Switch MouseEventHandler to use MouseRegions

Nathan Sobo and Max Brunsfeld created

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

Change summary

crates/auto_update/src/auto_update.rs           |   2 
crates/chat_panel/src/chat_panel.rs             |   2 
crates/command_palette/src/command_palette.rs   |   6 
crates/contacts_panel/src/contact_finder.rs     |   6 
crates/contacts_panel/src/contacts_panel.rs     |  28 +--
crates/contacts_panel/src/notifications.rs      |  15 -
crates/diagnostics/src/items.rs                 |   4 
crates/editor/src/editor.rs                     |   6 
crates/file_finder/src/file_finder.rs           |   6 
crates/gpui/src/app.rs                          |  20 +-
crates/gpui/src/elements/mouse_event_handler.rs | 132 +++++-------------
crates/gpui/src/presenter.rs                    |  50 ++++--
crates/gpui/src/scene.rs                        |   7 
crates/gpui/src/views/select.rs                 |   6 
crates/outline/src/outline.rs                   |   6 
crates/picker/src/picker.rs                     |  12 
crates/project_panel/src/project_panel.rs       |   2 
crates/project_symbols/src/project_symbols.rs   |   6 
crates/search/src/buffer_search.rs              |   4 
crates/search/src/project_search.rs             |   4 
crates/theme/src/theme.rs                       |   6 
crates/theme_selector/src/theme_selector.rs     |   4 
crates/workspace/src/lsp_status.rs              |   3 
crates/workspace/src/pane.rs                    |   2 
crates/workspace/src/sidebar.rs                 |   2 
crates/workspace/src/workspace.rs               |   4 
26 files changed, 150 insertions(+), 195 deletions(-)

Detailed changes

crates/auto_update/src/auto_update.rs 🔗

@@ -270,7 +270,7 @@ impl View for AutoUpdateIndicator {
                         )
                         .boxed()
                     })
-                    .on_click(|_, cx| cx.dispatch_action(DismissErrorMessage))
+                    .on_click(|_, _, cx| cx.dispatch_action(DismissErrorMessage))
                     .boxed()
                 }
                 AutoUpdateStatus::Idle => Empty::new().boxed(),

crates/chat_panel/src/chat_panel.rs 🔗

@@ -320,7 +320,7 @@ impl ChatPanel {
                 .boxed()
             })
             .with_cursor_style(CursorStyle::PointingHand)
-            .on_click(move |_, cx| {
+            .on_click(move |_, _, cx| {
                 let rpc = rpc.clone();
                 let this = this.clone();
                 cx.spawn(|mut cx| async move {

crates/command_palette/src/command_palette.rs 🔗

@@ -1,9 +1,9 @@
 use fuzzy::{StringMatch, StringMatchCandidate};
 use gpui::{
     actions,
-    elements::{ChildView, Flex, Label, MouseState, ParentElement},
+    elements::{ChildView, Flex, Label, ParentElement},
     keymap::Keystroke,
-    Action, Element, Entity, MutableAppContext, View, ViewContext, ViewHandle,
+    Action, Element, Entity, MouseState, MutableAppContext, View, ViewContext, ViewHandle,
 };
 use picker::{Picker, PickerDelegate};
 use settings::Settings;
@@ -203,7 +203,7 @@ impl PickerDelegate for CommandPalette {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &gpui::AppContext,
     ) -> gpui::ElementBox {

crates/contacts_panel/src/contact_finder.rs 🔗

@@ -1,7 +1,7 @@
 use client::{ContactRequestStatus, User, UserStore};
 use gpui::{
-    actions, elements::*, Entity, ModelHandle, MutableAppContext, RenderContext, Task, View,
-    ViewContext, ViewHandle,
+    actions, elements::*, Entity, ModelHandle, MouseState, MutableAppContext, RenderContext, Task,
+    View, ViewContext, ViewHandle,
 };
 use picker::{Picker, PickerDelegate};
 use settings::Settings;
@@ -105,7 +105,7 @@ impl PickerDelegate for ContactFinder {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &gpui::AppContext,
     ) -> ElementBox {

crates/contacts_panel/src/contacts_panel.rs 🔗

@@ -259,7 +259,7 @@ impl ContactsPanel {
     ) -> ElementBox {
         enum Header {}
 
-        let header_style = theme.header_row.style_for(&Default::default(), is_selected);
+        let header_style = theme.header_row.style_for(Default::default(), is_selected);
         let text = match section {
             Section::Requests => "Requests",
             Section::Online => "Online",
@@ -299,7 +299,7 @@ impl ContactsPanel {
                 .boxed()
         })
         .with_cursor_style(CursorStyle::PointingHand)
-        .on_click(move |_, cx| cx.dispatch_action(ToggleExpanded(section)))
+        .on_click(move |_, _, cx| cx.dispatch_action(ToggleExpanded(section)))
         .boxed()
     }
 
@@ -331,11 +331,7 @@ impl ContactsPanel {
             .constrained()
             .with_height(theme.row_height)
             .contained()
-            .with_style(
-                *theme
-                    .contact_row
-                    .style_for(&Default::default(), is_selected),
-            )
+            .with_style(*theme.contact_row.style_for(Default::default(), is_selected))
             .boxed()
     }
 
@@ -442,7 +438,7 @@ impl ContactsPanel {
         } else {
             CursorStyle::Arrow
         })
-        .on_click(move |_, cx| {
+        .on_click(move |_, _, cx| {
             if !is_host {
                 cx.dispatch_global_action(JoinProject {
                     contact: contact.clone(),
@@ -504,7 +500,7 @@ impl ContactsPanel {
                         .boxed()
                 })
                 .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(move |_, cx| {
+                .on_click(move |_, _, cx| {
                     cx.dispatch_action(RespondToContactRequest {
                         user_id,
                         accept: false,
@@ -526,7 +522,7 @@ impl ContactsPanel {
                         .boxed()
                 })
                 .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(move |_, cx| {
+                .on_click(move |_, _, cx| {
                     cx.dispatch_action(RespondToContactRequest {
                         user_id,
                         accept: true,
@@ -549,7 +545,7 @@ impl ContactsPanel {
                 })
                 .with_padding(Padding::uniform(2.))
                 .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(move |_, cx| cx.dispatch_action(RemoveContact(user_id)))
+                .on_click(move |_, _, cx| cx.dispatch_action(RemoveContact(user_id)))
                 .flex_float()
                 .boxed(),
             );
@@ -558,11 +554,7 @@ impl ContactsPanel {
         row.constrained()
             .with_height(theme.row_height)
             .contained()
-            .with_style(
-                *theme
-                    .contact_row
-                    .style_for(&Default::default(), is_selected),
-            )
+            .with_style(*theme.contact_row.style_for(Default::default(), is_selected))
             .boxed()
     }
 
@@ -862,7 +854,7 @@ impl View for ContactsPanel {
                                     .boxed()
                             })
                             .with_cursor_style(CursorStyle::PointingHand)
-                            .on_click(|_, cx| cx.dispatch_action(contact_finder::Toggle))
+                            .on_click(|_, _, cx| cx.dispatch_action(contact_finder::Toggle))
                             .boxed(),
                         )
                         .constrained()
@@ -910,7 +902,7 @@ impl View for ContactsPanel {
                                         },
                                     )
                                     .with_cursor_style(CursorStyle::PointingHand)
-                                    .on_click(move |_, cx| {
+                                    .on_click(move |_, _, cx| {
                                         cx.write_to_clipboard(ClipboardItem::new(
                                             info.url.to_string(),
                                         ));

crates/contacts_panel/src/notifications.rs 🔗

@@ -61,7 +61,7 @@ pub fn render_user_notification<V: View, A: Action + Clone>(
                     })
                     .with_cursor_style(CursorStyle::PointingHand)
                     .with_padding(Padding::uniform(5.))
-                    .on_click(move |_, cx| cx.dispatch_any_action(dismiss_action.boxed_clone()))
+                    .on_click(move |_, _, cx| cx.dispatch_any_action(dismiss_action.boxed_clone()))
                     .aligned()
                     .constrained()
                     .with_height(
@@ -76,13 +76,10 @@ pub fn render_user_notification<V: View, A: Action + Clone>(
                 .named("contact notification header"),
         )
         .with_children(body.map(|body| {
-            Label::new(
-                body.to_string(),
-                theme.body_message.text.clone(),
-            )
-            .contained()
-            .with_style(theme.body_message.container)
-            .boxed()
+            Label::new(body.to_string(), theme.body_message.text.clone())
+                .contained()
+                .with_style(theme.body_message.container)
+                .boxed()
         }))
         .with_children(if buttons.is_empty() {
             None
@@ -99,7 +96,7 @@ pub fn render_user_notification<V: View, A: Action + Clone>(
                                     .boxed()
                             })
                             .with_cursor_style(CursorStyle::PointingHand)
-                            .on_click(move |_, cx| cx.dispatch_any_action(action.boxed_clone()))
+                            .on_click(move |_, _, cx| cx.dispatch_any_action(action.boxed_clone()))
                             .boxed()
                         },
                     ))

crates/diagnostics/src/items.rs 🔗

@@ -159,7 +159,7 @@ impl View for DiagnosticIndicator {
                     .boxed()
             })
             .with_cursor_style(CursorStyle::PointingHand)
-            .on_click(|_, cx| cx.dispatch_action(crate::Deploy))
+            .on_click(|_, _, cx| cx.dispatch_action(crate::Deploy))
             .aligned()
             .boxed(),
         );
@@ -192,7 +192,7 @@ impl View for DiagnosticIndicator {
                     .boxed()
                 })
                 .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(|_, cx| cx.dispatch_action(GoToNextDiagnostic))
+                .on_click(|_, _, cx| cx.dispatch_action(GoToNextDiagnostic))
                 .boxed(),
             );
         }

crates/editor/src/editor.rs 🔗

@@ -679,7 +679,7 @@ impl CompletionsMenu {
                             },
                         )
                         .with_cursor_style(CursorStyle::PointingHand)
-                        .on_mouse_down(move |cx| {
+                        .on_mouse_down(move |_, cx| {
                             cx.dispatch_action(ConfirmCompletion {
                                 item_ix: Some(item_ix),
                             });
@@ -812,7 +812,7 @@ impl CodeActionsMenu {
                                 .boxed()
                         })
                         .with_cursor_style(CursorStyle::PointingHand)
-                        .on_mouse_down(move |cx| {
+                        .on_mouse_down(move |_, cx| {
                             cx.dispatch_action(ConfirmCodeAction {
                                 item_ix: Some(item_ix),
                             });
@@ -2603,7 +2603,7 @@ impl Editor {
                 })
                 .with_cursor_style(CursorStyle::PointingHand)
                 .with_padding(Padding::uniform(3.))
-                .on_mouse_down(|cx| {
+                .on_mouse_down(|_, cx| {
                     cx.dispatch_action(ToggleCodeActions {
                         deployed_from_indicator: true,
                     });

crates/file_finder/src/file_finder.rs 🔗

@@ -1,7 +1,7 @@
 use fuzzy::PathMatch;
 use gpui::{
-    actions, elements::*, AppContext, Entity, ModelHandle, MutableAppContext, RenderContext, Task,
-    View, ViewContext, ViewHandle,
+    actions, elements::*, AppContext, Entity, ModelHandle, MouseState, MutableAppContext,
+    RenderContext, Task, View, ViewContext, ViewHandle,
 };
 use picker::{Picker, PickerDelegate};
 use project::{Project, ProjectPath, WorktreeId};
@@ -226,7 +226,7 @@ impl PickerDelegate for FileFinder {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &AppContext,
     ) -> ElementBox {

crates/gpui/src/app.rs 🔗

@@ -460,7 +460,7 @@ impl TestAppContext {
                 view_id: handle.id(),
                 view_type: PhantomData,
                 titlebar_height: 0.,
-                hovered_region_id: None,
+                hovered_region_ids: Default::default(),
                 clicked_region_id: None,
                 refreshing: false,
             };
@@ -1080,7 +1080,7 @@ impl MutableAppContext {
                         window_id,
                         view_id,
                         titlebar_height,
-                        hovered_region_id: None,
+                        hovered_region_ids: Default::default(),
                         clicked_region_id: None,
                         refreshing: false,
                     })
@@ -3402,7 +3402,7 @@ pub struct RenderParams {
     pub window_id: usize,
     pub view_id: usize,
     pub titlebar_height: f32,
-    pub hovered_region_id: Option<MouseRegionId>,
+    pub hovered_region_ids: HashSet<MouseRegionId>,
     pub clicked_region_id: Option<MouseRegionId>,
     pub refreshing: bool,
 }
@@ -3411,14 +3411,14 @@ pub struct RenderContext<'a, T: View> {
     pub(crate) window_id: usize,
     pub(crate) view_id: usize,
     pub(crate) view_type: PhantomData<T>,
-    pub(crate) hovered_region_id: Option<MouseRegionId>,
+    pub(crate) hovered_region_ids: HashSet<MouseRegionId>,
     pub(crate) clicked_region_id: Option<MouseRegionId>,
     pub app: &'a mut MutableAppContext,
     pub titlebar_height: f32,
     pub refreshing: bool,
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Default)]
 pub struct MouseState {
     pub hovered: bool,
     pub clicked: bool,
@@ -3432,7 +3432,7 @@ impl<'a, V: View> RenderContext<'a, V> {
             view_id: params.view_id,
             view_type: PhantomData,
             titlebar_height: params.titlebar_height,
-            hovered_region_id: params.hovered_region_id,
+            hovered_region_ids: params.hovered_region_ids.clone(),
             clicked_region_id: params.clicked_region_id,
             refreshing: params.refreshing,
         }
@@ -3447,14 +3447,14 @@ impl<'a, V: View> RenderContext<'a, V> {
     }
 
     pub fn mouse_state<Tag: 'static>(&self, region_id: usize) -> MouseState {
-        let region_id = Some(MouseRegionId {
+        let region_id = MouseRegionId {
             view_id: self.view_id,
             tag: TypeId::of::<Tag>(),
             region_id,
-        });
+        };
         MouseState {
-            hovered: self.hovered_region_id == region_id,
-            clicked: self.clicked_region_id == region_id,
+            hovered: self.hovered_region_ids.contains(&region_id),
+            clicked: self.clicked_region_id == Some(region_id),
         }
     }
 

crates/gpui/src/elements/mouse_event_handler.rs 🔗

@@ -1,3 +1,5 @@
+use std::{any::TypeId, rc::Rc};
+
 use super::Padding;
 use crate::{
     geometry::{
@@ -6,40 +8,33 @@ use crate::{
     },
     platform::CursorStyle,
     scene::CursorRegion,
-    DebugContext, Element, ElementBox, ElementStateHandle, Event, EventContext, LayoutContext,
+    DebugContext, Element, ElementBox, Event, EventContext, LayoutContext, MouseRegion, MouseState,
     PaintContext, RenderContext, SizeConstraint, View,
 };
 use serde_json::json;
 
 pub struct MouseEventHandler {
-    state: ElementStateHandle<MouseState>,
     child: ElementBox,
+    tag: TypeId,
+    id: usize,
     cursor_style: Option<CursorStyle>,
-    mouse_down_handler: Option<Box<dyn FnMut(&mut EventContext)>>,
-    click_handler: Option<Box<dyn FnMut(usize, &mut EventContext)>>,
-    drag_handler: Option<Box<dyn FnMut(Vector2F, &mut EventContext)>>,
+    mouse_down_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
+    click_handler: Option<Rc<dyn Fn(Vector2F, usize, &mut EventContext)>>,
+    drag_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
     padding: Padding,
 }
 
-#[derive(Default)]
-pub struct MouseState {
-    pub hovered: bool,
-    pub clicked: bool,
-    prev_drag_position: Option<Vector2F>,
-}
-
 impl MouseEventHandler {
     pub fn new<Tag, V, F>(id: usize, cx: &mut RenderContext<V>, render_child: F) -> Self
     where
         Tag: 'static,
         V: View,
-        F: FnOnce(&MouseState, &mut RenderContext<V>) -> ElementBox,
+        F: FnOnce(MouseState, &mut RenderContext<V>) -> ElementBox,
     {
-        let state_handle = cx.element_state::<Tag, _>(id);
-        let child = state_handle.update(cx, |state, cx| render_child(state, cx));
         Self {
-            state: state_handle,
-            child,
+            id,
+            tag: TypeId::of::<Tag>(),
+            child: render_child(cx.mouse_state::<Tag>(id), cx),
             cursor_style: None,
             mouse_down_handler: None,
             click_handler: None,
@@ -53,18 +48,24 @@ impl MouseEventHandler {
         self
     }
 
-    pub fn on_mouse_down(mut self, handler: impl FnMut(&mut EventContext) + 'static) -> Self {
-        self.mouse_down_handler = Some(Box::new(handler));
+    pub fn on_mouse_down(
+        mut self,
+        handler: impl Fn(Vector2F, &mut EventContext) + 'static,
+    ) -> Self {
+        self.mouse_down_handler = Some(Rc::new(handler));
         self
     }
 
-    pub fn on_click(mut self, handler: impl FnMut(usize, &mut EventContext) + 'static) -> Self {
-        self.click_handler = Some(Box::new(handler));
+    pub fn on_click(
+        mut self,
+        handler: impl Fn(Vector2F, usize, &mut EventContext) + 'static,
+    ) -> Self {
+        self.click_handler = Some(Rc::new(handler));
         self
     }
 
-    pub fn on_drag(mut self, handler: impl FnMut(Vector2F, &mut EventContext) + 'static) -> Self {
-        self.drag_handler = Some(Box::new(handler));
+    pub fn on_drag(mut self, handler: impl Fn(Vector2F, &mut EventContext) + 'static) -> Self {
+        self.drag_handler = Some(Rc::new(handler));
         self
     }
 
@@ -107,6 +108,18 @@ impl Element for MouseEventHandler {
                 style,
             });
         }
+
+        cx.scene.push_mouse_region(MouseRegion {
+            view_id: cx.current_view_id(),
+            tag: self.tag,
+            region_id: self.id,
+            bounds,
+            hover: None,
+            click: self.click_handler.clone(),
+            mouse_down: self.mouse_down_handler.clone(),
+            drag: self.drag_handler.clone(),
+        });
+
         self.child.paint(bounds.origin(), visible_bounds, cx);
     }
 
@@ -114,81 +127,12 @@ impl Element for MouseEventHandler {
         &mut self,
         event: &Event,
         _: RectF,
-        visible_bounds: RectF,
+        _: RectF,
         _: &mut Self::LayoutState,
         _: &mut Self::PaintState,
         cx: &mut EventContext,
     ) -> bool {
-        let hit_bounds = self.hit_bounds(visible_bounds);
-        let mouse_down_handler = self.mouse_down_handler.as_mut();
-        let click_handler = self.click_handler.as_mut();
-        let drag_handler = self.drag_handler.as_mut();
-
-        let handled_in_child = self.child.dispatch_event(event, cx);
-
-        self.state.update(cx, |state, cx| match event {
-            Event::MouseMoved {
-                position,
-                left_mouse_down,
-            } => {
-                if !left_mouse_down {
-                    let mouse_in = hit_bounds.contains_point(*position);
-                    if state.hovered != mouse_in {
-                        state.hovered = mouse_in;
-                        cx.notify();
-                        return true;
-                    }
-                }
-                handled_in_child
-            }
-            Event::LeftMouseDown { position, .. } => {
-                if !handled_in_child && hit_bounds.contains_point(*position) {
-                    state.clicked = true;
-                    state.prev_drag_position = Some(*position);
-                    cx.notify();
-                    if let Some(handler) = mouse_down_handler {
-                        handler(cx);
-                    }
-                    true
-                } else {
-                    handled_in_child
-                }
-            }
-            Event::LeftMouseUp {
-                position,
-                click_count,
-                ..
-            } => {
-                state.prev_drag_position = None;
-                if !handled_in_child && state.clicked {
-                    state.clicked = false;
-                    cx.notify();
-                    if let Some(handler) = click_handler {
-                        if hit_bounds.contains_point(*position) {
-                            handler(*click_count, cx);
-                        }
-                    }
-                    true
-                } else {
-                    handled_in_child
-                }
-            }
-            Event::LeftMouseDragged { position, .. } => {
-                if !handled_in_child && state.clicked {
-                    let prev_drag_position = state.prev_drag_position.replace(*position);
-                    if let Some((handler, prev_position)) = drag_handler.zip(prev_drag_position) {
-                        let delta = *position - prev_position;
-                        if !delta.is_zero() {
-                            (handler)(delta, cx);
-                        }
-                    }
-                    true
-                } else {
-                    handled_in_child
-                }
-            }
-            _ => handled_in_child,
-        })
+        self.child.dispatch_event(event, cx)
     }
 
     fn debug(

crates/gpui/src/presenter.rs 🔗

@@ -31,7 +31,7 @@ pub struct Presenter {
     text_layout_cache: TextLayoutCache,
     asset_cache: Arc<AssetCache>,
     last_mouse_moved_event: Option<Event>,
-    hovered_region_id: Option<MouseRegionId>,
+    hovered_region_ids: HashSet<MouseRegionId>,
     clicked_region: Option<MouseRegion>,
     prev_drag_position: Option<Vector2F>,
     titlebar_height: f32,
@@ -56,7 +56,7 @@ impl Presenter {
             text_layout_cache,
             asset_cache,
             last_mouse_moved_event: None,
-            hovered_region_id: None,
+            hovered_region_ids: Default::default(),
             clicked_region: None,
             prev_drag_position: None,
             titlebar_height,
@@ -100,7 +100,7 @@ impl Presenter {
                     window_id: self.window_id,
                     view_id: *view_id,
                     titlebar_height: self.titlebar_height,
-                    hovered_region_id: self.hovered_region_id,
+                    hovered_region_ids: self.hovered_region_ids.clone(),
                     clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
                     refreshing: false,
                 })
@@ -118,7 +118,7 @@ impl Presenter {
                         window_id: self.window_id,
                         view_id: *view_id,
                         titlebar_height: self.titlebar_height,
-                        hovered_region_id: self.hovered_region_id,
+                        hovered_region_ids: self.hovered_region_ids.clone(),
                         clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
                         refreshing: true,
                     })
@@ -181,7 +181,7 @@ impl Presenter {
             asset_cache: &self.asset_cache,
             view_stack: Vec::new(),
             refreshing,
-            hovered_region_id: self.hovered_region_id,
+            hovered_region_ids: self.hovered_region_ids.clone(),
             clicked_region_id: self.clicked_region.as_ref().map(MouseRegion::id),
             titlebar_height: self.titlebar_height,
             app: cx,
@@ -198,14 +198,16 @@ impl Presenter {
             font_cache: &self.font_cache,
             text_layout_cache: &self.text_layout_cache,
             rendered_views: &mut self.rendered_views,
+            view_stack: Vec::new(),
             app: cx,
         }
     }
 
     pub fn dispatch_event(&mut self, event: Event, cx: &mut MutableAppContext) {
         if let Some(root_view_id) = cx.root_view_id(self.window_id) {
-            let mut unhovered_region = None;
-            let mut hovered_region = None;
+            let mut invalidated_views = Vec::new();
+            let mut hovered_regions = Vec::new();
+            let mut unhovered_regions = Vec::new();
             let mut clicked_region = None;
             let mut dragged_region = None;
 
@@ -213,6 +215,7 @@ impl Presenter {
                 Event::LeftMouseDown { position, .. } => {
                     for region in self.mouse_regions.iter().rev() {
                         if region.bounds.contains_point(position) {
+                            invalidated_views.push(region.view_id);
                             self.clicked_region = Some(region.clone());
                             self.prev_drag_position = Some(position);
                             break;
@@ -226,6 +229,7 @@ impl Presenter {
                 } => {
                     self.prev_drag_position.take();
                     if let Some(region) = self.clicked_region.take() {
+                        invalidated_views.push(region.view_id);
                         if region.bounds.contains_point(position) {
                             clicked_region = Some((region, position, click_count));
                         }
@@ -248,13 +252,18 @@ impl Presenter {
                         cx.platform().set_cursor_style(style_to_assign);
 
                         for region in self.mouse_regions.iter().rev() {
+                            let region_id = region.id();
                             if region.bounds.contains_point(position) {
-                                if hovered_region.is_none() {
-                                    hovered_region = Some(region.clone());
+                                if !self.hovered_region_ids.contains(&region_id) {
+                                    invalidated_views.push(region.view_id);
+                                    hovered_regions.push(region.clone());
+                                    self.hovered_region_ids.insert(region_id);
                                 }
                             } else {
-                                if self.hovered_region_id == Some(region.id()) {
-                                    unhovered_region = Some(region.clone())
+                                if self.hovered_region_ids.contains(&region_id) {
+                                    invalidated_views.push(region.view_id);
+                                    unhovered_regions.push(region.clone());
+                                    self.hovered_region_ids.remove(&region_id);
                                 }
                             }
                         }
@@ -279,10 +288,8 @@ impl Presenter {
                 _ => {}
             }
 
-            self.hovered_region_id = hovered_region.as_ref().map(MouseRegion::id);
-
             let mut event_cx = self.build_event_context(cx);
-            if let Some(unhovered_region) = unhovered_region {
+            for unhovered_region in unhovered_regions {
                 if let Some(hover_callback) = unhovered_region.hover {
                     event_cx.with_current_view(unhovered_region.view_id, |event_cx| {
                         hover_callback(false, event_cx);
@@ -290,7 +297,7 @@ impl Presenter {
                 }
             }
 
-            if let Some(hovered_region) = hovered_region {
+            for hovered_region in hovered_regions {
                 if let Some(hover_callback) = hovered_region.hover {
                     event_cx.with_current_view(hovered_region.view_id, |event_cx| {
                         hover_callback(true, event_cx);
@@ -316,7 +323,7 @@ impl Presenter {
 
             event_cx.dispatch_event(root_view_id, &event);
 
-            let invalidated_views = event_cx.invalidated_views;
+            invalidated_views.extend(event_cx.invalidated_views);
             let dispatch_directives = event_cx.dispatched_actions;
 
             for view_id in invalidated_views {
@@ -376,7 +383,7 @@ pub struct LayoutContext<'a> {
     pub app: &'a mut MutableAppContext,
     pub refreshing: bool,
     titlebar_height: f32,
-    hovered_region_id: Option<MouseRegionId>,
+    hovered_region_ids: HashSet<MouseRegionId>,
     clicked_region_id: Option<MouseRegionId>,
 }
 
@@ -405,7 +412,7 @@ impl<'a> LayoutContext<'a> {
                 view_id: handle.id(),
                 view_type: PhantomData,
                 titlebar_height: self.titlebar_height,
-                hovered_region_id: self.hovered_region_id,
+                hovered_region_ids: self.hovered_region_ids.clone(),
                 clicked_region_id: self.clicked_region_id,
                 refreshing: self.refreshing,
             };
@@ -469,6 +476,7 @@ impl<'a> UpgradeViewHandle for LayoutContext<'a> {
 
 pub struct PaintContext<'a> {
     rendered_views: &'a mut HashMap<usize, ElementBox>,
+    view_stack: Vec<usize>,
     pub scene: &'a mut Scene,
     pub font_cache: &'a FontCache,
     pub text_layout_cache: &'a TextLayoutCache,
@@ -478,10 +486,16 @@ pub struct PaintContext<'a> {
 impl<'a> PaintContext<'a> {
     fn paint(&mut self, view_id: usize, origin: Vector2F, visible_bounds: RectF) {
         if let Some(mut tree) = self.rendered_views.remove(&view_id) {
+            self.view_stack.push(view_id);
             tree.paint(origin, visible_bounds, self);
             self.rendered_views.insert(view_id, tree);
+            self.view_stack.pop();
         }
     }
+
+    pub fn current_view_id(&self) -> usize {
+        *self.view_stack.last().unwrap()
+    }
 }
 
 impl<'a> Deref for PaintContext<'a> {

crates/gpui/src/scene.rs 🔗

@@ -50,11 +50,12 @@ pub struct MouseRegion {
     pub region_id: usize,
     pub bounds: RectF,
     pub hover: Option<Rc<dyn Fn(bool, &mut EventContext)>>,
+    pub mouse_down: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
     pub click: Option<Rc<dyn Fn(Vector2F, usize, &mut EventContext)>>,
     pub drag: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
 }
 
-#[derive(Copy, Clone, Eq, PartialEq)]
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub struct MouseRegionId {
     pub view_id: usize,
     pub tag: TypeId,
@@ -242,6 +243,10 @@ impl Scene {
         self.active_layer().push_cursor_region(region);
     }
 
+    pub fn push_mouse_region(&mut self, region: MouseRegion) {
+        self.active_layer().push_mouse_region(region);
+    }
+
     pub fn push_image(&mut self, image: Image) {
         self.active_layer().push_image(image)
     }

crates/gpui/src/views/select.rs 🔗

@@ -119,7 +119,7 @@ impl View for Select {
                 .with_style(style.header)
                 .boxed()
             })
-            .on_click(move |_, cx| cx.dispatch_action(ToggleSelect))
+            .on_click(move |_, _, cx| cx.dispatch_action(ToggleSelect))
             .boxed(),
         );
         if self.is_open {
@@ -151,7 +151,9 @@ impl View for Select {
                                                 )
                                             },
                                         )
-                                        .on_click(move |_, cx| cx.dispatch_action(SelectItem(ix)))
+                                        .on_click(move |_, _, cx| {
+                                            cx.dispatch_action(SelectItem(ix))
+                                        })
                                         .boxed()
                                     }))
                                 },

crates/outline/src/outline.rs 🔗

@@ -4,8 +4,8 @@ use editor::{
 };
 use fuzzy::StringMatch;
 use gpui::{
-    actions, elements::*, geometry::vector::Vector2F, AppContext, Entity, MutableAppContext,
-    RenderContext, Task, View, ViewContext, ViewHandle,
+    actions, elements::*, geometry::vector::Vector2F, AppContext, Entity, MouseState,
+    MutableAppContext, RenderContext, Task, View, ViewContext, ViewHandle,
 };
 use language::Outline;
 use ordered_float::OrderedFloat;
@@ -231,7 +231,7 @@ impl PickerDelegate for OutlineView {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &AppContext,
     ) -> ElementBox {

crates/picker/src/picker.rs 🔗

@@ -1,14 +1,14 @@
 use editor::Editor;
 use gpui::{
     elements::{
-        ChildView, Flex, Label, MouseEventHandler, MouseState, ParentElement, ScrollTarget,
-        UniformList, UniformListState,
+        ChildView, Flex, Label, MouseEventHandler, ParentElement, ScrollTarget, UniformList,
+        UniformListState,
     },
     geometry::vector::{vec2f, Vector2F},
     keymap,
     platform::CursorStyle,
-    AppContext, Axis, Element, ElementBox, Entity, MutableAppContext, RenderContext, Task, View,
-    ViewContext, ViewHandle, WeakViewHandle,
+    AppContext, Axis, Element, ElementBox, Entity, MouseState, MutableAppContext, RenderContext,
+    Task, View, ViewContext, ViewHandle, WeakViewHandle,
 };
 use settings::Settings;
 use std::cmp;
@@ -34,7 +34,7 @@ pub trait PickerDelegate: View {
     fn render_match(
         &self,
         ix: usize,
-        state: &MouseState,
+        state: MouseState,
         selected: bool,
         cx: &AppContext,
     ) -> ElementBox;
@@ -92,7 +92,7 @@ impl<D: PickerDelegate> View for Picker<D> {
                                         .read(cx)
                                         .render_match(ix, state, ix == selected_ix, cx)
                                 })
-                                .on_mouse_down(move |cx| cx.dispatch_action(SelectIndex(ix)))
+                                .on_mouse_down(move |_, cx| cx.dispatch_action(SelectIndex(ix)))
                                 .with_cursor_style(CursorStyle::PointingHand)
                                 .boxed()
                             }));

crates/project_panel/src/project_panel.rs 🔗

@@ -839,7 +839,7 @@ impl ProjectPanel {
                 .with_padding_left(padding)
                 .boxed()
         })
-        .on_click(move |click_count, cx| {
+        .on_click(move |_, click_count, cx| {
             if kind == EntryKind::Dir {
                 cx.dispatch_action(ToggleExpanded(entry_id))
             } else {

crates/project_symbols/src/project_symbols.rs 🔗

@@ -3,8 +3,8 @@ use editor::{
 };
 use fuzzy::{StringMatch, StringMatchCandidate};
 use gpui::{
-    actions, elements::*, AppContext, Entity, ModelHandle, MutableAppContext, RenderContext, Task,
-    View, ViewContext, ViewHandle,
+    actions, elements::*, AppContext, Entity, ModelHandle, MouseState, MutableAppContext,
+    RenderContext, Task, View, ViewContext, ViewHandle,
 };
 use ordered_float::OrderedFloat;
 use picker::{Picker, PickerDelegate};
@@ -221,7 +221,7 @@ impl PickerDelegate for ProjectSymbolsView {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &AppContext,
     ) -> ElementBox {

crates/search/src/buffer_search.rs 🔗

@@ -290,7 +290,7 @@ impl BufferSearchBar {
                 .with_style(style.container)
                 .boxed()
         })
-        .on_click(move |_, cx| cx.dispatch_action(ToggleSearchOption(search_option)))
+        .on_click(move |_, _, cx| cx.dispatch_action(ToggleSearchOption(search_option)))
         .with_cursor_style(CursorStyle::PointingHand)
         .boxed()
     }
@@ -314,7 +314,7 @@ impl BufferSearchBar {
                 .with_style(style.container)
                 .boxed()
         })
-        .on_click(move |_, cx| match direction {
+        .on_click(move |_, _, cx| match direction {
             Direction::Prev => cx.dispatch_action(SelectPrevMatch),
             Direction::Next => cx.dispatch_action(SelectNextMatch),
         })

crates/search/src/project_search.rs 🔗

@@ -672,7 +672,7 @@ impl ProjectSearchBar {
                 .with_style(style.container)
                 .boxed()
         })
-        .on_click(move |_, cx| match direction {
+        .on_click(move |_, _, cx| match direction {
             Direction::Prev => cx.dispatch_action(SelectPrevMatch),
             Direction::Next => cx.dispatch_action(SelectNextMatch),
         })
@@ -699,7 +699,7 @@ impl ProjectSearchBar {
                 .with_style(style.container)
                 .boxed()
         })
-        .on_click(move |_, cx| cx.dispatch_action(ToggleSearchOption(option)))
+        .on_click(move |_, _, cx| cx.dispatch_action(ToggleSearchOption(option)))
         .with_cursor_style(CursorStyle::PointingHand)
         .boxed()
     }

crates/theme/src/theme.rs 🔗

@@ -2,9 +2,9 @@ mod theme_registry;
 
 use gpui::{
     color::Color,
-    elements::{ContainerStyle, ImageStyle, LabelStyle, MouseState},
+    elements::{ContainerStyle, ImageStyle, LabelStyle},
     fonts::{HighlightStyle, TextStyle},
-    Border,
+    Border, MouseState,
 };
 use serde::{de::DeserializeOwned, Deserialize};
 use serde_json::Value;
@@ -488,7 +488,7 @@ pub struct Interactive<T> {
 }
 
 impl<T> Interactive<T> {
-    pub fn style_for(&self, state: &MouseState, active: bool) -> &T {
+    pub fn style_for(&self, state: MouseState, active: bool) -> &T {
         if active {
             if state.hovered {
                 self.active_hover

crates/theme_selector/src/theme_selector.rs 🔗

@@ -1,6 +1,6 @@
 use fuzzy::{match_strings, StringMatch, StringMatchCandidate};
 use gpui::{
-    actions, elements::*, AppContext, Element, ElementBox, Entity, MutableAppContext,
+    actions, elements::*, AppContext, Element, ElementBox, Entity, MouseState, MutableAppContext,
     RenderContext, View, ViewContext, ViewHandle,
 };
 use picker::{Picker, PickerDelegate};
@@ -213,7 +213,7 @@ impl PickerDelegate for ThemeSelector {
     fn render_match(
         &self,
         ix: usize,
-        mouse_state: &MouseState,
+        mouse_state: MouseState,
         selected: bool,
         cx: &AppContext,
     ) -> ElementBox {

crates/workspace/src/lsp_status.rs 🔗

@@ -168,7 +168,8 @@ impl View for LspStatus {
                     self.failed.join(", "),
                     if self.failed.len() > 1 { "s" } else { "" }
                 );
-                handler = Some(|_, cx: &mut EventContext| cx.dispatch_action(DismissErrorMessage));
+                handler =
+                    Some(|_, _, cx: &mut EventContext| cx.dispatch_action(DismissErrorMessage));
             } else {
                 return Empty::new().boxed();
             }

crates/workspace/src/pane.rs 🔗

@@ -788,7 +788,7 @@ impl Pane {
                                             .with_cursor_style(CursorStyle::PointingHand)
                                             .on_click({
                                                 let pane = pane.clone();
-                                                move |_, cx| {
+                                                move |_, _, cx| {
                                                     cx.dispatch_action(CloseItem {
                                                         item_id,
                                                         pane: pane.clone(),

crates/workspace/src/sidebar.rs 🔗

@@ -293,7 +293,7 @@ impl View for SidebarButtons {
                                 .boxed()
                         })
                         .with_cursor_style(CursorStyle::PointingHand)
-                        .on_click(move |_, cx| {
+                        .on_click(move |_, _, cx| {
                             cx.dispatch_action(ToggleSidebarItem {
                                 side,
                                 item_index: ix,

crates/workspace/src/workspace.rs 🔗

@@ -1730,7 +1730,7 @@ impl Workspace {
                         .with_style(style.container)
                         .boxed()
                 })
-                .on_click(|_, cx| cx.dispatch_action(Authenticate))
+                .on_click(|_, _, cx| cx.dispatch_action(Authenticate))
                 .with_cursor_style(CursorStyle::PointingHand)
                 .aligned()
                 .boxed(),
@@ -1781,7 +1781,7 @@ impl Workspace {
         if let Some(peer_id) = peer_id {
             MouseEventHandler::new::<ToggleFollow, _, _>(replica_id.into(), cx, move |_, _| content)
                 .with_cursor_style(CursorStyle::PointingHand)
-                .on_click(move |_, cx| cx.dispatch_action(ToggleFollow(peer_id)))
+                .on_click(move |_, _, cx| cx.dispatch_action(ToggleFollow(peer_id)))
                 .boxed()
         } else {
             content