Advance way of using UIView convertRect method to detect CGRectIntersectsRect multiple times

Question

I recently asked a question regarding collision detection within subviews, with a perfect answer. I've come to the last point in implementing the collision on my application but I've come across a new issue.

Using convertRect was fine getting the CGRect from the subView. I needed it to be a little more complex as it wasn't exactly rectangles that needed to be detected.

on XCode I created an abstract class called TileViewController. Amongst other properties it has a IBOutlet UIView *detectionView; I now have multiple classes that inherit from TileViewController, and each class there are multiple views nested inside the detectionView which I have created using Interface Builder.

The idea is an object could be a certain shape or size, I've programatically placed these 'tiled' detection points bottom center of each object. A user can select an item and interactive with it, in this circumstance move it around.

Now the method itself works to an extent but I don't think it's working with the nested values properly as the detection is off.

A simplified version of this method works - Using CGRectIntersectsRect on the detectionView itself so I'm wondering if I'm looping through and checking the views correctly?

I wasn't sure whether it was comparing in the same view but I suspect it is, I did modify the code slightly at one point, rather then comparing the values in self.view I took the viewController.detectView's UIViews into the interactiveView.detectView but the outcome was the same.

It's rigged so the subviews change colour, but they change colour when they are not even touching, and when they do touch the wrong UIviews are changing colour

Many thanks in advance

Answer 1

I worked out my issue when using convertRect.

I thought I'd read the documentation again (believe me I've been reading it) but I missed a key piece of information previously. To use convertRect:toView: to use the method the view needs to be target of the conversion operation as mentioned in the doc, but I was using the view itself as the target instead of the parent view

interactRect = [detectInteractView convertRect:[detectInteractView frame] toView:parentView];

This is wrong, I know there isn't many details in this post but ultimately you can't use the same UIView as the target view, or at least if you can I couldn't get it to work here!