gistfile1.m

static char clickTargetScaleKey;
static char clickTargetWidthKey;
static char clickTargetHeightKey;

BOOL pointInsideWithEvent(
    UIView* self, SEL _cmd, CGPoint point, UIEvent* event) {
  NSNumber* clickTargetScaleNumber = 
      objc_getAssociatedObject(self, &clickTargetScaleKey);
  assert(clickTargetScaleNumber);
  float clickTargetScale = [clickTargetScaleNumber floatValue];

  CGRect clickBounds = self.bounds;

  float newWidth = clickBounds.size.width * clickTargetScale;
  float newHeight = clickBounds.size.height * clickTargetScale;

  clickBounds.origin.x -= (newWidth - clickBounds.size.width)/2;
  clickBounds.origin.y -= (newHeight - clickBounds.size.height)/2;
  clickBounds.size.width = newWidth;
  clickBounds.size.height = newHeight;

  // Use height/width overrides if set.
  NSNumber* clickTargetWidth =
      objc_getAssociatedObject(self, &clickTargetWidthKey);
  if (clickTargetWidth) {
    clickBounds.size.width = [clickTargetWidth floatValue];
  }
  NSNumber* clickTargetHeight =
      objc_getAssociatedObject(self, &clickTargetHeightKey);
  if (clickTargetHeight) {
    clickBounds.size.height = [clickTargetHeight floatValue];
  }

  return CGRectContainsPoint(clickBounds, point);
}