idle-tick-timer.ts

const events = ['mousedown', 'mousemove', 'keypress', 'scroll', 'touchstart'];

// tick timer for schedule jobs
// idle timer autoremove it self after stop
export class IdleTickTimer {
  private idleCount: number = 0;
  private stopIdleCount: number = 0;
  private idleTickCallback: { (tick: number, final: boolean): void };
  private intervalID: number;
  private activityCallback: { (): void } | null;

  private static instance: IdleTickTimer | null;

  private constructor(
    interval: number,
    stopIdleCount: number,
    tickCallback: { (idleCount: number, final: boolean): void },
  ) {
    this.idleCount = 0;
    this.stopIdleCount = stopIdleCount;
    this.idleTickCallback = tickCallback;
    this.intervalID = 0;
    this.activityCallback = null;

    // activity listener
    events.forEach((e) => {
      window.addEventListener(e, this);
    });

    this.intervalID = window.setInterval(
      () => this.onTimeout(),
      interval * 1000,
    );
  }

  // reset idle timer on activity
  public handleEvent() {
    this.idleCount = 0;

    if (this.activityCallback) this.activityCallback();
  }

  private onTimeout() {
    ++this.idleCount;

    const final = this.idleCount >= this.stopIdleCount;
    if (final) IdleTickTimer.stop();

    this.idleTickCallback(this.idleCount, final);
  }

  // interval (seconds)
  static start(
    interval: number,
    stopIdleCount: number,
    tickCallback: { (idleCount: number, final: boolean): void },
  ): void {
    // already started
    if (this.instance) return;

    this.instance = new IdleTickTimer(interval, stopIdleCount, tickCallback);
  }

  static stop() {
    if (!this.instance) return;

    this.instance.instanceStop();
    this.instance = null;
  }

  // stop timer and clear
  private instanceStop() {
    events.forEach((e) => {
      window.removeEventListener(e, this);
    });

    window.clearInterval(this.intervalID);
  }

  static setActivityCallback(cb: { (): void } | null) {
    if (this.instance) this.instance.activityCallback = cb;
  }
}