Question

In my program I have configured a UIView to be placed over a number of UIBUttons. This is so you can pan across the view and have the buttons move over as well as selecting the buttons themselves. However, it is not possible to select the buttons when they are underneath this UIView. Does anybody know how to configure a UIButton‘s userInteractionEnabled while it is under these conditions?

Answer 1

This technique has worked for me – caveat: I just typed this in it’s not compiled or nuthin it’s given as a starting point.

1. Create the buttons and place them at the top of the view hierarchy (i.e. where they interact normally and respond to taps, on top of the UIView)

2. When creating the buttons – keep a reference to them in an array.

   NSMutableArray* arrayOfPeskyButtons;

3. Keep a record of the button frames

   NSMutableArray* arrayOfPeskyFrames = [NSMutableArray mutableArray];
   for ((UIButton*)button in arrayOfPeskyButtons)
   {
       [arrayOfPeskyFrames addObject:[NSValue valueWithCGRect:button.frame];
   }
   

4. When your app responds to an action on the UIView – panning or if you change it to a UIScrollView (probably best btw), then move the frame of the buttons correspondingly so that they appear fixed in place to the user.

I have used this technique to create ‘overlays’ of buttons which sit on top of scrollviews and it works surprisingly well. Simply in the scrollView delegate method.

-(void)scrollViewDidScroll:(UIScrollView *)scrollView

take note of the scrollviews offset and adjust each of the frames of the buttons accordingly depending on the offset of the scrollView

 CGPoint offset = scrollView.contentOffset;

Iterate through the array of buttons and move them.

 int index = 0;
 for ((UIButton*)button in arrayOfPeskyButtons)
 {
     CGRect originalFrame = [[arrayOfPeskyFrames objectAtIndex:index]CGRectValue];
     CGRect currentFrame = button.frame;
     //adjust frame
     //e.g.
     currentFrame.origin.x = originalFrame.origin.x + offset.x;

     button.frame = currentFrame.;
     index++;
 }