Looking for guidance on detecting overlap of UIImageViews

Question

The scenario is that I have a UIViewController containing multiple "InteractiveUIImageViews" (inherited from UIImageView) each containing their own UIImage. In InteractiveUIImageView I have iplemented methods for touchesBegan, touchesMoved and touchesEnded to handle their movement and behaviour on screen. Certain objects of this type will be set as 'containers' (think recycle bin) with the objective being that when one image is dragged onto it, it will be removed from the screen and placed inside it to be potentially retrieved later.

My current thinking would be to call a new method in UIViewController from the touchesEnded method of my InteractiveUIImageView but being new to all this I'm not really sure how to go about doing that (e.g. calling a method from the 'parent') or indeed if this is the best way to achieve what I want to do.

Thanks in advance for any advice.

Answer 1

I'm afraid your question is (too me at least) a bit unclear. I get that your are trying drag a UIImage around a scene and drop it in drop-locations.

What is unclear is you class hierarchy. I believe that you are going about it in a wrong way. You shouldn't have to subclass UIImage at all.

Instead I would urge you to let the UIViewController manage the movement of the images. When you touch down on an image, you also touch down on its parent (containing) view.

What you have to to is then reposition the UIImage (all handled by the UIViewController) as you drag the image across the screen. When you let go you check if your finger was inside your drop-zone on touch up.