private void updateOnTouch(MotionEvent event) {
		boolean ignoreTouch = ignoreTouch(event.getX(), event.getY());
		if (ignoreTouch) {
			return;
		}
		setPressed(true);
		mTouchAngle = getTouchDegrees(event.getX(), event.getY());
		int progress = getProgressForAngle(mTouchAngle);
		onProgressRefresh(progress, true);
	}
Notification that the user has finished a touch gesture. Clients may
want to use this to re-enable advancing the seekarc.

@param seekArc
           The SeekArc in which the touch gesture began
SeekArc_library/src/com/triggertrap/seekarc/SeekArc.java