c# and gdi+ have a simple way to control the colors that are drawn. It’s basically a ColorMatrix. It’s a 5×5 matrix that is applied to each color if it is set. Adjusting brightness is just performing a translate on the color data, and contrast is performing a scale on the color. Gamma is a … Read more
There’s no such nice API for doing this on OS X. We have to use IOServiceGetMatchingServices to find “IODisplayConnect” (the display device) then use the kIODisplayBrightnessKey to set the brightness: func setBrightnessLevel(level: Float) { var iterator: io_iterator_t = 0 if IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceMatching(“IODisplayConnect”), &iterator) == kIOReturnSuccess { var service: io_object_t = 1 while service != 0 … Read more
Here is how you register a listener on the light sensor: private final SensorManager mSensorManager; private final Sensor mLightSensor; private float mLightQuantity; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // Obtain references to the SensorManager and the Light Sensor mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); mLightSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT); // Implement a listener to receive updates SensorEventListener listener = … Read more
OK, found the answer here: Refreshing the display from a widget? Basically, have to make a transparent activity that processes the brightness change. What’s not mentioned in the post is that you have to do: Settings.System.putInt(y.getContentResolver(),Settings.System.SCREEN_BRIGHTNESS_MODE, 0); Settings.System.putInt(y.getContentResolver(),Settings.System.SCREEN_BRIGHTNESS, brightnessLevel); then do WindowManager.LayoutParams lp = getWindow().getAttributes(); lp.screenBrightness = brightness; getWindow().setAttributes(lp); And if you call finish() right … Read more
It’s not clear why you want to avoid paintComponent(), but you can always alter the BufferedImage in a JLabel‘s ImageIcon using RescaleOp. Addendum: I sounds like you don’t want to overwrite the original image, so naturally it makes sense to alter a copy. Unfortunately, your example merely copies a reference to the original. Instead, use … Read more
This is the complete code I found to be working: Settings.System.putInt(this.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, 20); WindowManager.LayoutParams lp = getWindow().getAttributes(); lp.screenBrightness =0.2f;// 100 / 100.0f; getWindow().setAttributes(lp); startActivity(new Intent(this,RefreshScreen.class)); The code from my question does not work because the screen doesn’t get refreshed. So one hack on refreshing the screen is starting dummy activity and than in on create … Read more
You can use following: // Variable to store brightness value private int brightness; // 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; In your onCreate write: // Get the content resolver cResolver = getContentResolver(); // … Read more