A UITableView stops consuming touch events, so the parent's sliding menu can detect horizontal scrolling

Question

I force myself to desperately try to achieve something so simple.

I have a menu view, which, using the touch slides on the left, when using a gesture, does this by scrolling horizontally. I do not use gesture recognizers, I just use touchhesBegan, touchhesMoved, etc. And I track the x coordinate difference between the initial touch, intermediate and final touch. It works great.

But when I have a UITableView in the body, touch events no longer find their way up the hierarchy into the view that controls the menu. I tried to get around this by passing touches to superview / nextResponder, what kinds of work, but I see what touchsBegan and 2 touchsMoved calls before it just stops processing further down the hierarchy.

In particular, I have SlideMenuView, which has a menu view and a body view. Inside the body, I look at some point in a UITableView. I see (via NSLog) that the touch * methods call from start to finish just fine. I pass them on to the next responder and start seeing them also in SlideMenuView, but after two calls to touchsMoved they seem to stop in SlideMenuView, but continue in my UITableView.

I am using a UITableView for this, but I have not changed anything else inside it.

I know that this should be possible, as is done in the application for Facebook. You can scroll anywhere in the body, which scrolls horizontally and shows the menu. I want the same thing to happen naturally here, but it seems like something strange is happening, and the UITableView is consuming or destroying events.

Can anyone help me with this? Someone had to achieve this in a clean way.

Answer 1

Well, for someone interested - I found a clean solution.

Apple knows what they are doing. On the same day, we redefined touchesBegan , but then introduced GestureRecognizers . For some controls, such as UIScrollView (and any subclasses like UITableView ), they seem to destroy the event response system. I was to blame for believing that Gesture Recognizers not doing anything special and just connecting to these touchesBegan methods, ... - this is not true.

The safest way is to use Gesture Recognizers . In particular, there are some options for them that may make a difference. For example .cancelsTouchesInView = YES in my case.

So what I did, use PanGestureRecognizer in the menu view, set .cancelsTouchesInView to YES , and it works. I'm going to avoid touchesBegan , ... like a plague, and write custom gesture recognizers for something complicated.

Hope this helps someone pull their hair out like me!