I have a second window that has a view with a passthrough view inside of it. The passthrough works fine but I need it to recognize downSwipe gestures while still passing all other touch events to the view below it. How can I do this?
class PassThroughView: UIView {
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
print("Passing all touches to the next view (if any), in the view stack.")
return false
}
}
class MyVC: UIViewController {
lazy var backdropView: PassThroughView = {
let v = PassThroughView(frame: self.view.bounds)
v.backgroundColor = .clear
v.isUserInteractionEnabled = true
return v
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .clear
addGesture()
}
func addGesture() {
let swipeDown = UISwipeGestureRecognizer(target: self, action: #selector(handleGesture))
swipeDown.direction = .down
backdropView.addGestureRecognizer(swipeDown)
}
#objc func handleGesture(gesture: UISwipeGestureRecognizer) -> Void {
if gesture.direction == .down {
print("Swipe Down")
}
}
}
Related
I'm creating an app with swift.
I've made child classes from UIView. After making them and writing some processes there, I feel that I want them to detect touch events.
But they aren't children of UIButton.
I'd not like to force them to detect touch events using UIGestureRecognizer. Because UIGestureRecognizer needs to be used in UIViewController. I'd like to write codes of detecting touch just in the view.
Are there any ways to detect touch events just in UIView?
You can simply add the gesture to the subclass of UIView as other said, but if you want to include the gesture within the definition of the subclass and make it more modular, you can use the notification dispatch mechanism to broadcast the gesture to the registered view controller.
First, you create a name for the notification:
extension Notification.Name {
static let CustomViewTapped = Notification.Name("CustomViewTapped")
}
Then, you add the gesture to your custom view:
class CustomView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
let tap = UIGestureRecognizer(target: self, action: #selector(tapped))
self.addGestureRecognizer(tap)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
#objc func tapped(_ sender: UIGestureRecognizer) {
NotificationCenter.default.post(name: .CustomViewTapped, object: self)
}
}
And, finally, observe the broadcast from your view controller:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(customViewTapped), name: .CustomViewTapped, object: nil)
let customView = CustomView()
self.view.addSubview(customView)
}
#objc func customViewTapped(_ sender: UIGestureRecognizer) {
}
}
You can add UIGestureRecognizer to UIView. Another way you can add invisible UIButton on top of your UIView.
If you use UIView subclass, you can use something following and handle tap in action closure
class TappableView: UIView {
var action: (()->())? = nil
init(frame: CGRect) {
super.init(frame: frame)
initialization()
}
func initialization() {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap))
addGestureRecognizer(tapGesture)
}
#objc private func tapGesture() {
action?()
}
}
class childView: UIView {
var action: (()->())? = nil
init(frame: CGRect) {
super.init(frame: frame)
initialization()
}
func initialization() {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap))
addGestureRecognizer(tapGesture)
}
#objc private func tapGesture() {
//Action called here
}
}
//MARK:- View Tap Handler
extension UIView {
private struct OnClickHolder {
static var _closure:()->() = {}
}
private var onClickClosure: () -> () {
get { return OnClickHolder._closure }
set { OnClickHolder._closure = newValue }
}
func onTap(closure: #escaping ()->()) {
self.onClickClosure = closure
isUserInteractionEnabled = true
let tap = UITapGestureRecognizer(target: self, action: #selector(onClickAction))
addGestureRecognizer(tap)
}
#objc private func onClickAction() {
onClickClosure()
}
}
Usage:
override func viewDidLoad() {
super.viewDidLoad()
let view = UIView(frame: .init(x: 0, y: 0, width: 80, height: 50))
view.backgroundColor = .red
view.onTap {
print("View Tapped")
}
}
I have a view that is with the black border and it has two different views on it. And these views are overlapping in a small area. And each of them has own UITapGestureRecognizer. When I tap each item's discrete area, the action of that item is triggered. But when I tap the common area, only the second view's action is triggered. I want that both actions have to be triggered. How can I achieve this? Here is my code:
class ViewController: UIViewController {
#IBOutlet weak var view1: UIView!
#IBOutlet weak var view2: UIView!
#IBOutlet weak var outerView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
outerView.layer.borderWidth = 2.0
outerView.layer.borderColor = UIColor.black.cgColor
view1.layer.borderWidth = 2.0
view1.layer.borderColor = UIColor.red.cgColor
view2.layer.borderWidth = 2.0
view2.layer.borderColor = UIColor.blue.cgColor
self.initialize()
}
private func initialize(){
let tapGesture1 = UITapGestureRecognizer(target: self, action: #selector(detectTap1(_:)))
let tapGesture2 = UITapGestureRecognizer(target: self, action: #selector(detectTap2(_:)))
self.view1.addGestureRecognizer(tapGesture1)
self.view2.addGestureRecognizer(tapGesture2)
}
#objc func detectTap1(_ gesture : UITapGestureRecognizer) {
print("detectTap1")
}
#objc func detectTap2(_ gesture : UITapGestureRecognizer) {
print("detectTap2")
}
}
Kindly share your suggestions.
For this problem i have found this solution, maybe is not the best solution but it works, i will look for further improvements anyway
I had subclassed UIGestureRecognizer class
Updated
import UIKit
import UIKit.UIGestureRecognizerSubclass
class CustomGestureRecognizer: UIGestureRecognizer {
var anotherGestureRecognizer : CustomGestureRecognizer?
private var touchBeganSended : Bool = false
private var touchLocation : CGPoint?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesBegan(touches, with: event)
if let validTouch = touches.first?.location(in: self.view) {
if (self.view!.point(inside: validTouch, with: event)) {
if(!touchBeganSended) {
touchBeganSended = true
touchLocation = validTouch
anotherGestureRecognizer?.touchesBegan(touches, with: event)
state = .recognized
}
}
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesEnded(touches, with: event)
if let validTouch = touches.first?.location(in: self.view) {
if (self.view!.point(inside: validTouch, with: event)) {
if(touchBeganSended) {
touchBeganSended = false
anotherGestureRecognizer?.touchesEnded(touches, with: event)
state = .recognized
}
}
}
}
override func location(in view: UIView?) -> CGPoint {
if let desiredView = view {
if(desiredView == self.view) {
return touchLocation ?? CGPoint(x: 0, y: 0)
} else {
return super.location(in: view)
}
} else {
return super.location(in: view)
}
}
}
Updated
then you need to modify your initialize() method to this one, with the last update you don't need to take into account which view is on top on view hierarchy
private func initialize(){
let tapGesture1 = CustomGestureRecognizer(target: self, action: #selector(detectTap1(_:)))
let tapGesture2 = CustomGestureRecognizer(target: self, action: #selector(detectTap2(_:)))
tapGesture1.cancelsTouchesInView = true
tapGesture1.delegate = self
tapGesture2.cancelsTouchesInView = true
tapGesture2.delegate = self
self.view1.addGestureRecognizer(tapGesture1)
tapGesture1.anotherGestureRecognizer = tapGesture2
tapGesture2.anotherGestureRecognizer = tapGesture1
self.view2.addGestureRecognizer(tapGesture2)
}
this works as you can see here
Try the following:
private func initialize(){
let tapGesture1 = UITapGestureRecognizer(target: self, action: #selector(detectTap1(_:)))
let tapGesture2 = UITapGestureRecognizer(target: self, action: #selector(detectTap2(_:)))
tapGesture1.cancelsTouchesInView = false
tapGesture2.cancelsTouchesInView = false
self.view1.addGestureRecognizer(tapGesture1)
self.view2.addGestureRecognizer(tapGesture2)
}
When you set
gesture.cancelsTouchesInView = false
it propagates the gesture to the views underneath.
Try to implement this UIGestureRecognizerDelegate method:
class ViewController: UIViewController, UIGestureRecognizerDelegate {
...
...
private func initialize() {
...
gesture1.delegate = self
gesture2.delegate = self
...
}
func gestureRecognizer(
_ gestureRecognizer: UIGestureRecognizer,
shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer
) -> Bool {
// its up to you
//guard otherGestureRecognizer == yourAnotherGesture else { return false }
return true
}
Looking to add a tap gesture to an array of UIViews - without success. Tap seems not to be recognised at this stage.
In the code (extract) below:
Have a series of PlayingCardViews (each a UIView) showing on the main view.
Brought together as an array: cardView.
Need to be able to tap each PlayingCardView independently (and then to be able to identify which one was tapped).
#IBOutlet private var cardView: [PlayingCardView]!
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action: #selector(tapCard(sender: )))
for index in cardView.indices {
cardView[index].isUserInteractionEnabled = true
cardView[index].addGestureRecognizer(tap)
cardView[index].tag = index
}
}
#objc func tapCard (sender: UITapGestureRecognizer) {
if sender.state == .ended {
let cardNumber = sender.view.tag
print("View tapped !")
}
}
You need
#objc func tapCard (sender: UITapGestureRecognizer) {
let clickedView = cardView[sender.view!.tag]
print("View tapped !" , clickedView )
}
No need to check state here as the method with this gesture type is called only once , also every view should have a separate tap so create it inside the for - loop
for index in cardView.indices {
let tap = UITapGestureRecognizer(target: self, action: #selector(tapCard(sender: )))
I will not recommend the selected answer. Because creating an array of tapGesture doesn't make sense to me in the loop. Better to add gesture within PlaycardView.
Instead, such layout should be designed using UICollectionView. If in case you need to custom layout and you wanted to use scrollView or even UIView, then the better approach is to create single Gesture Recognizer and add to the superview.
Using tap gesture, you can get the location of tap and then you can get the selectedView using that location.
Please refer to below example:
import UIKit
class PlayCardView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = UIColor.red
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
backgroundColor = UIColor.red
}
}
class SingleTapGestureForMultiView: UIViewController {
var viewArray: [UIView]!
var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
scrollView = UIScrollView(frame: UIScreen.main.bounds)
view.addSubview(scrollView)
let tapGesture = UITapGestureRecognizer(target: self,
action: #selector(tapGetsure(_:)))
scrollView.addGestureRecognizer(tapGesture)
addSubviews()
}
func addSubviews() {
var subView: PlayCardView
let width = UIScreen.main.bounds.width;
let height = UIScreen.main.bounds.height;
let spacing: CGFloat = 8.0
let noOfViewsInARow = 3
let viewWidth = (width - (CGFloat(noOfViewsInARow+1) * spacing))/CGFloat(noOfViewsInARow)
let viewHeight = (height - (CGFloat(noOfViewsInARow+1) * spacing))/CGFloat(noOfViewsInARow)
var yCordinate = spacing
var xCordinate = spacing
for index in 0..<20 {
subView = PlayCardView(frame: CGRect(x: xCordinate, y: yCordinate, width: viewWidth, height: viewHeight))
subView.tag = index
xCordinate += viewWidth + spacing
if xCordinate > width {
xCordinate = spacing
yCordinate += viewHeight + spacing
}
scrollView.addSubview(subView)
}
scrollView.contentSize = CGSize(width: width, height: yCordinate)
}
#objc
func tapGetsure(_ gesture: UITapGestureRecognizer) {
let location = gesture.location(in: scrollView)
print("location = \(location)")
var locationInView = CGPoint.zero
let subViews = scrollView.subviews
for subView in subViews {
//check if it subclass of PlayCardView
locationInView = subView.convert(location, from: scrollView)
if subView.isKind(of: PlayCardView.self) {
if subView.point(inside: locationInView, with: nil) {
// this view contains that point
print("Subview at \(subView.tag) tapped");
break;
}
}
}
}
}
You can try to pass the view controller as parameter to the views so they can call a function on parent view controller from the view. To reduce memory you can use protocols. e.x
protocol testViewControllerDelegate: class {
func viewTapped(view: UIView)
}
class testClass: testViewControllerDelegate {
#IBOutlet private var cardView: [PlayingCardView]!
override func viewDidLoad() {
super.viewDidLoad()
for cardView in self.cardView {
cardView.fatherVC = self
}
}
func viewTapped(view: UIView) {
// the view that tapped is passed ass parameter
}
}
class PlayingCardView: UIView {
weak var fatherVC: testViewControllerDelegate?
override func awakeFromNib() {
super.awakeFromNib()
let gr = UITapGestureRecognizer(target: self, action: #selector(self.viewDidTap))
self.addGestureRecognizer(gr)
}
#objc func viewDidTap() {
fatherVC?.viewTapped(view: self)
}
}
Does UILabel have any value that can be set in order to make it selectable?
I have a label that I want to be selectable, (long press and a copy btn shows up) kinda like in Safari.
Self-contained Solution (Swift 5)
You can adapt the solution from #BJHSolutions and NSHipster to make the following self-contained SelectableLabel:
import UIKit
/// Label that allows selection with long-press gesture, e.g. for copy-paste.
class SelectableLabel: UILabel {
override func awakeFromNib() {
super.awakeFromNib()
isUserInteractionEnabled = true
addGestureRecognizer(
UILongPressGestureRecognizer(
target: self,
action: #selector(handleLongPress(_:))
)
)
}
override var canBecomeFirstResponder: Bool {
return true
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return action == #selector(copy(_:))
}
// MARK: - UIResponderStandardEditActions
override func copy(_ sender: Any?) {
UIPasteboard.general.string = text
}
// MARK: - Long-press Handler
#objc func handleLongPress(_ recognizer: UIGestureRecognizer) {
if recognizer.state == .began,
let recognizerView = recognizer.view,
let recognizerSuperview = recognizerView.superview {
recognizerView.becomeFirstResponder()
UIMenuController.shared.setTargetRect(recognizerView.frame, in: recognizerSuperview)
UIMenuController.shared.setMenuVisible(true, animated:true)
}
}
}
Yes, you need to implement a UIMenuController from a long press gesture applied to your UILabel. There is an excellent article about this on NSHipster, but the gist of the article is the following.
Create a subclass of UILabel and implement the following methods:
override func canBecomeFirstResponder() -> Bool {
return true
}
override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
return (action == "copy:")
}
// MARK: - UIResponderStandardEditActions
override func copy(sender: AnyObject?) {
UIPasteboard.generalPasteboard().string = text
}
Then in your view controller, you can add a long press gesture to your label:
let gestureRecognizer = UILongPressGestureRecognizer(target: self, action: "handleLongPressGesture:")
label.addGestureRecognizer(gestureRecognizer)
and handle the long press with this method:
func handleLongPressGesture(recognizer: UIGestureRecognizer) {
if let recognizerView = recognizer.view,
recognizerSuperView = recognizerView.superview
{
let menuController = UIMenuController.sharedMenuController()
menuController.setTargetRect(recognizerView.frame, inView: recognizerSuperView)
menuController.setMenuVisible(true, animated:true)
recognizerView.becomeFirstResponder()
}}
NOTE: This code is taken directly from the NSHipster article, I am just including it here for SO compliance.
UILabel inherits from UIView so you can just add a long press gesture recognizer to the label. Note that you have to change isUserInteractionEnabled to true, because it defaults to false for labels.
import UIKit
class ViewController: UIViewController {
let label = UILabel()
override func viewDidLoad() {
view.addSubview(label)
label.text = "hello"
label.translatesAutoresizingMaskIntoConstraints = false
label.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
label.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
let longPressGestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(longPressLabel(longPressGestureRecognizer:)))
label.addGestureRecognizer(longPressGestureRecognizer)
label.isUserInteractionEnabled = true
}
#objc private func longPressLabel (longPressGestureRecognizer: UILongPressGestureRecognizer) {
if longPressGestureRecognizer.state == .began {
print("long press began")
} else if longPressGestureRecognizer.state == .ended {
print("long press ended")
}
}
}
I've implemented a UILabel subclass that provides all of the functionality needed. Note that if you're using this with interface builder, you'll need to adjust the init methods.
/// A label that can be copied.
class CopyableLabel: UILabel
{
// MARK: - Initialisation
/// Creates a new label.
init()
{
super.init(frame: .zero)
let gestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPressGesture(_:)))
self.addGestureRecognizer(gestureRecognizer)
self.isUserInteractionEnabled = true
}
required init?(coder aDecoder: NSCoder)
{
fatalError("init(coder:) has not been implemented")
}
// MARK: - Responder chain
override var canBecomeFirstResponder: Bool
{
return true
}
// MARK: - Actions
/// Method called when a long press is triggered.
func handleLongPressGesture(_ gestuerRecognizer: UILongPressGestureRecognizer)
{
guard let superview = self.superview else { return }
let menuController = UIMenuController.shared
menuController.setTargetRect(self.frame, in: superview)
menuController.setMenuVisible(true, animated:true)
self.becomeFirstResponder()
}
override func copy(_ sender: Any?)
{
UIPasteboard.general.string = self.text
}
}
what i want to achieve is when user touch on UIImageView set Image1, when user lifts his finger set Image2.
i can only get UIGestureRecognizerState.Ended with this code
var tap = UITapGestureRecognizer(target: self, action: Selector("tappedMe:"))
imageView.addGestureRecognizer(tap)
imageView.userInteractionEnabled = true
func tappedMe(gesture: UITapGestureRecognizer)
{
if gesture.state == UIGestureRecognizerState.Began{
imageView.image=originalImage
dbgView.text="Began"
}else if gesture.state == UIGestureRecognizerState.Ended{
imageView.image=filteredImage
dbgView.text="Ended"
}else if gesture.state == UIGestureRecognizerState.Cancelled{
imageView.image=filteredImage
dbgView.text="Cancelled"
}else if gesture.state == UIGestureRecognizerState.Changed{
imageView.image=filteredImage
dbgView.text="Changed"
}
}
The UITapGestureRecognizer doesn't change it's state to .Began, but the UILongPressGestureRecognizer does. If you for some reason font want to override the touch callbacks directly you could use a UILongPressGestureRecognizer with a very short minimumPressDuration of like 0.1 to achieve the effect.
Example by #Daij-Djan:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var tap = UILongPressGestureRecognizer(target: self, action: Selector("pressedMe:"))
tap.minimumPressDuration = 0
self.view.addGestureRecognizer(tap)
self.view.userInteractionEnabled = true
}
func pressedMe(gesture: UITapGestureRecognizer) {
if gesture.state == .Began{
self.view.backgroundColor = UIColor.blackColor()
} else if gesture.state == .Ended {
self.view.backgroundColor = UIColor.whiteColor()
}
}
}
Here is the solution:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
if touch.view == self {
//began
}
}
super.touchesBegan(touches, with: event)
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
if touch.view == self {
//end
}
}
super.touchesEnded(touches, with: event)
}
Note: Put this inside a UIView SubClass and add: userInteractionEnabled = true inside the init block
The best and most practical solution would be to embed your UIImageView within a UIControl subclass.
By default UIImageView has user interaction enabled. If you create a simple UIControl subclass you can easily add your image view into it and then use the following methods to achieve what you want:
let control = CustomImageControl()
control.addTarget(self, action: "imageTouchedDown:", forControlEvents: .TouchDown)
control.addTarget(self, action: "imageTouchedUp:", forControlEvents: [ .TouchUpInside, .TouchUpOutside ])
The advantages of doing it this way is that you get access to all of the different touch events saving you time from having to detect them yourself.
Depending on what you want to do, you could also override var highlighted: Bool or var selected: Bool to detect when the user is interacting with the image.
It's better to do it this way so that your user has a consistent user experience with all the controls in their app.
A simple implementation would look something like this:
final class CustomImageControl: UIControl {
let imageView: UIImageView = UIImageView()
override init(frame: CGRect) {
super.init(frame: frame)
// setup our image view
imageView.translatesAutoresizingMaskIntoConstraints = false
addSubview(imageView)
imageView.leadingAnchor.constraintEqualToAnchor(leadingAnchor).active = true
imageView.trailingAnchor.constraintEqualToAnchor(trailingAnchor).active = true
imageView.topAnchor.constraintEqualToAnchor(topAnchor).active = true
imageView.bottomAnchor.constraintEqualToAnchor(bottomAnchor).active = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
final class MyViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let control = CustomImageControl()
control.translatesAutoresizingMaskIntoConstraints = false
control.imageView.image = ... // set your image here.
control.addTarget(self, action: "imageTouchedDown:", forControlEvents: .TouchDown)
control.addTarget(self, action: "imageTouchedUp:", forControlEvents: [ .TouchUpInside, .TouchUpOutside ])
view.addSubview(control)
control.centerXAnchor.constraintEqualToAnchor(view.centerXAnchor).active = true
control.centerYAnchor.constraintEqualToAnchor(view.centerYAnchor).active = true
}
#objc func imageTouchedDown(control: CustomImageControl) {
// pressed down on the image
}
#objc func imageTouchedUp(control: CustomImageControl) {
// released their finger off the image
}
}