From 2ab7341fa50865d6f0c26da59f945321ef839c5f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=A9ctor=20Ram=C3=B3n=20Jim=C3=A9nez?=
 <hector0193@gmail.com>
Date: Tue, 12 May 2020 10:09:30 +0200
Subject: [PATCH] Implement `State::with_content` in `pane_grid`

---
 native/src/widget/pane_grid.rs         |  2 +
 native/src/widget/pane_grid/content.rs | 12 +++++
 native/src/widget/pane_grid/state.rs   | 61 +++++++++++++++++++-------
 wgpu/src/widget/pane_grid.rs           |  4 +-
 4 files changed, 62 insertions(+), 17 deletions(-)
 create mode 100644 native/src/widget/pane_grid/content.rs

diff --git a/native/src/widget/pane_grid.rs b/native/src/widget/pane_grid.rs
index 4c0eeed2..076ae76f 100644
--- a/native/src/widget/pane_grid.rs
+++ b/native/src/widget/pane_grid.rs
@@ -9,6 +9,7 @@
 //! [`pane_grid` example]: https://github.com/hecrj/iced/tree/0.1/examples/pane_grid
 //! [`PaneGrid`]: struct.PaneGrid.html
 mod axis;
+mod content;
 mod direction;
 mod node;
 mod pane;
@@ -16,6 +17,7 @@ mod split;
 mod state;
 
 pub use axis::Axis;
+pub use content::Content;
 pub use direction::Direction;
 pub use node::Node;
 pub use pane::Pane;
diff --git a/native/src/widget/pane_grid/content.rs b/native/src/widget/pane_grid/content.rs
new file mode 100644
index 00000000..6b0bd99a
--- /dev/null
+++ b/native/src/widget/pane_grid/content.rs
@@ -0,0 +1,12 @@
+use crate::pane_grid::Axis;
+
+#[derive(Debug, Clone)]
+pub enum Content<T> {
+    Split {
+        axis: Axis,
+        ratio: f32,
+        a: Box<Content<T>>,
+        b: Box<Content<T>>,
+    },
+    Pane(T),
+}
diff --git a/native/src/widget/pane_grid/state.rs b/native/src/widget/pane_grid/state.rs
index 4cda818c..41f3cffd 100644
--- a/native/src/widget/pane_grid/state.rs
+++ b/native/src/widget/pane_grid/state.rs
@@ -1,6 +1,6 @@
 use crate::{
     keyboard,
-    pane_grid::{node::Node, Axis, Direction, Pane, Split},
+    pane_grid::{Axis, Content, Direction, Node, Pane, Split},
     Hasher, Point, Rectangle, Size,
 };
 
@@ -53,23 +53,24 @@ impl<T> State<T> {
     /// [`State`]: struct.State.html
     /// [`Pane`]: struct.Pane.html
     pub fn new(first_pane_state: T) -> (Self, Pane) {
-        let first_pane = Pane(0);
+        (Self::with_content(Content::Pane(first_pane_state)), Pane(0))
+    }
 
+    pub fn with_content(content: impl Into<Content<T>>) -> Self {
         let mut panes = HashMap::new();
-        let _ = panes.insert(first_pane, first_pane_state);
 
-        (
-            State {
-                panes,
-                internal: Internal {
-                    layout: Node::Pane(first_pane),
-                    last_id: 0,
-                    action: Action::Idle { focus: None },
-                },
-                modifiers: keyboard::ModifiersState::default(),
+        let (layout, last_id) =
+            Self::distribute_content(&mut panes, content.into(), 0);
+
+        State {
+            panes,
+            internal: Internal {
+                layout,
+                last_id,
+                action: Action::Idle { focus: None },
             },
-            first_pane,
-        )
+            modifiers: keyboard::ModifiersState::default(),
+        }
     }
 
     /// Returns the total amount of panes in the [`State`].
@@ -110,7 +111,7 @@ impl<T> State<T> {
         self.panes.iter_mut()
     }
 
-    /// Returns the layout tree stored in the [`State`].
+    /// Returns the layout of the [`State`].
     ///
     /// [`State`]: struct.State.html
     pub fn layout(&self) -> &Node {
@@ -266,6 +267,36 @@ impl<T> State<T> {
             None
         }
     }
+
+    fn distribute_content(
+        panes: &mut HashMap<Pane, T>,
+        content: Content<T>,
+        next_id: usize,
+    ) -> (Node, usize) {
+        match content {
+            Content::Split { axis, ratio, a, b } => {
+                let (a, next_id) = Self::distribute_content(panes, *a, next_id);
+                let (b, next_id) = Self::distribute_content(panes, *b, next_id);
+
+                (
+                    Node::Split {
+                        id: Split(next_id),
+                        axis,
+                        ratio,
+                        a: Box::new(a),
+                        b: Box::new(b),
+                    },
+                    next_id + 1,
+                )
+            }
+            Content::Pane(state) => {
+                let id = Pane(next_id);
+                let _ = panes.insert(id, state);
+
+                (Node::Pane(id), next_id + 1)
+            }
+        }
+    }
 }
 
 #[derive(Debug, Clone)]
diff --git a/wgpu/src/widget/pane_grid.rs b/wgpu/src/widget/pane_grid.rs
index 54438f5c..6f437df7 100644
--- a/wgpu/src/widget/pane_grid.rs
+++ b/wgpu/src/widget/pane_grid.rs
@@ -11,8 +11,8 @@
 use crate::Renderer;
 
 pub use iced_native::pane_grid::{
-    Axis, Direction, DragEvent, Focus, KeyPressEvent, Node, Pane, ResizeEvent,
-    Split, State,
+    Axis, Content, Direction, DragEvent, Focus, KeyPressEvent, Node, Pane,
+    ResizeEvent, Split, State,
 };
 
 /// A collection of panes distributed using either vertical or horizontal splits