Struct VirtualViewManager 

pub struct VirtualViewManager { /* private fields */ }

Manages VirtualView lifecycle, including re-invocation and PipelineId generation

Tracks which VirtualViews have been invoked, assigns unique DOM IDs to nested virtual views, and determines when VirtualViews need to be re-invoked (e.g., when the container bounds expand or the user scrolls near an edge).

Implementations

impl VirtualViewManager

pub fn new() -> Self

Creates a new VirtualViewManager with no tracked VirtualViews

pub fn debug_counts(&self) -> (usize, usize)

(states, pipeline_ids). Used by AZ_E2E_TEST to watch growth.

pub fn begin_frame(&mut self)

Called at the start of each frame (currently a no-op)

pub fn get_or_create_nested_dom_id( &mut self, dom_id: DomId, node_id: NodeId, ) -> DomId

Gets or creates a unique nested DOM ID for a VirtualView

Returns the existing DOM ID if the VirtualView was previously registered, otherwise allocates a new unique ID and initializes the VirtualView state.

pub fn get_nested_dom_id(&self, dom_id: DomId, node_id: NodeId) -> Option<DomId>

Gets the nested DOM ID for a VirtualView if it exists

pub fn get_or_create_pipeline_id( &mut self, dom_id: DomId, node_id: NodeId, ) -> PipelineId

Gets or creates a WebRender PipelineId for a VirtualView

PipelineIds are used by WebRender to identify distinct rendering contexts.

pub fn was_virtual_view_invoked(&self, dom_id: DomId, node_id: NodeId) -> bool

Returns whether the VirtualView has ever been invoked

pub fn get_virtual_scroll_size( &self, dom_id: DomId, node_id: NodeId, ) -> Option<LogicalSize>

Returns the virtual scroll size for a VirtualView (if set by the callback)

pub fn get_scroll_size( &self, dom_id: DomId, node_id: NodeId, ) -> Option<LogicalSize>

Returns the scroll size for a VirtualView (actual content size, if set by the callback)

pub fn update_virtual_view_info( &mut self, dom_id: DomId, node_id: NodeId, scroll_size: LogicalSize, virtual_scroll_size: LogicalSize, ) -> Option<()>

Updates the VirtualView’s content size information

Called after the VirtualView callback returns to record the actual content dimensions. If the new size is larger than previously recorded, clears the expansion flag to allow BoundsExpanded re-invocation.

pub fn mark_invoked( &mut self, dom_id: DomId, node_id: NodeId, reason: VirtualViewCallbackReason, ) -> Option<()>

Marks a VirtualView as invoked for a specific reason

Updates internal state flags based on the callback reason to prevent duplicate callbacks for the same trigger condition.

pub fn reset_all_invocation_flags(&mut self)

Reset invocation flags for ALL tracked VirtualViews

After layout_results.clear(), the child DOMs no longer exist in memory. This method ensures check_reinvoke() returns InitialRender for every VirtualView, so the callbacks re-run and re-populate layout_results.

Called from layout_and_generate_display_list() after clearing layout results.

pub fn force_reinvoke(&mut self, dom_id: DomId, node_id: NodeId) -> Option<()>

Force a VirtualView to be re-invoked on the next layout pass

Clears all invocation flags, causing check_reinvoke() to return InitialRender. Used by trigger_virtual_view_rerender() to manually refresh VirtualView content.

pub fn check_reinvoke( &mut self, dom_id: DomId, node_id: NodeId, scroll_manager: &ScrollManager, layout_bounds: LogicalRect, ) -> Option<VirtualViewCallbackReason>

Checks whether a VirtualView needs to be re-invoked and returns the reason

Returns Some(reason) if the VirtualView callback should be invoked:

• InitialRender: VirtualView has never been invoked
• BoundsExpanded: Container grew larger than content
• EdgeScrolled: User scrolled near an edge (for lazy loading)

Returns None if no re-invocation is needed.

pub fn get_all_virtual_view_infos(&self) -> Vec<VirtualViewDebugInfo>

Returns debug info for all tracked VirtualViews

Each entry contains: (parent_dom_id, parent_node_id, nested_dom_id, scroll_size, virtual_scroll_size, was_invoked, last_bounds)

Trait Implementations

impl Clone for VirtualViewManager

fn clone(&self) -> VirtualViewManager

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VirtualViewManager

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

Formats the value using the given formatter.

impl Default for VirtualViewManager

fn default() -> VirtualViewManager

Returns the “default value” for a type.