触摸时显示视图控制器

Question

I want to implement a hold-to-preview button that brings up a view containing an AVPlayerLayer , which plays as long as the touch doesn't end. The video player is contained in a different view controller, and I am hoping to be able to use presentViewController:animated: when presenting it, and not just add it as a subview and child view controller.

My question is about how to deal with the touch event. I see two possible ways:

• I try to transfer the active touch down event to the presented view controller (not sure if even possible), or
• I try to keep the original view controller's gesture recognizer active, and then let the video view controller know when it's time to dismiss itself. I'm hoping this could be achieved either by just setting the presented view controller's userInteractionEnabled to false, or perhaps using a UIViewControllerTransitioningDelegate to present it, and then just skip calling completeTransition: or something similar (I believe touches don't register on the new view until you complete the animation, but please correct me if I'm wrong).

Answer 1

My question is about how to deal with the touch event.

Touches are always associated with the view that they start in. You can't transfer the touch to a different view. I've never tried it, but the options I think you should explore first are:

• Use view controller containment. Make your preview view controller a child view controller of the one where the touch originates. That way the parent and its view hierarchy never go away, although they could be covered up.

• Attach the gesture recognizer to the window. A window is a view, and should be able to have gesture recognizers. You could make the gesture recognizer's target the app delegate or some other object that will always be around, and have the delegate post a notification when the recognizer is triggered. Again, I haven't tried this, but it seems like it should work.