Apply many color filters to the same drawable
This is the approach I ended using: Manipulate the Drawable
bitmap on a Canvas
and apply as many layers as I need, using Paint
, it works not only for color filters, but also for any kind of image blending.
...
Drawable myBackground = createBackground(getResources().getColor(R.color.Green));
setBackgroundDrawable(myBackground);
...
private Drawable createBackground(int color) {
Canvas canvas = new Canvas();
Bitmap buttonImage = BitmapFactory.decodeResource(getResources(), R.drawable.btn_image);
Bitmap buttonShadows = BitmapFactory.decodeResource(getResources(), R.drawable.btn_shadows);
Bitmap buttonHighLights = BitmapFactory.decodeResource(getResources(), R.drawable.btn_highlights);
Bitmap result = Bitmap.createBitmap(buttonImage.getWidth(), buttonImage.getHeight(), Bitmap.Config.ARGB_8888);
canvas.setBitmap(result);
Paint paint = new Paint();
paint.setFilterBitmap(false);
// Color
paint.setColorFilter(new PorterDuffColorFilter(color, Mode.MULTIPLY));
canvas.drawBitmap(buttonImage, 0, 0, paint);
paint.setColorFilter(null);
// Shadows
paint.setXfermode(new PorterDuffXfermode(Mode.MULTIPLY));
canvas.drawBitmap(buttonShadows, 0, 0, paint);
// HighLights
paint.setXfermode(new PorterDuffXfermode(Mode.SCREEN));
canvas.drawBitmap(buttonHighLights, 0, 0, paint);
paint.setXfermode(null);
return new BitmapDrawable(getResources(), result);
}
Caveat: setBackgroundDrawable(Drawable d)
is deprecated, while setBackground(Drawable d)
is only available from api 16 on, so if you have like me a min target api-14 max target api-17 you have no "clean" way to set the drawable as background. I sticked with the deprecated call.