Triggering events with certain delays without interrupting the program flow

Elokuu

Hi there, Anyone has an idea on how do I trigger events with a certain delay while the rest of the program continues running?

I have a event (beat) triggered at certain intervals with the help of the Clock class of the the beads library. At each of this event (beat) I trigger some new events with certain small delays. For instance the beat comes every second and should trigger 6 short events 50ms apart. The problem is that the "short" delays add to the "long" delay. So the main timer (the one second interval) is affected by the 6 50ms delay, which means the main timer event (beat) would be then 1,3seonds apart.

Is there any way how I can implement the short delay without affecting the main timer?

Thank you

GoToLoop

For starters, I've got this thread and this example below:

http://forum.processing.org/two/discussion/1725/millis-and-timer

/** 
 * TimerTask (v1.3)
 * by GoToLoop (2013/Dec)
 * 
 * forum.processing.org/two/discussion/1725/millis-and-timer
 */

import java.util.Timer;
import java.util.TimerTask;

final Timer t = new Timer();
boolean hasFinished = true;

void draw() {
  if (hasFinished) {
    final float waitTime = random(10);
    createScheduleTimer(waitTime);

    println("\n\nTimer scheduled for "
      + nf(waitTime, 0, 2) + " secs.\n");
  }

  if ((frameCount & 0xF) == 0)   print('.');
}

void createScheduleTimer(final float sec) {
  hasFinished = false;

  t.schedule(new TimerTask() {
    public void run() {
      print(" " + nf(sec, 0, 2));
      hasFinished = true;
    }
  }
  , (long) (sec*1e3));
}

Elokuu

Thanks for the fast reply. This pretty much answered my question. But I have one more problem. I need a couple of timer, so I'm using a for loop to create all the tasks. But the task should depend on the index i of the for loop. But as the index i is a non final variable, I can't really use the index i in the run() function. It looks like this:

      for(int i=0;i < 6; i++){
        t.schedule(new TimerTask() {
          public void run() {
            call_a_function_which_depends_on_the_index(i);
          }
        }
        , (long) (10*i));
}

Is there a way to "finalize" the i by creating a new final variable?

Thanks

GoToLoop

Is there a way to "finalize" the i by creating a new final variable?

Surprisingly there is! Merely declare a final variable inside the loop block.
Then assign the current iterator value to it! :ar!

for (int i = 0; i != 6;) {
  final int ii = i++;

  t.schedule(new TimerTask() {
    public void run() {
      myClosureTimedFunction(ii);
    }
  }
  , 10*ii);
}

GoToLoop

Just for amusement, here's my 1st clunky attempt before realizing a mere final variable would do it! :O)
I've extended the TimerTask abstract class as TimerTasked.
The new constructor accepted a parameter as id for the instance:

void createScheduleTimer(float sec) {
  hasFinished = false;

  t.schedule(new TimerTasked(sec) {
    public void run() {
      hasFinished = true;
      print(nf(id, 0, 2));
    }
  }
  , (long) (sec*1e3));
}

abstract class TimerTasked extends TimerTask {
  final float id;

  TimerTasked(float num) {
    id = num;
  }
}

GoToLoop

P.S.: Bumped my original v1.22 to v1.3! Now it declares parameter sec as final. And accesses it inside run()! \m/

void createScheduleTimer(final float sec) {
  hasFinished = false;

  t.schedule(new TimerTask() {
    public void run() {
      print(" " + nf(sec, 0, 2));
      hasFinished = true;
    }
  }
  , (long) (sec*1e3));
}