pan gesture of UIImageView interfers the scroll - xcode

Question

I want to implement the functionality of pan gesture to a imageview, this imageview is a subview of a scroll view. the problem is when i try to scroll the scrollview the pan gesture of the imageview gets recognized, and the scrollview does not scroll.
please help me with this.
this is the code for initializing the pan to the uiimageview:
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[[[scrollView subviews] objectAtIndex:i] addGestureRecognizer:panRecognizer];
the imageview has the user set to "YES"
and the action for it
-(void)move:(UIPanGestureRecognizer *)sender
{
[[[[[sender view] superview] superview] superview] bringSubviewToFront:sender.view];
if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {
if ([[[sender view] superview] superview] == itemView) // adds the imageview in the item scroll
{
int tag = [[sender view] tag] / 100;
UIScrollView *tempScroll = (UIScrollView *)[itemView viewWithTag:-tag];
CGRect frame = CGRectFromString([itemFrameDict objectForKey:[NSString stringWithFormat:#"%i",[[sender view] tag]]]);
CGAffineTransform transform = temp.transform;
UIImageView *tempImageView = [[UIImageView alloc] initWithImage: [(UIImageView *) [sender view] image]];
tempImageView.tag = [[sender view] tag];
//NSLog(#"[sender view] superview] : %#", [[sender view] superview]);
tempImageView.frame = frame;
[tempImageView setTransform:transform];
[tempImageView setFrame:frame];
[tempImageView setUserInteractionEnabled:YES];
[tempScroll addSubview:tempImageView];
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[tempImageView addGestureRecognizer:panRecognizer];
UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
[singleTapGestureRecognizer setNumberOfTapsRequired:1];
[tempImageView addGestureRecognizer:singleTapGestureRecognizer];
}
}
if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateChanged)
{
CGPoint translatedPoint = [sender locationInView:[[sender view] superview]] ;
newTranslatedPoint = [[[sender view] superview] convertPoint:translatedPoint toView:self.view];
if ([sender view].frame.size.width == 35 && [sender view].frame.size.height == 35)
[[sender view] sizeToFit];
[sender view].center = CGPointMake(newTranslatedPoint.x, newTranslatedPoint.y); //startFrame;
[self.view addSubview:[sender view]];
}
if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded)
{
CGPoint newPoint = [[[sender view] superview] convertPoint:newTranslatedPoint toView:itemView];
if (newPoint.y < 0)// || !viewUp)
{
//NSLog(#" baseView");
[baseView addSubview:[sender view]];
UITapGestureRecognizer *doubleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
[doubleTapGestureRecognizer setNumberOfTapsRequired:2];
[[sender view] addGestureRecognizer:doubleTapGestureRecognizer];
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scale:)];
[pinchRecognizer setDelegate:self];
[[sender view] addGestureRecognizer:pinchRecognizer];
UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[rotationRecognizer setDelegate:self];
[[sender view] addGestureRecognizer:rotationRecognizer];
}
else if (newPoint.y > 0)// && viewUp )
{
//NSLog(#" itemView");
int tag = [[sender view] tag] / 100;
UIScrollView *tempScroll = (UIScrollView *)[itemView viewWithTag:-tag];
CGRect frame = CGRectFromString([itemFrameDict objectForKey:[NSString stringWithFormat:#"%i",[[sender view] tag]]]);
CGAffineTransform transform = temp.transform;
[[sender view] setTransform:transform];
[[sender view] setFrame:frame];
[tempScroll addSubview:[sender view]];
}
}
}

Answer 1

I'm not sure I understand what you're trying to achieve exactly by using a UIPanGestureRecognizer on a UIImageView that is already in a UIScrollView. But from your description, it sounds like you want the UIScrollView to do it's thing and for the UIPanGestureRecognizer to not block that. I believe you need to implement this delegate method for your UIPanGestureRecognizer:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
Please read the UIGestureRecognizerDelegate Protocol reference in regards to allowing simultaneous gesture recognition. According to the documentation:
The default implementation returns NO—no two gestures can be
recognized simultaneously.
/* EDIT */
From UIPanGestureRecognizer - Only vertical or horizontal:
Implement just one direction for a UIPanGestureRecognizer. This is for a vertical pan:
- (BOOL)gestureRecognizerShouldBegin:(UIPanGestureRecognizer *)panGestureRecognizer {
CGPoint translation = [panGestureRecognizer translationInView:someView];
return fabs(translation.y) > fabs(translation.x);
}