I have a UIScrollView that has a zooming UIImageView, ie it implements:
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
I'm trying to add a UIRotationGestureRecognizer to this imageView and I do it as follows:
_rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[self.imageView addGestureRecognizer:_rotationGestureRecognizer];
-(void)rotate:(id)sender
{
UIRotationGestureRecognizer *rotationGestureRecognizer = [(UIRotationGestureRecognizer*)sender retain];
if(rotationGestureRecognizer.state == UIGestureRecognizerStateEnded)
{
self.lastRotation = 0.0;
return;
}
CGFloat rotation = 0.0 - (self.lastRotation - rotationGestureRecognizer.rotation);
rotationGestureRecognizer.view.transform = CGAffineTransformRotate(rotationGestureRecognizer.view.transform, rotation);
self.lastRotation = rotationGestureRecognizer.rotation;
[rotationGestureRecognizer release];
}
I'm just wondering, is it possible to even do this? It seems the UIScrollView is blocking the touches to my UIImageView because nothing is happening. Does Apple recommend to not do this with a zooming view in a UIScrollView?
Following code is working.Add gesture to scrollView instead of imageView.
UIRotationGestureRecognizer* _rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[self.scrollView addGestureRecognizer:_rotationGestureRecognizer];
Swift 5 Version:
let rotationGestureRecognizer = UIRotationGestureRecognizer(target: self, action: #selector(self.rotate(_:)))
scrollView.addGestureRecognizer(rotationGestureRecognizer)
-(void)rotate:(UIRotationGestureRecognizer *)sender
{
[self bringSubviewToFront:[(UIRotationGestureRecognizer*)sender view]];
if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded)
{
lastRotation = 0.0;
return;
}
CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform, rotation);
[[(UIRotationGestureRecognizer*)sender view] setTransform:newTransform];
lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
}
Related
I'm using SPUserResizableView to resize my view. i had added rotation funcitionality to it . when i touch corner handel view should rotate for this purpose i have added some code but its not working properly. here is my code :
CGPoint center = CGPointMake(CGRectGetMidX([view bounds]), CGRectGetMidY([view bounds]));
CGPoint currentTouchPoint = [touch locationInView:view];
CGPoint previousTouchPoint = [touch previousLocationInView:view];
CGFloat angleInRadians = atan2f(currentTouchPoint.y - center.y, currentTouchPoint.x - center.x) - atan2f(previousTouchPoint.y - center.y, previousTouchPoint.x - center.x);
[self setTransform:CGAffineTransformRotate([view transform], angleInRadians)];
Note: when user touch corner handel a method get called in which i have written this piece of code. If user touches edges handel that method wont called.
Thanks.
try this :
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scale:)];
[pinchRecognizer setDelegate:self];
[imgBg addGestureRecognizer:pinchRecognizer]; // imgBg is my imageview you can set your view
UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[rotationRecognizer setDelegate:self];
[imgBg addGestureRecognizer:rotationRecognizer];
#pragma mark -
#pragma mark - GestureRecognizer Method
-(void)scale:(id)sender {
[viewGesture bringSubviewToFront:[(UIPinchGestureRecognizer*)sender view]];
if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
lastScale = 1.0; // declacre float instance in .h file
return;
}
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];
lastScale = [(UIPinchGestureRecognizer*)sender scale];
}
-(void)rotate:(id)sender {
[viewGesture bringSubviewToFront:[(UIRotationGestureRecognizer*)sender view]];
if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
lastRotation = 0.0;
return;
}
CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);
[[(UIRotationGestureRecognizer*)sender view] setTransform:newTransform];
lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
}
I am trying to pinch an image via UIPinchGestureRecognizer but , the problem is my code does not work properly and actually it could not zoom my image
-(void) pinching: (UIPinchGestureRecognizer *) sender {
CGAffineTransform myTransformation =
CGAffineTransformMakeScale(sender.scale, sender.scale);
sender.view.transform = myTransformation;
}
- (void)viewDidLoad
{
UIPinchGestureRecognizer *pinch =
[[UIPinchGestureRecognizer alloc]
initWithTarget:self
action:#selector(pinching:)];
pinch.delegate = self;
[imageBG addGestureRecognizer:pinch];
[imageBG setUserInteractionEnabled:YES];
[imageBG setMultipleTouchEnabled:YES];
}
Try using a UIScrollView.
To do this, create it
self.scrollView = [[UIScrollView alloc] initWithFrame:...];
self.scrollView.delegate = self;
self.scrollView.maximumZoomScale = 2.0; // adjust as you need
self.scrollView.minimumZoomScale = 0.5; // adjust as you need
[self.scrollView addSubview:self.imageView];
and add the delegate method:
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.imageView;
}
just take one variable in .h file like bellow..
CGFloat lastScale;
and use this type of code...
in viewWillAppear: method just add it..
- (void)viewWillAppear:(BOOL)animated
{
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scale:)];
[pinchRecognizer setDelegate:self];
[yourImageView addGestureRecognizer:pinchRecognizer];
}
-(void)scale:(id)sender {
if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
lastScale = 1.0;
return;
}
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];
yourImageView.transform = newTransform
lastScale = [(UIPinchGestureRecognizer*)sender scale];
}
try this code also..
You need to add a scrollView to enable zooming. Add your imageView as a subView of the scroll view. Set the delegate for UIScrollViewDelegate to self. Implement the delegate methods.
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
//return the imageview here
return self.imageView;
}
Scale your imageview here:
- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(float)scale withCenter:(CGPoint)center
You can refer this example from Apple .
I am working on customizing images. My requirement is to stretch or shrink image in touch direction & cropping image. I have done cropping but how I can stretch & shrink image in touch direction. Is it possible?
Your question in not clear.but if you want to scale or rotate image with touch event.then in viewdidload write this code.
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc]
initWithTarget:self action:#selector(rotateImage:)];
[self.view addGestureRecognizer:rotationGesture];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]
initWithTarget:self action:#selector(scaleImage:)];
[self.view addGestureRecognizer:pinchGesture];
[pinchGesture release];
And using this code you can rotate or scale images in touch direction.
- (void)scaleImage:(UIPinchGestureRecognizer *)recognizer
{
if([recognizer state] == UIGestureRecognizerStateEnded) {
previousScale = 1.0;
return;
}
CGFloat newScale = 1.0 - (previousScale - [recognizer scale]);
CGAffineTransform currentTransformation = yourimage.transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransformation,
newScale, newScale);
yourimage.transform = newTransform;
previousScale = [recognizer scale];
}
- (void)rotateImage:(UIRotationGestureRecognizer *)recognizer
{
if([recognizer state] == UIGestureRecognizerStateEnded) {
previousRotation = 0.0;
return;
}
CGFloat newRotation = 0.0 - (previousRotation - [recognizer rotation]);
CGAffineTransform currentTransformation = yourimage.transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransformation, newRotation);
yourimage.transform = newTransform;
previousRotation = [recognizer rotation];
}
How to rotate UIImageView with two fingure touch in iOS SDK..as I know this is very simple but because of I am new in this technology so cant understand...
How to use UIRotationGestureRecognizer to implement this...
Please help me to solve this problem...
Thanks.
Code this on view did load or the imageview create function : m_ctrlImgVwShowImage - your's imageview
UIRotationGestureRecognizer *rotationRecognizer = [[[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)] autorelease];
[rotationRecognizer setDelegate:self];
[m_ctrlImgVwShowImage addGestureRecognizer:rotationRecognizer];
//lastRotation is a cgfloat member variable
-(void)rotate:(id)sender {
if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
_lastRotation = 0.0;
return;
}
CGFloat rotation = 0.0 - (_lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);
CGAffineTransform currentTransform = m_ctrlImgVwShowImage.transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);
[m_ctrlImgVwShowImage setTransform:newTransform];
_lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
}
I want to rotate the uiimageview also scale the image view so how do i detect touch gesture that user is scaling or user is rotating?
Beginning in iOS 3.2, Apple introduced the use of UIGestureRecognizer's. The two that you would be interested in are UIPinchGestureRecognizer and UIRotationGestureRecognizer. To use a pinch gesture you could do the following:
- (void)viewDidLoad {
UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(handlePinchGesture:)];
[imageView addGestureRecognizer:pinch];
[pinch release];
}
- (void)handlePinchGesture:(UIGestureRecognizer *)sender {
NSLog(#"New Scale: %f", sender.scale);
}
You could do something similar for the UIRotationGestureRecognizer then.
in your viewcontroller.h file write down this properties
IBOutlet UIImageView *imgRotate;
CGFloat lastScale;
CGFloat lastRotation;
now in your viewcontroller.m file write the below code,
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scale:)];
[pinchRecognizer setDelegate:self];
[imgRotate addGestureRecognizer:pinchRecognizer];
UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[rotationRecognizer setDelegate:self];
[imgRotate addGestureRecognizer:rotationRecognizer];
}
-(void)scale:(id)sender
{
if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded)
{
lastScale = 1.0;
return;
}
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];
[imgRotate setTransform:newTransform];
lastScale = [(UIPinchGestureRecognizer*)sender scale];
}
-(void)rotate:(id)sender
{
if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded)
{
lastRotation = 0.0;
return;
}
CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);
[[(UIRotationGestureRecognizer*)sender view] setTransform:newTransform];
[imgRotate setTransform:newTransform];
lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch view] == imgRotate) {
CGPoint location = [touch locationInView:self.view];
imgRotate.center = location;
}
}