Struct Engine 

pub struct Engine { /* private fields */ }

The Engine is the central coordinator. One Engine instance per application.

Implementations

impl Engine

pub fn new(platform: Arc<dyn PlatformBridge>) -> Self

Create a new Engine with the given platform bridge.

pub fn apply_commit(&mut self, batch: &IrBatch) -> Result<(), EngineError>

Process a batch of IR commands from the reconciler. This is the main entry point — called after every React commit.

The flow:

1. Decode IR commands (create/update/delete/move nodes)
2. Apply to shadow tree + mark dirty
3. Recompute layout ONLY for dirty subtrees (Taffy)
4. Diff against previous layout
5. Issue platform bridge calls (mount phase)

pub fn enqueue_commit(&self, batch: IrBatch, priority: Priority)

Enqueue a batch via the scheduler (called from JS via JSI). The scheduler handles priority ordering and frame coalescing.

pub fn process_frame(&mut self) -> Result<(), EngineError>

Process all pending scheduled work for this frame. Called by the platform’s vsync/display-link callback.

pub fn navigate(&mut self, action: NavigationAction) -> Vec<NavigationEvent>

Handle a navigation action.

pub fn navigator(&self) -> &Navigator

Get the navigator (for DevTools inspection).

pub fn focus_manager(&mut self) -> &mut FocusManager

Get the focus manager.

pub fn scheduler_stats(&self) -> FrameStats

Get scheduler stats (for DevTools).

pub fn handle_event(&mut self, event: InputEvent) -> EventResult

Handle a native input event. Called by the platform bridge when the OS delivers touch/mouse/keyboard events.

pub fn handle_sync(&self, call: &SyncCall) -> SyncResult

Handle a synchronous call from JS. This takes &self — compile-time guarantee that no mutation happens.

RULE: No UI mutation allowed on the sync path.

pub fn handle_async(&mut self, call: AsyncCall)

Handle an asynchronous call from JS. This takes &mut self — mutations are allowed.

pub fn tree(&self) -> &ShadowTree

Get the shadow tree (for DevTools inspection).

pub fn layout(&self) -> &LayoutEngine

Get the layout engine (for DevTools layout overlay).