Struct RuntimeHandle 

pub struct RuntimeHandle { /* private fields */ }

A cheap handle to a Runtime. It does not keep the runtime alive, and its calls do nothing once the runtime is dropped.

Implementations

impl RuntimeHandle

pub fn id(&self) -> RuntimeId

Returns the id of the runtime.

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

Returns the number of state cells and, of those, the number free for reuse.

pub fn state_arena_debug_stats(&self) -> StateArenaDebugStats

Returns the sizes of the runtime’s state arena, for leak and memory checks.

pub fn debug_stats(&self) -> RuntimeDebugStats

Returns the sizes of the runtime’s queues and tables, for leak and memory checks.

pub fn live_ui_task_labels(&self) -> Vec<(u64, String)>

Returns the id and label of every spawned UI task that has not finished.

pub fn schedule(&self)

Marks the runtime as needing a frame and asks its scheduler for one.

pub fn enqueue_ui_task(&self, task: Box<dyn FnOnce() + 'static>)

Schedules work that must run on the runtime thread.

The closure executes on the UI thread immediately when the runtime drains its local queue, so it may capture Rc/RefCell values. Calling this from any other thread is a logic error and will panic in debug builds via the inner assertion.

pub fn spawn_ui<F>(&self, fut: F) -> Option<TaskHandle>

where F: Future<Output = ()> + 'static,

Spawns fut on the UI thread, where drain_ui polls it whenever it is woken. Returns None if the runtime is gone.

pub fn cancel_task(&self, id: u64)

Cancels the spawned UI task id and drops its future.

pub fn has_task(&self, id: u64) -> bool

Whether the runtime still holds the spawned task id.

pub fn post_ui(&self, task: impl FnOnce() + Send + 'static)

Enqueues work from any thread to run on the UI thread.

The closure must be Send because it may cross threads before executing on the runtime thread. Use this when posting from background work.

pub fn register_ui_cont<T: 'static>( &self, f: impl FnOnce(T) + 'static, ) -> Option<u64>

Registers f to run once on the UI thread when UiDispatcher::post_invoke sends a T for the returned id. Returns None if the runtime is gone.

pub fn cancel_ui_cont(&self, id: u64)

Removes the continuation id without running it.

pub fn drain_ui(&self)

Runs the work posted to the UI thread, including woken tasks, until none is left.

pub fn has_pending_ui(&self) -> bool

Returns true if posted UI work has not run yet.

pub fn register_frame_callback( &self, callback: impl FnOnce(u64) + 'static, ) -> Option<u64>

Registers callback to run once on the next frame with the frame time in nanoseconds. Returns None if the runtime is gone.

pub fn register_perpetual_frame_callback( &self, callback: impl FnOnce(u64) + 'static, ) -> Option<u64>

Registers callback to run once on the next frame, for a long-lived loop that registers again after every frame. It does not count in has_transient_frame_callbacks.

pub fn cancel_frame_callback(&self, id: u64)

Cancels the frame callback id if it has not run.

pub fn drain_frame_callbacks(&self, frame_time_nanos: u64)

Delivers callbacks registered before this display frame. Timestamps use one monotonic nanosecond epoch; duplicate or older timestamps are ignored. A callback registered during delivery waits for a newer frame timestamp.

pub fn last_frame_time_nanos(&self) -> Option<u64>

Animation-clock time of the most recent frame-callback drain (see Runtime::last_frame_time_nanos).

pub fn frame_clock(&self) -> FrameClock

Returns a clock for the frames of this runtime.

pub fn set_needs_frame(&self, value: bool)

Sets or clears the request for a frame.

pub fn has_updates(&self) -> bool

Returns true if node updates are queued or any recompose scope is invalid.

pub fn forget_movable(&self, id: Key)

Releases the retained state of the movable content with identity id at the composition’s next opportunity. See crate::forget_movable.

pub fn has_invalid_scopes(&self) -> bool

Returns true if a recompose scope has been invalidated and not yet recomposed.

pub fn has_frame_callbacks(&self) -> bool

Returns true if any frame callback, transient or perpetual, is waiting.

pub fn has_transient_frame_callbacks(&self) -> bool

Returns true if a callback from register_frame_callback is waiting. Perpetual callbacks do not count.

pub fn assert_ui_thread(&self)

Panics in debug builds when called off the runtime’s UI thread.

pub fn dispatcher(&self) -> UiDispatcher

Returns a dispatcher that posts work to the UI thread from any thread.

Trait Implementations

impl Clone for RuntimeHandle

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.