How to programmatically control whether the screen may or may not turn off.

android_FLAG_KEEP_SCREEN_ON.java

// Android Java
// How to programmatically control whether the screen may or may not turn off.
//
// By Andrew Kingdom
// MIT license
//

package com.example.sample;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.WindowManager;

public class MainActivity extends AppCompatActivity {
    
    private boolean getFlagScreenOn() {
        boolean value = (getWindow().getAttributes().flags & WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) != 0;
        return value;
    }
    private void setFlagKeepScreenOn(boolean value) {
        getWindow().setFlags(
                value ? WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON : 0,
                WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
        );
    }
}