Zoom with UIScrollView and rotate with UIRotationGestureRecognizer - iphone

Question

I'm trying to have an UIImageView rotate inside a UIScrollView but when I try to zoom/unzoom, my rotation gets back to 0.
Here's the code for my rotation :
- (void)rotateImage:(UIRotationGestureRecognizer*)rotate
{
if ([rotate state] == UIGestureRecognizerStateEnded)
{
rotateAngle += [spin rotation];
return;
}
myView.transform = CGAffineTransformMakerotation(rotateAngle + [rotate rotation]);
}
Concerning the UIScrollView, I just return myView in -(UIView*)viewForZoomingInScrollView:
And a last information, in my interface builder, this is my view stack :
UIImageView
UIView (myView)
UISCrollView
Which means that I have a UIView between the UIImageView and the UIScrollView

Answer 1

I would rather suggest you to handle zoom using pinch gesture. It will look more neat and even . add pinch gesture to the view . for zooming add the following code in its selector method
- (void)handlePinch:(UIPinchGestureRecognizer *)recognizer
{
myView.transform = CGAffineTransformScale(recogniser.view.transform, recognizer.scale, recognizer.scale);
recognizer.scale = 1;
}
for rotating ,
-(void)handleRotate:(UIRotationGestureRecognizer *)rec
{
myView.transform = CGAffineTransformRotate(rec.view.transform, rec.rotation);
rec.rotation = 0;
}
make sure you declare self as the delegate for both the gesture and implement the following delegate method
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
remove myView from
-(UIView*)viewForZoomingInScrollView:
method before implementing my solution. let just gesture alone handle the zooming and not scrollview.:) Good luck

Answer 2

for pinch Gesture
use the code from apple library
Don't forgot to add UIGestureRecognizerDelegate,UIScrollViewDelegate
self.ScrollView= [[UIScrollView alloc]init];
self.ScrollView.frame = CGRectMake(0, 0, DEVICE_WIDTH, DEVICE_HEIGHT);
[self.view addSubview:self.ScrollView];
// for pinch Gesture
self.ScrollView.minimumZoomScale=0.5;
self.ScrollView.maximumZoomScale=6.0;
self.ScrollView.contentSize=CGSizeMake(imageView.frame.size.width, imageView.frame.size.height);
self.ScrollView.delegate = self;
[self.ScrollView addSubview:imageView];
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return imageView;
}
For rotation ,
UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:#selector(handleRotate:)];
rotation.delegate =self;
[self.ScrollView addGestureRecognizer:rotation];
- (IBAction)handleRotate:(UIRotationGestureRecognizer *)recognizer {
recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation);
recognizer.rotation = 0;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}