PNG transparency and touches in android

Question

I have a png, when I save it it is a square image, but inside the square png is a circle (sometimes its other shapes). How can I check when the user is over what is inside the png and a graphic rather than when a user is inside a png but is over transparency?

Answer 1

Yea, you can do this, you just need to manually check the color of the pixel where the touch occurred.

int color = Bitmap.getPixel(x,y); // x and y are the location of the touch event in Bitmap space
int alpha = Color.getAlpha(color);
boolean isTransparent = (alpha==0);

Note: Depending on how you implement your touch listener will might need to convert the x,y location of the touch event to the x,y coordinates of the image view.