Keep screen on in Activity - does not work with FLAG_KEEP_SCREEN_ON

Question

For a long time I thought that I knew how to stop the screen from going into sleep mode, I simply used this code in my Activity:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

However, I realized that this only worked when my phone was in "developer mode", ie when the USB debugging (Settings --> Developer options --> USB debugging) was enabled/checked. Then the above code indeed stops the screen/device to go to sleep.

When that debugging is not checked, then my screen goes to sleep like there's no tomorrow. I am running Android 4.04 on my device, and

 android:minSdkVersion="12"
 android:targetSdkVersion="16"

Edit

I have tested with Commonsware's suggestion, and added the setKeepScreenOn() to the code, so it looks like this:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); 
View root = findViewById(android.R.id.content); 
if (root != null)
    root.setKeepScreenOn(true);

I have also checked so that this code is actually executed, and it is. But it doesn't change a thing.

Embonpoint

Ill try it, but it seems that the FLAG_KEEP_SCREEN_ON might even work if the app is "deployed" via Eclipse, but not if I download the exact same code from Google Play. And yet, everyone "out there" on the net says that FLAG_KEEP_SCREEN_ON works... I cant be the only one with this issue? – Embonpoint

Since I have never used FLAG_KEEP_SCREEN_ON, and only have ever used setKeepScreenOn() (as it is simpler), I cannot comment regarding the efficacy of your FLAG_KEEP_SCREEN_ON code. – Archaize

Ok, it doesnt work with the setKeepScreenOn() either. – Embonpoint

Since this stuff works for lots of other developers on lots of other apps, I'd say the issue is with your device. – Archaize

Its a Samsung S2, android version 4.0.4. Sounds too mainstream to not work... The same issue is for Samsung S3 Mini, that I bought 1 week ago. – Embonpoint

github.com/commonsguy/cw-omnibus/tree/master/MiscUI/… That sample project demonstrates the use of setKeepScreenOn() for a "delayed timeout", where you want to keep the screen lit for a while, but not indefinitely if the user is not actively using your app. This sample has worked successfully on all hardware that I have tried it on. – Archaize

Thanks for that CommonsWare. I use the same code/methods that you use, and cannot really see why it shouldnt work in my case. I will do some debug-printouts, as there seem to be some form of difference if there is a debugger connected, if the phone is in "developer mode" etc... – Embonpoint

ted, do you have the same problem with setKeepScreenOn() on a View? – Orchard

I tried CommonsWare's suggestion and it works perfectly, (I just used setKeepScreenOn() on android.R.id.content, without the FLAG_KEEP_SCREEN_ON flag). I also tried it without the developer mode nor the run feature from Eclipse (I copied the APK file to the device and run the installer) and it works smoothly. – Kwon

So, a long time later, I think the screen is actually kept on normally, but I have seen sometimes that it doesnt. But I havent looked at it further... – Embonpoint

Is the window/view having this flag visible while the phone goes to sleep? – Morph

I've been looking at this today and have found that I'm able to keep the screen on if I do it during OnCreate(). It works using either method (FLAG_KEEP_SCREEN_ON flag or View.setKeepScreenOn(true)). If I try to keep the screen on sometime after OnCreate() (based on user input, for example), it doesn't work. – Dace

Answer 1

i was facing same problem, i was using one activity for my project and all the other screen are fragments then i used the android:keepScreenOn="true" in main activity.

please try to use this and let me know if you didn't get your desire result.

Thanks.

Assibilate

Answer 2

Only solution which realy works in my app is WakeLock in main application class. Unfortunately the SCREEN_BRIGHT_WAKE_LOCK flag is deprecated!

public class MyApp extends Application {
    PowerManager.WakeLock screenOnWakeLock;
    @Override
    public void onCreate() {
        super.onCreate();
        PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
        wakeLock =  powerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK,"ScreenlockTag");
        wakeLock.acquire();
    }

    @Override
    public void onTerminate()
    {
        if (screenOnWakeLock != null && screenOnWakeLock.isHeld())
            screenOnWakeLock.release();
        super.onTerminate();
    }
}

Ovotestis