Question

I have made an app that wakes up the screen when it receives a text message. I came up with the following code to wake the screen.

PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);

        boolean isScreenOn = pm.isScreenOn();

    if(!isScreenOn ){

final PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My tag");
        wl.acquire();

        Toast.makeText(getBaseContext(), "This is WAKEUP SCREEN", Toast.LENGTH_SHORT).show();
        Thread timer = new Thread(){
            public void run(){
                try {
                    sleep(5000);
                } catch (InterruptedException e) {
                    // TODO: handle exception
                }finally{
                    wl.release();
                }
            }
        };
        timer.start();
    }

Now the problem is that if I comment out or remove the statement Toast.makeText(getBaseContext(), "This is WAKEUP SCREEN", Toast.LENGTH_SHORT).show(); my screen wont wakeup. I am not sure what is the problem here… and I am using android 2.3.

Answer 1

Use PowerManager.SCREEN_DIM_WAKE_LOCK|PowerManager.ACQUIRE_CAUSES_WAKEUP instead of just PowerManager.SCREEN_DIM_WAKE_LOCK, and see if that helps.