update dock

crates/workspace/src/workspace.rs

@@ -1,4 +1,4 @@
-use dock::{DockArea, DockLayout, DockPlacement, SignedDockSkin, panel_handle};
+use dock::{DockArea, DockEvent, DockLayout, DockPlacement, SignedDockSkin, panel_handle};
 use gpui::prelude::*;
 use gpui::{Context, Entity, Render, Subscription, Window, div, px};
 use gpui_component::{Root, StyledExt, Theme};
@@ -40,6 +40,32 @@ impl Workspace {
 
         let mut subscriptions = vec![];
 
+        // A bottom/right dock whose last panel was dragged away is removed
+        // entirely: base keeps the emptied region, which would otherwise
+        // linger as a bare strip. Deferred, because the event arrives while
+        // the area is mid-update.
+        let dock_for_pruning = dock.clone();
+        subscriptions.push(cx.subscribe_in(
+            &dock,
+            window,
+            move |_, _, event: &DockEvent, window, cx| {
+                if !matches!(event, DockEvent::LayoutChanged) {
+                    return;
+                }
+                let dock = dock_for_pruning.clone();
+                cx.spawn_in(window, async move |_, window| {
+                    _ = dock.update_in(window, |area, window, cx| {
+                        for placement in [DockPlacement::Bottom, DockPlacement::Right] {
+                            if area.is_empty(placement, cx) {
+                                area.remove_dock(placement, window, cx);
+                            }
+                        }
+                    });
+                })
+                .detach();
+            },
+        ));
+
         subscriptions.push(cx.observe_window_appearance(window, |_this, window, cx| {
             Theme::sync_system_appearance(Some(window), cx);
         }));