9

In my application I need to know when device is locked (on HTC's it looks like short press on "power" button). So the question is: which event is triggered when device is locked? Or device is going to sleep?

Barmaley
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3 Answers3

5

You should extend BroadcastReceiver and implement onReceive, like this: 

public class YourBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (Intent.ACTION_SCREEN_OFF.equalsIgnoreCase(intent.getAction())) {
            //screen has been switched off!
        }
    }
}

Then you just have to register it and you'll start receiving events when the screen is switched off: 

IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
appBroadcastReceiver = new AppBroadcastReceiver(yourActivity);
registerReceiver(appBroadcastReceiver, filter);
pandre
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  • If you're wanting to check if the device is locked, you could use the method from [this solution](http://stackoverflow.com/questions/4260794/how-to-tell-if-device-is-sleeping/4261021#4261021). Unfortunately there's no broadcast for the device locking, but I find it useful to be able to check if it's locked or not. – Chris Aug 06 '11 at 22:32
3

There is a better way:

KeyguardManager myKM = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
if( myKM.inKeyguardRestrictedInputMode()) {
 //it is locked
} else {
 //it is not locked
}
Shaul Rosenzweig
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  • Did you try isDeviceLocked for Android 5.1 http://developer.android.com/reference/android/app/KeyguardManager.html#isDeviceLocked()? – Maksim Dmitriev Apr 03 '15 at 10:05
0

In addition to the above answer, in-case you want to trigger some action when your app is at the foreground:

You could use the event called onResume() to trigger your own function when your app takes the spotlight from a previously resting state, i.e, if your app was at the background(paused/minimized...)

protected void onResume()
{
    super.onResume();

    //call user-defined function here
}
Augiwan
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