diff --git a/packages/dockview-core/src/__tests__/array.spec.ts b/packages/dockview-core/src/__tests__/array.spec.ts
index 46e5dcb5c..9e3f0055a 100644
--- a/packages/dockview-core/src/__tests__/array.spec.ts
+++ b/packages/dockview-core/src/__tests__/array.spec.ts
@@ -3,7 +3,6 @@ import {
     last,
     pushToEnd,
     pushToStart,
-    range,
     sequenceEquals,
     tail,
 } from '../array';
@@ -37,12 +36,6 @@ describe('array', () => {
         expect(arr1).toEqual([3, 1, 2, 4]);
     });
 
-    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]);
-    });
-
     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);
diff --git a/packages/dockview-core/src/__tests__/math.spec.ts b/packages/dockview-core/src/__tests__/math.spec.ts
index 6b1e26d4b..47c47587d 100644
--- a/packages/dockview-core/src/__tests__/math.spec.ts
+++ b/packages/dockview-core/src/__tests__/math.spec.ts
@@ -1,4 +1,4 @@
-import { clamp } from '../math';
+import { clamp, range } from '../math';
 
 describe('math', () => {
     describe('clamp', () => {
@@ -14,4 +14,10 @@ describe('math', () => {
             );
         });
     });
+
+    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]);
+    });
 });
diff --git a/packages/dockview-core/src/array.ts b/packages/dockview-core/src/array.ts
index b2e0a7e34..227744927 100644
--- a/packages/dockview-core/src/array.ts
+++ b/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
diff --git a/packages/dockview-core/src/dnd/droptarget.ts b/packages/dockview-core/src/dnd/droptarget.ts
index 8e2c62ad7..8a1901484 100644
--- a/packages/dockview-core/src/dnd/droptarget.ts
+++ b/packages/dockview-core/src/dnd/droptarget.ts
@@ -4,7 +4,6 @@ import { CompositeDisposable } from '../lifecycle';
 import { DragAndDropObserver } from './dnd';
 import { clamp } from '../math';
 import { Direction } from '../gridview/baseComponentGridview';
-import { isBooleanValue } from '../types';
 
 function numberOrFallback(maybeNumber: any, fallback: number): number {
     return typeof maybeNumber === 'number' ? maybeNumber : fallback;
@@ -120,7 +119,7 @@ export class Droptarget extends CompositeDisposable {
                         return;
                     }
 
-                    if (isBooleanValue(this.options.canDisplayOverlay)) {
+                    if (typeof this.options.canDisplayOverlay === 'boolean') {
                         if (!this.options.canDisplayOverlay) {
                             return;
                         }
diff --git a/packages/dockview-core/src/dockview/components/panel/content.ts b/packages/dockview-core/src/dockview/components/panel/content.ts
index 0b294abe2..75859e4d2 100644
--- a/packages/dockview-core/src/dockview/components/panel/content.ts
+++ b/packages/dockview-core/src/dockview/components/panel/content.ts
@@ -32,7 +32,7 @@ export class ContentContainer
     private readonly _onDidBlur = new Emitter<void>();
     readonly onDidBlur: Event<void> = this._onDidBlur.event;
 
-    get element() {
+    get element(): HTMLElement {
         return this._element;
     }
 
@@ -51,15 +51,15 @@ export class ContentContainer
         // 4) register mouseMove events (if no buttons are present we take this as a dragEnd event)
     }
 
-    show() {
+    show(): void {
         this.element.style.display = '';
     }
 
-    hide() {
+    hide(): void {
         this.element.style.display = 'none';
     }
 
-    public openPanel(panel: IDockviewPanel) {
+    public openPanel(panel: IDockviewPanel): void {
         if (this.panel === panel) {
             return;
         }
@@ -105,14 +105,14 @@ export class ContentContainer
         // noop
     }
 
-    public closePanel() {
+    public closePanel(): void {
         if (this.panel?.view?.content?.element) {
             this._element.removeChild(this.panel.view.content.element);
             this.panel = undefined;
         }
     }
 
-    public dispose() {
+    public dispose(): void {
         this.disposable.dispose();
         super.dispose();
     }
diff --git a/packages/dockview-core/src/dockview/components/titlebar/tabsContainer.ts b/packages/dockview-core/src/dockview/components/titlebar/tabsContainer.ts
index bb73409ad..2472945a4 100644
--- a/packages/dockview-core/src/dockview/components/titlebar/tabsContainer.ts
+++ b/packages/dockview-core/src/dockview/components/titlebar/tabsContainer.ts
@@ -12,7 +12,7 @@ import { toggleClass } from '../../../dom';
 import { IDockviewPanel } from '../../dockviewPanel';
 
 export interface TabDropIndexEvent {
-    event: DragEvent;
+    readonly event: DragEvent;
     readonly index: number;
 }
 
@@ -23,7 +23,6 @@ export interface ITabsContainer extends IDisposable {
     height: number | undefined;
     delete: (id: string) => void;
     indexOf: (id: string) => number;
-    at: (index: number) => ITab;
     onDrop: Event<TabDropIndexEvent>;
     setActive: (isGroupActive: boolean) => void;
     setActivePanel: (panel: IDockviewPanel) => void;
@@ -55,11 +54,11 @@ export class TabsContainer
     private readonly _onDrop = new Emitter<TabDropIndexEvent>();
     readonly onDrop: Event<TabDropIndexEvent> = this._onDrop.event;
 
-    get panels() {
+    get panels(): string[] {
         return this.tabs.map((_) => _.value.panelId);
     }
 
-    get size() {
+    get size(): number {
         return this.tabs.length;
     }
 
@@ -114,21 +113,17 @@ export class TabsContainer
         }
     }
 
-    public get element() {
+    get element(): HTMLElement {
         return this._element;
     }
 
-    public isActive(tab: ITab) {
+    public isActive(tab: ITab): boolean {
         return (
             this.selectedIndex > -1 &&
             this.tabs[this.selectedIndex].value === tab
         );
     }
 
-    public at(index: number) {
-        return this.tabs[index]?.value;
-    }
-
     public indexOf(id: string): number {
         return this.tabs.findIndex((tab) => tab.value.panelId === id);
     }
@@ -214,7 +209,7 @@ export class TabsContainer
     private addTab(
         tab: IValueDisposable<ITab>,
         index: number = this.tabs.length
-    ) {
+    ): void {
         if (index < 0 || index > this.tabs.length) {
             throw new Error('invalid location');
         }
@@ -235,7 +230,7 @@ export class TabsContainer
         }
     }
 
-    public delete(id: string) {
+    public delete(id: string): void {
         const index = this.tabs.findIndex((tab) => tab.value.panelId === id);
 
         const tabToRemove = this.tabs.splice(index, 1)[0];
@@ -246,14 +241,17 @@ export class TabsContainer
         value.element.remove();
     }
 
-    public setActivePanel(panel: IDockviewPanel) {
+    public setActivePanel(panel: IDockviewPanel): void {
         this.tabs.forEach((tab) => {
             const isActivePanel = panel.id === tab.value.panelId;
             tab.value.setActive(isActivePanel);
         });
     }
 
-    public openPanel(panel: IDockviewPanel, index: number = this.tabs.length) {
+    public openPanel(
+        panel: IDockviewPanel,
+        index: number = this.tabs.length
+    ): void {
         if (this.tabs.find((tab) => tab.value.panelId === panel.id)) {
             return;
         }
@@ -292,11 +290,11 @@ export class TabsContainer
         this.addTab(value, index);
     }
 
-    public closePanel(panel: IDockviewPanel) {
+    public closePanel(panel: IDockviewPanel): void {
         this.delete(panel.id);
     }
 
-    public dispose() {
+    public dispose(): void {
         super.dispose();
 
         this.tabs.forEach((tab) => {
diff --git a/packages/dockview-core/src/dockview/components/titlebar/voidContainer.ts b/packages/dockview-core/src/dockview/components/titlebar/voidContainer.ts
index 992dcf2f4..1737c87aa 100644
--- a/packages/dockview-core/src/dockview/components/titlebar/voidContainer.ts
+++ b/packages/dockview-core/src/dockview/components/titlebar/voidContainer.ts
@@ -15,7 +15,7 @@ export class VoidContainer extends CompositeDisposable {
     private readonly _onDrop = new Emitter<DroptargetEvent>();
     readonly onDrop: Event<DroptargetEvent> = this._onDrop.event;
 
-    get element() {
+    get element(): HTMLElement {
         return this._element;
     }
 
diff --git a/packages/dockview-core/src/dockview/components/watermark/watermark.ts b/packages/dockview-core/src/dockview/components/watermark/watermark.ts
index 48664bec7..adeed029a 100644
--- a/packages/dockview-core/src/dockview/components/watermark/watermark.ts
+++ b/packages/dockview-core/src/dockview/components/watermark/watermark.ts
@@ -18,7 +18,7 @@ export class Watermark
     private group: DockviewGroupPanel | undefined;
     private params: GroupPanelPartInitParameters | undefined;
 
-    get element() {
+    get element(): HTMLElement {
         return this._element;
     }
 
@@ -61,19 +61,19 @@ export class Watermark
         );
     }
 
-    update(_event: PanelUpdateEvent) {
+    update(_event: PanelUpdateEvent): void {
         // noop
     }
 
-    focus() {
+    focus(): void {
         // noop
     }
 
-    layout(_width: number, _height: number) {
+    layout(_width: number, _height: number): void {
         // noop
     }
 
-    init(_params: WatermarkRendererInitParameters) {
+    init(_params: WatermarkRendererInitParameters): void {
         this.render();
     }
 
@@ -82,11 +82,11 @@ export class Watermark
         this.render();
     }
 
-    dispose() {
+    dispose(): void {
         super.dispose();
     }
 
-    private render() {
+    private render(): void {
         const isOneGroup = !!(
             this.params && this.params.containerApi.size <= 1
         );
diff --git a/packages/dockview-core/src/dockview/options.ts b/packages/dockview-core/src/dockview/options.ts
index 1594249bf..6e83797d7 100644
--- a/packages/dockview-core/src/dockview/options.ts
+++ b/packages/dockview-core/src/dockview/options.ts
@@ -13,11 +13,11 @@ import {
     DockviewGroupPanelApi,
 } from './dockviewGroupPanel';
 import { ISplitviewStyles, Orientation } from '../splitview/splitview';
-import { FrameworkFactory } from '../types';
 import { PanelTransfer } from '../dnd/dataTransfer';
 import { IDisposable } from '../lifecycle';
 import { Position } from '../dnd/droptarget';
 import { IDockviewPanel } from './dockviewPanel';
+import { FrameworkFactory } from '../panel/componentFactory';
 
 export interface IGroupControlRenderer extends IDisposable {
     readonly element: HTMLElement;
diff --git a/packages/dockview-core/src/gridview/basePanelView.ts b/packages/dockview-core/src/gridview/basePanelView.ts
index d10a27be7..375b37a47 100644
--- a/packages/dockview-core/src/gridview/basePanelView.ts
+++ b/packages/dockview-core/src/gridview/basePanelView.ts
@@ -9,9 +9,9 @@ import {
 import { PanelApi, PanelApiImpl } from '../api/panelApi';
 
 export interface BasePanelViewState {
-    id: string;
-    component: string;
-    params?: Record<string, any>;
+    readonly id: string;
+    readonly component: string;
+    readonly params?: Record<string, any>;
 }
 
 export interface BasePanelViewExported<T extends PanelApi> {
@@ -35,9 +35,7 @@ export abstract class BasePanelView<T extends PanelApiImpl>
     protected part?: IFrameworkPart;
     protected _params?: PanelInitParameters;
 
-    /**
-     * Provide an IFrameworkPart that will determine the rendered UI of this view piece.
-     */
+    // provide an IFrameworkPart that will determine the rendered UI of this view piece.
     protected abstract getComponent(): IFrameworkPart;
 
     get element(): HTMLElement {
diff --git a/packages/dockview-core/src/gridview/options.ts b/packages/dockview-core/src/gridview/options.ts
index c224a73b4..8125f9127 100644
--- a/packages/dockview-core/src/gridview/options.ts
+++ b/packages/dockview-core/src/gridview/options.ts
@@ -1,6 +1,6 @@
 import { GridviewPanel } from './gridviewPanel';
 import { ISplitviewStyles, Orientation } from '../splitview/splitview';
-import { FrameworkFactory } from '../types';
+import { FrameworkFactory } from '../panel/componentFactory';
 
 export interface GridviewComponentOptions {
     proportionalLayout: boolean;
diff --git a/packages/dockview-core/src/lifecycle.ts b/packages/dockview-core/src/lifecycle.ts
index 20f1eb425..d71947174 100644
--- a/packages/dockview-core/src/lifecycle.ts
+++ b/packages/dockview-core/src/lifecycle.ts
@@ -18,7 +18,7 @@ export namespace Disposable {
 export class CompositeDisposable {
     private readonly disposables: IDisposable[];
 
-    public static from(...args: IDisposable[]) {
+    public static from(...args: IDisposable[]): CompositeDisposable {
         return new CompositeDisposable(...args);
     }
 
diff --git a/packages/dockview-core/src/math.ts b/packages/dockview-core/src/math.ts
index dea86579a..4ee363902 100644
--- a/packages/dockview-core/src/math.ts
+++ b/packages/dockview-core/src/math.ts
@@ -1,4 +1,4 @@
-export const clamp = (value: number, min: number, max: number) => {
+export const clamp = (value: number, min: number, max: number): number => {
     if (min > max) {
         throw new Error(`${min} > ${max} is an invalid condition`);
     }
@@ -9,3 +9,24 @@ export const sequentialNumberGenerator = () => {
     let value = 1;
     return { next: () => (value++).toString() };
 };
+
+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;
+};
diff --git a/packages/dockview-core/src/panel/componentFactory.ts b/packages/dockview-core/src/panel/componentFactory.ts
index 58ae86356..d88fb64ad 100644
--- a/packages/dockview-core/src/panel/componentFactory.ts
+++ b/packages/dockview-core/src/panel/componentFactory.ts
@@ -1,4 +1,6 @@
-import { FrameworkFactory } from '../types';
+export interface FrameworkFactory<T> {
+    createComponent: (id: string, componentId: string, component: any) => T;
+}
 
 export function createComponent<T>(
     id: string,
diff --git a/packages/dockview-core/src/paneview/options.ts b/packages/dockview-core/src/paneview/options.ts
index 72d4e0be7..91fd9c6fe 100644
--- a/packages/dockview-core/src/paneview/options.ts
+++ b/packages/dockview-core/src/paneview/options.ts
@@ -1,4 +1,4 @@
-import { FrameworkFactory } from '../types';
+import { FrameworkFactory } from '../panel/componentFactory';
 import { PaneviewDndOverlayEvent } from './paneviewComponent';
 import { IPaneBodyPart, IPaneHeaderPart, PaneviewPanel } from './paneviewPanel';
 
diff --git a/packages/dockview-core/src/splitview/options.ts b/packages/dockview-core/src/splitview/options.ts
index 05c492e4c..e79eb0b0a 100644
--- a/packages/dockview-core/src/splitview/options.ts
+++ b/packages/dockview-core/src/splitview/options.ts
@@ -1,8 +1,8 @@
 import { IPanel, PanelInitParameters } from '../panel/types';
 import { IView, SplitViewOptions, LayoutPriority } from './splitview';
-import { FrameworkFactory } from '../types';
 import { SplitviewPanel } from './splitviewPanel';
 import { SplitviewComponent } from './splitviewComponent';
+import { FrameworkFactory } from '../panel/componentFactory';
 
 export interface PanelViewInitParameters extends PanelInitParameters {
     minimumSize?: number;
diff --git a/packages/dockview-core/src/splitview/splitview.scss b/packages/dockview-core/src/splitview/splitview.scss
index 7d329cf12..99b91b925 100644
--- a/packages/dockview-core/src/splitview/splitview.scss
+++ b/packages/dockview-core/src/splitview/splitview.scss
@@ -120,6 +120,7 @@
         position: relative;
         height: 100%;
         width: 100%;
+        background-color: var(--dv-background-color);
 
         .view {
             height: 100%;
diff --git a/packages/dockview-core/src/splitview/splitview.ts b/packages/dockview-core/src/splitview/splitview.ts
index 7925bd578..88db24df3 100644
--- a/packages/dockview-core/src/splitview/splitview.ts
+++ b/packages/dockview-core/src/splitview/splitview.ts
@@ -11,7 +11,8 @@ import {
 } from '../dom';
 import { clamp } from '../math';
 import { Event, Emitter } from '../events';
-import { pushToStart, pushToEnd, range, firstIndex } from '../array';
+import { pushToStart, pushToEnd, firstIndex } from '../array';
+import { range } from '../math';
 import { ViewItem } from './viewItem';
 
 export enum Orientation {
diff --git a/packages/dockview-core/src/svg.ts b/packages/dockview-core/src/svg.ts
index 6b51350b6..bf0360191 100644
--- a/packages/dockview-core/src/svg.ts
+++ b/packages/dockview-core/src/svg.ts
@@ -3,7 +3,7 @@ const createSvgElementFromPath = (params: {
     width: string;
     viewbox: string;
     path: string;
-}) => {
+}): SVGSVGElement => {
     const svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
     svg.setAttributeNS(null, 'height', params.height);
     svg.setAttributeNS(null, 'width', params.width);
@@ -17,7 +17,7 @@ const createSvgElementFromPath = (params: {
     return svg;
 };
 
-export const createCloseButton = () =>
+export const createCloseButton = (): SVGSVGElement =>
     createSvgElementFromPath({
         width: '11',
         height: '11',
@@ -25,7 +25,7 @@ export const createCloseButton = () =>
         path: 'M2.1 27.3L0 25.2L11.55 13.65L0 2.1L2.1 0L13.65 11.55L25.2 0L27.3 2.1L15.75 13.65L27.3 25.2L25.2 27.3L13.65 15.75L2.1 27.3Z',
     });
 
-export const createExpandMoreButton = () =>
+export const createExpandMoreButton = (): SVGSVGElement =>
     createSvgElementFromPath({
         width: '11',
         height: '11',
@@ -33,7 +33,7 @@ export const createExpandMoreButton = () =>
         path: 'M12 14.15L0 2.15L2.15 0L12 9.9L21.85 0.0499992L24 2.2L12 14.15Z',
     });
 
-export const createChevronRightButton = () =>
+export const createChevronRightButton = (): SVGSVGElement =>
     createSvgElementFromPath({
         width: '11',
         height: '11',
diff --git a/packages/dockview-core/src/theme.scss b/packages/dockview-core/src/theme.scss
index c2581f7b6..daa0ffaef 100644
--- a/packages/dockview-core/src/theme.scss
+++ b/packages/dockview-core/src/theme.scss
@@ -1,4 +1,5 @@
 @mixin dockview-theme-core-mixin {
+    --dv-background-color: black;
     --dv-paneview-active-outline-color: dodgerblue;
     --dv-tabs-and-actions-container-font-size: 13px;
     --dv-tabs-and-actions-container-height: 35px;
diff --git a/packages/dockview-core/src/types.ts b/packages/dockview-core/src/types.ts
index e5bd8f0d3..935d54b21 100644
--- a/packages/dockview-core/src/types.ts
+++ b/packages/dockview-core/src/types.ts
@@ -1,11 +1,3 @@
-export interface FrameworkFactory<T> {
-    createComponent: (id: string, componentId: string, component: any) => T;
-}
-
-export function isBooleanValue(value: any): value is boolean {
-    return typeof value === 'boolean';
-}
-
 export type FunctionOrValue<T> = (() => T) | T;
 
 export type Optional<T, K extends keyof T> = Pick<Partial<T>, K> & Omit<T, K>;
diff --git a/packages/dockview/src/splitview/view.ts b/packages/dockview/src/splitview/view.ts
index 51a7aa53b..926e3ed9f 100644
--- a/packages/dockview/src/splitview/view.ts
+++ b/packages/dockview/src/splitview/view.ts
@@ -16,7 +16,7 @@ export class ReactPanelView extends SplitviewPanel {
         super(id, component);
     }
 
-    getComponent() {
+    getComponent(): ReactPart<ISplitviewPanelProps> {
         return new ReactPart(
             this.element,
             this.reactPortalStore,
diff --git a/packages/docs/docs/components/dockview.mdx b/packages/docs/docs/components/dockview.mdx
index a61471905..727fd5abf 100644
--- a/packages/docs/docs/components/dockview.mdx
+++ b/packages/docs/docs/components/dockview.mdx
@@ -24,6 +24,7 @@ import CustomHeadersDockview from '@site/sandboxes/customheader-dockview/src/app
 import DockviewNative from '@site/sandboxes/fullwidthtab-dockview/src/app';
 import DockviewNative2 from '@site/sandboxes/nativeapp-dockview/src/app';
 import DockviewSetTitle from '@site/sandboxes/updatetitle-dockview/src/app';
+// import { attach as attachDockviewVanilla } from '@site/sandboxes/vanilla-dockview/src/app';
 
 # Dockview
 
@@ -656,6 +657,22 @@ const GroupControlComponent = (props: IDockviewGroupControlProps) => {
     <DockviewGroupControl />
 </Container>
 
+### Constraints
+
+You may wish to specify a minimum or maximum height or width for a group which can be done through the group api.
+
+```tsx
+api.group.api.setConstraints(...)
+```
+
+> Constraints are currently only supported for groups and not individual panels.
+> If you specific a constraint on a group and move a panel within that group to another group it will no
+> longer be subject to those constraints since those constraints were on the group and not on the individual panel.
+
+<Container height={500}>
+    <DockviewConstraints />
+</Container>
+
 ## Events
 
 <Container height={600}>
@@ -685,8 +702,14 @@ hello 2
     <App />
 </div>
 
-## Contraints
+<!-- ## VanillaJS
 
-<Container>
-    <DockviewConstraints />
-</Container>
+> Note: This section is experimental and support for Vanilla JS is a work in progress.
+
+The `dockview` package contains `ReactJS` wrappers for the core library.
+The core library is published as an independant package under the name `dockview-core` which you can install standalone.
+
+> When using `dockview` there is no need to also install `dockview-core`.
+> `dockview-core` is a dependency of `dockview` and automatically installed during the installation process of `dockview` via `npm install dockview`.
+
+<Container injectVanillaJS={attachDockviewVanilla} /> -->
diff --git a/packages/docs/src/components/container.tsx b/packages/docs/src/components/container.tsx
index 1dd825811..09be369e9 100644
--- a/packages/docs/src/components/container.tsx
+++ b/packages/docs/src/components/container.tsx
@@ -30,12 +30,24 @@ export const CreateCloseButton = () =>
     });
 
 export const Container = (props: {
-    children: React.ReactNode;
+    children?: React.ReactNode;
     height?: number;
+    injectVanillaJS?: (parent: HTMLElement) => void;
 }) => {
+    const ref = React.useRef<HTMLDivElement>(null);
+
+    React.useEffect(() => {
+        if (!props.injectVanillaJS) {
+            return;
+        }
+
+        props.injectVanillaJS(ref.current);
+    }, [props.injectVanillaJS]);
+
     return (
         <>
             <div
+                ref={ref}
                 style={{
                     height: props.height ? `${props.height}px` : '300px',
                 }}