How to do something repeatedly while a button is pressed?

Question

I'm developing a TV-Remote Simulator app in Android using a specific middleware (not of importance).

In the case of Volume Buttons (Volume+ and Volume-), what I'm trying to do is to send the "Volume Up" signal repeatedly while its button is pressed.

That's what I tried at last (code for one of the buttons, the other must be identical except for the names):

Declared a boolean variable
```
boolean pressedUp = false;
```

Declared a inner class with the following AsyncTask:

class SendVolumeUpTask extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... arg0) {
        while(pressedUp) {
            SendVolumeUpSignal();
    }
    return null;
}

}

Add the listener to the button:

final Button buttonVolumeUp = (Button) findViewById(R.id.volup);
buttonVolumeUp.setOnTouchListener(new View.OnTouchListener() {

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {

        case MotionEvent.ACTION_DOWN:

            if(pressedUp == false){
                pressedUp = true;
                new SendVolumeUpTask().execute();
            }

        case MotionEvent.ACTION_UP:

            pressedUp = false;

    }
        return true;
    }
});

I've also tried with simple threads as in Increment-Decrement counter while button is pressed but neither worked. The application works finely for the rest of the buttons (channels, etc.), but volume changing is completely ignored.

score 3 · Accepted Answer · answered Nov 27 '12 at 12:36

3

You forgot to add a break; at the end of the MotionEvent.ACTION_DOWN: case. That means the line pressedUp = false; gets executed even on that action. The correct thing to do would be:

@Override
public boolean onTouch(View v, MotionEvent event) {
    switch (event.getAction()) {

    case MotionEvent.ACTION_DOWN:

        if(pressedUp == false){
            pressedUp = true;
            new SendVolumeUpTask().execute();
        }
    break;
    case MotionEvent.ACTION_UP:

        pressedUp = false;

}
    return true;
}

answered Nov 27 '12 at 12:36

Tas Morf

3,065
1
12
8

Thanks, now signals are sent. However, it sends a lot of signals for a short pressing period. Perhaps a counter should work. – Truncarlos Nov 27 '12 at 12:43
4

I would recommend having an interval between calls to SendVolumeUpSignal(); For example try this: `while(pressedUp) { SendVolumeUpSignal(); Thread.sleep(100);}` – Tas Morf Nov 29 '12 at 11:58

score 2 · Answer 2 · answered Nov 27 '12 at 12:02

2

Have you considered

Starting your repititive task on the onKeyDown event
Stopping the task on the onKeyUp event ?

answered Nov 27 '12 at 12:02

Vinay W

9,912
8
41
47

1

Aren't those methods for physical keys of the device? I meant tactile ones in my remote App – Truncarlos Nov 27 '12 at 12:17
yeah, the name suggests so.. but they are not :-) – Vinay W Nov 27 '12 at 12:58

How to do something repeatedly while a button is pressed?

2 Answers2