Question about UIGestureRecognizer

[el3ktro]

Hi,
I have the following situation: One view covering the whole screen, several subviews all over the place.

In the view controller (which controls the large root view) I've implemented several gesture recognizers, like this:

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(didSingleTap:)];
[singleTap setNumberOfTapsRequired:1];
[singleTap setNumberOfTouchesRequired:1];
[[self view] addGestureRecognizer:singleTap];
[singleTap release];

I then have implemented the selector method in the view controller like this:

- (void)didSingleTap:(UITapGestureRecognizer*)gestureRecognizer {
}

This works all fine. What I need to do though: In didSingleTap I have to find out if the tap has occurred on top of one of the subviews. I know I can get the location of the touch with locationInView:, but this just gives me a coordinate. I need to get the actual UIView object on which the touch has occurred, so that I can manipulate the object that has been touched.

Before I have used gesture recognizers, I manually implemented touchesBegan:WithEvent: etc. in the root view, which worked fine and which actually gives me a UITouch object that contains a reference to the object on which the tap has occurred. But this means I have to manually implement the view, which I don't need and want (if possible).

One thing I thought of was to actually implement the gesture recognizers in each subview and use the root view controller as their action target. Would this work?

[A Person]

Originally Posted by el3ktro

Hi,
I have the following situation: One view covering the whole screen, several subviews all over the place.

In the view controller (which controls the large root view) I've implemented several gesture recognizers, like this:

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(didSingleTap:)];
[singleTap setNumberOfTapsRequired:1];
[singleTap setNumberOfTouchesRequired:1];
[[self view] addGestureRecognizer:singleTap];
[singleTap release];

I then have implemented the selector method in the view controller like this:

- (void)didSingleTap:(UITapGestureRecognizer*)gestureRecognizer {
}

This works all fine. What I need to do though: In didSingleTap I have to find out if the tap has occurred on top of one of the subviews. I know I can get the location of the touch with locationInView:, but this just gives me a coordinate. I need to get the actual UIView object on which the touch has occurred, so that I can manipulate the object that has been touched.

Before I have used gesture recognizers, I manually implemented touchesBegan:WithEvent: etc. in the root view, which worked fine and which actually gives me a UITouch object that contains a reference to the object on which the tap has occurred. But this means I have to manually implement the view, which I don't need and want (if possible).

One thing I thought of was to actually implement the gesture recognizers in each subview and use the root view controller as their action target. Would this work?

Well one thing you could do is in the

- (void)didSingleTap:(UITapGestureRecognizer*)gestureRecognizer {
}

you could either make CGRects that contain the bounds of your subviews and then go

- (void)didSingleTap:(UITapGestureRecognizer*)gestureRecognizer {
      CGPoint touchPoint = [gestureRecognizer locationInView:nil];
      if(CGRectContainsPoint(subViewRectOne, touchPoint)) {
         // do something
      }
}

and then just have if statements like that for every subview and if there is too many sub views then maybe try a for each or just a regular for loop.