Changing screen brightness efficiently

Question

I need to change the screen brightness programmatically. I read multiple solutions like this Can't apply system screen brightness programmatically in Android .

My problem is that those solutions implies changing the activity to be effective (having something like a dummy activity finishing immediately) and I would like to avoid the overhead of an activity switch.

Is there any other solution... maybe using native code so that the screen brightness will change immediately ?

Answer 1

The following affects immediately the single activity, no need to restart it. The activity also remembers the screenBrightness attribute over pause/resume.

WindowManager.LayoutParams lp = getWindow().getAttributes();
lp.screenBrightness = 1; // 0f - no backlight ... 1f - full backlight
getWindow().setAttributes(lp);

But it has no effect if you have automatic backlight level enabled in the system settings. This solution should help to turn off automatic backlight.