Android - How to stop and pause timer

Question

I have been running through alot of issues try to pause and unpause a timer, and if I lock the orientation to portrait or landscape it works, but thats not exactly what I want to do. Of course, the onCreate method is called when you change orientation, so im canceling my timertask and setting it to null, but after running through the orientation more than once, it doesnt cancel the timertask anymore. Ive looked through other peoples questions on here but none seem to hold the answer to my quesiton. Heres my code. Its a little sloppy at the moment because ive been trying about everything I can to get it to work.

public class singleTimer extends Activity implements OnClickListener {

private Integer setTime = 0;
private Integer tmrSeconds = 0;
private Integer tmrMilliSeconds = 0;
private Timer myTimer = new Timer();
private TimerTask myTimerTask;
private TextView timerText;
private boolean isPaused = true;

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.single_timer);
    Bundle extras = getIntent().getExtras();
    setTime = extras.getInt("com.bv.armyprt.timer_duration");
    if (myTimerTask != null) {
        myTimerTask.cancel();
        myTimerTask = null;
    }
    if (savedInstanceState != null) {
        if (savedInstanceState.getInt("tmrSeconds") == 0) {
            tmrSeconds = setTime;
        } else {
            tmrSeconds = savedInstanceState.getInt("tmrSeconds");
            tmrMilliSeconds = savedInstanceState.getInt("tmrMilliseconds");

            if (isPaused == false) {
                myTimer = new Timer();
                myTimerTask = new TimerTask() {
                    @Override
                    public void run() {
                        TimerMethod();
                    }
                };
                myTimer.schedule(myTimerTask, 0, 100);
            }

        }
    } else {
        tmrSeconds = setTime;
    }
    timerText = (TextView)findViewById(R.id.timerText);
    timerText.setText(String.format("%03d.%d", tmrSeconds, tmrMilliSeconds));

    TextView timerDesc = (TextView)findViewById(R.id.timerDescription);
    timerDesc.setText("Timer for: " + setTime.toString());
    Button startButton = (Button)findViewById(R.id.timerStart);
    Button stopButton = (Button)findViewById(R.id.timerStop);
    Button closeButton = (Button)findViewById(R.id.timerClose);
    closeButton.setOnClickListener(this);
    startButton.setOnClickListener(this);
    stopButton.setOnClickListener(this);

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case (R.id.timerStart):
        isPaused = false;
        myTimer = new Timer();
        myTimerTask = new TimerTask() {
            @Override
            public void run() {
                TimerMethod();
            }
        };
        myTimer.schedule(myTimerTask,0, 100);
        break;

    case (R.id.timerStop):
        isPaused = true;
        myTimerTask.cancel();
        myTimerTask = null;
        myTimer.cancel();

        break;

    case (R.id.timerClose):
        onDestroy();
        this.finish();
        break;
    }

}
private void TimerMethod()
{
    //This method is called directly by the timer
    //and runs in the same thread as the timer.
    //We call the method that will work with the UI
    //through the runOnUiThread method.
    this.
    tmrMilliSeconds--;
    this.runOnUiThread(Timer_Tick);
}

private Runnable Timer_Tick = new Runnable() {
    public void run() {

    //This method runs in the same thread as the UI.               
        if (tmrSeconds > 0) {
            if (tmrMilliSeconds <= 0) {
                tmrSeconds--;
                tmrMilliSeconds = 9;
            }
        } else {
            Vibrator v = (Vibrator)getSystemService(Context.VIBRATOR_SERVICE);
            v.vibrate(1000);
            myTimer.cancel();
            tmrSeconds = setTime;
            tmrMilliSeconds = 0;
            isPaused = true;
        }

    //Do something to the UI thread here
        timerText.setText(String.format("%03d.%d", tmrSeconds, tmrMilliSeconds));
    }
};

@Override
public void onSaveInstanceState(Bundle savedInstanceState){
    savedInstanceState.putInt("setTimer", setTime);
    savedInstanceState.putInt("tmrSeconds", tmrSeconds);
    savedInstanceState.putInt("tmrMilliseconds", tmrMilliSeconds);

    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    setTime = savedInstanceState.getInt("setTimer");
    tmrSeconds = savedInstanceState.getInt("tmrSeconds");
    tmrMilliSeconds = savedInstanceState.getInt("tmrMilliSeconds");
}
}

Answer 1

you can simply add a boolean variable

boolean stopTImer = false ;

and in your timerTask , do something like this :

@Overrride
public void run(){
if(!stopTimer){
//do stuff ...
//...
}

and when you want to stop it , put the boolean to true

Answer 2

You should stop the timer during onStop. Android might create another instance of your Activity and you will lose the reference to your previous timer(task) when you change orientation.

All objects tied to an activity follow the activity lifecycle. That means you have to store the references to objects elsewhere if you want to keep them even if the activity gets deleted (which can happen quite often).