Make pointer events affect focus

masonry/src/doc/06_masonry_concepts.md

@@ -57,9 +57,13 @@ Focus marks whether a widget receives text events.
 
 To give a simple example, when you click a textbox, the textbox gets focus: anything you type on your keyboard will be sent to that textbox.
 
-Focus can be changed with the tab key, or by clicking on a widget, both which Masonry automatically handles.
-Masonry will only give focus to widgets that accept focus (see [`Widget::accepts_focus`]).
-Widgets can also use context types to request focus.
+Focus will be changed:
+
+- When users press the Tab key: Masonry will automatically pick the next widget in the tree that accepts focus [`Widget::accepts_focus`]. (If no widget is currently focused, its starting point will be the most recently clicked widget.)
+- When users click outside the currently focused widget: Masonry will automatically remove focus.
+
+Widgets that want to gain focus when clicked should call [`EventCtx::request_focus`] inside [`Widget::on_pointer_event`].
+Other context types can also request focus.
 
 If a widget gains or loses focus it will get a [`FocusChanged`] event.
 
@@ -108,3 +112,5 @@ They should not be relied upon to check code correctness, but are meant to help
 [`PointerLeave`]: crate::PointerEvent::PointerLeave
 [`FocusChanged`]: crate::Update::FocusChanged
 [`Widget::accepts_focus`]: crate::Widget::accepts_focus
+[`EventCtx::request_focus`]: crate::EventCtx::request_focus
+[`Widget::on_pointer_event`]: crate::Widget::on_pointer_event

masonry/src/passes/event.rs

@@ -105,6 +105,26 @@ pub(crate) fn run_on_pointer_event_pass(root: &mut RenderRoot, event: &PointerEv
 
     let target_widget_id = get_pointer_target(root, event.position());
 
+    if matches!(event, PointerEvent::PointerDown(..)) {
+        if let Some(target_widget_id) = target_widget_id {
+            // The next tab event assign focus around this widget.
+            root.global_state.most_recently_clicked_widget = Some(target_widget_id);
+
+            // If we click outside of the focused widget, we clear the focus.
+            if let Some(focused_widget) = root.global_state.focused_widget {
+                // Focused_widget isn't ancestor of target_widget_id
+                if !root
+                    .widget_arena
+                    .states
+                    .get_id_path(target_widget_id)
+                    .contains(&focused_widget.to_raw())
+                {
+                    root.global_state.next_focused_widget = None;
+                }
+            }
+        }
+    }
+
     let handled = run_event_pass(
         root,
         target_widget_id,
@@ -174,11 +194,9 @@ pub(crate) fn run_on_text_event_pass(root: &mut RenderRoot, event: &TextEvent) -
             && key.state == ElementState::Pressed
             && handled == Handled::No
         {
-            if !mods.shift_key() {
-                root.global_state.next_focused_widget = root.widget_from_focus_chain(true);
-            } else {
-                root.global_state.next_focused_widget = root.widget_from_focus_chain(false);
-            }
+            let forward = !mods.shift_key();
+            let next_focused_widget = root.widget_from_focus_chain(forward);
+            root.global_state.next_focused_widget = next_focused_widget;
             handled = Handled::Yes;
         }
     }

masonry/src/render_root.rs

@@ -74,6 +74,7 @@ pub(crate) struct RenderRootState {
     pub(crate) focused_widget: Option<WidgetId>,
     pub(crate) focused_path: Vec<WidgetId>,
     pub(crate) next_focused_widget: Option<WidgetId>,
+    pub(crate) most_recently_clicked_widget: Option<WidgetId>,
     pub(crate) scroll_request_targets: Vec<(WidgetId, Rect)>,
     pub(crate) hovered_path: Vec<WidgetId>,
     pub(crate) pointer_capture_target: Option<WidgetId>,
@@ -198,6 +199,7 @@ impl RenderRoot {
                 focused_widget: None,
                 focused_path: Vec::new(),
                 next_focused_widget: None,
+                most_recently_clicked_widget: None,
                 scroll_request_targets: Vec::new(),
                 hovered_path: Vec::new(),
                 pointer_capture_target: None,
@@ -616,7 +618,10 @@ impl RenderRoot {
     }
 
     pub(crate) fn widget_from_focus_chain(&mut self, forward: bool) -> Option<WidgetId> {
-        let focused_widget = self.global_state.focused_widget;
+        let focused_widget = self
+            .global_state
+            .focused_widget
+            .or(self.global_state.most_recently_clicked_widget);
         let focused_idx = focused_widget.and_then(|focused_widget| {
             self.focus_chain()
                 .iter()