UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipedGesture:)];
swipe.direction = UISwipeGestureRecognizerDirectionRight;
swipe.numberOfTouchesRequired = 1;
[self.myLabel.superview addGestureRecognizer:swipe];
- (void)swipedGesture:(UIGestureRecognizer *)recognizer
{
NSLog(#"I swiped ;)");
}
So, this is what happens: I have a label called myLabel. and when I swipe right it should print the NSLog I swiped, but nothing happens. What's the reason? What have I done wrong here? Could someone help me edit my code to make this work ?
Dont you need to add this swipe gesture to the UILabel? you are adding it to the superview of that label.
change - [self.myLabel.superview addGestureRecognizer:swipe];
to - [self.myLabel addGestureRecognizer:swipe];
UPDATE: Also as justin points, please set userInteractionEnabled to YES for the label like so - [self.myLabel setUserInteractionEnabled:YES];
The gesture recognizer won't work unless you set userInteractionEnabled to YES on the label.
Related
For the past four hours, I have tried many Stack Overlow solutions but none have helped solve my problem.
Here it is,
I have a UIScrollView
Within that ScrollView there is one custom UILabel and 8 custom UIImageViews
I want to detect a long press
Something like this works
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressDidFire:)];
longPress.minimumPressDuration = 0.5;
[scroll addGestureRecognizer:longPress]; //scroll defined elsewhere
However, if I replace the scroll with any subviews of scroll, the long press event never fires.
How do I detect a long press of a subview of a scroll view?
This is quite a messy hack, however, since I can detect long presses of a scroll view, is there any way where I can detect the
position of the press so that I can see which specific subview is
being pressed.
Also, (insert subview here).userInteractionEnabled = YES, I set this property for all my subviews of the scroll view, so this should not be a problem.
I have also tried using touchesBegan and touchesEnded method as suggested elsewhere in Stack Overflow.
Also, for the image views, I do set a new UILongPressGestureRecognizer for every custom image view, using a for loop, as I am aware of the 1 view per gesture recognizer rule.
From A First Time iOS Developer,
Graham
P.S. I'd really prefer if I could find a solution for 1. rather than the messy 2.
More Code As Requested:
In the Init of the view Controller
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressDidFire:)];
longPress.minimumPressDuration = 0.5;
[self.titleLabel addGestureRecognizer:longPress]; //titleLabel property initialized elsewhere
[mainView addSubview:self.titleLabel];
In a "load images" method
for (NSData * dataImg in results) {
//Does some work turning data into an image, into an image view called img
img.delegate = self;
img.userInteractionEnabled = YES;
UILongPressGestureRecognizer *aLongPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressDidFire:)];
aLongPress.minimumPressDuration = 0.5;
[img addGestureRecognizer:aLongPress];
[imgContainer addSubview:img];
}
Even More Code + Notes
self.view (UIView)
->scroll (UIScrollView)
->->mainView (UIView)
->->->titleLabel (UILabel)
->->->imgContainer (UIView)
->->->->images (UIImageViews)
[self.view addSubview:scroll];
[scroll addSubview:mainView];
[mainView addSubview:self.titleLabel];
[mainView addSubview:imgContainer];
[imgContainer addSubview:img]; //done 8x via for loop
Thanks to #RegularExpression's answer, I now am aware that the mainView is getting pressed, but not its subviews, so I need to find a way to display the mainView's subviews above it. :)
Another update, titleLabel works. ImageViews still don't work though. :(
I know this is a bit late and an answer has been chosen, but in case someone else wants a nice simple solution if you've got iOS7.
Inside your delegate of the UILongPressGestureRecognizer implement the gestureRecognizer:shouldRequireFailureOfGestureRecognizer:otherGestureRecognizer selector
Check if otherGestureRecognizer is a UIPanGestureRecognizer and return YES, otherwise return NO
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
if ([otherGestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]) {
return YES;
}
return NO;
}
The scroll view will actually produce a UIScrollViewPanGestureRecognizer, which is part of the private API, but it's a subclass of UIPanGestureRecognizer so the above works fine.
To support iOS6 or below, then you'll need to loop through the gestureRecognizers of the UIScrollView, detect which one is a UIPanGestureRecognizer and perform the requireGestureRecognizerToFail selector on your UILongPressGestureRecogizer with that.
your code seems to be fine,it should work i think.i used below code and its working fine for me.
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(handleLongPress:)];
longPress.delegate = (id)self;
longPress.minimumPressDuration=0.05;
imageView.userInteractionEnabled = YES;
[imageView addGestureRecognizer:longPress];
and its method,
- (IBAction)handleLongPress:(UILongPressGestureRecognizer *)sender {
NSLog(#"detected");
if (sender.state == UIGestureRecognizerStateEnded){
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Alert" message:#"YES" delegate:nil cancelButtonTitle:#"OK" otherButtonTitles: nil];
[alert show];
}
}
Here i took imageView as subview of scrollview as u said
Since your UIScrollView is the common parent, that's probably where your gesture recognizer needs to be. You can determine which subview is being pressed by looking at the location of the point supplied in your action. So, the individual subviews do not need gesture recognizers.
So, you would do something like this:
- (void)longPressDidFire:(UILongPressGestureRecognizer *)sender
{
if (sender.state == UIGestureRecognizerStateEnded)
CGPoint point = [sender locationInView:scroll];
UIView *tappedView = [scroll hitTest:point withEvent:nil];
So, then you have the view that was long-pressed.
Other things that could cause the action not to fire would be a delegate problem or if the scroll is contained by another view that is intercepting the touch.
HTH
Instead of
[scroll addGestureRecognizer:longPress];
Add the gesture on your subviews, right after you declare them and before you add them to scrollview
[subview addGestureRecognizer:longPress];
Woohoo it works!
The problem was:
imgContainer was a UIView with an empty frame with several UIImageViews as subviews
I was under the impression that as I added a subview to imgContainer, imgContainer would expand.
This is not true.
I had to set imgContainer's frame to the same content frame as the scroll view and then everything became ok.
I hope this answer helps any other future iOS firs timers like me.
I had a project which contains lots of UIButton, using xcode 4.5 and storyboard and ARC. after testing in ios6, everything goes fine. But in ios5, UIButton touch up inside event not working, the action not called. I tried to use touch down and it works. However, I have a lot of UIButton, I cannot change that one by one. what's more, the touch down event does give a good experience.
I used code below in many of my view controllers:
in viewDidLoad:
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(dismissKeyboard)];
[self.view addGestureRecognizer:tap];
-(void)dismissKeyboard {
[aTextField resignFirstResponder];
}
this might be the reason. I will check it out later. But it works in ios6.
Do you know what's wrong ? Thanks very much!
I had the same problem to you.
That's because the touch event in iOS5 is prevented when the gestureRecognizer you registered captures the event.
There are two solutions.
One:
1) Add a new view inside your view. It should have the same level to the buttons. The priority of the buttons should be higher than the new view.
2) change the call of 'addGestureRecognizer' to the new view.
[self.newView addGestureRecognizer:tap];
Two:
1) Implement the code below. You should return NO when the point is in the buttons.
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
CGPoint point = [gestureRecognizer locationInView:self.view];
NSLog(#"x = %.0f, y = %.0f", point.x, point.y);
if (CGRectContainsPoint(self.testBtn.layer.frame, point))
return NO;
return YES;
}
ps.
you should import QuartzCore.h to access layer's attributes.
#import <QuartzCore/QuartzCore.h>
Just use the property "cancelsTouchesInView" (NO) on UITapGestureRecognizer tap
Example:
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(didTap)];
gesture.cancelsTouchesInView = NO;
[self.view addGestureRecognizer:gesture];
Override your button parent view pointinside method, setting a new custom frame size that contains your button.
I am using UISwipeGestureRecognizer for left and right direction swipe in my main view as follow:
UISwipeGestureRecognizer *recognizer1,*recognizer;
recognizer1 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipeFromleft:)];
[recognizer1 setDirection:(UISwipeGestureRecognizerDirectionLeft)];
[self.view addGestureRecognizer:recognizer1];
[recognizer1 release];
recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipeFromright:)];
[recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];
[self.view addGestureRecognizer:recognizer];
[recognizer release];
and in this same view I am also using touch event like touch begin,move and end.
Both are used for different purpose.
My problem is that when I touch my view and moving it from left to right or right to left;
UISwipeGestureRecognizer is called in between the touch began and touch moved method which i dont want
so anyone know how can i avoid this type of thing?
how can i tell the view that i am now want to use touch event or i am using UISwipeGestureRecognition
Take a look at reference there is a property called cancelsTouchesInView. So the way I see it is to determine if you want to handle the gesture or standard touch in swipeHandlers, and set the cancelsTouchesInView property accordingly
I've added a TapGestureRecognizer to my self.view:
tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTap:)];
tap.numberOfTapsRequired = 1;
tap.numberOfTouchesRequired = 1;
[self.view addGestureRecognizer:tap];
[tap release];
The view contains a single UIScrollView with images and labels. I want to detect if the user taps on a label or not.
- (void)singleTap:(UIGestureRecognizer*)gestureRecognizer {
CGPoint pt = [gestureRecognizer locationInView:self.view];
UIView *v = [self.view hitTest:pt withEvent:nil];
if ([v isKindOfClass:[UILabel class]]) {
NSLog(#"label!");
return;
}
// else do other stuff if its not a label
However I don't see the label! in my log.
I think it's because userInteractionEnabled is by default NO on UILabels. Try turning that on.
EDIT: It was really a guess, but just to confirm, Apple docs on [UIView hitTest:withEvent:] state:
This method ignores view objects that are hidden, that have disabled user interaction, or have an alpha level less than 0.01.
Your subviews, such as the labels themself, actually hide the user interactions from the underlying view.
Why don't you add the gesture recognizers to your label(s).
Alternatively you may want to use UIButton for the labels.
Or -
if you do not want to determine which label has been touched, you may want to add an invisible view (an empty view, neither a hidden one nor one with alpha=0) on top of all labels and add the gesture recognizers to those.
I have a UIView inside of a UIScrollView, both created using IB. The UIView scrolls horizontally inside the UIScrollView. I want to detect left and right 2 finger swipes.
Borrowing from the sample code I found in SmpleGestureRecognizers, I have put the following code in the viewDidLoad method of the UIScrollView's ViewController...
UIGestureRecognizer *recognizer;
UISwipeGestureRecognizer *swipeRightRecognizer, *swipeLeftRecognizer;
recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipeFrom:)];
swipeRightRecognizer = (UISwipeGestureRecognizer *)recognizer;
swipeRightRecognizer.numberOfTouchesRequired = 2;
[self.view addGestureRecognizer:swipeRightRecognizer];
[recognizer release];
recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleSwipeFrom:)];
swipeLeftRecognizer = (UISwipeGestureRecognizer *)recognizer;
swipeLeftRecognizer.numberOfTouchesRequired = 2;
swipeLeftRecognizer.direction = UISwipeGestureRecognizerDirectionLeft;
[self.view addGestureRecognizer:swipeLeftRecognizer];
[recognizer release];
I have set in the viewcontroller.h. and have the following delegate method...
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
return YES;
}
I am assuming this is a valid gestureRecognizer delegate method, but I cannot find any reference to it in the documentation.
I do not get any errors but nothing happens when I do a 2 finger swipe. The delegate method is not called and neither is my action method. I tried removing the numbeOfTouchesRequired call to see if it might work with a single finger swipe to no avail.
Am I adding the gestureRecognizers to the right view? I tried adding it to the UIView, the UIScrollView as well as self.view.superView.
The sample code runs great. The only difference I can see between my implementation of the code and the sample code is the fact that I used IB to create the views and the sample code did not. I suspect that something is consuming the swipe gesture before it gets to my recognizers.
What am I doing wrong.
Thanks,
John
I had the same problem and I solved by using UIPanGestureRecognizer instead of UISwipeGestureRecognizer.
To emulate the detection of swipe, we'll play with the speed of gesture in scrollview.
If the speed of x direction >= 3000 (for example) the swipe will be detected.
If x>0 it will be a right swipe.
The code I implemented to resolve your situation is:
In a uiscrollview named _scroll1:
UIPanGestureRecognizer *pan;
pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(Swipe4ScrollViews:)];
[pan setMinimumNumberOfTouches:2];
[_scroll1 addGestureRecognizer:pan];
[pan release];
With a global BOOL variable named _panning, Swipe4ScrollViews will do the hard job:
-(void)Swipe4ScrollViews:(UIPanGestureRecognizer *)sender
{
if(sender.state == UIGestureRecognizerStateBegan) _panning = NO;
CGPoint v =[sender velocityInView:_scroll1];
NSLog(#"%f, %f",v.x,v.y);
if( (abs(v.x) >= UMBRAL) && !_panning)
{
_panning = YES;
[sender cancelsTouchesInView];
if(v.x>0) NSLog(#"Right");
else NSLog(#"Left");
[self doSomething];
}
}
I encapsulated it on a UIGestureRecognizer subclass: UISwipe4ScrollGestureRecognizer
The biggest difference between the sample code and your code is that your code involves a UIScrollView.
Internally, scroll views, table views, and web views all use gesture recognizers to some degree. If you're expecting to receive gestures within those views – gestures that are similar to the ones already supported internally – they will almost certainly be consumed or significantly delayed before you can get to them. Receiving gestures outside or above those views should work fine, if your use case supports it.
Try setting the delayContentTouches-property of the UIScrollView to NO, maybe it'll help.