Implement update_anim pass

masonry/src/contexts.rs

@@ -443,6 +443,7 @@ impl_context_method!(MutateCtx<'_>, EventCtx<'_>, LifeCycleCtx<'_>, {
     /// Request an animation frame.
     pub fn request_anim_frame(&mut self) {
         trace!("request_anim_frame");
+        self.widget_state.needs_anim = true;
         self.widget_state.request_anim = true;
     }
 

masonry/src/passes/update.rs

@@ -4,11 +4,12 @@
 use std::collections::HashSet;
 
 use cursor_icon::CursorIcon;
-use tracing::trace;
+use tracing::{info_span, trace};
 
-use crate::passes::merge_state_up;
-use crate::render_root::{RenderRoot, RenderRootSignal};
-use crate::{LifeCycleCtx, StatusChange, Widget, WidgetId, WidgetState};
+use crate::passes::{merge_state_up, recurse_on_children};
+use crate::render_root::{RenderRoot, RenderRootSignal, RenderRootState};
+use crate::tree_arena::ArenaMut;
+use crate::{LifeCycle, LifeCycleCtx, StatusChange, Widget, WidgetId, WidgetState};
 
 fn get_id_path(root: &RenderRoot, widget_id: Option<WidgetId>) -> Vec<WidgetId> {
     let Some(widget_id) = widget_id else {
@@ -145,3 +146,52 @@ pub(crate) fn run_update_pointer_pass(root: &mut RenderRoot, root_state: &mut Wi
     // Pass root widget state to synthetic state create at beginning of pass
     root_state.merge_up(root.widget_arena.get_state_mut(root.root.id()).item);
 }
+
+// ----------------
+
+fn update_anim_for_widget(
+    global_state: &mut RenderRootState,
+    mut widget: ArenaMut<'_, Box<dyn Widget>>,
+    mut state: ArenaMut<'_, WidgetState>,
+    elapsed_ns: u64,
+) {
+    let _span = widget.item.make_trace_span().entered();
+
+    if !state.item.needs_anim {
+        return;
+    }
+
+    if state.item.request_anim {
+        let mut ctx = LifeCycleCtx {
+            global_state,
+            widget_state: state.item,
+            widget_state_children: state.children.reborrow_mut(),
+            widget_children: widget.children.reborrow_mut(),
+        };
+        widget
+            .item
+            .lifecycle(&mut ctx, &LifeCycle::AnimFrame(elapsed_ns));
+    }
+
+    state.item.needs_anim = false;
+    state.item.request_anim = false;
+
+    let id = state.item.id;
+    let parent_state = state.item;
+    recurse_on_children(
+        id,
+        widget.reborrow_mut(),
+        state.children,
+        |widget, mut state| {
+            update_anim_for_widget(global_state, widget, state.reborrow_mut(), elapsed_ns);
+            parent_state.merge_up(state.item);
+        },
+    );
+}
+
+pub(crate) fn run_update_anim_pass(root: &mut RenderRoot, elapsed_ns: u64) {
+    let _span = info_span!("update_anim").entered();
+
+    let (root_widget, root_state) = root.widget_arena.get_pair_mut(root.root.id());
+    update_anim_for_widget(&mut root.state, root_widget, root_state, elapsed_ns);
+}

masonry/src/render_root.rs

@@ -24,7 +24,7 @@ use crate::passes::compose::root_compose;
 use crate::passes::event::{root_on_access_event, root_on_pointer_event, root_on_text_event};
 use crate::passes::mutate::{mutate_widget, run_mutate_pass};
 use crate::passes::paint::root_paint;
-use crate::passes::update::run_update_pointer_pass;
+use crate::passes::update::{run_update_anim_pass, run_update_pointer_pass};
 use crate::text::TextBrush;
 use crate::tree_arena::TreeArena;
 use crate::widget::WidgetArena;
@@ -203,9 +203,13 @@ impl RenderRoot {
                 let last = self.last_anim.take();
                 let elapsed_ns = last.map(|t| now.duration_since(t).as_nanos()).unwrap_or(0) as u64;
                 let root_state = self.root_state();
-                if root_state.request_anim {
-                    root_state.request_anim = false;
-                    self.root_lifecycle(LifeCycle::AnimFrame(elapsed_ns));
+                if root_state.needs_anim {
+                    run_update_anim_pass(self, elapsed_ns);
+
+                    let mut root_state =
+                        self.widget_arena.get_state_mut(self.root.id()).item.clone();
+                    self.post_event_processing(&mut root_state);
+
                     self.last_anim = Some(now);
                 }
                 Handled::Yes

masonry/src/widget/widget_pod.rs

@@ -374,10 +374,8 @@ impl<W: Widget> WidgetPod<W> {
 
                 true
             }
-            LifeCycle::AnimFrame(_) => {
-                state.request_anim = false;
-                true
-            }
+            // Animations have been moved to the update_anim pass
+            LifeCycle::AnimFrame(_) => false,
             LifeCycle::DisabledChanged(ancestors_disabled) => {
                 state.update_focus_chain = true;
 

masonry/src/widget/widget_state.rs

@@ -108,8 +108,10 @@ pub struct WidgetState {
     /// The accessibility method must be called on this widget or a descendant
     pub(crate) needs_accessibility: bool,
 
-    /// Any descendant has requested an animation frame.
+    /// An animation must run on this widget
     pub(crate) request_anim: bool,
+    /// An animation must run on this widget or a descendant
+    pub(crate) needs_anim: bool,
 
     pub(crate) update_focus_chain: bool,
 
@@ -183,6 +185,7 @@ impl WidgetState {
             request_accessibility: true,
             needs_accessibility: true,
             has_focus: false,
+            needs_anim: true,
             request_anim: true,
             focus_chain: Vec::new(),
             children: Bloom::new(),
@@ -208,11 +211,12 @@ impl WidgetState {
             needs_layout: false,
             request_compose: false,
             needs_compose: false,
-            needs_paint: false,
             request_paint: false,
+            needs_paint: false,
             request_accessibility: false,
             needs_accessibility: false,
             request_anim: false,
+            needs_anim: false,
             children_changed: false,
             update_focus_chain: false,
             ..WidgetState::new(id, "<root>")
@@ -250,7 +254,7 @@ impl WidgetState {
         self.needs_layout |= child_state.needs_layout;
         self.needs_compose |= child_state.needs_compose;
         self.needs_paint |= child_state.needs_paint;
-        self.request_anim |= child_state.request_anim;
+        self.needs_anim |= child_state.needs_anim;
         self.needs_accessibility |= child_state.needs_accessibility;
         self.children_disabled_changed |= child_state.children_disabled_changed;
         self.children_disabled_changed |=