How to add a Gesture Recogniser in imageview in iOS? - ios

Question

i add a UIPanGestureRecognizer to my imageview then Gesture Recognizer is added but my imageview image is panned in to my view i want only image is panned inside of the imageview on in the view how it is possible?
i write a code for that on viewdidload
UIPanGestureRecognizer *pangesture=[[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(panGestureDetected:)];
[pangesture setDelegate:self];
[self.zoomImage addGestureRecognizer:pangesture];
and method for that is
- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer
{
UIGestureRecognizerState state = [recognizer state];
if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
{
CGPoint translation = [recognizer translationInView:recognizer.view];
[recognizer.view setTransform:CGAffineTransformTranslate(recognizer.view.transform, translation.x, translation.y)];
[recognizer setTranslation:CGPointZero inView:recognizer.view];
}
}
then imageView image is panned in my View but i want image Panned only inside of imageview if it possible then give me solution.
here my original imageview Size is like as
and when i added UIPanGEstureRecognizer then it look like as
image are panned in View but i want to zoom it inside of imageview size please give me solution for that.

Answer 1

take UIScrollView and add UIImageView inside the scrollview and pangesture on scrollview ..
set delegate for scrollview and do the code
- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
// Return the view that we want to zoom
return self.zoomImage;
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
// The scroll view has zoomed, so we need to re-center the contents
[self centerScrollViewContents];
}
- (void)centerScrollViewContents {
CGSize boundsSize = scrollView.bounds.size;
CGRect contentsFrame = self.zoomImage.frame;
if (contentsFrame.size.width < boundsSize.width) {
contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
} else {
contentsFrame.origin.x = 0.0f;
}
if (contentsFrame.size.height < boundsSize.height) {
contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
} else {
contentsFrame.origin.y = 0.0f;
}
self.zoomImage.frame = contentsFrame;
}
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
// Get the location within the image view where we tapped
CGPoint pointInView = [recognizer locationInView:imageView];
// Get a zoom scale that's zoomed in slightly, capped at the maximum zoom scale specified by the scroll view
CGFloat newZoomScale = scrollView.zoomScale * 1.5f;
newZoomScale = MIN(newZoomScale, scrollView.maximumZoomScale);
// Figure out the rect we want to zoom to, then zoom to it
CGSize scrollViewSize = scrollView.bounds.size;
CGFloat w = scrollViewSize.width / newZoomScale;
CGFloat h = scrollViewSize.height / newZoomScale;
CGFloat x = pointInView.x - (w / 2.0f);
CGFloat y = pointInView.y - (h / 2.0f);
CGRect rectToZoomTo = CGRectMake(x, y, w, h);
[scrollView zoomToRect:rectToZoomTo animated:YES];
}
- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
// Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
CGFloat newZoomScale = scrollView.zoomScale / 1.5f;
newZoomScale = MAX(newZoomScale, scrollView.minimumZoomScale);
[scrollView setZoomScale:newZoomScale animated:YES];
}

Answer 2

UIImage object's userInteractEnable is NO by default, so you can't interact with it. Try self.zoomImage.userInteractEnable = YES

Answer 3

Try this:
Add another UIView under the imageView, make its size exactly the same as your imageView. Then set your imageView as this UIView's subview by drag and drop the imageView on top of this UIView (Assuming you are using StoryBoard or xib).
After that, if you are using StoryBoard or xib, then go to Attributes Inspector, select this UIView, tick Click Subviews. If not, just set view.clipsToBounds = YES;