Right now, I have two different UILabels each with their own long press and pan UIGestureRecognizers (setup through the storyboard). My final goal is to have each UILabel change color when long pressed, and without lifting their finger to end the long press, to change the value of the UILabel itself when the user pans up and down or side to side.
Right now, each UILabel has its own pan gesture method and long press gesture method. Is there any way to have a single long press/pan method for both UILabels but also have the ability to do something for one label and something else for another?
Also, is there a better approach to doing this? Eventually, I would also like to implement visual feedback when changing the value of the labels, such as in the form of animations.
I am new to iOS programming and programming in general and detailed answers are greatly appreciated. Thanks.
You can have a single function.No need to have seperate gestures for seperate Label.Example
//First add tag value to ur labels
label_one.tag=1;
label_two.tag=2;
UIPanGestureRecognizer * _panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self
action:#selector(handlePanGesture:)];
_panGestureRecognizer.delegate = self;
[label_one addGestureRecognizer:_panGestureRecognizer];
UIPanGestureRecognizer * _panGestureRecognizer_two = [[UIPanGestureRecognizer alloc] initWithTarget:self
action:#selector(handlePanGesture:)];
_panGestureRecognizer_two.delegate = self;
[label_two addGestureRecognizer:_panGestureRecognizer_two];
-(void)handlePanGesture:(UIPanGestureRecognizer*)sender{
if(sender.tag==1){
}
else if(sender.tag==2){
}
}
Same goes for other gesture as well
My app shows an UIView which contains four UIButtons, one of them removes the UIView, but I also need is to remove the UIView, including all containing buttons when the user taps outside it.
This is how I remove the UIView using a button action:
-(IBAction)closeSideTasks: (id)sender
{
UIView * backgroundView = (UIView *)[self.view viewWithTag:7];
[backgroundView removeFromSuperview];
}
Any help or advice is welcome.
MORE INFORMATION:
This is the scenario: there is a table view. If the user swipes from left to right on a row, then the UIView appears on the right side of the view. The UIView *newView is removed after tapping on each of the buttons inside it and executing each button action. But may be the user does not tap on any of the buttons, and the UIView remains on the view. Then, what I want to achieve is a way that the UIView *newView gets removed if the user taps anywhere outside it, to prevent that it remains always on the view...
Check out UITapGestureRecognizer.
Example:
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] init];
tapGesture.delegate = self;
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
[tapGesture addTarget:self action:#selector(tapChangeImage)];
[self.profileImageView addGestureRecognizer:tapGesture];
Now add the action method:
#pragma tap gestures
-(void)tapChangeImage{
// Remove view from superview!
}
Put a large button, full screen, with no graphics, no text, and a clear background. Have its action also remove the background
I have a UIImageView inside of a custom cell. I am creating a custom tap gesture recognizer for when the UIImageView is tapped to load another detail view.
The tap gesture is set up like so:
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:event:)];
tapRecognizer.cancelsTouchesInView = YES;
tapRecognizer.numberOfTapsRequired = 1;
tapRecognizer.delegate = (id)self;
[cell.userImage addGestureRecognizer:tapRecognizer];
cell.userImage.userInteractionEnabled = YES;
I am using imageTapped:event: so that I can detect what cell the user is tapping and load the data accordingly. The problem is I get this error:
If I get rid of event like so, its works perfectly with no issues.
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
I have used this method before in another application but for some reason I cannot get it to work properly with this error. Anyone recognize what this is? Thanks!
You need to read the documentation on UIGestureRecognizer...
A gesture recognizer has one or more target-action pairs associated
with it. If there are multiple target-action pairs, they are discrete,
and not cumulative. Recognition of a gesture results in the dispatch
of an action message to a target for each of those pairs. The action
methods invoked must conform to one of the following signatures:
- (void)handleGesture;
- (void)handleGesture:(UIGestureRecognizer *)gestureRecognizer;
Using one of these signatures will prevent the crash as you have already observed. You could then access the image view that was involved in the gesture by inspecting the recognizer's view property, and from this you will be able to access the appropriate UITableView cell.
I would like to get notified when a user clicks any part of the background of my UIView; basically if the user clicks outside of any control that is on my UIView (tables, textfields, buttons, etc).
How do I go about it? I tried doing this:
if ([touch.view isKindOf:[UIView class]]) {
do something....
}
But, obviously all controls extend UIView... so, I'm a bit stuck.
You should be able to do the following:
backgroundView.userInteractionEnabled = YES;
UITapGestureRecognizer *tap = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapHit:)] autorelease];
[backgroundView addGestureRecognizer:tap];
-(void) tapHit:(UITapGestureRecognizer *tap) {
NSLog( #"background tapped" );
}
One way you could do this is add a separate background view that is a child of your VC's main view. You can simply make it transparent so it doesn't interfere with your styling. Place is in the behind all the other children views. Then register your GR on that view.
I have placed an image (UIImageView) on the navigation bar. Now I want to detect the touch event and want to handle the event. How can I do that?
In practical terms, don't do that.
Instead add a button with Custom style (no button graphics unless you specify images) over the UIImageView. Then attach whatever methods you want called to that.
You can use that technique for many cases where you really want some area of the screen to act as a button instead of messing with the Touch stuff.
A UIImageView is derived from a UIView which is derived from UIResponder so it's ready to handle touch events. You'll want to provide the touchesBegan, touchesMoved, and touchesEnded methods and they'll get called if the user taps the image. If all you want is a tap event, it's easier to just use a custom button with the image set as the button image. But if you want finer-grain control over taps, moves, etc. this is the way to go.
You'll also want to look at a few more things:
Override canBecomeFirstResponder and return YES to indicate that the view can become the focus of touch events (the default is NO).
Set the userInteractionEnabled property to YES. The default for UIViews is YES, but for UIImageViews is NO so you have to explicitly turn it on.
If you want to respond to multi-touch events (i.e. pinch, zoom, etc) you'll want to set multipleTouchEnabled to YES.
To add a touch event to a UIImageView, use the following in your .m file:
UITapGestureRecognizer *newTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(myTapMethod)];
[myImageView setUserInteractionEnabled:YES];
[myImageView addGestureRecognizer:newTap];
-(void)myTapMethod{
// Treat image tap
}
You can also add a UIGestureRecognizer. It does not require you to add an additional element in your view hierarchy, but still provides you will all the nicely written code for handling touch events with a fairly simple interface:
UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc]
initWithTarget:self action:#selector(handleSwipe:)];
swipeRight.direction = UISwipeGestureRecognizerDirectionRight;
[imgView_ addGestureRecognizer:swipeRight];
[swipeRight release];
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc]
initWithTarget:self action:#selector(handleSwipe:)];
swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
[imgView_ addGestureRecognizer:swipeLeft];
[swipeLeft release];
I've been on different threads on the past few hours trying to find a solution for my problem, to no avail. I see that many developers share this problem, and I think people here know about this. I have multiple images inside a UIScrollView, trying to get tap events on them.
I am not getting any events from an UIImangeView, but I do get an event from a similar UILable with very similar parameters I am setting to it. Under iOS 5.1.
I have already done the following:
set setUserInteractionEnabled to YES for both `UIImageView and parent
view .
set setMultipleTouchEnabled to YES for UIImageView.
Tried subclassing UIImageView, didn't help any.
Attaching some code below, in this code I initialize both a UIImageView and UILabel, the label works fine in terms of firing events. I tried keeping out irrelevant code.
UIImageView *single_view = [[UIImageView alloc]initWithFrame:CGRectMake(200, 200, 100, 100)];
single_view.image = img;
single_view.layer.zPosition = 4;
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
[single_view addGestureRecognizer:singleTap];
[single_view setMultipleTouchEnabled:YES];
[single_view setUserInteractionEnabled:YES];
[self.myScrollView addSubview:single_view];
self.myScrollView.userInteractionEnabled = YES;
UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
testLabel.backgroundColor = [UIColor redColor];
[self.myScrollView addSubview:testLabel];
[testLabel addGestureRecognizer:singleTap];
[testLabel setMultipleTouchEnabled:YES];
[testLabel setUserInteractionEnabled:YES];
testLabel.layer.zPosition = 4;
And the method which handles the event:
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
UIView *tappedView = [gesture.view hitTest:[gesture locationInView:gesture.view] withEvent:nil];
NSLog(#"Touch event on view: %#", [tappedView class]);
}
As said, the label tap is received.
Instead of making a touchable UIImageView then placing it on the navbar, you should just create a UIBarButtonItem, which you make out of a UIImageView.
First make the image view:
UIImageView *yourImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"nameOfYourImage.png"]];
Then make the barbutton item out of your image view:
UIBarButtonItem *yourBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:yourImageView];
Then add the bar button item to your navigation bar:
self.navigationItem.rightBarButtonItem = yourBarButtonItem;
Remember that this code goes into the view controller which is inside a navigation controller viewcontroller array. So basically, this "touchable image-looking bar button item" will only appear in the navigation bar when this view controller when it's being shown. When you push another view controller, this navigation bar button item will disappear.
You might want to override the touchesBegan:withEvent: method of the UIView (or subclass) that contains your UIImageView subview.
Within this method, test if any of the UITouch touches fall inside the bounds of the UIImageView instance (let's say it is called imageView).
That is, does the CGPoint element [touch locationInView] intersect with with the CGRect element [imageView bounds]? Look into the function CGRectContainsPoint to run this test.
First, you should place an UIButton and then either you can add a background image for this button, or you need to place an UIImageView over the button.
Or:
You can add the tap gesture to a UIImageView so that get the click action when tap on the UIImageView.
For those of you looking for a Swift 4 solution to this answer, you can use the following to detect a touch event on a UIImageView.
let gestureRecognizer: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(imageViewTapped))
imageView.addGestureRecognizer(gestureRecognizer)
imageView.isUserInteractionEnabled = true
You will then need to define your selector as follows:
#objc func imageViewTapped() {
// Image has been tapped
}
Add gesture on that view. Add an image into that view, and then it would be detecting a gesture on the image too. You could try with the delegate method of the touch event. Then in that case it also might be detecting.