Screen on/off toggle through code in Android

Question

There are a few questions already on StackOverflow related to turning the screen on / off, however not a single solution has worked for me.

1. I do not want to use a wakelock as it's no longer recommended. My app wakes up the screen using WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON, which is far simpler and doesn't lead to a situation where one can drain the entire battery if you forget to release it.

2. Setting brightness to 0 like the following code also does not work. On my two test phones (Samsung Galaxy S2 and S3), this code only dims the screen, but does not turn it off.

   layoutParam.screenBrightness = 0;
   layoutParam.flags |= LayoutParams.FLAG_KEEP_SCREEN_ON;
   getWindow().setAttributes(layoutParam);
   

My scenario - it's a VoIP app which turns on the screen for an incoming call, but then needs to switch off the screen (but keep the CPU running) if the user holds the phone up to their face. The proximity sensor code is running fine.

Answer 1

Have you tried changing the Screen off timeout value?

Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_OFF_TIMEOUT, 1000);

The value of 1000 means 1000 milliseconds, or 1 second, you can change it if you want. Afterwards change it back to the standard like this

Settings.System.putInt(getContentResolver(),Settings.System.SCREEN_OFF_TIMEOUT,-1);

This requiers a permission in the manifest file:

<uses-permission android:name="android.permission.WRITE_SETTINGS"/>