Cool. 

This is some sample code that I've used for this in the past :

Yes, sorry... that's one that's almost always imported (at least I always copy it from my other code) so forgot about it...

Hi,

I'm trying to use your code to change brightness during execution, but I get the exception :
"android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views."

Here is my code :

1. void setScreenLuminosity(float lum) {
     lum = constrain (lum, 0.0, 1.0);
     WindowManager.LayoutParams layoutParams = getWindow().getAttributes();
     layoutParams.screenBrightness = lum;
     getWindow().setAttributes(layoutParams);
    
   }
2. void onCreate(Bundle bundle) {
     super.onCreate(bundle);
     getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
   
   }

I call setScreenLuminosity from draw().
How can I access the view of the main thread ?

Thanks for Your help :)

Here is my final solution to change brightness during runtime :

public void setScreenLuminosity(final float lum) {
  runOnUiThread(new Runnable() {
    public void run() {
      float lum2 = constrain (lum, 0.05, 0.95);
      WindowManager.LayoutParams layoutParams = getWindow().getAttributes();
      layoutParams.screenBrightness = lum2;
      getWindow().setAttributes(layoutParams);
    }
  }
  );
}