dock: Hide toggle button when side dock is not exist. (#431)

crates/ui/src/dock/dock.rs

@@ -296,7 +296,7 @@ impl Render for Dock {
             })
             // Bottom Dock should keep the title bar, then user can click the Toggle button
             .when(!self.open && self.placement.is_bottom(), |this| {
-                this.h(px(30.))
+                this.h(px(29.))
             })
             .map(|this| match &self.panel {
                 DockItem::Split { view, .. } => this.child(view.clone()),

crates/ui/src/dock/tab_panel.rs

@@ -385,13 +385,21 @@ impl TabPanel {
 
         let view_entity_id = cx.view().entity_id();
         let dock_area = self.dock_area.upgrade()?.read(cx);
+
         let toggle_button_panels = dock_area.toggle_button_panels;
 
         // Check if current TabPanel's entity_id matches the one stored in DockArea for this placement
         if !match placement {
-            DockPlacement::Left => toggle_button_panels.left == Some(view_entity_id),
+            DockPlacement::Left => {
-            DockPlacement::Right => toggle_button_panels.right == Some(view_entity_id),
+                dock_area.left_dock.is_some() && toggle_button_panels.left == Some(view_entity_id)
-            DockPlacement::Bottom => toggle_button_panels.bottom == Some(view_entity_id),
+            }
+            DockPlacement::Right => {
+                dock_area.right_dock.is_some() && toggle_button_panels.right == Some(view_entity_id)
+            }
+            DockPlacement::Bottom => {
+                dock_area.bottom_dock.is_some()
+                    && toggle_button_panels.bottom == Some(view_entity_id)
+            }
         } {
             return None;
         }

crates/ui/src/scroll/scrollable_mask.rs

@@ -117,7 +117,7 @@ impl Element for ScrollableMask {
                     bounds,
                     border_widths: Edges::all(px(1.0)),
                     border_color: color,
-                    background: gpui::transparent_white().into(),
+                    background: gpui::transparent_white(),
                     corner_radii: Corners::all(px(0.)),
                 });
             }

crates/ui/src/scroll/scrollbar.rs

@@ -460,7 +460,7 @@ impl Element for Scrollbar {
                     cx.paint_quad(PaintQuad {
                         bounds,
                         corner_radii: (0.).into(),
-                        background: gpui::transparent_black().into(),
+                        background: gpui::transparent_black(),
                         border_widths: if is_vertical {
                             Edges {
                                 top: px(0.),