Currently, I have a collection view with a UILongPressGestureRecognizer on the cell in cellForItemAt:
let longPress = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPressOnCell))
cell.addGestureRecognizer(longPress)
When the user holds down on a cell, it triggers a function to show a menu called cellDeleteAppear(). However, after the menu is on the screen, the user can then hold down on another cell which will cause the menu to pop up again.
#objc func handleLongPressOnCell(_ sender: UILongPressGestureRecognizer) {
if sender.state == .began {
cellDeleteAppear()
let gestureLocation = sender.location(in: self.trayCollectionView)
if let indexPath = self.trayCollectionView.indexPathForItem(at: gestureLocation) {
indexPathForDeletion = indexPath
trayCollectionView.allowsSelection = false
} else {
print("long press error at index path")
}
}
}
My goal is: while the menu is active, the user should not be able to hold down on another cell to trigger the menu to pop up. Any help is appreciated!
Then do
var menuShown = false
#objc func handleLongPressOnCell(_ sender: UILongPressGestureRecognizer) {
if sender.state == .began {
guard !menuShown else { return }
menuShown = true
And when you hide it do
menuShown = false
I have a SpringButton which I want to drag. This is my code:
var gesture = UIPanGestureRecognizer(target: self, action: #selector(userDragged))
card.addGestureRecognizer(gesture)
var cardIsCurrentlyMoving = false
func userDragged(gesture: UIPanGestureRecognizer){
if !cardIsCurrentlyMoving{
if let button = gesture.view as? SpringButton {
if gesture.state == .began {
print("begon")
cardIsCurrentlyMoving = true
startPosition = button.center
} else if gesture.state == .changed {
print("changed")
} else if gesture.state == .ended{
print("ended")
cardIsCurrentlyMoving = false
}
}
}
}
The function gets called, and the state gets changed to .began. However, when trying to move the button nothing happens. This is because cardIsCurrentlyMoving is set to true in .began, but never back to false, because gesture.state .changed and .ended never gets called.
When I release my finger and touch the button again, nothing happens as well. Why does UIPanGestureRecognizer not executes .changed and .ended?
Thanks.
I think you need to check your if statement
if !cardIsCurrentlyMoving{
}
Pan Gesture continuously calls method with changed state. So userDragged func called continuously but just because of your above if statement, control doesn't go inside if statement.
So i'll suggest to use this, instead of yours.
func userDragged(gesture: UIPanGestureRecognizer){
if let button = gesture.view as? SpringButton {
if gesture.state == .began {
print("begon")
cardIsCurrentlyMoving = true
startPosition = button.center
} else if gesture.state == .changed {
print("changed")
} else if gesture.state == .ended{
print("ended")
cardIsCurrentlyMoving = false
}
}
}
say, I have a button lying under UITableView, how can I click the button through the UITableViewCell but do not trigger the cell click event:
The reason I put the button behind the tableview is that I want to see and click the button under the cell whose color set to be clear, and when I scroll the table, the button can be covered by cell which is not with clear color
I created a sample project and got it working:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let tap = UITapGestureRecognizer(target: self, action: #selector(TableViewVC.handleTap))
tap.numberOfTapsRequired = 1
self.view.addGestureRecognizer(tap)
}
func handleTap(touch: UITapGestureRecognizer) {
let touchPoint = touch.locationInView(self.view)
let isPointInFrame = CGRectContainsPoint(button.frame, touchPoint)
print(isPointInFrame)
if isPointInFrame == true {
print("button pressed")
}
}
To check of button is really being pressed we need to use long tap gesture:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let tap = UILongPressGestureRecognizer(target: self, action: #selector(TableViewVC.handleTap))
tap.minimumPressDuration = 0.01
self.view.addGestureRecognizer(tap)
}
func handleTap(touch: UILongPressGestureRecognizer) {
let touchPoint = touch.locationInView(self.view)
print(" pressed")
if touch.state == .Began {
let isPointInFrame = CGRectContainsPoint(button.frame, touchPoint)
print(isPointInFrame)
if isPointInFrame == true {
print("button pressed")
button.backgroundColor = UIColor.lightGrayColor()
}
}else if touch.state == .Ended {
button.backgroundColor = UIColor.whiteColor()
}
}
Get the touch point on the main view. Then use following method to check the touch point lies inside the button frame or not.
bool CGRectContainsPoint(CGRect rect, CGPoint point)
You can write your custom view to touch button or special view behind the topview
class MyView: UIView {
override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
for subview in self.subviews {
if subview is UIButton {
let subviewPoint = self.convertPoint(point, toView: subview)
if subview.hitTest(subviewPoint, withEvent: event) != nil { // if touch inside button view, return button to handle event
return subview
}
}
}
// if not inside button return nomal action
return super.hitTest(point, withEvent: event)
}
}
Then set your controller view to custom MyView class
By default, if you drag right from the left edge of the screen, it will drag away the ViewController and take it off the stack.
I want to extend this functionality to the entire screen. When the user drags right anywhere, I'd like the same to happen.
I know that I can implement a swipe right gesture and simply call self.navigationController?.popViewControllerAnimated(true)
However, there is no "dragging" motion. I want the user to be able to right-drag the view controller as if it's an object, revealing what's underneath. And, if it's dragged past 50%, dismiss it. (Check out instagram to see what I mean.)
Made a demo project in Github https://github.com/rishi420/SwipeRightToPopController
I've used UIViewControllerAnimatedTransitioning protocol
From the doc:
// This is used for percent driven interactive transitions, as well as for container controllers ...
Added a UIPanGestureRecognizer to the controller's view. This is the action of the gesture:
func handlePanGesture(panGesture: UIPanGestureRecognizer) {
let percent = max(panGesture.translationInView(view).x, 0) / view.frame.width
switch panGesture.state {
case .Began:
navigationController?.delegate = self
navigationController?.popViewControllerAnimated(true)
case .Changed:
percentDrivenInteractiveTransition.updateInteractiveTransition(percent)
case .Ended:
let velocity = panGesture.velocityInView(view).x
// Continue if drag more than 50% of screen width or velocity is higher than 1000
if percent > 0.5 || velocity > 1000 {
percentDrivenInteractiveTransition.finishInteractiveTransition()
} else {
percentDrivenInteractiveTransition.cancelInteractiveTransition()
}
case .Cancelled, .Failed:
percentDrivenInteractiveTransition.cancelInteractiveTransition()
default:
break
}
}
Steps:
Calculate the percentage of drag on the view
.Begin: Specify which segue to perform and assign UINavigationController delegate. delegate will be needed for InteractiveTransitioning
.Changed: UpdateInteractiveTransition with percentage
.Ended: Continue remaining transitioning if drag 50% or more or higher velocity else cancel
.Cancelled, .Failed: cancel transitioning
References:
UIPercentDrivenInteractiveTransition
https://github.com/visnup/swipe-left
https://github.com/robertmryan/ScreenEdgeGestureNavigationController
https://github.com/groomsy/custom-navigation-animation-transition-demo
Create a pan gesture recogniser and move the interactive pop gesture recogniser's targets across.
Add your recogniser to the pushed view controller's viewDidLoad and voila!
Edit: Updated the code with more detailed solution.
import os
import UIKit
public extension UINavigationController {
func fixInteractivePopGestureRecognizer(delegate: UIGestureRecognizerDelegate) {
guard
let popGestureRecognizer = interactivePopGestureRecognizer,
let targets = popGestureRecognizer.value(forKey: "targets") as? NSMutableArray,
let gestureRecognizers = view.gestureRecognizers,
// swiftlint:disable empty_count
targets.count > 0
else { return }
if viewControllers.count == 1 {
for recognizer in gestureRecognizers where recognizer is PanDirectionGestureRecognizer {
view.removeGestureRecognizer(recognizer)
popGestureRecognizer.isEnabled = false
recognizer.delegate = nil
}
} else {
if gestureRecognizers.count == 1 {
let gestureRecognizer = PanDirectionGestureRecognizer(axis: .horizontal, direction: .right)
gestureRecognizer.cancelsTouchesInView = false
gestureRecognizer.setValue(targets, forKey: "targets")
gestureRecognizer.require(toFail: popGestureRecognizer)
gestureRecognizer.delegate = delegate
popGestureRecognizer.isEnabled = true
view.addGestureRecognizer(gestureRecognizer)
}
}
}
}
public enum PanAxis {
case vertical
case horizontal
}
public enum PanDirection {
case left
case right
case up
case down
case normal
}
public class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
let axis: PanAxis
let direction: PanDirection
public init(axis: PanAxis, direction: PanDirection = .normal, target: AnyObject? = nil, action: Selector? = nil) {
self.axis = axis
self.direction = direction
super.init(target: target, action: action)
}
override public func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if state == .began {
let vel = velocity(in: view)
switch axis {
case .horizontal where abs(vel.y) > abs(vel.x):
state = .cancelled
case .vertical where abs(vel.x) > abs(vel.y):
state = .cancelled
default:
break
}
let isIncrement = axis == .horizontal ? vel.x > 0 : vel.y > 0
switch direction {
case .left where isIncrement:
state = .cancelled
case .right where !isIncrement:
state = .cancelled
case .up where isIncrement:
state = .cancelled
case .down where !isIncrement:
state = .cancelled
default:
break
}
}
}
}
In your collection view for example:
open override func didMove(toParent parent: UIViewController?) {
navigationController?.fixInteractivePopGestureRecognizer(delegate: self)
}
// MARK: - UIGestureRecognizerDelegate
extension BaseCollection: UIGestureRecognizerDelegate {
public func gestureRecognizer(
_ gestureRecognizer: UIGestureRecognizer,
shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer
) -> Bool {
otherGestureRecognizer is PanDirectionGestureRecognizer
}
}
Swift 4 version of the accepted answer by #Warif Akhand Rishi
Even though this answer does work there are 2 quirks that I found out about it.
if you swipe left it also dismisses just as if you were swiping right.
it's also very delicate because if even a slight swipe is directed in either direction it will dismiss the vc.
Other then that it definitely works and you can swipe either right or left to dismiss.
class ViewController: UIGestureRecognizerDelegate, UINavigationControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.interactivePopGestureRecognizer?.delegate = self
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
view.addGestureRecognizer(panGesture)
}
#objc func handlePanGesture(_ gesture: UIPanGestureRecognizer){
let interactiveTransition = UIPercentDrivenInteractiveTransition()
let percent = max(gesture.translation(in: view).x, 0) / view.frame.width
switch gesture.state {
case .began:
navigationController?.delegate = self
// *** use this if the vc is PUSHED on the stack **
navigationController?.popViewController(animated: true)
// *** use this if the vc is PRESENTED **
//navigationController?.dismiss(animated: true, completion: nil)
case .changed:
interactiveTransition.update(percent)
case .ended:
let velocity = gesture.velocity(in: view).x
// Continue if drag more than 50% of screen width or velocity is higher than 1000
if percent > 0.5 || velocity > 1000 {
interactiveTransition.finish()
} else {
interactiveTransition.cancel()
}
case .cancelled, .failed:
interactiveTransition.cancel()
default:break
}
}
}
The cleanest way is to subclass your navigation controller and add a directional pan gesture recognizer to its view that borrows its target/action properties from the default interaction pan gesture recognizer.
First, create a directional pan gesture recognizer that simply puts itself into a failed state if the initial gesture is not in the desired direction.
class DirectionalPanGestureRecognizer: UIPanGestureRecognizer {
enum Direction {
case up
case down
case left
case right
}
private var firstTouch: CGPoint?
var direction: Direction
init(direction: Direction, target: Any? = nil, action: Selector? = nil) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
firstTouch = touches.first?.location(in: view)
super.touchesBegan(touches, with: event)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
switch state {
case .possible:
if let firstTouch = firstTouch,
let thisTouch = touches.first?.location(in: view) {
let deltaX = thisTouch.x - firstTouch.x
let deltaY = thisTouch.y - firstTouch.y
switch direction {
case .up:
if abs(deltaY) > abs(deltaX),
deltaY < 0 {
break
} else {
state = .failed
}
case .down:
if abs(deltaY) > abs(deltaX),
deltaY > 0 {
break
} else {
state = .failed
}
case .left:
if abs(deltaX) > abs(deltaY),
deltaX < 0 {
break
} else {
state = .failed
}
case .right:
if abs(deltaX) > abs(deltaY),
deltaX > 0 {
break
} else {
state = .failed
}
}
}
default:
break
}
super.touchesMoved(touches, with: event)
}
override func reset() {
firstTouch = nil
super.reset()
}
}
Then subclass UINavigationController and perform all of the logic in there.
class CustomNavigationController: UINavigationController {
let popGestureRecognizer = DirectionalPanGestureRecognizer(direction: .right)
override func viewDidLoad() {
super.viewDidLoad()
replaceInteractivePopGestureRecognizer()
}
private func replaceInteractivePopGestureRecognizer() {
guard let targets = interactivePopGestureRecognizer?.value(forKey: "targets") else {
return
}
popGestureRecognizer.setValue(targets, forKey: "targets")
popGestureRecognizer.delegate = self
view.addGestureRecognizer(popGestureRecognizer)
interactivePopGestureRecognizer?.isEnabled = false // this is optional; it just disables the default recognizer
}
}
And then conform to the delegate. We only need the first method, gestureRecognizerShouldBegin. The other two methods are optional.
Most apps that have this feature enabled won't work if the user is in a scroll view and it's still scrolling; the scroll view must come to a complete stop before the swipe-to-pop gesture is recognized. This is not how it works with the default recognizer so the last two methods of this delegate (1) allow simultaneous gesturing with scroll views but (2) force the pop recognizer to fail when competing with the scroll view.
// MARK: - Gesture recognizer delegate
extension CustomNavigationController: UIGestureRecognizerDelegate {
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return viewControllers.count > 1
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if otherGestureRecognizer.view is UIScrollView {
return true
}
return false
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if otherGestureRecognizer.view is UIScrollView {
return true
}
return false
}
}
You need to investigate the interactivePopGestureRecognizer property of your UINavigationController.
Here is a similar question with example code to hook this up.
UINavigationController interactivePopGestureRecognizer working abnormal in iOS7
I think this is easier than the suggested solution and also works for all viewControllers inside that navigation and also for nested scrollviews.
https://stackoverflow.com/a/58779146/8517882
Just install the pod and then use EZNavigationController instead of UINavigationController to have this behavior on all view controllers inside that navigation controller.
Answers are too complicated. There is a simple solution. Add next line to your base navigation controller, or navigation controller that you want to have this ability:
self.interactivePopGestureRecognizer?.delegate = nil
Swipe Right to dismiss the View Controller
Swift 5 Version -
(Also removed the gesture recognition when swiping from right - to - left)
Important -
In ‘Attributes inspector’ of VC2, set the ‘Presentation’ value from ‘Full Screen’ to ‘Over Full Screen’. This will allow VC1 to be visible during dismissing VC2 via gesture — without it, there will be black screen behind VC2 instead of VC1.
class ViewController: UIGestureRecognizerDelegate, UINavigationControllerDelegate {
var initialTouchPoint: CGPoint = CGPoint(x: 0, y: 0)
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.interactivePopGestureRecognizer?.delegate = self
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
view.addGestureRecognizer(panGesture)
}
#objc func handlePanGesture(_ sender: UIPanGestureRecognizer) {
let touchPoint = sender.location(in: self.view?.window)
let percent = max(sender.translation(in: view).x, 0) / view.frame.width
let velocity = sender.velocity(in: view).x
if sender.state == UIGestureRecognizer.State.began {
initialTouchPoint = touchPoint
} else if sender.state == UIGestureRecognizer.State.changed {
if touchPoint.x - initialTouchPoint.x > 0 {
self.view.frame = CGRect(x: touchPoint.x - initialTouchPoint.x, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height)
}
} else if sender.state == UIGestureRecognizer.State.ended || sender.state == UIGestureRecognizer.State.cancelled {
if percent > 0.5 || velocity > 1000 {
navigationController?.popViewController(animated: true)
} else {
UIView.animate(withDuration: 0.3, animations: {
self.view.frame = CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height)
})
}
}
}
}
I have a view that has panGesture functionality, but I need to send a pan-gesture from one point to another programatically. Is there a way to do this in swift using an animation with a specific time interval? Here is my attempt at calling the pan gesture programmatically:
var upPanPoint = CGPoint(x: contentView.center.x, y: contentView.center.y + 500)
var upPan = panGestureRecognizer.setTranslation(upPanPoint, inView: self)
onSwipe(upPan)
here is the code that recognizes the pan gesture:
func onSwipe(panGestureRecognizer : UIPanGestureRecognizer!) {
let view = panGestureRecognizer.view!
print(view)
switch (panGestureRecognizer.state) {
case UIGestureRecognizerState.Began:
if (panGestureRecognizer.locationInView(view).y < view.center.y) {
self.viewState.rotationDirection = .RotationAwayFromCenter
} else {
self.viewState.rotationDirection = .RotationTowardsCenter
}
case UIGestureRecognizerState.Ended:
self.finalizePosition()
default:
let translation : CGPoint = panGestureRecognizer.translationInView(view)
view.center = self.viewState.originalCenter + translation
self.rotateForTranslation(translation, withRotationDirection: self.viewState.rotationDirection)
self.executeOnPanForTranslation(translation)
}
}
// The Pan Gesture
func createPanGestureRecognizer(targetView: UIImageView) {
var panGesture = UIPanGestureRecognizer(target: self, action:("handlePanGesture:"))
targetView.addGestureRecognizer(panGesture)
}
func handlePanGesture(panGesture: UIPanGestureRecognizer) {
// get translation
var translation = panGesture.translationInView(view)
panGesture.setTranslation(CGPointZero, inView: view)
println(translation)
// create a new Label and give it the parameters of the old one
var label = panGesture.view as UIImageView
label.center = CGPoint(x: label.center.x+translation.x, y: label.center.y+translation.y)
label.multipleTouchEnabled = true
label.userInteractionEnabled = true
if panGesture.state == UIGestureRecognizer.State.began {
// add something you want to happen when the Label Panning has started
}
if panGesture.state == UIGestureRecognizer.State.ended {
// add something you want to happen when the Label Panning has ended
}
if panGesture.state == UIGestureRecognizer.State.changed {
// add something you want to happen when the Label Panning has been change ( during the moving/panning )
} else {
// or something when its not moving
}
}
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(self.panGesture))
self.imageView.addGestureRecognizer(panGesture)
#objc func panGesture(sender: UIPanGestureRecognizer){
let point = sender.location(in: view)
let panGesture = sender.view
panGesture?.center = point
print(point)
}
With Swift version 4.2 you can set pan gesture programmatically using below code:
let panGesture = UIPanGestureRecognizer(target: self, action:(#selector(self.handleGesture(_:))))
self.view.addGestureRecognizer(panGesture)
#objc func handleGesture(_ sender: UIPanGestureRecognizer) {
switch sender.state {
case .began:
case .changed:
case .cancelled:
case .ended:
default:
break
}
}