Double-tapping to zoom on UIImageView - iphone

I'm looking at Apple's example code from the ScrollViewSuite. I must be doing something wrong in comparison. In their RootViewController, they do:
- (void)loadView {
[super loadView];
// set the tag for the image view
[imageView setTag:ZOOM_VIEW_TAG];
// add gesture recognizers to the image view
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTapsRequired:2];
[twoFingerTap setNumberOfTouchesRequired:2];
[imageView addGestureRecognizer:singleTap];
[imageView addGestureRecognizer:doubleTap];
[imageView addGestureRecognizer:twoFingerTap];
[singleTap release];
[doubleTap release];
[twoFingerTap release];
// calculate minimum scale to perfectly fit image width, and begin at that scale
float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width;
[imageScrollView setMinimumZoomScale:minimumScale];
[imageScrollView setZoomScale:minimumScale];
}
In IB, they have their imageView as a subView of the imageScrollView. My .xib is set up the same way. I put this code in my viewDidLoad instead of loadView. I do not get any calls when I double tap on my imageView. I'm wondering why. Here is my version of what they did:
- (void)viewDidLoad {
[self updateOnScreenImages]; // this is where my imageView.image property gets set
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
doubleTap.numberOfTapsRequired = 2;
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTouchesRequired:2];
[self.imageView addGestureRecognizer:doubleTap];
[self.imageView addGestureRecognizer:twoFingerTap];
[doubleTap release];
[twoFingerTap release];
}
Is there something I am doing wrong compared to what Apple is doing? The logic seems pretty similar to me. But I'm not getting my callbacks when I double tap. I tried adding the gestures to the self.scrollView as well, but that doesn't work either. Thoughts? Thanks!

Try to add:
self.imageView.userInteractionEnabled = YES;
by default UIImageViews have that property set to NO
(apple may have changed it in XIB file, and you may have lost that...)

#import "RootViewController.h"
#define ZOOM_VIEW_TAG 100
#define ZOOM_STEP 1.5
#interface RootViewController (UtilityMethods)
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center;
#end
#implementation RootViewController
#synthesize imageScrollView, imageView, mySlider;
- (IBAction) sliderValueChanged:(UISlider *)sender {
mySlider.value = [NSString stringWithFormat:imageScrollView.[sender value]];
//mySlider.value = [NSString stringWithFormat:#" %.1f", [sender value]];
//myTextField.text = [NSString stringWithFormat:#" %.1f", [sender value]];
}
- (void)loadView {
[super loadView];
// set the tag for the image view
[imageView setTag:ZOOM_VIEW_TAG];
// add gesture recognizers to the image view
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTapsRequired:2];
[twoFingerTap setNumberOfTouchesRequired:2];
[imageView addGestureRecognizer:singleTap];
[imageView addGestureRecognizer:doubleTap];
[imageView addGestureRecognizer:twoFingerTap];
[singleTap release];
[doubleTap release];
[twoFingerTap release];
// calculate minimum scale to perfectly fit image width, and begin at that scale
float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width;
[imageScrollView setMinimumZoomScale:minimumScale];
[imageScrollView setZoomScale:minimumScale];
}
- (void)viewDidUnload {
self.imageScrollView = nil;
self.imageView = nil;
}
- (void)dealloc {
[imageScrollView release];
[imageView release];
[super dealloc];
}
#pragma mark UIScrollViewDelegate methods
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return [imageScrollView viewWithTag:ZOOM_VIEW_TAG];
}
/************************************** NOTE **************************************/
/* The following delegate method works around a known bug in zoomToRect:animated: */
/* In the next release after 3.0 this workaround will no longer be necessary */
/**********************************************************************************/
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale {
[scrollView setZoomScale:scale+0.01 animated:NO];
[scrollView setZoomScale:scale animated:NO];
}
#pragma mark TapDetectingImageViewDelegate methods
- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
// single tap does nothing for now
}
- (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];
}
- (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer {
// two-finger tap zooms out
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;
}
#end

Related

Choose different UIPanGestureRecognizer touches

Ok so I have a app with a left menu and a right view controller which are controlled by the UIPanGestureRecognizer. So when a user swipes the bezel (20px) of the edge of the screen it navigates.
In a settings view controller I have UISwitches which control various other things, but one of them I want to control how many touches the UIPanGestureRecognizer will take.
The switch is set up properly and sends the user defaults to the other view controller, but on the receiving end of it, it won't read what the user has selected.
UIPanGestureRecognizer * pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGestureCallback:)];
//Switch for SwipeNav
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[pan setMinimumNumberOfTouches:2];
[pan setMaximumNumberOfTouches:2];
}else{
[pan setMinimumNumberOfTouches:1];
[pan setMaximumNumberOfTouches:1];
}
[pan setDelegate:self];
[self.view addGestureRecognizer:pan];
How can I make it so when the switch is on, it uses 2 touches to navigate, and off it acts like normal?
Any assistance is always appreciated. Thank you.
UPDATED with settings sync code.
if (swipe){
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setBool:self.swipe.on forKey:#"SwipeNav"];
[userDefaults synchronize];
if ([swipe isOn]) {
[swipe setOn:YES animated:YES];
[self.tableView reloadData];
[[UIApplication sharedApplication] reloadInputViews];
} else {
[swipe setOn:NO animated:YES];
[self.tableView reloadData];
[[UIApplication sharedApplication] reloadInputViews];
}
}
I created a new project and tried to reproduce the problem that you are seeing and everything seems to work as expected. When switch is on the you need two buttons to pan and when switch is off you only need one. Let me know if that points you in the right direction. Your code seems to be correct.
I copy pasted the handlePan function from How to use UIPanGestureRecognizer to move object? iPhone/iPad
Created everything programmatically and copy pasted your code to save the state of the switch. Here is the code from two UIViewControllers
//
// ViewController.m
// StackOverflowSwitch
//
//
//
//
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic,strong) UIButton *myButton;
#property (nonatomic,strong) UISwitch *switchOn;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.myButton = [[UIButton alloc]initWithFrame:CGRectMake(10, 100, 150, 150)];
self.switchOn = [[UISwitch alloc]initWithFrame:CGRectMake(10, 300, 100, 100)];
self.myButton.backgroundColor =[UIColor grayColor];
[self.myButton setTitle:#"Click Me" forState:UIControlStateNormal];
[self.myButton addTarget:self action:#selector(click:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:self.switchOn];
[self.view addSubview:self.myButton];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)click:(UIButton *)sender
{
[self performSegueWithIdentifier:#"NextViewController" sender:self];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if(self.switchOn.on){
NSLog(#"switch is on");
}else{
NSLog(#"switch is off");
}
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setBool:self.switchOn.on forKey:#"SwipeNav"];
[userDefaults synchronize];
}
#end
//////
#import "SecondViewController.h"
#interface SecondViewController() <UIGestureRecognizerDelegate>
#property (strong,nonatomic) UIView *myView;
#end
#implementation SecondViewController
-(void)viewDidLoad
{
[super viewDidLoad];
self.myView = [[UIView alloc]initWithFrame:CGRectMake(10, 10, 200, 200)];
self.myView.backgroundColor = [UIColor redColor];
[self.view addSubview:self.myView];
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[pan setMinimumNumberOfTouches:2];
[pan setMaximumNumberOfTouches:2];
}else{
[pan setMinimumNumberOfTouches:1];
[pan setMaximumNumberOfTouches:1];
}
[pan setDelegate:self];
[self.view addGestureRecognizer:pan];
[self.myView addGestureRecognizer:pan];
}
-(void)handlePan:(UIPanGestureRecognizer *)recognizer
{
CGPoint translation = [recognizer translationInView:self.view];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self.view];
if (recognizer.state == UIGestureRecognizerStateEnded) {
CGPoint velocity = [recognizer velocityInView:self.view];
CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
CGFloat slideMult = magnitude / 200;
NSLog(#"magnitude: %f, slideMult: %f", magnitude, slideMult);
float slideFactor = 0.1 * slideMult; // Increase for more of a slide
CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor),
recognizer.view.center.y + (velocity.y * slideFactor));
finalPoint.x = MIN(MAX(finalPoint.x, 0), self.view.bounds.size.width);
finalPoint.y = MIN(MAX(finalPoint.y, 0), self.view.bounds.size.height);
[UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
recognizer.view.center = finalPoint;
} completion:nil];
}
}
#end
///// Update
I am not exactly sure how [[UIApplication sharedApplication] reloadInputViews]; calls the function to update the UIPanGestureRecongizer in your code but i tried to recreate your functionality as close as possible by having the setupView method called every time i click the UISwitch
I created a custom view with UIPanGestureReconginzer in there and a method that I call from the UIViewController to update setNumberOfTouches. The view works as expected. The key here is not to initialize a new UIPanGuestureRecongizer but update the existing one. I assume in your app UIViewController or UIView which has the UIPanGuestureRecongizer is not being fully reloaded.
I created a property UIPanGuestureRecongizer which gets initialized the first time it's being accessed and then gets updated when switch is being pressed. Here is the custom UIView code. Let me know if you have any questions regarding the code.
#import "MyTestView.h"
#interface MyTestView() <UIGestureRecognizerDelegate>
#property(nonatomic,strong) UIPanGestureRecognizer *panGesture;
#end
#implementation MyTestView
-(instancetype)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self setupView];
}
return self;
}
-(UIPanGestureRecognizer *)panGesture
{
//lazy instantiation
if (!_panGesture) {
_panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
}
return _panGesture;
}
-(void)setupView
{
//this gets called everytime the UISwitch is being pressed.
NSLog(#"Setup views");
self.backgroundColor = [UIColor redColor];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[self.panGesture setMinimumNumberOfTouches:2];
[self.panGesture setMaximumNumberOfTouches:2];
}else{
[self.panGesture setMinimumNumberOfTouches:1];
[self.panGesture setMaximumNumberOfTouches:1];
}
[self.panGesture setDelegate:self];
[self addGestureRecognizer:self.panGesture];
}
-(void)handlePan:(UIPanGestureRecognizer *)recognizer
{
CGPoint translation = [recognizer translationInView:self];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self];
if (recognizer.state == UIGestureRecognizerStateEnded) {
CGPoint velocity = [recognizer velocityInView:self];
CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
CGFloat slideMult = magnitude / 200;
NSLog(#"magnitude: %f, slideMult: %f", magnitude, slideMult);
float slideFactor = 0.1 * slideMult; // Increase for more of a slide
CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor),
recognizer.view.center.y + (velocity.y * slideFactor));
finalPoint.x = MIN(MAX(finalPoint.x, 0), self.bounds.size.width);
finalPoint.y = MIN(MAX(finalPoint.y, 0), self.bounds.size.height);
[UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
recognizer.view.center = finalPoint;
} completion:nil];
}
}
#end
Alright, so after much testing/code flipping, I think I have found my solution.
So a little more backstory, I use MMDrawerController, so the method above about placing [self setupView]; in (instancetype)initWithCoder didn't do anything. The setupView or in my case is called "setupGestureRecognizers" is loaded in the viewDidLoad. Anywhere else it wouldn't load the gesture's at all.
With my current switch code and gesture loading I have this:
-(UIPanGestureRecognizer *)panGestureNav {
if (!_panGesture) {
_panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGestureCallback:)];
}
return _panGesture;
}
-(void)setupGestureRecognizers{
switchOn = [[NSUserDefaults standardUserDefaults] boolForKey:#"SwipeNav"];
if (switchOn == YES) {
// 2 Finger SwipeNav
[self.panGestureNav setMinimumNumberOfTouches:2];
[self.panGestureNav setMaximumNumberOfTouches:2];
NSLog(#"2 Finger Nav");
}else {
[self.panGestureNav setMinimumNumberOfTouches:1];
[self.panGestureNav setMaximumNumberOfTouches:1];
NSLog(#"Normal Nav");
}
[self.panGestureNav setDelegate:self];
[self.view addGestureRecognizer:self.panGestureNav];
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGestureCallback:)];
[tap setDelegate:self];
[self.view addGestureRecognizer:tap];
}
Which would normally work, but this library does things differently, so I have to look into their gesture calling and what I ended up doing was calling it here:
-(MMOpenDrawerGestureMode)possibleOpenGestureModesForGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer withTouch:(UITouch*)touch{
CGPoint point = [touch locationInView:self.childControllerContainerView];
MMOpenDrawerGestureMode possibleOpenGestureModes = MMOpenDrawerGestureModeNone;
if([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]){
[self setupGestureRecognizers]; <------------
So now it loads and functions as I want.
Thank you Yan so all of your assistance. Hope this helps somebody.

How to zoom into a selected area of image in iPhone?

I have an ImageView when clicked on that imageview, transparent circle should be created and again when double clicking on that circle, particular Image in that circle area should be zoomed.Any suggestion would be appreciated.
I think this code will helpfull to you
- (id)initWithImage:(UIImage *)image {
self = [super initWithImage:image];
if (self) {
[self setUserInteractionEnabled:YES];
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTapsRequired:2];
[twoFingerTap setNumberOfTouchesRequired:2];
[self addGestureRecognizer:singleTap];
[self addGestureRecognizer:doubleTap];
[self addGestureRecognizer:twoFingerTap];
[singleTap release];
[doubleTap release];
[twoFingerTap release];
}
return self;
}
#pragma mark Private
- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
if ([delegate respondsToSelector:#selector(tapDetectingImageView:gotSingleTapAtPoint:)])
[delegate tapDetectingImageView:self gotSingleTapAtPoint:[gestureRecognizer locationInView:self]];
}
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
if ([delegate respondsToSelector:#selector(tapDetectingImageView:gotDoubleTapAtPoint:)])
[delegate tapDetectingImageView:self gotDoubleTapAtPoint:[gestureRecognizer locationInView:self]];
}
- (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer {
if ([delegate respondsToSelector:#selector(tapDetectingImageView:gotTwoFingerTapAtPoint:)])
[delegate tapDetectingImageView:self gotTwoFingerTapAtPoint:[gestureRecognizer locationInView:self]];
}

UITapGestureRecognizer for UIImageView on UIScrollView never called iOS5

I am adding a UIImageView as a subview to a UIScrollView then i set the image.
Im trying to to use UITapGestureRecognizer.
The selector of the UITapGestureRecognizer is never called in iOS 5 (in iOS 6 it DOES!).
Tried many variations. this is my code:
UIImageView *imgView = [[UIImageView alloc]initWithFrame:CGRectMake(index*(IMAGE_WIDTH+10), 10.0, IMAGE_WIDTH, IMAGE_HEIGHT)];
[imgView setImageWithURL:[NSURL URLWithString:meal.RecommendedImageURL] placeholderImage:[UIImage imageNamed:#""]];
imgView.layer.cornerRadius = 4;
[imgView.layer setMasksToBounds:YES];
[imgView setUserInteractionEnabled:YES];
[imgView setMultipleTouchEnabled:YES];
[scrollView addSubview:imgView];
if (IOS_NEWER_OR_EQUAL_TO_5)
{
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[imgView addGestureRecognizer:tapGestureRecognizer];
tapGestureRecognizer.numberOfTapsRequired = 1;
tapGestureRecognizer.enabled = YES;
tapGestureRecognizer.delegate = self;
[tapGestureRecognizer setCancelsTouchesInView:NO];
}
this is my selector which is only called in iOS5:
- (void) imageTapped: (UITapGestureRecognizer *)recognizer
{
//Code to handle the gesture
UIImageView *tappedImageView = (UIImageView*)recognizer.view;
GGFullscreenImageViewController *vc = [[GGFullscreenImageViewController alloc] init];
vc.liftedImageView = tappedImageView;
vc.liftedImageView.contentMode = UIViewContentModeScaleAspectFit;
if (IOS_NEWER_OR_EQUAL_TO_5) {
[self.parentViewController presentViewController:vc animated:YES completion:nil];
}
else
{
[self.parentViewController presentModalViewController:vc animated:YES];
}
}
In addition to that, i tried to setCancelsTouchesInView to YES in my UIScrollView but it doesn't work either.
Thanks for your help!
try to add Gesture in Scrollview then check iskind of class image view
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[scrollview addGestureRecognizer:tapGestureRecognizer];
tapGestureRecognizer.numberOfTapsRequired = 1;
tapGestureRecognizer.enabled = YES;
tapGestureRecognizer.delegate = self;
[tapGestureRecognizer setCancelsTouchesInView:NO];
- (BOOL)gestureRecognizer:(UITapGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// test if our control subview is on-screen
if ([touch.view isKindOfClass:[UIImageView class]]) {
// we touched a button, slider, or other UIControl
return YES;
}return NO;
}
Implement the 3 methods of UIGestureRecognizerDelegate & return default values:
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer;
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer;
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch;
Ok i solved it very EASILY!
the problem was setting the delegate of the UITapGestureRecognizer to self.
when i removed the delegate = self, it started working :)
Thanks for your assistance

UIImageView zoom, tap, gestures don't work

I am using Apple code for just zoom the UIImageView on taps and gestures. But its not work ?
Please see this Apple's link apple code for image zooming by taps and gestures
-(void)veiwDidLoad
{
[super viewDidLoad];// Edited my self
imageView.userInteractionEnabled = YES; // Edited my self
//All code below same.... like Apple's code
// set the tag for the image view
[imageView setTag:ZOOM_VIEW_TAG];
// add gesture recognizers to the image view
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTapsRequired:2];
[twoFingerTap setNumberOfTouchesRequired:2];
[imageView addGestureRecognizer:singleTap];
[imageView addGestureRecognizer:doubleTap];
[imageView addGestureRecognizer:twoFingerTap];
[singleTap release];
[doubleTap release];
[twoFingerTap release];
// calculate minimum scale to perfectly fit image width, and begin at that scale
float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width;
[imageScrollView setMinimumZoomScale:minimumScale];
[imageScrollView setZoomScale:minimumScale];
}
Make sure that you set your imageView to be userInteractionEnabled = YES; .. its assign to NO by default.
change the function name from
-(void) veiwDidLoad
to
-(void) viewDidLoad
I has a problem like that as well, does that fix it?

How to use gesture recognizer in an OpenGLES application of iPhone?

While I know how to use gesture recognizer in a view-based application,but when I apply the same ideas in a OpenGLSE-based application:
for example,
I add a TapGestureRecognizer,and when I tap on the EAGLView,it crashes.
So can anyone show me a standard usage of UITapGestureRecognizer in an OpenGLES-based application?
best wishes.
Here some sample code from one of my opengles games with gesture support. (Doesn't crash and hope it helps)
- (void)viewDidLoad {
[super viewDidLoad];
CGRect rect = [[UIScreen mainScreen] bounds];
rect.size.height = 320;
rect.size.width = 480;
rect.origin.x = 0;
rect.origin.y = 0;
glView = [[EAGLView alloc] initWithFrame:rect pixelFormat:GL_RGB565_OES depthFormat:GL_DEPTH_COMPONENT16_OES preserveBackbuffer:NO];
[self.view addSubview: glView];
[glView addSubview: minimapView];
if(!shell->InitApplication())
printf("InitApplication error\n");
[NSTimer scheduledTimerWithTimeInterval:(1.0 / kFPS) target:self selector:#selector(update) userInfo:nil repeats:YES];
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(Panned:)];
[glView addGestureRecognizer:[pan autorelease]];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(Tapped:)];
[glView addGestureRecognizer:[tap autorelease]];
UITapGestureRecognizer *dbltap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(DoubleTapped:)];
[dbltap setNumberOfTapsRequired:2];
[glView addGestureRecognizer:[dbltap autorelease]];
UILongPressGestureRecognizer *longpress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(LongPressed:)];
[glView addGestureRecognizer:[longpress autorelease]];
}
And the selector function
- (void) LongPressed:(UILongPressGestureRecognizer*)sender{
NSLog(#"Long Pressed");
}