tiles: To support close panel. (#674)

- Add `remove_panel` method to DockArea.

crates/ui/src/dock/dock.rs

@@ -276,6 +276,17 @@ impl Dock {
         cx.notify();
     }
 
+    /// Remove item from the Dock.
+    pub fn remove_panel(
+        &mut self,
+        panel: Arc<dyn PanelView>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        self.panel.remove_panel(panel, window, cx);
+        cx.notify();
+    }
+
     fn render_resize_handle(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
         let axis = self.placement.axis();
         let view = cx.entity().clone();

crates/ui/src/dock/mod.rs

@@ -368,6 +368,32 @@ impl DockItem {
         }
     }
 
+    /// Remove a panel from the dock item.
+    pub fn remove_panel(&self, panel: Arc<dyn PanelView>, window: &mut Window, cx: &mut App) {
+        match self {
+            DockItem::Tabs { view, .. } => {
+                view.update(cx, |tab_panel, cx| {
+                    tab_panel.remove_panel(panel, window, cx);
+                });
+            }
+            DockItem::Split { items, view, .. } => {
+                // For each child item, set collapsed state
+                for item in items {
+                    item.remove_panel(panel.clone(), window, cx);
+                }
+                view.update(cx, |split, cx| {
+                    split.remove_panel(panel, window, cx);
+                });
+            }
+            DockItem::Tiles { view, .. } => {
+                view.update(cx, |tiles, cx| {
+                    tiles.remove(panel, window, cx);
+                });
+            }
+            DockItem::Panel { .. } => {}
+        }
+    }
+
     pub fn set_collapsed(&self, collapsed: bool, window: &mut Window, cx: &mut App) {
         match self {
             DockItem::Tabs { view, .. } => {
@@ -567,6 +593,7 @@ impl DockArea {
     }
 
     /// Determine if the dock area is locked.
+    #[inline]
     pub fn is_locked(&self) -> bool {
         self.locked
     }
@@ -674,8 +701,6 @@ impl DockArea {
     }
 
     /// Add a panel item to the dock area at the given placement.
-    ///
-    /// If the left, bottom, right dock is not present, it will set the dock at the placement.
     pub fn add_panel(
         &mut self,
         panel: Arc<dyn PanelView>,
@@ -732,6 +757,56 @@ impl DockArea {
         }
     }
 
+    /// Remove panel from the DockArea at the given placement.
+    pub fn remove_panel(
+        &mut self,
+        panel: Arc<dyn PanelView>,
+        placement: DockPlacement,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        match placement {
+            DockPlacement::Left => {
+                if let Some(dock) = self.left_dock.as_mut() {
+                    dock.update(cx, |dock, cx| {
+                        dock.remove_panel(panel, window, cx);
+                    });
+                }
+            }
+            DockPlacement::Right => {
+                if let Some(dock) = self.right_dock.as_mut() {
+                    dock.update(cx, |dock, cx| {
+                        dock.remove_panel(panel, window, cx);
+                    });
+                }
+            }
+            DockPlacement::Bottom => {
+                if let Some(dock) = self.bottom_dock.as_mut() {
+                    dock.update(cx, |dock, cx| {
+                        dock.remove_panel(panel, window, cx);
+                    });
+                }
+            }
+            DockPlacement::Center => {
+                self.items.remove_panel(panel, window, cx);
+            }
+        }
+        cx.notify();
+    }
+
+    /// Remove a panel from all docks.
+    pub fn remove_panel_from_all_docks(
+        &mut self,
+        panel: Arc<dyn PanelView>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        self.remove_panel(panel.clone(), DockPlacement::Center, window, cx);
+        self.remove_panel(panel.clone(), DockPlacement::Left, window, cx);
+        self.remove_panel(panel.clone(), DockPlacement::Right, window, cx);
+        self.remove_panel(panel.clone(), DockPlacement::Bottom, window, cx);
+    }
+
     /// Load the state of the DockArea from the DockAreaState.
     ///
     /// See also [DockeArea::dump].

crates/ui/src/dock/tab_panel.rs

@@ -81,6 +81,8 @@ pub struct TabPanel {
     collapsed: bool,
     /// When drag move, will get the placement of the panel to be split
     will_split_placement: Option<Placement>,
+    /// Is TabPanel used in Tiles.
+    in_tiles: bool,
 }
 
 impl Panel for TabPanel {
@@ -158,9 +160,15 @@ impl TabPanel {
             zoomed: false,
             collapsed: false,
             closable: true,
+            in_tiles: false,
         }
     }
 
+    /// Mark the TabPanel as being used in Tiles.
+    pub(super) fn set_in_tiles(&mut self, in_tiles: bool) {
+        self.in_tiles = in_tiles;
+    }
+
     pub(super) fn set_parent(&mut self, view: WeakEntity<StackPanel>) {
         self.stack_panel = Some(view);
     }
@@ -1063,6 +1071,20 @@ impl TabPanel {
         if let Some(panel) = self.active_panel(cx) {
             self.remove_panel(panel, window, cx);
         }
+
+        // Remove self from the parent DockArea.
+        // This is ensure to remove from Tiles
+        if self.panels.is_empty() && self.in_tiles {
+            let tab_panel = Arc::new(cx.entity());
+            window.defer(cx, {
+                let dock_area = self.dock_area.clone();
+                move |window, cx| {
+                    _ = dock_area.update(cx, |this, cx| {
+                        this.remove_panel_from_all_docks(tab_panel, window, cx);
+                    });
+                }
+            });
+        }
     }
 }
 
@@ -1088,7 +1110,10 @@ impl Render for TabPanel {
             zoomable: self.zoomable(cx),
             active_panel,
         };
-        if !state.draggable {
+
+        // 1. When is the final panel in the dock, it will not able to close.
+        // 2. When is in the Tiles, it will always able to close (by active panel state).
+        if !state.draggable && !self.in_tiles {
             state.closable = false;
         }
 

crates/ui/src/dock/tiles.rs

@@ -361,10 +361,13 @@ impl Tiles {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        assert!(
+        let Ok(tab_panel) = item.panel.view().downcast::<TabPanel>() else {
-            item.panel.view().downcast::<TabPanel>().is_ok(),
+            panic!("only allows to add TabPanel type")
-            "only allows to add TabPanel type"
+        };
-        );
+
+        tab_panel.update(cx, |tab_panel, _| {
+            tab_panel.set_in_tiles(true);
+        });
 
         self.panels.push(item.clone());
         window.defer(cx, {