Swift - Using gesture recognizers on an image but not the view

Question

I have an UIImageView containing a single image. In storyboard I placed a pan gesture recognizer on the image view. It works, however, I can only reposition the entire UIImageView and not just the image. In the example below I want the red frame to remain the same, always. I only want to reposition the underlying image.

The code for my pinch gesture recognizer is obviously transforming the imageView which is the problem. But I don't see a way to attach the gesture recognizers to the image itself. Or if that's even what I should be trying to do...

@IBAction func scaleImage(_ sender: UIPinchGestureRecognizer) {
   imageView.transform = CGAffineTransform(scaleX: sender.scale, y: sender.scale)
}

Answer 1

When you're saying

reposition the entire UIImageView and not just the image

it sounds like you think that there's some view container for image inside UIImageView.

But it's not true. UIImageView is already the lowest level you can get. There's a layer underneath, but it's bound to the view.

When you're changing transform of UIImageView this affects gestures calculation, that's the reason of your problems.

I suggest you wrapping UIImageView with UIView and adding gesture recognizer for this container view.

Also depending on your needs, the simplest solution may be placing image inside a UIScrollView and enabling zoom, this will allow user both to zoom and scroll through image.