Last active
April 20, 2017 00:26
-
-
Save EvAlex/f9de5838a87f9a9e9ebc4e2425a761b7 to your computer and use it in GitHub Desktop.
TypeScript Timer based on requestAnimationFrame()
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| class Timer { | |
| private _tasks: ITimerTask[] = []; | |
| private _enabled = false; | |
| register(fn: Function, period: number, dueTime = 0): number { | |
| const id = this._tasks.map(t => t.id).reduce((p, c) => p > c ? p : c, 0) + 1; | |
| this._tasks.push({ | |
| id: id, | |
| registerTime: new Date(), | |
| lastRunTime: null, | |
| dueTime: dueTime, | |
| period: period, | |
| fn: fn | |
| }); | |
| if (this._tasks.length === 1) { | |
| this.start(); | |
| } | |
| return id; | |
| } | |
| unregister(id: number) { | |
| const match = this._tasks.filter(t => t.id === id)[0]; | |
| if (match) { | |
| const i = this._tasks.indexOf(match); | |
| this._tasks.splice(i, 1); | |
| if (this._tasks.length === 0) { | |
| this.stop(); | |
| } | |
| } | |
| } | |
| private start() { | |
| this._enabled = true; | |
| const handler = () => { | |
| this.runRegisteredTasks(new Date()); | |
| if (this._enabled) { | |
| window.requestAnimationFrame(handler); | |
| } | |
| }; | |
| window.requestAnimationFrame(handler); | |
| } | |
| private stop() { | |
| this._enabled = false; | |
| } | |
| private runRegisteredTasks(time: Date) { | |
| const toRun = this.getTasksToRun(time); | |
| this.runTasks(toRun); | |
| } | |
| private getTasksToRun(time: Date): ITimerTask[] { | |
| const toRun: ITimerTask[] = []; | |
| for (const task of this._tasks) { | |
| if (task.lastRunTime === null && time.getTime() > task.registerTime.getTime() + task.dueTime) { | |
| toRun.push(task); | |
| } else { | |
| const lastRunTimeLatency = (task.lastRunTime.getTime() - (task.registerTime.getTime() + task.dueTime)) % task.period; | |
| const lastIntendedRunTime = task.lastRunTime.getTime() - lastRunTimeLatency; | |
| const nextRunTime = lastIntendedRunTime + task.period; | |
| if (time.getTime() > nextRunTime) { | |
| toRun.push(task); | |
| } | |
| } | |
| } | |
| return toRun; | |
| } | |
| private runTasks(tasks: ITimerTask[]) { | |
| for (const task of tasks) { | |
| task.fn(); | |
| } | |
| } | |
| } | |
| export const timer = new Timer(); | |
| interface ITimerTask { | |
| id: number; | |
| registerTime: Date; | |
| lastRunTime: Date; | |
| dueTime: number; | |
| period: number; | |
| fn: Function; | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment