Detect touch in UICollectionView - ios

I need to stop autorotatation, if user touches to photo slider.
I use UITapGestureRecognizer to detect touch at UICollectionView:
override func viewDidLoad() {
super.viewDidLoad()
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.tapCollectionView(_:)))
collectionView.addGestureRecognizer(tapGesture)
}
func tapCollectionView(_ sender: UITapGestureRecognizer) {
print("touch")
}
It works when I tap on collection view.
But when I'm touching collection view and scrolling this collection view, my function 'tapCollectionView' is not called.

It helped me:
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
// Stop your timer here
timer?.invalidate()
}
}

Related

UITapGestureRecognizer is not invoked when I clicked button with IBAction

I have UITextField and UIButton in my application.
To hide system keyboard which is shown when UITextField is clicked, I added UITapGestureRecognizer to my view.
override func viewDidLoad() {
super.viewDidLoad()
let tapGesture = UITapGestureRecognizer.init(target: self, action: #selector(didTap(_:)))
view.addGestureRecognizer(tapGesture)
}
#objc func didTap(_ recognizer: UIGestureRecognizer) {
view.endEditing(true)
}
#IBAction func onClickedButton(_ sender: Any) {
print("aaa")
}
This code worked very well when I touched outside of my button.
However, when I clicked the button which has IBAction(onClickedButton), the keyboard did not disappear and only the message "aaa" printed in output console.
What I want to do is to hide keyboard and invoke IBAction at the same time. In other words, I want to invoke Tap gesture and IBAction at the same time, when I clicked my button.
How can I acheive this?
I found the solution.
Just setting
tapGesture.cancelsTouchesInView = false
can acheive this.
By doing like this, tapGesture hides keyboard and after that, passes touch event to the UIButton.
You can just add view.endEditing(true) to your onClickedButton.
try this
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let tapGesture = UITapGestureRecognizer.init(target: self, action: #selector(didTap(_:)))
view.addGestureRecognizer(tapGesture)
}
#objc func didTap(_ recognizer: UIGestureRecognizer) {
view.endEditing(true)
}
#IBAction func onClickedButton(_ sender: Any) {
print("aaa")
view.endEditing(true)
}
}

UILabel set onClick

I'm building an application in Swift 3, so I want to call a function if I click on a particular UILabel, so I'm write this code but not works:
let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.tapFunction))
self.labelTemp.isUserInteractionEnabled = true
self.labelTemp.addGestureRecognizer(tap)
How can I render UILabel clickable ?
Set user interaction enabled for the UILabel and add the below code in the viewDidLoad()
self.label.isUserInteractionEnabled = true
let tap = UITapGestureRecognizer(target: self, action: #selector(self.labelTapped))
self.label.addGestureRecognizer(tap)
Add the tap action function as below :
#objc func labelTapped(_ gestureRecognizer: UITapGestureRecognizer) {
print("Label clicked")
}
Please make user that there is no other transparent view overlapping the UILabel in the view. If the UILabel is a part of another view then please make sure that the container View's user interaction is enabled.
Hope this helps.
Your selector should be an #objc func within self.
<#YourLabel#>.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.handleLabelTap)))
And when the user taps the label it will trigger:
#objc func handleLabelTap() {
// handle label tap here
}
You are lacking a function to trigger when the gesture touch is recognized. You need to add following:
let tap = UITapGestureRecognizer(target: self, action: #selector(tapFunction(_:)))
self.labelTemp.isUserInteractionEnabled = true
self.labelTemp.addGestureRecognizer(tap)
#objc func tapFunction(_ gestureRecognizer: UITapGestureRecognizer) {
// handle label tap here
}
Please ensure that You have connected the outlet to UILabel because I have created simple demo code by copy-paste your code and it is worked as expected.
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action: #selector(tapFunction))
self.labelTemp.isUserInteractionEnabled = true
self.labelTemp.addGestureRecognizer(tap)
}
#objc func tapFunction() {
print("tapFunction")
}
I suggest, Please remove UILabel from UIViewController and add it again.
Download sample code
Note: - Please ensure that user-interaction of UILabelis enabled
First you need to add Tap Gesture into storyboard
Create Action of that particular gesture
override func viewDidLoad() {
super.viewDidLoad()
let tapOnLabel = UITapGestureRecognizer(target: self, action: #selector(self.tapGestireAction))
self.labelTemp.isUserInteractionEnabled = true
self.labelTemp.addGestureRecognizer(tapOnLabel)
}
#IBAction func tapGestureAction(_ sender: UITapGestureRecognizer) {
//Perform action
}

Calling function when user taps anywhere on screen

In my app I have a small menu I made which is basically a UIView with two button on it. The menu opens when the user taps a button and closes also when the user taps the same button. I'd like the menu to close when the user taps anywhere outside of the menu UIView.
The menu:
You can also apply this easy way
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.tapBlurButton(_:)))
self.view.addGestureRecognizer(tapGesture)
func tapBlurButton(_ sender: UITapGestureRecognizer) {
if //checkmenuopen
{
closemenuhere
}
}
For that when you show the small menu, add below it a invisible button (UIColor.clear) with the entire screen as a frame. And it's action is to dismiss the menu of yours.
Make sure when you dismiss the small menu to dismiss thus button as well.
Hope this helps!
You can use basically touches began function
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
print("TAPPED SOMEWHERE ON VIEW")
}
There are several solutions to your case:
1- Implementing touchesBegan(_:with:) method in your ViewController:
Tells this object that one or more new touches occurred in a view or
window.
Simply, as follows:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
// do something
}
2- Add a UITapGestureRecognizer to the main view of your ViewController:
override func viewDidLoad() {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(doSomething(_:)))
view.addGestureRecognizer(tapGesture)
}
func doSomething(_ sender: UITapGestureRecognizer) {
print("do something")
}
Or -of course- you could implement the selector without the parameter:
override func viewDidLoad() {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(doSomething))
view.addGestureRecognizer(tapGesture)
}
func doSomething() {
print("do something")
}
3- You could also follow Mohammad Bashir Sidani's answer.
I would suggest to make sure add the appropriate constraints to your button whether it has been added programmatically or by storyboard.
I'm not sure the code below will work in your case, just a advice.
class ViewController: UIViewController {
var closeMenuGesture: UITapGestureRecognizer!
override func viewDidLoad() {
super.viewDidLoad()
closeMenuGesture = UITapGestureRecognizer(target: self, action: #selector(closeMenu))
closeMenuGesture.delegate = self
// or closeMenuGesture.isEnable = false
}
#IBAction func openMenu() {
view.addGestureRecognizer(closeMenuGesture)
// or closeMenuGesture.isEnabled = true
}
#IBAction func closeMenu() {
view.removeGestureRecognizer(closeMenuGesture)
// or closeMenuGesture.isEnabled = false
}
}
extension ViewController: UIGestureRecognizerDelegate {
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
return touch.view === self.view // only valid outside menu UIView
}
}
And I never be in this situation so not sure making enable/disable closeMenuGesture is enough to ensure other controls work normally, or to add/remove closeMenuGesture is more insured.

GestureRecognizer taking all Touch Input

I have this Setup in my Storyboard.
In my first ViewController Scene I have a MapView from MapBox. In there I have put a TextField (AddressTextField). On that TextField when touching the view, i'm running self.addressTextField.resignFirstResponder(), but after that neither the mapview, nor any other element in there or in the Embedded Segues react on a touch or click. Probably this is because I didn't completely understand the system of the First Responder. I'm thankful for every help.
Edit 1:
I think I know what's going on now, but I don't know how to fix it. When I add the Gesture Recognizer to the View (or to the mapView, that doesn't matter), the other UIViews and the MapView do not recognize my Tap-Gestures anymore. When I am not adding the Recognizer everything works fine. It seems as if the Gesture Recognizer is recognizing every tap I make on either the UIViews or the MapView and therefore other gestures are not recognized.
Edit 2:
I just added a print() to dismissKeyboard(). As soon as any Touch Event gets recognized on the MapView or the other UIViews, dismissKeyboard() gets called. So I think my thought of Edit 1 was correct. Does anyone know how I can solve this, so that it's not only dismissKeyboard() that gets called ?
Some Code:
func dismissKeyboard(){
self.addressTextField.resignFirstResponder()
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
dismissKeyboard()
return true
}
//Class (only partially)
class ViewController: UIViewController, MGLMapViewDelegate, CLLocationManagerDelegate, UITextFieldDelegate {
override func viewDidLoad(){
mapView.delegate = self
addressTextField.delegate = self
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
self.mapView.addGestureRecognizer(tap)
}
}
Others are just #IBActions linked to the Buttons, or other elements.
try this:
func dismissKeyboard(){
view.endEditing(true)
}
hope it helps!
After I knew the real issue I was able to solve the problem. I declared a var keyboardEnabled. Then I added these lines to my class.
class ViewController: UIViewController, UIGestureRecognizerDelegate {
var keyboardEnabled = false
override func viewDidLoad(){
super.viewDidLoad()
//Looks for single tap
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
self.mapView.addGestureRecognizer(tap)
}
/* Setting keyboardEnabled */
//Editing Target did end
#IBAction func editingTargetDidEnd(_ sender: Any) {
keyboardEnabled = false
}
//Editing TextField Started
#IBAction func editingAdressBegin(_ sender: Any) {
keyboardEnabled = true
}
//Call this function when the tap is recognized.
func dismissKeyboard() {
self.mapView.endEditing(true)
keyboardEnabled = false
}
//Implementing the delegate method, so that I can add a statement
//decide when the gesture should be recognized or not
//Delegate Method of UITapGestureRecognizer
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
return keyboardEnabled
}
}
With this solution keyboardEnabled takes care of deciding wether my UIGestureRecognizer should react or not. If the Recognizer doesn't react, the Gesture is simply passed on to the UIViews or other Elements that are in my MapView.
Thanks for all your answers!

How do I trigger a collection view's didSelectItemAtIndexPath: on tap while it's scrolling?

The default behavior while a collection view is mid-scroll:
tap #1: stops the scrolling
tap #2: triggers didSelectItemAtIndexPath
What I want while a collection view is mid-scroll:
tap #1: triggers didSelectItemAtIndexPath
What would be a clean, correct approach to achieve this? FWIW, I realize this might be unexpected behavior.
I think the best approach is to use the UICollectionView addGestureRecognizer to add a touch gesture recognizer, then process the touch gesture (e.g. get the touch location in the collection view, use that to get the indexPath of the item that was touched, then call the collectionView.didSelectItemAtIndexPath yourself). As for the scrolling, you could use the UISrollViewDelegate methods to disable user interaction on the collection view once the scroll starts, then re-enable user interaction on the collection view once the scrolling stops and/or in the viewDidDisappear view controller function.
Like this:
public class MyViewController: UIViewController {
#IBOutlet weak var collectionView: UICollectionView!
var collectionViewTap:UITapGestureRecognizer?
override public func viewDidLoad() {
collectionViewTap = UITapGestureRecognizer(target: self, action: #selector(handleTap))
self.view.addGestureRecognizer(collectionViewTap!)
}
override public func viewDidDisappear(animated: Bool) {
collectionView.userInteractionEnabled = true
}
func handleTap (sender:UITapGestureRecognizer) {
let touchPoint = sender.locationOfTouch(0, inView: collectionView)
let indexPath = collectionView.indexPathForItemAtPoint(touchPoint)
if (indexPath != nil) {
collectionView(collectionView, didSelectItemAtIndexPath: indexPath!)
}
}
public func scrollViewWillBeginDragging(scrollView: UIScrollView) {
collectionView.userInteractionEnabled = false
}
public func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
collectionView.userInteractionEnabled = true
}
}
In your initializer for the collection view, add an additional target for the pan gesture
self.panGestureRecognizer.addTarget(self, action: #selector(allowSelectionOfItemDuringScroll(_:)))
Then, you can implement it like this:
#objc private func allowSelectionOfItemDuringScroll(_ sender: UIPanGestureRecognizer) {
let yTranslation = sender.translation(in: self).y
var isScrolling: Bool {
if sender.state == .began {
return false
}
if isDragging && isDecelerating {
return false
}
return isDragging || isDecelerating
}
if yTranslation == 0 && isScrolling {
let selectionPoint = sender.translation(in: self)
if let index = indexPathForItem(at: selectionPoint) {
self.delegate?.collectionView?(self, didSelectItemAt: index)
}
}

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