android - Setting the screen brightness to maximum level

Question

I'm a newbie to this field of android development. These days i'm developing an app and I want to set the screen brightness to maximum level once I open the app, and set it back to the previous level once I exit the app. Can someone come up with the full source code for this? I read almost every thread in stackoverflow regarding this issue. And I couldn't understand where to put those suggested codes. But if u can come up with the full code, then I'll be able to understand everything. Thanks!

Answer 1

You can use this

public class MainActivity extends AppCompatActivity {

private int brightness=255;
//Content resolver used as a handle to the system's settings
private ContentResolver cResolver;
//Window object, that will store a reference to the current window
private Window window;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    cResolver = getContentResolver();

    //Get the current window
    window = getWindow();

    try
    {
        // To handle the auto


        Settings.System.putInt(cResolver,
                Settings.System.SCREEN_BRIGHTNESS_MODE, Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
        //Get the current system brightness
        brightness = Settings.System.getInt(cResolver, Settings.System.SCREEN_BRIGHTNESS);
    }
    catch (Settings.SettingNotFoundException e)
    {
        //Throw an error case it couldn't be retrieved
        Log.e("Error", "Cannot access system brightness");
        e.printStackTrace();
    }

    Settings.System.putInt(cResolver, Settings.System.SCREEN_BRIGHTNESS, brightness);
    //Get the current window attributes
    WindowManager.LayoutParams layoutpars = window.getAttributes();
    //Set the brightness of this window
    layoutpars.screenBrightness = brightness / (float)100;
    //Apply attribute changes to this window
    window.setAttributes(layoutpars);
 }
}

And the most important permission in the manifest

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

Asking for Write Settings permission in API 23

private boolean checkSystemWritePermission() {
boolean retVal = true;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    retVal = Settings.System.canWrite(this);
    Log.d(TAG, "Can Write Settings: " + retVal);
    if(retVal){
        Toast.makeText(this, "Write allowed :-)", Toast.LENGTH_LONG).show();
    }else{
        Toast.makeText(this, "Write not allowed :-(", Toast.LENGTH_LONG).show();
       Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS);
       intent.setData(Uri.parse("package:" + getActivity().getPackageName()));
       startActivity(intent);
    }
  }
 return retVal;
}