Using the fact that you can tell whether or not coordinates belong in a circle with the equation x² + y² <= radius²
when the circle's center is (0, 0), I think the following should work.
public class ImageOnTouchListener implements View.OnTouchListener {
// TODO Adjust this value
private static int QUADRANT_RADIUS = 100; // in pixels
// TODO Adjust this value
private static int SPACE_BETWEEN_QUADRANTS = 5; // in pixels
@Override
public boolean onTouch(View v, MotionEvent event) {
int relativeX = (int) (event.getX() - v.getX());
int relativeY = (int) (event.getY() - v.getY());
int center = QUADRANT_RADIUS + (SPACE_BETWEEN_QUADRANTS / 2);
boolean isInsideCircle = Math.pow(relativeX - center, 2) + Math.pow(relativeY - center, 2) <= Math.pow(center, 2);
boolean isInsideBottomLeftQuadrant = isInsideCircle &&
relativeX <= QUADRANT_RADIUS &&
relativeY >= QUADRANT_RADIUS + SPACE_BETWEEN_QUADRANTS;
boolean isInsideBottomRightQuadrant = isInsideCircle &&
relativeX >= QUADRANT_RADIUS + SPACE_BETWEEN_QUADRANTS &&
relativeY >= QUADRANT_RADIUS + SPACE_BETWEEN_QUADRANTS;
boolean isInsideTopLeftQuadrant = isInsideCircle &&
relativeX <= QUADRANT_RADIUS &&
relativeY <= QUADRANT_RADIUS;
boolean isInsideTopRightQuadrant = isInsideCircle &&
relativeX >= QUADRANT_RADIUS + SPACE_BETWEEN_QUADRANTS &&
relativeY <= QUADRANT_RADIUS;
boolean isActionUp = event.getAction() == MotionEvent.ACTION_UP;
if (isActionUp) {
if (isInsideBottomLeftQuadrant) {
// Handle bottom left quadrant click
buttonClick();
return true;
} else if (isInsideBottomRightQuadrant) {
// Handle bottom right quadrant click
} // etc.
}
return false;
}
}
You'll need to adjust the QUADRANT_RADIUS
and SPACE_BETWEEN_QUADRANTS
values, and then either handle all touch events from a single view (like my snippet does) or have a slightly different touch listener per image.