How to make Timer.periodic cancel itself when a condition is reached?

Question

Timer.periodic() is great to have a function repeatedly execute, but is it possible to have the the timer cancel itself if an arbitrary condition is reached outside the function being executed by the timer?

Answer 1

You get the timer passed into the callback. You can just call cancel() on it:

Timer.periodic(const Duration(seconds: 1), (timer) {   if(condition) {     timer.cancel();   } }); 

or

Timer timer;  startTimer() {   timer = Timer.periodic(const Duration(seconds: 1), (timer) {     if(condition) {       cancelTimer();     }   }); }  cancelTimer() {   timer.cancel(); } 

this way the timer can be cancelled independent of a timer event.