rxjs-zone-less/es2015/scheduler/animation-frame/AnimationFrameAction.js

A set of wrappers for RxJS to avoid unnecessary change detection and zone interference in Angular.

import { animationFrameProvider } from '../../internals/animationFrameProvider';
import { AsyncAction } from '../async/AsyncAction';
export class AnimationFrameAction extends AsyncAction {
    constructor(scheduler, work) {
        super(scheduler, work);
        this.scheduler = scheduler;
        this.work = work;
    }
    requestAsyncId(scheduler, id, delay = 0) {
        // 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 = animationFrameProvider.requestAnimationFrame(() => scheduler.flush(undefined))));
    }
    recycleAsyncId(scheduler, id, delay = 0) {
        // 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.some((action) => action.id === id)) {
            animationFrameProvider.cancelAnimationFrame(id);
            scheduler._scheduled = undefined;
        }
        // Return undefined so the action knows to request a new async id if it's rescheduled.
        return undefined;
    }
}