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copied!<p>Nimrod wrote:</p> <blockquote> <p>somewhere set the eventInterceptDelegate to a view controller that you want to intercept events</p> </blockquote> <p>I didn't immediately understand this statement. For the benefit of anyone else who had the same problem as me, the way I did it was by adding the following code to my UIView subclass which must detect touches.</p> <pre><code>- (void) viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; // Register to receive touch events MyApplicationAppDelegate *appDelegate = (MyApplicationAppDelegate *) [[UIApplication sharedApplication] delegate]; EventInterceptWindow *window = (EventInterceptWindow *) appDelegate.window; window.eventInterceptDelegate = self; } - (void) viewWillDisappear:(BOOL) animated { // Deregister from receiving touch events MyApplicationAppDelegate *appDelegate = (MyApplicationAppDelegate *) [[UIApplication sharedApplication] delegate]; EventInterceptWindow *window = (EventInterceptWindow *) appDelegate.window; window.eventInterceptDelegate = nil; [super viewWillDisappear:animated]; } - (BOOL) interceptEvent:(UIEvent *) event { NSLog(@"interceptEvent is being called..."); return NO; } </code></pre> <p><br/> This version of <code>interceptEvent:</code> is a simple implementation of pinch-to-zoom detection. NB. Some code was taken from Beginning iPhone 3 Development by Apress.</p> <pre><code>CGFloat initialDistance; - (BOOL) interceptEvent:(UIEvent *) event { NSSet *touches = [event allTouches]; // Give up if user wasn't using two fingers if([touches count] != 2) return NO; UITouchPhase phase = ((UITouch *) [touches anyObject]).phase; CGPoint firstPoint = [[[touches allObjects] objectAtIndex:0] locationInView:self.view]; CGPoint secondPoint = [[[touches allObjects] objectAtIndex:1] locationInView:self.view]; CGFloat deltaX = secondPoint.x - firstPoint.x; CGFloat deltaY = secondPoint.y - firstPoint.y; CGFloat distance = sqrt(deltaX*deltaX + deltaY*deltaY); if(phase == UITouchPhaseBegan) { initialDistance = distance; } else if(phase == UITouchPhaseMoved) { CGFloat currentDistance = distance; if(initialDistance == 0) initialDistance = currentDistance; else if(currentDistance - initialDistance > kMinimumPinchDelta) NSLog(@"Zoom in"); else if(initialDistance - currentDistance > kMinimumPinchDelta) NSLog(@"Zoom out"); } else if(phase == UITouchPhaseEnded) { initialDistance = 0; } return YES; } </code></pre> <p><br/> Edit: While this code worked 100% fine in the iPhone simulator, when I ran it on an iPhone device I encountered strange bugs related to the table scrolling. If this also happens to you, then force the <code>interceptEvent:</code> method to return NO in all cases. This means that the superclass will also process the touch event, but fortunately this did not break my code.</p>

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