How to bring a view to the front on tapping them? ios - ios

I am creating an instance of an image view every time a button is pressed. The last instance created is brought to the front. How do I bring a different instance to the front by tapping on it?
- (void) hatsPressed {
NSLog(#"HAT PRESSED");
hat2Image = [[UIImageView alloc] initWithFrame:CGRectMake(120, 50, 100, 100)];
hat2Image.image = [UIImage imageNamed:#"hat2"];
[self.view addSubview:hat2Image];
[self.view bringSubviewToFront:hat2Image];
hat2Image.userInteractionEnabled = YES;
UITapGestureRecognizer * recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
recognizer.delegate = self;
[hat2Image addGestureRecognizer:recognizer];
[hat2Image addGestureRecognizer:_hat2Pan];
[hat2Image addGestureRecognizer:_hat2Pinch];
[hat2Image addGestureRecognizer:_hat2Rotate];
}

The way I'd do it...
Add a gesture recognizer to each of the image view you instantiate.
The handler of that gesture needs to call a delegate method in the super view or controller where the image views are added to.
When calling that delegate in your controller or view just call
[self.view bringSubviewToFront:myTappedView];
*I'd recycle the image views... creating one for each tap is not a very good way to do it.
let me know if you need some more details.

Related

Using UITapGesture to dismiss a view controller but it selects cell buttons underneath, can I stop this from happening?

In my program I have a method to dismiss a UIView that pops up when I want to add a friend. I want this view to be dismissed when the used taps off the screen. This works however it also taps on any table cells underneath it and presses any buttons that are there. Code is below:
In my viewDidLoad:
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]
initWithTarget:self
action:#selector(dismissKeyboard)];
tap.cancelsTouchesInView = NO;
and:
-(void)dismissKeyboard {
[self.nameField removeFromSuperview];
[self.addFriendView removeFromSuperview];
}
Is there any way I can get around this to stop elements under being selected?

Open an other ViewController by touching a UILabel

I have a ViewController with full of names, basically a contact list. When you touch one of the names, you will get a detail screen with informations: name, organization, building, phone number, email, etc. It uses a navigation controller, so you can go back to the phonebook.
I have a custom map in my application (basically a picture, with several layers and with a pin, that show you where you are on the picture). I would like to achieve that when someone touch the building UILabel it goes my MapViewController with some parameters. It's a simple UILabel, but contains useful information, something like 15/A building. I have the exact x,y coordinates for the buildings.
My main problem is that I don't really know how to set up the touch event on the UILabel and go to a new view controller, with parameters.
I guess I need to make in my mapviewcontroller new initiation methods to be able to get parameters and display them.
So to summarize: how can I navigate to an other view controller with touch event and how can I initiate that view controller with parameters. It's important that I can reach my map without any buildings parameters as well from my menu.
Any help appreciated.
Alternatively you can also add a hidden button over your label. This button will handle the touch event.
Use Tap gesture for it
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(labelTapped)];
tapGestureRecognizer.numberOfTapsRequired = 1;
[myLabel addGestureRecognizer:tapGestureRecognizer];
myLabel.userInteractionEnabled = YES;
//Create a Tap Gesture and set it on your Label.
UILabel *yourLabel=[[UILabel alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];
[yourLabel setTextColor:[UIColor blackColor]];
[yourLabel setTextAlignment:NSTextAlignmentCenter];
[yourLabel setText:#"Address"];
[self.view addSubview:yourLabel];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(TapGestureRecognizerLabel:)];
[tap setNumberOfTouchesRequired:1];
[yourLabel addGestureRecognizer:tap];
-(void)TapGestureRecognizerLabel:(UIGestureRecognizer *)gestureRecognizer
{
[self.navigationController pushViewController:targetControllerObj animated:YES];
}

how to place a subview on a cell so it does not block the tapgesture of its superview(cell)

I have the following code on a custom cell -
PSCollectionViewTapGestureRecognizer *gr = [[PSCollectionViewTapGestureRecognizer alloc] initWithTarget:self action:#selector(didSelectView:)];
gr.delegate = self;
[newView addGestureRecognizer:gr];
newView.userInteractionEnabled = YES;
how can i pass this gesture to its subviews? instead of adding a new gesture on subview.
currently the subview is blocking half of the view but tapping on it doesn't do anything.
needed to disable subviews interaction

UITapGestureRecognizer Recognize taps on main view (not inputs or buttons)

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.

How can I detect the touch event of an UIImageView?

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.

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