Crop UIImageView and gesture recognizer - ios

Question

I have ImageView that I crop to circle with this:
self.contentMode = UIViewContentModeScaleAspectFill;
self.layer.cornerRadius = self.bounds.size.height / 2.0;
self.layer.masksToBounds = YES;
Then I added gesture recognizer to it, but it fires in cropped area.
How can I avoid firing it in cropped area?

Answer 1

A more general and flexible way to mask your image is with a CAShapeLayer. You can create any shape, including a circle, to use as a mask. By using this approach to crop your image view instead of using cornerRadius, you can check if the touch point is within the layer's path (a UIBezierPath). In the UIImageView subclass add the following code to create the mask, and create a property, shape, in the .h file.
self.shape = [UIBezierPath bezierPathWithOvalInRect:self.bounds];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = self.shape.CGPath;
self.layer.mask = shapeLayer;
In the controller, add the tap gesture recognizer, and use this code in its action method,
-(void)handleTap:(UITapGestureRecognizer *) tapper {
CGPoint touchPoint = [tapper locationInView:tapper.view];
if ([self.imageView.shape containsPoint:touchPoint]) {
NSLog(#"touched");
// do what you want with the touch here
}
}

Answer 2

Set your class conforms to UIGestureRecognizerDelegate
Set your gesture delegate to self
Then use this delegate to decide that if you want it fire or not
-(BOOL) gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
Example Code
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
CGPoint touchPoint = [touch locationInView:self.imageview];
if (CGRectContainsPoint(self.imageview.bounds, touchPoint)) {
CGFloat centerX = CGRectGetMidX(self.imageview.bounds);
CGFloat centerY = CGRectGetMidY(self.imageview.bounds);
CGFloat radius2 = pow((touchPoint.x -centerX),2)+ pow((touchPoint.y - centerY), 2);
if (radius2 < pow(CGRectGetWidth(self.imageview.frame)/2, 2)) {
return YES;
}
}
return NO;}