Hover updates after widget removal

This also fixes some inconsistencies that arose when the focus widget
was "stuck" on a removed widget. Button previously handled it hackily in
a redraw function, but now Gooey handles it automatically without
needing to wait for a repaint.

examples/tic-tac-toe.rs

@@ -141,9 +141,14 @@ fn game_end(winner: Option<Player>, app: &Dynamic<AppState>) -> impl MakeWidget
     };
 
     label
-        .and("Play Again".into_button().on_click(move |_| {
-            app.set(AppState::Playing);
-        }))
+        .and(
+            "Play Again"
+                .into_button()
+                .on_click(move |_| {
+                    app.set(AppState::Playing);
+                })
+                .into_default(),
+        )
         .into_rows()
         .centered()
         .expand()

src/context.rs

@@ -21,7 +21,7 @@ use crate::utils::IgnorePoison;
 use crate::value::{Dynamic, IntoValue, Value};
 use crate::widget::{EventHandling, ManagedWidget, WidgetId, WidgetInstance, WidgetRef};
 use crate::window::sealed::WindowCommand;
-use crate::window::{RunningWindow, ThemeMode};
+use crate::window::{CursorState, RunningWindow, ThemeMode};
 use crate::ConstraintLimit;
 
 /// A context to an event function.
@@ -185,7 +185,10 @@ impl<'context, 'window> EventContext<'context, 'window> {
 
         let mut activation_changes = 0;
         while activation_changes < MAX_ITERS {
-            let active = self.pending_state.active.clone();
+            let active = self
+                .pending_state
+                .active
+                .and_then(|w| self.current_node.tree.widget(w));
             if self.current_node.tree.active_widget() == active.as_ref().map(|w| w.node_id) {
                 break;
             }
@@ -202,13 +205,16 @@ impl<'context, 'window> EventContext<'context, 'window> {
                 Err(()) => false,
             };
             if new {
-                if let Some(active) = self.pending_state.active.clone() {
+                let active = self
+                    .pending_state
+                    .active
+                    .and_then(|w| self.current_node.tree.widget(w));
+                if let Some(active) = &active {
                     active
                         .lock()
                         .as_widget()
-                        .activate(&mut self.for_other(&active));
+                        .activate(&mut self.for_other(active));
                 }
-                self.pending_state.active = active;
             } else {
                 break;
             }
@@ -222,7 +228,10 @@ impl<'context, 'window> EventContext<'context, 'window> {
 
         let mut focus_changes = 0;
         while focus_changes < MAX_ITERS {
-            let focus = self.pending_state.focus.clone();
+            let focus = self
+                .pending_state
+                .focus
+                .and_then(|w| self.current_node.tree.widget(w));
             if self.current_node.tree.focused_widget() == focus.as_ref().map(|w| w.node_id) {
                 break;
             }
@@ -235,7 +244,7 @@ impl<'context, 'window> EventContext<'context, 'window> {
                 drop(focus_context);
 
                 if accept_focus {
-                    break Some(focus);
+                    break Some(focus.id());
                 } else if let Some(next_focus) =
                     focus.explicit_focus_target(self.pending_state.focus_is_advancing)
                 {
@@ -244,11 +253,7 @@ impl<'context, 'window> EventContext<'context, 'window> {
                     break self.next_focus_after(focus, self.pending_state.focus_is_advancing);
                 }
             });
-            let new = match self
-                .current_node
-                .tree
-                .focus(self.pending_state.focus.as_ref())
-            {
+            let new = match self.current_node.tree.focus(self.pending_state.focus) {
                 Ok(old) => {
                     if let Some(old) = old {
                         let mut old_context = self.for_other(&old);
@@ -259,7 +264,11 @@ impl<'context, 'window> EventContext<'context, 'window> {
                 Err(()) => false,
             };
             if new {
-                if let Some(focus) = self.pending_state.focus.clone() {
+                if let Some(focus) = self
+                    .pending_state
+                    .focus
+                    .and_then(|w| self.current_node.tree.widget(w))
+                {
                     focus.lock().as_widget().focus(&mut self.for_other(&focus));
                 }
             } else {
@@ -270,13 +279,40 @@ impl<'context, 'window> EventContext<'context, 'window> {
         if focus_changes == MAX_ITERS {
             tracing::error!("focus change force stopped after {focus_changes} sequential changes");
         }
+
+        // Check that our hover widget still exists. If not, we should try to find a new one.
+        if let Some(hover) = self.current_node.tree.hovered_widget() {
+            if self.current_node.tree.widget_from_node(hover).is_none() {
+                self.update_hovered_widget();
+            }
+        }
     }
 
-    fn next_focus_after(
-        &mut self,
-        mut focus: ManagedWidget,
-        advance: bool,
-    ) -> Option<ManagedWidget> {
+    pub(crate) fn update_hovered_widget(&mut self) {
+        self.cursor.widget = None;
+        if let Some(location) = self.cursor.location {
+            for widget in self.current_node.tree.widgets_under_point(location) {
+                let mut widget_context = self.for_other(&widget);
+                let Some(widget_layout) = widget_context.last_layout() else {
+                    continue;
+                };
+                let relative = location - widget_layout.origin;
+
+                if widget_context.hit_test(relative) {
+                    widget_context.hover(relative);
+                    drop(widget_context);
+                    self.cursor.widget = Some(widget.id());
+                    break;
+                }
+            }
+        }
+
+        if self.cursor.widget.is_none() {
+            self.clear_hover();
+        }
+    }
+
+    fn next_focus_after(&mut self, mut focus: ManagedWidget, advance: bool) -> Option<WidgetId> {
         // First, look within the current focus for any focusable children.
         let stop_at = focus.id();
         if let Some(focus) = self.next_focus_within(&focus, None, stop_at, advance) {
@@ -304,7 +340,7 @@ impl<'context, 'window> EventContext<'context, 'window> {
         focus: &ManagedWidget,
         stop_at: WidgetId,
         advance: bool,
-    ) -> Option<ManagedWidget> {
+    ) -> Option<WidgetId> {
         self.next_focus_within(&focus.parent()?, Some(focus.id()), stop_at, advance)
     }
 
@@ -317,7 +353,7 @@ impl<'context, 'window> EventContext<'context, 'window> {
         start_at: Option<WidgetId>,
         stop_at: WidgetId,
         advance: bool,
-    ) -> Option<ManagedWidget> {
+    ) -> Option<WidgetId> {
         let mut visual_order = self.get(&LayoutOrder);
         if !advance {
             visual_order = visual_order.rev();
@@ -346,9 +382,9 @@ impl<'context, 'window> EventContext<'context, 'window> {
                 .as_widget()
                 .accept_focus(&mut self.for_other(&child))
             {
-                return Some(child);
+                return Some(child.id());
             } else if let Some(next_focus) = self.widget().explicit_focus_target(advance) {
-                return Some(next_focus);
+                return Some(next_focus.id());
             } else if let Some(focus) = self.next_focus_within(&child, None, stop_at, advance) {
                 return Some(focus);
             }
@@ -705,6 +741,7 @@ pub struct WidgetContext<'context, 'window> {
     redraw_status: &'context InvalidationStatus,
     window: &'context mut RunningWindow<'window>,
     theme: Cow<'context, ThemePair>,
+    cursor: &'context mut CursorState,
     pending_state: PendingState<'context>,
     effective_styles: Styles,
     cache: WidgetCacheKey,
@@ -717,6 +754,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
         theme: &'context ThemePair,
         window: &'context mut RunningWindow<'window>,
         theme_mode: ThemeMode,
+        cursor: &'context mut CursorState,
     ) -> Self {
         let enabled = current_node.enabled(&WindowHandle {
             kludgine: window.handle(),
@@ -727,11 +765,11 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
                 focus: current_node
                     .tree
                     .focused_widget()
-                    .and_then(|id| current_node.tree.widget_from_node(id)),
+                    .and_then(|id| current_node.tree.widget_from_node(id).map(|w| w.id())),
                 active: current_node
                     .tree
                     .active_widget()
-                    .and_then(|id| current_node.tree.widget_from_node(id)),
+                    .and_then(|id| current_node.tree.widget_from_node(id).map(|w| w.id())),
                 focus_is_advancing: false,
             }),
             effective_styles: current_node.effective_styles(),
@@ -740,6 +778,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
                 enabled,
                 invalidation: current_node.invalidation(),
             },
+            cursor,
             current_node,
             redraw_status,
             theme: Cow::Borrowed(theme),
@@ -757,6 +796,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
             pending_state: self.pending_state.borrowed(),
             cache: self.cache,
             effective_styles: self.effective_styles.clone(),
+            cursor: &mut *self.cursor,
         }
     }
 
@@ -793,6 +833,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
                 window: &mut *self.window,
                 theme,
                 pending_state: self.pending_state.borrowed(),
+                cursor: &mut *self.cursor,
             }
         })
     }
@@ -829,7 +870,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
     /// contexts for the currently firing event are dropped.
     pub fn focus(&mut self) {
         self.pending_state.focus_is_advancing = true;
-        self.pending_state.focus = Some(self.current_node.clone());
+        self.pending_state.focus = Some(self.current_node.id());
     }
 
     pub(crate) fn clear_focus(&mut self) {
@@ -859,16 +900,11 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
     /// Widget events relating to activation changes are deferred until after
     /// the all contexts for the currently firing event are dropped.
     pub fn activate(&mut self) -> bool {
-        if self
-            .pending_state
-            .active
-            .as_ref()
-            .map_or(true, |active| active != &self.current_node)
-        {
-            self.pending_state.active = Some(self.current_node.clone());
-            true
-        } else {
+        if self.pending_state.active == Some(self.current_node.id()) {
             false
+        } else {
+            self.pending_state.active = Some(self.current_node.id());
+            true
         }
     }
 
@@ -895,7 +931,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
     /// Returns true if this widget is currently the active widget.
     #[must_use]
     pub fn active(&self) -> bool {
-        self.pending_state.active.as_ref() == Some(&self.current_node)
+        self.pending_state.active == Some(self.current_node.id())
     }
 
     /// Returns true if this widget is currently hovered, even if the cursor is
@@ -914,7 +950,7 @@ impl<'context, 'window> WidgetContext<'context, 'window> {
     /// Returns true if this widget is currently focused for user input.
     #[must_use]
     pub fn focused(&self) -> bool {
-        self.pending_state.focus.as_ref() == Some(&self.current_node)
+        self.pending_state.focus == Some(self.current_node.id())
     }
 
     /// Returns true if this widget is the target to activate when the user
@@ -1100,8 +1136,8 @@ enum PendingState<'a> {
 #[derive(Default)]
 struct PendingWidgetState {
     focus_is_advancing: bool,
-    focus: Option<ManagedWidget>,
-    active: Option<ManagedWidget>,
+    focus: Option<WidgetId>,
+    active: Option<WidgetId>,
 }
 
 impl PendingState<'_> {

src/tree.rs

@@ -231,24 +231,27 @@ impl Tree {
         let hovered = new_hover
             .map(|new_hover| data.widget_hierarchy(new_hover.node_id, self))
             .unwrap_or_default();
-        let unhovered = match data.update_tracked_widget(new_hover, self, |data| &mut data.hover) {
-            Ok(Some(old_hover)) => {
-                let mut old_hovered = data.widget_hierarchy(old_hover.node_id, self);
-                // For any widgets that were shared, remove them, as they don't
-                // need to have their events fired again.
-                let mut new_index = 0;
-                while !old_hovered.is_empty() && old_hovered.get(0) == hovered.get(new_index) {
-                    old_hovered.remove(0);
-                    new_index += 1;
+        let unhovered =
+            match data.update_tracked_widget(new_hover.map(ManagedWidget::id), self, |data| {
+                &mut data.hover
+            }) {
+                Ok(Some(old_hover)) => {
+                    let mut old_hovered = data.widget_hierarchy(old_hover.node_id, self);
+                    // For any widgets that were shared, remove them, as they don't
+                    // need to have their events fired again.
+                    let mut new_index = 0;
+                    while !old_hovered.is_empty() && old_hovered.get(0) == hovered.get(new_index) {
+                        old_hovered.remove(0);
+                        new_index += 1;
+                    }
+                    old_hovered
                 }
-                old_hovered
-            }
-            _ => Vec::new(),
-        };
+                _ => Vec::new(),
+            };
         HoverResults { unhovered, hovered }
     }
 
-    pub fn focus(&self, new_focus: Option<&ManagedWidget>) -> Result<Option<ManagedWidget>, ()> {
+    pub fn focus(&self, new_focus: Option<WidgetId>) -> Result<Option<ManagedWidget>, ()> {
         let mut data = self.data.lock().ignore_poison();
         data.update_tracked_widget(new_focus, self, |data| &mut data.focus)
     }
@@ -264,7 +267,9 @@ impl Tree {
         new_active: Option<&ManagedWidget>,
     ) -> Result<Option<ManagedWidget>, ()> {
         let mut data = self.data.lock().ignore_poison();
-        data.update_tracked_widget(new_active, self, |data| &mut data.active)
+        data.update_tracked_widget(new_active.map(ManagedWidget::id), self, |data| {
+            &mut data.active
+        })
     }
 
     pub fn widget(&self, id: WidgetId) -> Option<ManagedWidget> {
@@ -334,7 +339,7 @@ impl Tree {
         self.data.lock().ignore_poison().focus
     }
 
-    pub(crate) fn widgets_at_point(&self, point: Point<Px>) -> Vec<ManagedWidget> {
+    pub(crate) fn widgets_under_point(&self, point: Point<Px>) -> Vec<ManagedWidget> {
         let data = self.data.lock().ignore_poison();
         data.render_info.widgets_under_point(point, &data, self)
     }
@@ -489,12 +494,13 @@ impl TreeData {
 
     fn update_tracked_widget(
         &mut self,
-        new_widget: Option<&ManagedWidget>,
+        new_widget: Option<WidgetId>,
         tree: &Tree,
         property: impl FnOnce(&mut Self) -> &mut Option<LotId>,
     ) -> Result<Option<ManagedWidget>, ()> {
+        let new_widget = new_widget.and_then(|w| self.widget_from_id(w, tree));
         match (
-            mem::replace(property(self), new_widget.map(|w| w.node_id)),
+            mem::replace(property(self), new_widget.as_ref().map(|w| w.node_id)),
             new_widget,
         ) {
             (Some(old_widget), Some(new_widget)) if old_widget == new_widget.node_id => Err(()),

src/widgets/button.rs

@@ -219,11 +219,6 @@ impl Button {
             kind,
         };
 
-        // TODO this should be genericized to happen automatically.
-        if !context.enabled() {
-            context.blur();
-        }
-
         if context.is_default() {
             kind.colors_for_default(visual_state, context)
         } else {

src/window.rs

@@ -278,7 +278,8 @@ struct GooeyWindow<T> {
     root: ManagedWidget,
     contents: Drawing,
     should_close: bool,
-    mouse_state: MouseState,
+    cursor: CursorState,
+    mouse_buttons: AHashMap<DeviceId, AHashMap<MouseButton, WidgetId>>,
     redraw_status: InvalidationStatus,
     initial_frame: bool,
     occluded: Dynamic<bool>,
@@ -319,6 +320,7 @@ where
                             &self.current_theme,
                             window,
                             self.theme_mode.get(),
+                            &mut self.cursor,
                         ),
                         kludgine,
                     )
@@ -331,6 +333,7 @@ where
                         &self.current_theme,
                         window,
                         self.theme_mode.get(),
+                        &mut self.cursor,
                     ),
                     kludgine,
                 )
@@ -345,6 +348,7 @@ where
                     &self.current_theme,
                     window,
                     self.theme_mode.get(),
+                    &mut self.cursor,
                 ),
                 kludgine,
             )
@@ -466,11 +470,11 @@ where
             root,
             contents: Drawing::default(),
             should_close: false,
-            mouse_state: MouseState {
+            cursor: CursorState {
                 location: None,
                 widget: None,
-                devices: AHashMap::default(),
             },
+            mouse_buttons: AHashMap::default(),
             redraw_status: InvalidationStatus::default(),
             initial_frame: true,
             occluded,
@@ -517,6 +521,7 @@ where
                 &self.current_theme,
                 &mut window,
                 self.theme_mode.get(),
+                &mut self.cursor,
             ),
             gfx: Exclusive::Owned(Graphics::new(graphics)),
         };
@@ -684,11 +689,9 @@ where
         is_synthetic: bool,
     ) {
         let target = self.root.tree.focused_widget().unwrap_or(self.root.node_id);
-        let target = self
-            .root
-            .tree
-            .widget_from_node(target)
-            .expect("missing widget");
+        let Some(target) = self.root.tree.widget_from_node(target) else {
+            return;
+        };
         let mut window = RunningWindow::new(window, &self.focused, &self.occluded);
         let mut target = EventContext::new(
             WidgetContext::new(
@@ -697,6 +700,7 @@ where
                 &self.current_theme,
                 &mut window,
                 self.theme_mode.get(),
+                &mut self.cursor,
             ),
             kludgine,
         );
@@ -731,6 +735,7 @@ where
                                 &self.current_theme,
                                 &mut window,
                                 self.theme_mode.get(),
+                                &mut self.cursor,
                             ),
                             kludgine,
                         );
@@ -798,6 +803,7 @@ where
                 &self.current_theme,
                 &mut window,
                 self.theme_mode.get(),
+                &mut self.cursor,
             ),
             kludgine,
         );
@@ -833,6 +839,7 @@ where
                 &self.current_theme,
                 &mut window,
                 self.theme_mode.get(),
+                &mut self.cursor,
             ),
             kludgine,
         );
@@ -849,10 +856,24 @@ where
         position: PhysicalPosition<f64>,
     ) {
         let location = Point::<Px>::from(position);
-        self.mouse_state.location = Some(location);
+        self.cursor.location = Some(location);
 
         let mut window = RunningWindow::new(window, &self.focused, &self.occluded);
-        if let Some(state) = self.mouse_state.devices.get(&device_id) {
+
+        EventContext::new(
+            WidgetContext::new(
+                self.root.clone(),
+                &self.redraw_status,
+                &self.current_theme,
+                &mut window,
+                self.theme_mode.get(),
+                &mut self.cursor,
+            ),
+            kludgine,
+        )
+        .update_hovered_widget();
+
+        if let Some(state) = self.mouse_buttons.get(&device_id) {
             // Mouse Drag
             for (button, handler) in state {
                 let Some(handler) = self.root.tree.widget(*handler) else {
@@ -865,6 +886,7 @@ where
                         &self.current_theme,
                         &mut window,
                         self.theme_mode.get(),
+                        &mut self.cursor,
                     ),
                     kludgine,
                 );
@@ -873,37 +895,6 @@ where
                 };
                 context.mouse_drag(location - last_rendered_at.origin, device_id, *button);
             }
-        } else {
-            // Hover
-            let mut context = EventContext::new(
-                WidgetContext::new(
-                    self.root.clone(),
-                    &self.redraw_status,
-                    &self.current_theme,
-                    &mut window,
-                    self.theme_mode.get(),
-                ),
-                kludgine,
-            );
-            self.mouse_state.widget = None;
-            for widget in self.root.tree.widgets_at_point(location) {
-                let mut widget_context = context.for_other(&widget);
-                let Some(widget_layout) = widget_context.last_layout() else {
-                    continue;
-                };
-                let relative = location - widget_layout.origin;
-
-                if widget_context.hit_test(relative) {
-                    widget_context.hover(relative);
-                    drop(widget_context);
-                    self.mouse_state.widget = Some(widget.id());
-                    break;
-                }
-            }
-
-            if self.mouse_state.widget.is_none() {
-                context.clear_hover();
-            }
         }
     }
 
@@ -913,7 +904,7 @@ where
         kludgine: &mut Kludgine,
         _device_id: DeviceId,
     ) {
-        if self.mouse_state.widget.take().is_some() {
+        if self.cursor.widget.take().is_some() {
             let mut window = RunningWindow::new(window, &self.focused, &self.occluded);
             let mut context = EventContext::new(
                 WidgetContext::new(
@@ -922,6 +913,7 @@ where
                     &self.current_theme,
                     &mut window,
                     self.theme_mode.get(),
+                    &mut self.cursor,
                 ),
                 kludgine,
             );
@@ -947,6 +939,7 @@ where
                         &self.current_theme,
                         &mut window,
                         self.theme_mode.get(),
+                        &mut self.cursor,
                     ),
                     kludgine,
                 )
@@ -954,10 +947,8 @@ where
 
                 if let (ElementState::Pressed, Some(location), Some(hovered)) = (
                     state,
-                    &self.mouse_state.location,
-                    self.mouse_state
-                        .widget
-                        .and_then(|id| self.root.tree.widget(id)),
+                    self.cursor.location,
+                    self.cursor.widget.and_then(|id| self.root.tree.widget(id)),
                 ) {
                     if let Some(handler) = recursively_handle_event(
                         &mut EventContext::new(
@@ -967,6 +958,7 @@ where
                                 &self.current_theme,
                                 &mut window,
                                 self.theme_mode.get(),
+                                &mut self.cursor,
                             ),
                             kludgine,
                         ),
@@ -974,12 +966,11 @@ where
                             let Some(layout) = context.last_layout() else {
                                 return IGNORED;
                             };
-                            let relative = *location - layout.origin;
+                            let relative = location - layout.origin;
                             context.mouse_down(relative, device_id, button)
                         },
                     ) {
-                        self.mouse_state
-                            .devices
+                        self.mouse_buttons
                             .entry(device_id)
                             .or_default()
                             .insert(button, handler.id());
@@ -987,18 +978,19 @@ where
                 }
             }
             ElementState::Released => {
-                let Some(device_buttons) = self.mouse_state.devices.get_mut(&device_id) else {
+                let Some(device_buttons) = self.mouse_buttons.get_mut(&device_id) else {
                     return;
                 };
                 let Some(handler) = device_buttons.remove(&button) else {
                     return;
                 };
                 if device_buttons.is_empty() {
-                    self.mouse_state.devices.remove(&device_id);
+                    self.mouse_buttons.remove(&device_id);
                 }
                 let Some(handler) = self.root.tree.widget(handler) else {
                     return;
                 };
+                let cursor_location = self.cursor.location;
                 let mut context = EventContext::new(
                     WidgetContext::new(
                         handler,
@@ -1006,12 +998,13 @@ where
                         &self.current_theme,
                         &mut window,
                         self.theme_mode.get(),
+                        &mut self.cursor,
                     ),
                     kludgine,
                 );
 
                 let relative = if let (Some(last_rendered), Some(location)) =
-                    (context.last_layout(), self.mouse_state.location)
+                    (context.last_layout(), cursor_location)
                 {
                     Some(location - last_rendered.origin)
                 } else {
@@ -1060,10 +1053,9 @@ fn recursively_handle_event(
 }
 
 #[derive(Default)]
-struct MouseState {
-    location: Option<Point<Px>>,
-    widget: Option<WidgetId>,
-    devices: AHashMap<DeviceId, AHashMap<MouseButton, WidgetId>>,
+pub(crate) struct CursorState {
+    pub(crate) location: Option<Point<Px>>,
+    pub(crate) widget: Option<WidgetId>,
 }
 
 pub(crate) mod sealed {