| import { AsyncAction } from './AsyncAction'; |
| import { AnimationFrameScheduler } from './AnimationFrameScheduler'; |
| import { SchedulerAction } from '../types'; |
| |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| export class AnimationFrameAction<T> extends AsyncAction<T> { |
| |
| constructor(protected scheduler: AnimationFrameScheduler, |
| protected work: (this: SchedulerAction<T>, state?: T) => void) { |
| super(scheduler, work); |
| } |
| |
| protected requestAsyncId(scheduler: AnimationFrameScheduler, id?: any, delay: number = 0): any { |
| // If delay is greater than 0, request as an async action. |
| if (delay !== null && delay > 0) { |
| return super.requestAsyncId(scheduler, id, delay); |
| } |
| // Push the action to the end of the scheduler queue. |
| scheduler.actions.push(this); |
| // If an animation frame has already been requested, don't request another |
| // one. If an animation frame hasn't been requested yet, request one. Return |
| // the current animation frame request id. |
| return scheduler.scheduled || (scheduler.scheduled = requestAnimationFrame( |
| () => scheduler.flush(null))); |
| } |
| protected recycleAsyncId(scheduler: AnimationFrameScheduler, id?: any, delay: number = 0): any { |
| // If delay exists and is greater than 0, or if the delay is null (the |
| // action wasn't rescheduled) but was originally scheduled as an async |
| // action, then recycle as an async action. |
| if ((delay !== null && delay > 0) || (delay === null && this.delay > 0)) { |
| return super.recycleAsyncId(scheduler, id, delay); |
| } |
| // If the scheduler queue is empty, cancel the requested animation frame and |
| // set the scheduled flag to undefined so the next AnimationFrameAction will |
| // request its own. |
| if (scheduler.actions.length === 0) { |
| cancelAnimationFrame(id); |
| scheduler.scheduled = undefined; |
| } |
| // Return undefined so the action knows to request a new async id if it's rescheduled. |
| return undefined; |
| } |
| } |