How to detect a MEDIA_BUTTON double click?

Question

It seems to be easy and should look like:

private long DOUBLE_CLICK_DELAY = 150;
private long lastButtonClick = // oldValue
private long currentButtonClick = System.currentTimeMillis();
...
if (currentButtonClick - lastButtonClick < DOUBLE_CLICK_DELAY ) // bla-bla

but I can't save the old value of previuous click in a BroadcastReceiver. Should I save it in a temporary database o something? (No activity used)

public class RemoteControlReceiver extends BroadcastReceiver {

@Override
  public void onReceive(Context context, Intent intent) {
    if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction())) {
      if (/* DOUBLE_CLICK */){
        Toast.makeText(context, "Tra-la-la!", 100).show();      
      }
    }
  } 

}

You mention that no activity is used, but where do you keep the button then? — gianpi, Dec 02 '11 at 23:18
Do you know what is the MEDIA_BUTTON? It is the headset button. — Ghedeon, Dec 03 '11 at 09:28
I didn't know actually :) Since you have the context and you only want to store a value, how about using the SharedPreferences? — gianpi, Dec 03 '11 at 09:41
Why can't you save the old value of previuous click in a BroadcastReceiver? What's wrong with a [static variable](http://stackoverflow.com/q/15168803/1357272)? — ih8ie8, Mar 22 '13 at 04:01

score 2 · Answer 1 · answered Dec 11 '11 at 15:07

Well, thanks to @gianpi it's working with SharedPreferences. But not sure about of good reading/writing speed in this case. Whatever, if anybodys's intrested:

@Override
  public void onReceive(Context context, Intent intent) {
    if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction())) {
      KeyEvent keyEvent = (KeyEvent) intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
        if (keyEvent != null) {
            if (keyEvent.getAction() == KeyEvent.ACTION_UP) {
                SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, 0);
                long last = settings.getLong("last", 0);
                long delta = System.currentTimeMillis() - last;
                if (delta < DOUBLE_CLICK_DELAY) {             
                  context.startService(new Intent(context, MyService.class));
                }
                SharedPreferences.Editor editor = settings.edit();
                editor.putLong("last", System.currentTimeMillis());
                editor.commit();
            }
        }
     }
  }

score 1 · Answer 2 · answered Jun 29 '13 at 23:56

Maybe the post is already a little bit old but today I was facing the same issue and I found a better (or at least more "elegant") solution instead of using the shared preferences.

Declare the global variables as static in your MainActivity:

static final long DOUBLE_CLICK_DELAY = 150;
static long lastButtonClick = 0; // oldValue
static long currentButtonClick = System.currentTimeMillis();

Now from your RemoteControlReceiver class do the following:

@Override
public void onReceive(Context context, Intent intent) {
    String intentAction = intent.getAction();
    if (!Intent.ACTION_MEDIA_BUTTON.equals(intentAction)) {
        return;
    }
    KeyEvent event = (KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
    if (event == null) {
        return;
    }
    int action = event.getAction();
    if (action == KeyEvent.ACTION_DOWN) {
        // Do something for action down
    }
    else if(action == KeyEvent.ACTION_UP){
        MainActivity.lastPressTime = MainActivity.newPressTime;
        MainActivity.newPressTime = System.currentTimeMillis();
        long delta = MainActivity.newPressTime - MainActivity.lastPressTime;

        // Case for double click
        if(delta < MainActivity.DOUBLE_CLICK_DELAY){
            // Do something for double click
        }
    }
}

How to detect a MEDIA_BUTTON double click?

2 Answers2