Double tap to Zoom with UIScrollView - xcode

Question

I am using Apple's source code. I am sure there is just a snippet that I have messed up. I have a form that I have made programmatically. When I double tap the recognizer fires and goes through the motions but I it won't actually zoom. Any suggestions? Thanks for the help
imageScrollView.delegate=self;
CGRect fullScreenRect=[[UIScreen mainScreen] applicationFrame];
imageScrollView=[[UIScrollView alloc]initWithFrame:fullScreenRect];
imageScrollView.contentSize=CGSizeMake(750,1250);
imageScrollView.minimumZoomScale=1.0;
imageScrollView.maximumZoomScale=5.0;
[imageScrollView setZoomScale:imageScrollView.minimumZoomScale];
self.view=imageScrollView;
[imageScrollView release];
Added a bunch of UItextfields/labels to the scrollview.
aircraftType = [[UITextField alloc]initWithFrame:CGRectMake(170, 32, 150, 15)];
aircraftType.font=[UIFont systemFontOfSize:10];
aircraftType.borderStyle = UITextBorderStyleRoundedRect;
aircraftType.placeholder = #"Aicraft Type";
aircraftType.delegate = self;
[self.view addSubview:aircraftType];
#pragma mark UIScrollViewDelegate methods
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return [imageScrollView viewWithTag:ZOOM_VIEW_TAG];
}
#pragma mark TapDetectingImageViewDelegate methods
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
// double tap zooms in
float newScale = [imageScrollView zoomScale] * ZOOM_STEP;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[imageScrollView zoomToRect:zoomRect animated:YES];
}
#pragma mark Utility methods
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center {
CGRect zoomRect;
// the zoom rect is in the content view's coordinates.
// At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds.
// As the zoom scale decreases, so more content is visible, the size of the rect grows.
zoomRect.size.height = [imageScrollView frame].size.height / scale;
zoomRect.size.width = [imageScrollView frame].size.width / scale;
// choose an origin so as to get the right center.
zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}