From d7b8a189e49a1a4bb634676a2821af83cfc6ecd6 Mon Sep 17 00:00:00 2001
From: K Simmons <keith@zed.dev>
Date: Sat, 22 Oct 2022 11:41:37 -0700
Subject: [PATCH] fix issue where empty pane is created

---
 crates/gpui/src/presenter.rs      |  4 ++--
 crates/workspace/src/pane.rs      | 27 +++++++++++++++++----------
 crates/workspace/src/workspace.rs | 15 ++++++---------
 3 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/crates/gpui/src/presenter.rs b/crates/gpui/src/presenter.rs
index 16ea5da642..b04dde7e06 100644
--- a/crates/gpui/src/presenter.rs
+++ b/crates/gpui/src/presenter.rs
@@ -391,7 +391,7 @@ impl Presenter {
                             //Ensure that hover entrance events aren't sent twice
                             if self.hovered_region_ids.insert(region.id()) {
                                 valid_regions.push(region.clone());
-                                if region.notify_on_hover {
+                                if region.notify_on_hover || region.notify_on_move {
                                     notified_views.insert(region.id().view_id());
                                 }
                             }
@@ -399,7 +399,7 @@ impl Presenter {
                             // Ensure that hover exit events aren't sent twice
                             if self.hovered_region_ids.remove(&region.id()) {
                                 valid_regions.push(region.clone());
-                                if region.notify_on_hover {
+                                if region.notify_on_hover || region.notify_on_move {
                                     notified_views.insert(region.id().view_id());
                                 }
                             }
diff --git a/crates/workspace/src/pane.rs b/crates/workspace/src/pane.rs
index 9f103946bf..1d50a846b4 100644
--- a/crates/workspace/src/pane.rs
+++ b/crates/workspace/src/pane.rs
@@ -1373,6 +1373,7 @@ impl Pane {
                 .and_then(|margin| Self::drop_split_direction(event.position, event.region, margin))
             {
                 cx.dispatch_action(SplitWithItem {
+                    from: dragged_item.pane.clone(),
                     item_id_to_move: dragged_item.item.id(),
                     pane_to_split: pane.clone(),
                     split_direction,
@@ -1476,9 +1477,13 @@ impl View for Pane {
                                     cx,
                                     |state, cx| {
                                         let overlay_color = Self::tab_overlay_color(true, cx);
+                                        // Hovered will cause a render when the mouse enters regardless
+                                        // of if mouse position was accessed before
+                                        let hovered = state.hovered();
                                         let drag_position = cx
                                             .global::<DragAndDrop<Workspace>>()
                                             .currently_dragged::<DraggedItem>(cx.window_id())
+                                            .filter(|_| hovered)
                                             .map(|_| state.mouse_position());
 
                                         Stack::new()
@@ -1498,25 +1503,27 @@ impl View for Pane {
                                             )
                                             .with_children(drag_position.map(|drag_position| {
                                                 Canvas::new(move |region, _, cx| {
-                                                    let overlay_region =
-                                                        if let Some(split_direction) =
+                                                    if region.contains_point(drag_position) {
+                                                        let overlay_region = if let Some(
+                                                            split_direction,
+                                                        ) =
                                                             Self::drop_split_direction(
                                                                 drag_position,
                                                                 region,
                                                                 100., /* Replace with theme value */
-                                                            )
-                                                        {
+                                                            ) {
                                                             split_direction.along_edge(region, 100.)
                                                         } else {
                                                             region
                                                         };
 
-                                                    cx.scene.push_quad(Quad {
-                                                        bounds: overlay_region,
-                                                        background: overlay_color,
-                                                        border: Default::default(),
-                                                        corner_radius: 0.,
-                                                    });
+                                                        cx.scene.push_quad(Quad {
+                                                            bounds: overlay_region,
+                                                            background: overlay_color,
+                                                            border: Default::default(),
+                                                            corner_radius: 0.,
+                                                        });
+                                                    }
                                                 })
                                                 .boxed()
                                             }))
diff --git a/crates/workspace/src/workspace.rs b/crates/workspace/src/workspace.rs
index 512ca23950..4263f83ef1 100644
--- a/crates/workspace/src/workspace.rs
+++ b/crates/workspace/src/workspace.rs
@@ -127,6 +127,7 @@ pub struct OpenSharedScreen {
 }
 
 pub struct SplitWithItem {
+    from: WeakViewHandle<Pane>,
     pane_to_split: WeakViewHandle<Pane>,
     split_direction: SplitDirection,
     item_id_to_move: usize,
@@ -216,12 +217,14 @@ pub fn init(app_state: Arc<AppState>, cx: &mut MutableAppContext) {
     cx.add_action(
         |workspace: &mut Workspace,
          SplitWithItem {
+             from,
              pane_to_split,
              item_id_to_move,
              split_direction,
          }: &_,
          cx| {
             workspace.split_pane_with_item(
+                from.clone(),
                 pane_to_split.clone(),
                 *item_id_to_move,
                 *split_direction,
@@ -1975,26 +1978,20 @@ impl Workspace {
 
     pub fn split_pane_with_item(
         &mut self,
+        from: WeakViewHandle<Pane>,
         pane_to_split: WeakViewHandle<Pane>,
         item_id_to_move: usize,
         split_direction: SplitDirection,
         cx: &mut ViewContext<Self>,
     ) {
-        if let Some(pane_to_split) = pane_to_split.upgrade(cx) {
+        if let Some((pane_to_split, from)) = pane_to_split.upgrade(cx).zip(from.upgrade(cx)) {
             if &pane_to_split == self.dock_pane() {
                 warn!("Can't split dock pane.");
                 return;
             }
 
             let new_pane = self.add_pane(cx);
-            Pane::move_item(
-                self,
-                pane_to_split.clone(),
-                new_pane.clone(),
-                item_id_to_move,
-                0,
-                cx,
-            );
+            Pane::move_item(self, from.clone(), new_pane.clone(), item_id_to_move, 0, cx);
             self.center
                 .split(&pane_to_split, &new_pane, split_direction)
                 .unwrap();