UIScrollView detect user taps - ios

Question

I'm using UIScrollView with PagingEnabled, inside UIScrollView I added three UIImage. It's work fine.
I'm wondering how can I detect if the user taps between two squares in UIImage,for example: in the attached image how can I detect if the user taps between squares 1 and 2 or if the user taps between squares 2 and 3?
Any ideas?
Thanks.

Answer 1

Add Gestures to image view
imageView.userInteractionEnabled = YES;
UIPinchGestureRecognizer *pgr = [[UIPinchGestureRecognizer alloc]
initWithTarget:self action:#selector(handlePinch:)];
pgr.delegate = self;
[imageView addGestureRecognizer:pgr];
[pgr release];
:
:
- (void)handlePinch:(UIPinchGestureRecognizer *)pinchGestureRecognizer
{
//handle pinch...
}

Answer 2

For detecting single or multiple taps use UITapGestureRecognizer, its a subclass of UIGestureRecognizer. You should not forget to set the userInteractionEnabled property to YES, because UIImageView- class changes the default value to NO.
self.imageView.userInteractionEnabled = YES;
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(handleTap:)];
// Set the number of taps, if needed
[tapRecognizer setNumberOfTouchesRequired:1];
// and add the recognizer to our imageView
[imageView addGestureRecognizer:tapRecognizer];
- (void)handleTap:(UITapGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateEnded) {
// if you want to know, if user tapped between two objects
// you need to get the coordinates of the tap
CGPoint point = [sender locationInView:self.imageView];
// use the point
NSLog(#"Tap detected, point: x = %f y = %f", point.x, point.y );
// then you can do something like
// assuming first square's coordinates: x: 20.f y: 20.f width = 10.f height: 10.f
// Construct the frames manually
CGRect firstSquareRect = CGRectMake(20.f, 20.f, 10.f, 10.f);
CGRect secondSquareRect = CGRectMake(60.f, 10.f, 10.f, 10.f);
if(CGRectContainsPoint(firstSquareRect, point) == NO &&
CGRectContainsPoint(secondSquareRect, point) == NO &&
point.y < (firstSquareRect.origin.y + firstSquareRect.size.height) /* the tap-position is above the second square */ ) {
// User tapped between the two objects
}
}
}