Add an element to pane to take care of wiring initial mouse handlers

crates/workspace/src/pane.rs

@@ -24,8 +24,8 @@ use gpui::{
     keymap_matcher::KeymapContext,
     platform::{CursorStyle, NavigationDirection},
     Action, AnyViewHandle, AnyWeakViewHandle, AppContext, AsyncAppContext, Entity, EventContext,
-    ModelHandle, MouseButton, MutableAppContext, PromptLevel, Quad, RenderContext, Task, View,
-    ViewContext, ViewHandle, WeakViewHandle,
+    ModelHandle, MouseButton, MouseRegion, MutableAppContext, PromptLevel, Quad, RenderContext,
+    Task, View, ViewContext, ViewHandle, WeakViewHandle,
 };
 use project::{Project, ProjectEntryId, ProjectPath};
 use serde::Deserialize;
@@ -1706,6 +1706,93 @@ impl NavHistory {
     }
 }
 
+pub struct PaneBackdrop {
+    child_view: usize,
+    child: ElementBox,
+}
+impl PaneBackdrop {
+    pub fn new(pane_item_view: usize, child: ElementBox) -> Self {
+        PaneBackdrop {
+            child,
+            child_view: pane_item_view,
+        }
+    }
+}
+
+impl Element for PaneBackdrop {
+    type LayoutState = ();
+
+    type PaintState = ();
+
+    fn layout(
+        &mut self,
+        constraint: gpui::SizeConstraint,
+        cx: &mut gpui::LayoutContext,
+    ) -> (Vector2F, Self::LayoutState) {
+        let size = self.child.layout(constraint, cx);
+        (size, ())
+    }
+
+    fn paint(
+        &mut self,
+        bounds: RectF,
+        visible_bounds: RectF,
+        _: &mut Self::LayoutState,
+        cx: &mut gpui::PaintContext,
+    ) -> Self::PaintState {
+        let background = cx.global::<Settings>().theme.editor.background;
+
+        let visible_bounds = bounds.intersection(visible_bounds).unwrap_or_default();
+
+        cx.scene.push_quad(gpui::Quad {
+            bounds: RectF::new(bounds.origin(), bounds.size()),
+            background: Some(background),
+            ..Default::default()
+        });
+
+        let child_view_id = self.child_view;
+        cx.scene.push_mouse_region(
+            MouseRegion::new::<Self>(child_view_id, 0, visible_bounds).on_down(
+                gpui::MouseButton::Left,
+                move |_, cx| {
+                    let window_id = cx.window_id;
+                    cx.focus(window_id, Some(child_view_id))
+                },
+            ),
+        );
+
+        cx.paint_layer(Some(bounds), |cx| {
+            self.child.paint(bounds.origin(), visible_bounds, cx)
+        })
+    }
+
+    fn rect_for_text_range(
+        &self,
+        range_utf16: std::ops::Range<usize>,
+        _bounds: RectF,
+        _visible_bounds: RectF,
+        _layout: &Self::LayoutState,
+        _paint: &Self::PaintState,
+        cx: &gpui::MeasurementContext,
+    ) -> Option<RectF> {
+        self.child.rect_for_text_range(range_utf16, cx)
+    }
+
+    fn debug(
+        &self,
+        _bounds: RectF,
+        _layout: &Self::LayoutState,
+        _paint: &Self::PaintState,
+        cx: &gpui::DebugContext,
+    ) -> serde_json::Value {
+        gpui::json::json!({
+            "type": "Pane Back Drop",
+            "view": self.child_view,
+            "child": self.child.debug(cx),
+        })
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;