Struct TreeNode 

pub struct TreeNode {

    pub children: Vec<NodeId>,
    pub keyed_children: HashMap<u64, NodeId>,
    pub hits: Vec<HitRegion>,
    pub hits_at: Vec<HitRegionAt>,
    pub nested_scrolls: Vec<(Rect, ScrollHandler)>,
    pub scrolls: Vec<ScrollRegion>,
    pub zooms: Vec<ZoomRegion>,
    pub focus: Vec<FocusNode>,
    pub overlays: Vec<OverlayEntry>,
    pub transforms: Vec<TransformLayerEntry>,
    pub semantics: Vec<Semantics>,
    pub editable: Option<EditableDecl>,
    pub scroll_ctrl: Option<ScrollController>,
    pub anim: Option<f32>,
    pub anim_channels: Vec<Option<f32>>,
    pub focus_node: Option<FocusNode>,
    pub text_edit: TextEditState,
    pub tag: &'static str,
    pub last_constraints: Option<Constraints>,
    pub cached_size: Option<Size>,
    pub cached_picture: Option<Arc<Picture>>,
    pub cached_rect: Option<Rect>,
    pub paint_dirty: bool,
    pub hovered: bool,
    pub pressed: bool,
    pub pointer_mode: u8,
    pub hover_regions: Vec<Rect>,
    pub long_hits: Vec<HitRegion>,
    /* private fields */
}

One render-tree node. Declared data is cleared when the node is repainted (begin) and persists untouched otherwise.

Fields

children: Vec<NodeId>

keyed_children: HashMap<u64, NodeId>

Children addressed by RenderTree::keyed_slot instead of position — see the module doc’s “Identity” section. Only ScreenTransitionView (screen_transition_view.rs) uses this; every other widget’s children live in children/cursor above, untouched.

hits: Vec<HitRegion>

hits_at: Vec<HitRegionAt>

nested_scrolls: Vec<(Rect, ScrollHandler)>

Nested-scroll chain links declared this node (D-NESTED-SCROLL) — see ScrollHandler’s own doc. Separate from hits_at: a plain slider-style positional drag always fully “consumes” a gesture by definition, but a ScrollView’s pan needs to report exhaustion so an enclosing scrollable ancestor gets a turn.

scrolls: Vec<ScrollRegion>

zooms: Vec<ZoomRegion>

focus: Vec<FocusNode>

overlays: Vec<OverlayEntry>

transforms: Vec<TransformLayerEntry>

semantics: Vec<Semantics>

editable: Option<EditableDecl>

Editable text content declared this paint (D112/Phase 28 Step 1) — current value, rect, and the on_change callback. Cleared each repaint like hits/scrolls; the engine’s key/click dispatch reads it fresh rather than caching, since a rebuild may swap in a different on_change closure.

scroll_ctrl: Option<ScrollController>

The node’s implicit scroll position (D101) — created lazily by the first scrollable painted at this position, survives rebuilds like Flutter’s ScrollPosition.

anim: Option<f32>

A persistent eased scalar (0..1) for toggle transitions — advanced by PaintCtx::animate_to. None until first observed (then snaps).

anim_channels: Vec<Option<f32>>

Multiple independent persistent eased scalars for a widget that needs to animate more than one value at once (e.g. a Switch’s position AND its hover/press state-layer) — advanced by PaintCtx::animate_channel, indexed by an explicit channel id. Each entry is None until first observed (then snaps), exactly like anim. Grows on demand; persists across repaints and cache-hit frames like the other retained state.

focus_node: Option<FocusNode>

This node’s rosace_a11y::FocusNode (D112/Phase 28 Step 1) — created lazily by super::PaintCtx::focus_node, survives rebuilds like scroll_ctrl above.

text_edit: TextEditState

Persistent cursor/selection state for an editable node (D091/D112) — NOT cleared on repaint, so the caret survives a rebuild with the same displayed value.

tag: &'static str

Widget type name at this position; a mismatch resets the caches.

last_constraints: Option<Constraints>

Constraints used for the last successful layout pass.

cached_size: Option<Size>

Size returned by the last layout pass.

cached_picture: Option<Arc<Picture>>

Display list from the last paint pass.

cached_rect: Option<Rect>

World-space rect of the last paint (also the damage extent).

paint_dirty: bool

When true, the subtree must re-layout/re-paint this frame.

hovered: bool

True while the cursor is over this node’s hit/hover region.

pressed: bool

True from MouseDown until MouseUp on this node — drives press/tap feedback (D108/Phase 26 Step 1), same dispatcher-owned shape as hovered.

pointer_mode: u8

Pointer interception: 1 = ignore (subtree transparent to hits), 2 = absorb (consume everything in rect). Declared per paint.

hover_regions: Vec<Rect>

Hover-only regions (tooltips) — participate in hover_test but not in click dispatch.

long_hits: Vec<HitRegion>

Long-press callbacks with their rects.

Trait Implementations

impl Default for TreeNode

fn default() -> TreeNode

Returns the “default value” for a type.