Time in java/android + crashing app

Question

OK guys, I am making an android timer app which keeps crashing. I am using a chronometer which resets when it reaches 25 minutes and then starts again. This is being done by a for loop in the start button onclicklistener. In the loop i have another while loop in which i assing a long type variable the value of elapsed time by the statement

// Contents of while loop inside for loop

 while(found==1){
                temp = chrono.getBase() + SystemClock.elapsedRealtime();
                if(temp == 25*60*1000){
                    found--;
                }

I multiplied by 1000 because time is measured in milliseconds? Am i doing this wrong or is it something else. Thanks.

Maybe add temp >= 25*60*1000? maybe more time had passed since last time you checked, and then the loop never ends... — BobTheBuilder, Feb 07 '13 at 13:01
found is initialised to 1, it is so that the while loop breaks after temp equals specified value,and since while loop is last in the for bracket for loop starts again. — user2018473, Feb 07 '13 at 13:03
What it is not working? from the question text I could not understand what is your problem — Thomas, Mar 02 '13 at 10:39

score 2 · Answer 1 · answered Feb 07 '13 at 13:16

2

The while loop probably blocks the main UI thread until the condition found==1 is met. What you probably need is a Timer and a TimerTask. Or, as recommended in this article, you can start a Runnable using a handler to update the chronometer time every 50 or 100 msec. Here is an example (not tested and adapted from the linked article!):

private Handler handler = new Handler();
handler.postDelayed(runnable, 100);

private Runnable runnable = new Runnable() {
   @Override
   public void run() {
      /* do what you need to do */
      boolean isTimerReady=foobar();
      /* and here comes the "trick" */
      if (!isTimerReady) handler.postDelayed(this, 100);
   }
};

This starts foobar() every 100 msec. foobar() should return a boolean value - basically the calculations in your while loop, and update the user interface. Once foobar() returns true, the Runnable is not restarted.

answered Feb 07 '13 at 13:16

unbehagen

113
5

1 more question plz? For finding time since the stopwatch has been started i am doing it right . Temp is the variable which holds that. – user2018473 Feb 07 '13 at 13:36
Depends on the value of ´chrono.getBase()´. I think the correct calculation should be ´elapsedRealtime - initialTime´. – unbehagen Feb 07 '13 at 13:50
Sorry I was unable to try this foobar activity? that time. I am trying to implement it now but dont understand how. What I want is for the chronometer to reset after 25 minutes. My question is that what goes into this runnable,the time check? – user2018473 Feb 10 '13 at 05:33

score 0 · Answer 2 · answered Feb 07 '13 at 13:06

0

You are killing the CPU, and probably never stopping. The likelihood of temp being EXACTLY 25 * 60 * 1000 is very low. Change that "==" check to ">=". Also, use a "boolean" for found: it makes more sense.

answered Feb 07 '13 at 13:06

David Lavender

8,021
3
35
55

Time in java/android + crashing app

2 Answers2