hacking ios ui responder chain

Question

I'm facing a delicated problem handling touch events. This is problably not a usual stuff to make but i think it is possible. I just don't know how...

I have a Main View (A) and Main View (B) with a lot of subviews 1,2,3,4,5,...

MainView
 SubView(A)
   1
   2
   3
 SubView(B)
   1
   2
   3

Some of these sub sub views (1,2,4) are scrollviews.

It happens that I want to change between A and B with a two finger pan.

I have tried to attach a UIPanGestureRecognizer to MainView but the scrollviews cancel the touches and it only works sometimes.

I need a consistent method to first capture the touches, detect if it is a two finger pan, and only then decide if it will pass the touches downwards (or upwards... i'm not sure) the responder chain.

I tried to create a top level view to handle that, but I cant make to have the touches being passed through that view.

I have found a lot of people with similar problems but couldn't find a solution to this problem from their solutions.

If any one could give me a light, that would be great as i'm already desperate with this.

Answer 1

You can create a top level view to capture the touches and the coordinates of touches then you can check if the coordinates of touch is inside of the sub views. You can do that using

BOOL CGRectContainsPoint(CGRect rect, CGPoint point)

Method. Rect is a frame of the view, and point is point of touch.

Please not that the frames and touch locations are relative to their super views, therefore you need to convert them to coordinate system of app window.

Or maybe it can be more helpful

Receiving touch events on more then one UIView simultaneously