Bad access on UITapGestureRecognizer - ios

I'm trying to add an UITapGestureRecognizer on my UIView. This is a part of the code of my UIViewController.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
// Create and initialize a tap gesture
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(respondToTapGesture:)];
// Specify that the gesture must be a single tap
tapRecognizer.numberOfTapsRequired = 1;
// Add the tap gesture recognizer to the view
[self.view addGestureRecognizer:tapRecognizer];
}
-(void) respondToTapGesture:(UITapGestureRecognizer *)gr {
NSLog(#"It's working !");
}
The problem is that when I tap on the view, I have this message :
0x396e25d0: ldr r3, [r4, #8] < Thread 1 : EXC_BAD_ACCESS (code=1, address=0x8)
Does anyone has an idea ?

One of the possibilities of this error is if you are doing this on a modal view or something like that and it has already deallocced. Be sure to remove the gesture recognizer from self.view.window before going back/dismissing the viewcontroller that has the uiGestureRecognizer.
Has something to do with allocation or delegate methods!

Related

iOS tap recognizer to catch all taps

I want a pretty simple thing - in my top controller (which is navigation controller) to set up a tap gesture recognizer which will catch all the taps everywhere on the view. Currently when I tap on a button the system is not even thinking to bother my recognizer (except the gestureRecognizer:shouldReceiveTouch: delegate method, where I return YES). Instead, it just executes a button click. So I want to install "the strongest" recognizer on a view hierarchy no matter what.
You might try putting an empty UIView on top of all other views and add the UITapGestureRecognizer to it. We do something similar with help overlays. The biggest issue is figuring out how and when to ignore the touches so the underlying buttons get them when needed.
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UIButton *b = [UIButton buttonWithType:UIButtonTypeInfoDark];
b.frame = CGRectMake(50,50, b.bounds.size.width, b.bounds.size.height );
[self.view addSubview:b];
UIView *invisibleView = [[UIView alloc] initWithFrame:self.view.bounds];
invisibleView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[invisibleView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapHit:)]];
[self.view addSubview:invisibleView];
}
-(void)tapHit:(UITapGestureRecognizer*)tap {
NSLog( #"tapHit" );
}
#end

UIScreenEdgePanGestureRecognizer does not react to view controller

I have a view controller that have a label, and I want to perform panning to the right on that label.
So what I did so far is:
*add a pan gesture to the label in the nib file
*created a didPan method:
- (IBAction)didPan:(UIScreenEdgePanGestureRecognizer *)sender;
and the implementation:
- (IBAction)didPan:(UIScreenEdgePanGestureRecognizer *)sender {
CGPoint newTranslation = [sender translationInView:self.homeLabel];
self.homeLabel.transform = CGAffineTransformMakeTranslation(newTranslation.x, 0);
}
and changed the screen edge pan gesture recogniser to right.
I thought it should pan now but its now, what am I doing wrong?
tnx
So I had some time to try it out myself.
Here's what the Interface Builder looks like with -didPan IBAction connected.
However that didn't work for me. I did some searching and found this also on StackOverflow.
Possible bug with UIScreenEdgePanGestureRecognizer in Interface Builder
So, I would suggest you try implementing it the old fashion way in code.
Try this:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIScreenEdgePanGestureRecognizer *swipeFromLeft = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:#selector(didPan:)];
swipeFromLeft.edges = UIRectEdgeLeft;
[self.view addGestureRecognizer:swipeFromLeft];
UIScreenEdgePanGestureRecognizer *swipeFromRight = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:#selector(didPan:)];
swipeFromRight.edges = UIRectEdgeRight;
[self.view addGestureRecognizer:swipeFromRight];
}

touch on uiimage in uitableview section does not get detected

I want to add a gesture recognizer to a UIImageView in a UITableViewCell.
I've subclassed this cell, and implemented the gesture code, but it does not seem to be working .
This is the code for my subclassed .m file:
- (id)initWithCoder:(NSCoder *)coder {
self = [super initWithCoder:coder];
if (self) {
[self.settingsView setUserInteractionEnabled:YES];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(didRecognizeTapOnSettings)];
[tap setNumberOfTouchesRequired:1];
[tap setNumberOfTapsRequired:1];
[self.settingsView addGestureRecognizer:tap];
}
return self;
}
I'm using initwithcoder since I'm using storyboards, and that seems to be working far better than initwithframe. For some odd reason, didRecognizeTapOnSettings does not get called. I've set the delegate of the UIGestureRecognizer in my .h file as well.
IBOutlets are not yet set inside an init method, so self.settingsView is going to be nil. Move the code you have in the if(self) block to awakeFromNib, and then it should work.
try using
[tap setMinimumPressDuration:0.1f];
then you said you are setting your delegate for the gesture then if you are planning to use your delegate methods for the tapGesture you should set the delegate to self.
tap.delegate = self;
What's the hierarchy in your views? Your UITableViewCell might be catching the tap event instead of your UIImageView. As an experiment try to disable the userInteractions in the UITableViewCell contentView I'm assuming that you added the UIImageView in the contentView of your cell.
Let me know if that worked

Limit Gesture Recognizer to Only One Specific UIView?

I have a UIView called myView on myViewController. I have a UIGestureRecognizer called swipeLeft (code below) that detects when a user swipes left on it.
The problem is: myViewController recognises the same gesture on the whole screen and performs another action. So I would like my app to perform myMethod when you swipeLeft in this particular area of myViewController, the area being myView.
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self
action:#selector(myMethod:)];
swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
swipeLeft.delaysTouchesBegan = YES;
[self.myView addGestureRecognizer:swipeLeft];
More details: I am using RESideMenu and myViewController is the right menu, so when it is visible, the whole view of myViewController recognises swipes in all directions. I would like to change the recogniser in this particular UIView myView.
Thanks!
First you will need to add the swipe gesture to your view controllers header file.
#property (strong, nonatomic) UISwipeGestureRecognizer *swipeLeft;
If you look in DEMORootViewController.m, you will see this call:
self.rightMenuViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"rightMenuViewController"];
This will call your awakeFromNib, and it's your first chance to do something. In here you will create that swipe gesture. You can not add it to your view yet though, because your outlets are not set at this point. The first time they are set is in viewDidLoad, so that's where you will add the gesture to your view. So add this to your view controllers implementation file
- (void)awakeFromNib
{
self.swipeLeft = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:#selector(myMethod:)];
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.swipeView addGestureRecognizer:self.swipeLeft];
}
- (void)myMethod:(UISwipeGestureRecognizer *)swipe
{
NSLog(#"Did swipe") ;
}
Finally you will need to tell the pan gesture in RESideMenu.m to fail whenever our swipeLeft gesture occurs. The way to do that is to add the following code to RESideMenu.m at line 220. That's at the end of the viewDidLoad method.
if ([self.rightMenuViewController isKindOfClass:[DEMOVC class]]) {
DEMOVC *rightVC = (DEMOVC *)self.rightMenuViewController;
if (rightVC.swipeLeft) {
[panGestureRecognizer requireGestureRecognizerToFail:rightVC.swipeGesture];
} } }
This is assuming your custom VC is called DEMOVC. You will also need to import your custom VC to RESideMenu.m like this:
#import "DEMOVC.h"
Please let me know if this worked out for you, and if there's something else I can help you with.

Subview and UIWebView UIGesture doesn't work

I recently got into trouble with a View Controller which has a UIWebView in it and a subview which I would like to add to the View Controller.
That's the View with the UIWebView:
http://cl.ly/image/03473l0e3a2L
My target is, to add a Share Menu which does work without problems:
http://cl.ly/image/3b273t2o3P00
But now I have the problem, that I set gesture recognizers for the social icons + labels (twitter,facebook,mail) - but these gesture recognizers don't do anything.
The ShareView is a UIView Subclass and I add the Gesture Recognizers this way:
UITapGestureRecognizer *fbTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(fbTapped:)];
fbTap.numberOfTapsRequired = 1;
fbTap.numberOfTouchesRequired = 1;
fbTap.delegate = self;
[fbImage addGestureRecognizer:fbTap];
[fbLabel addGestureRecognizer:fbTap];
UITapGestureRecognizer *twTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(twTapped:)];
twTap.numberOfTapsRequired = 1;
twTap.numberOfTouchesRequired = 1;
twTap.delegate = self;
[twImage addGestureRecognizer:twTap];
[twLabel addGestureRecognizer:twTap];
UITapGestureRecognizer *mailTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(mailTapped:)];
mailTap.numberOfTapsRequired = 1;
mailTap.numberOfTouchesRequired = 1;
mailTap.delegate = self;
[mailImage addGestureRecognizer:mailTap];
[mailLabel addGestureRecognizer:mailTap];
I think the Label and the UIImageView names do explain themselves. Every Label and ImageView has set userInteractionEnabled to YES. The ShareView is also enabled for Userinteractions and I did set UIGestureRecognizerDelegate to it.
The fbTapped,mailTapped and twTapped functions do send a Notification to the Main View (the view which has the webview and the ShareView in it).
But now when I click on the labels or imageviews, nothing happendes.
I did read on stackoverflow that the UIWebView in the MainView could interrupt the recognization? But I don't know how to solve this problem.
Would be really happy If you could help me or point me into the right direction to solve this problem.
I hope this piece of code will point you to the right direction:
1.Add a gesture recognizer delegate :
#interface myclass <UIGestureRecognizerDelegate>
{
//Whatever you are doing with gestures
}
2.Implement the delegate method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
//Do your stuff
return YES;
}
check if the control reaches this delegate

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