Struct ChangeAccumulator 

pub struct ChangeAccumulator {
    pub per_node: BTreeMap<NodeId, NodeChangeReport>,
    pub max_scope: RelayoutScope,
    pub mounted_nodes: Vec<NodeId>,
    pub unmounted_nodes: Vec<NodeId>,
}

Unified change report that merges information from all three change paths:

1. DOM reconciliation (compute_node_changes after reconcile_dom)
2. CSS restyle (restyle_on_state_change for hover/focus/active)
3. Runtime edits (words_changed, css_properties_changed, images_changed)

This is the single source of truth for “what work needs to happen this frame”.

Fields

per_node: BTreeMap<NodeId, NodeChangeReport>

Per-node change info. Key is the new-DOM NodeId.

max_scope: RelayoutScope

Maximum RelayoutScope across all changed nodes. Quick check: if this is None, we can skip layout entirely.

mounted_nodes: Vec<NodeId>

Nodes that are newly mounted (no old counterpart). These always need full layout.

unmounted_nodes: Vec<NodeId>

Nodes that were unmounted (no new counterpart). Used for cleanup (remove from scroll/focus/cursor managers).

Implementations

impl ChangeAccumulator

pub fn new() -> Self

pub fn is_empty(&self) -> bool

Returns true if no changes were detected at all.

pub fn needs_layout(&self) -> bool

Returns true if layout work is needed (any node has scope > None).

pub fn needs_paint_only(&self) -> bool

Returns true if only paint work is needed (no layout).

pub fn is_visually_unchanged(&self) -> bool

Returns true if only non-visual changes occurred (callbacks, dataset, a11y).

pub fn add_dom_change( &mut self, new_node_id: NodeId, change_set: NodeChangeSet, relayout_scope: RelayoutScope, text_change: Option<TextChange>, changed_css_properties: Vec<CssPropertyType>, )

Add a node change from DOM reconciliation (Path A).

pub fn add_text_change( &mut self, node_id: NodeId, old_text: String, new_text: String, )

Add a text change (from runtime edit or DOM reconciliation).

pub fn add_css_change( &mut self, node_id: NodeId, prop_type: CssPropertyType, scope: RelayoutScope, )

Add a CSS property change (from runtime edit or restyle).

pub fn add_image_change(&mut self, node_id: NodeId, scope: RelayoutScope)

Add an image change (from runtime edit or DOM reconciliation).

pub fn add_mount(&mut self, node_id: NodeId)

Add a mounted (new) node.

pub fn add_unmount(&mut self, node_id: NodeId)

Add an unmounted (removed) node.

pub fn merge_restyle_result(&mut self, restyle: &RestyleResult)

Merge a RestyleResult (from restyle_on_state_change()) into this accumulator.

This is the bridge between Path B (restyle) and the unified change pipeline. Each ChangedCssProperty is classified via relayout_scope() to determine whether it affects layout or only paint.

pub fn merge_extended_diff( &mut self, extended: &ExtendedDiffResult, old_node_data: &[NodeData], new_node_data: &[NodeData], )

Populate this accumulator from an ExtendedDiffResult + the old/new DOM data.

This converts per-node NodeChangeSet flags into full NodeChangeReports with RelayoutScope classification.

Trait Implementations

impl Clone for ChangeAccumulator

fn clone(&self) -> ChangeAccumulator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ChangeAccumulator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ChangeAccumulator

fn default() -> ChangeAccumulator

Returns the “default value” for a type.