructor(
+        element: HTMLElement,
+        private readonly accessor: DockviewComponent,
+        private readonly group: DockviewGroupPanel
+    ) {
+        super(element);
+
+        this.addDisposables(
+            addDisposableListener(
+                element,
+                'pointerdown',
+                (e) => {
+                    if (e.shiftKey) {
+                        /**
+                         * You cannot call e.preventDefault() because that will prevent drag events from firing
+                         * but we also need to stop any group overlay drag events from occuring
+                         * Use a custom event marker that can be checked by the overlay drag events
+                         */
+                        quasiPreventDefault(e);
+                    }
+                },
+                true
+            )
+        );
+    }
+
+    override isCancelled(_event: DragEvent): boolean {
+        if (this.group.api.location.type === 'floating' && !_event.shiftKey) {
+            return true;
+        }
+        return false;
+    }
+
+    getData(dragEvent: DragEvent): IDisposable {
+        const dataTransfer = dragEvent.dataTransfer;
+
+        this.panelTransfer.setData(
+            [new PanelTransfer(this.accessor.id, this.group.id, null)],
+            PanelTransfer.prototype
+        );
+
+        const style = window.getComputedStyle(this.el);
+
+        const bgColor = style.getPropertyValue(
+            '--dv-activegroup-visiblepanel-tab-background-color'
+        );
+        const color = style.getPropertyValue(
+            '--dv-activegroup-visiblepanel-tab-color'
+        );
+
+        if (dataTransfer) {
+            const ghostElement = document.createElement('div');
+
+            ghostElement.style.backgroundColor = bgColor;
+            ghostElement.style.color = color;
+            ghostElement.style.padding = '2px 8px';
+            ghostElement.style.height = '24px';
+            ghostElement.style.fontSize = '11px';
+            ghostElement.style.lineHeight = '20px';
+            ghostElement.style.borderRadius = '12px';
+            ghostElement.style.position = 'absolute';
+            ghostElement.style.pointerEvents = 'none';
+            ghostElement.style.top = '-9999px';
+            ghostElement.textContent = `Multiple Panels (${this.group.size})`;
+
+            addGhostImage(dataTransfer, ghostElement, { y: -10, x: 30 });
+        }
+
+        return {
+            dispose: () => {
+                this.panelTransfer.clearData(PanelTransfer.prototype);
+            },
+        };
+    }
+}