How to detect volume up and down long pressed together?

Question

How to check if both volume up and volume down buttons are pressed together for few seconds in Android device ?

And if pressed, I need to call a function. This detection should work if my application is installed in any android device. Any near solution will also do.

score 3 · Accepted Answer · answered Apr 19 '18 at 06:14

3

You need to detect when the both of the keys are pressed using onKeyDown callback, something like should work:

public boolean up,down;

public boolean onKeyDown(int keyCode, KeyEvent event) {
   if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN){
      down = true;
   } else if(keyCode == KeyEvent.KEYCODE_VOLUME_UP){
      up = true;
   }
   if(up && down) {
    // Two buttons pressed, call your function
   }
   return true;
}

public boolean onKeyUp(int keyCode, KeyEvent event) {
  if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN){
    down = false;
  } else if(keyCode == KeyEvent.KEYCODE_VOLUME_UP){
    up = false;
  }
  return true;
}

answered Apr 19 '18 at 06:14

dan

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And what can I do to check if it had been pressed for some amount of time, say 2 seconds ? – Abhishek Singh Apr 19 '18 at 06:20
You can use a new variable like: `upKeyTime = event.getEventTime();` to determine the amount of time that the key was pressed. – dan Apr 19 '18 at 06:24
1

just one more thing ! What should i do to make it work even when the application is in background or when the screen is off. Because this is for emergency application and i need to detect the buttons press even if the application is not running or the phone is locked. Is it possible? – Abhishek Singh Apr 19 '18 at 06:59
@AbhishekSingh `Is it possible?` no, it is not – pskink Apr 19 '18 at 07:06
@AbhishekSingh Unfortunately the keypress works only while the app is in foreground, and from a service you are not allowed to retrieved them. See here: https://developer.android.com/training/keyboard-input/index.html. But, you should create another question, maybe there are some workarounds. – dan Apr 19 '18 at 07:09
@dan thank you so much. It helped me a lot to proceed further. – Abhishek Singh Apr 19 '18 at 08:30
@AbhishekSingh You're welcome. You should vote/accept the answer it it helped. – dan Apr 19 '18 at 08:31

score 1 · Answer 2 · answered Apr 19 '18 at 06:27

1

You need to override some methods and apply your logic there: for example, create following variables

private static final int PRESS_INTERVAL = 1000;
private long upKeyTime = 0;

Override the following

 @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (KeyEvent.KEYCODE_VOLUME_DOWN == event.getKeyCode()) {
            if ((event.getEventTime() - upKeyTime) < PRESS_INTERVAL) {
                Toast.makeText(this, "Pressed together", Toast.LENGTH_SHORT).show();
            }
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }


    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        if (KeyEvent.KEYCODE_VOLUME_UP == keyCode) {
            upKeyTime = event.getEventTime();
        }
        return super.onKeyUp(keyCode, event);
    }

This code will print a toast if the user presses volume down key after volume up key within 1 second. I hope you can change this code to the down-up key combination as this is the up-down combination.

answered Apr 19 '18 at 06:27

Somesh Kumar

8,088
4
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Thank you so much. This code worked. And do you know any way so that i can use this detection even when the phone is locked or the application is not opened? – Abhishek Singh Apr 19 '18 at 08:31
I am afraid this is not possible as stated [here](https://stackoverflow.com/questions/3454710/onkeydown-in-a-service-global-hot-keys) by @RomainGuy – Somesh Kumar Apr 19 '18 at 09:57
@AbhishekSingh Just a Note: You should change your selected answers too frequently. Yesterday you changed your selected answer many times.. and today you did the same. Just select the one which suits you. – Somesh Kumar Apr 20 '18 at 11:09
I am new here and i thought it is possible to mark more than one answer to be correct, so whenever I saw unchecked answer, i clicked on it, later I got to know about only one selection. Sorry and thank you :) – Abhishek Singh Apr 20 '18 at 23:31

Alireza Barakati · Answer 3 · 2020-01-22T14:05:05.103

public static final int VOLUME_PRESSED__INTERVAL = 100;
private long upKeyEventTime = 0;
private long downKeyEventTime = 0;

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
        if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
            downKeyEventTime = event.getEventTime();
        } else {
            upKeyEventTime = event.getEventTime();
        }
        if (Math.abs(upKeyEventTime - downKeyEventTime)<= VOLUME_PRESSED__INTERVAL){
            //TODO call your method
            return false;
        }
    }

    return super.onKeyDown(keyCode, event);
}

If you want more accuracy you can set VOLUME_PRESSED__INTERVAL = 0;

How to detect volume up and down long pressed together?

3 Answers3