Stop timer when use another app


i have a gamer with a timer, when i use another app the timer still working i want the timer stop when i am not in the game how i can achieve that
this is the code

      this.counter$ = Observable.timer(0, this.tick)
    .map(() => --this.timer).finally(() =>{  this.endTimer();});

i also tried this code

  // this.counter$ = timer(0,this.tick).pipe(
    //   take(this.timer),
    //   map(() => --this.timer)
    // ).finally(() =>{  this.endTimer();});


Look into the pause and resume events.


I tried it and its works​:heart_eyes::heart_eyes: