Having some issues getting this to override its superclass - keep getting the error "method does not override any method from its superclass". The collection view and the pan is all set-up, I just want to disable sideways panning (if that's a word).
I'm sticking this right at the bottom of my class:
override func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
if let panGestureRecognizer = gestureRecognizer as? UIPanGestureRecognizer {
let translation = panGestureRecognizer.translationInView(collectionView!)
if fabs(translation.y) > fabs(translation.x) {
return true
}
return false
}
return false
}
Any ideas? I'll post my jazzy collectionview and it's panning-abilities as a rewards for those that contribute.
You can't override that method because it's not part of your superclass (UICollectionView). You need to adopt the UIGestureRecognizerDelegate protocol in your class and remove the override.
Assuming you've created a UIPanGestureRecognizer, either in storyboard or programatically, you need to set the delegate of that UIPanGestureRecognizer to self whenever your view loads.
Also, don't forget to add the panRecognizer to your collection view.
panGesture.delegate = self
collectionView.addGestureRecognizer(panGesture)
Related
I have a problem where I have a UIScrollView and a Header (UIView) inside my main View and my Header is over my UIScrollView as such:
UIView.
|
|- UIScrollView.
|
|- Header. (UIView)
I want my header to be able to detect taps on it, but I also want my scroll view to be able to scroll when I drag over my Header which right now it is not possible because my Header is over it and is blocking the scroll.
To sum up, I want my Header to detect taps but forward scrolls to my UIScrollView.
To tackle this problem I tried multiple things, and here are some of them:
Adding a UIPanGestureRecognizer to my Header so it is able to detect dragging
Adding a UITapGestureRecognizer to my Header so it is able to detect tapping
Setting isUserInteractionEnabled = false when dragging begins so the gesture can be passed to the next UIResponder which in this case is my UIScrollView
Setting isUserInteractionEnabled = true once my dragging has finished so it can again detect tapping
This is the code snippet:
override func viewLoad() {
myScreenEdgePanGestureRecognizer = UIPanGestureRecognizer(target: self, action:#selector(handlePan))
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action:#selector(handleTap(_:)))
headerView.addGestureRecognizer(myScreenEdgePanGestureRecognizer)
headerView.addGestureRecognizer(tapGestureRecognizer)
}
#objc func handlePan(_ sender: UITapGestureRecognizer){
print("dragging")
if headerView.isUserInteractionEnabled{
headerView.isUserInteractionEnabled = false
}
if sender.state == .began {
} else if sender.state == .ended {
headerView.isUserInteractionEnabled = true
}
}
#objc func handleTap(_ sender: UITapGestureRecognizer){
print("tapped")
}
At this point I see how dragging and tapping are being detected just fine, but for some reason isUserInteractionEnabled = false seems to not be changing how the view is behaving. This code is acting as isUserInteractionEnabled is always true no mater what.
Things that I have also tried besides this:
overriding the hitTest function inside UIButton
overriding touchesBegan, touchesMoved, touchesEnded methods overriding next
setting the variable to return ScrollView as the next UIResponder
setting the isExclusiveTouch method in UIButton
changing the isUserInteractionEnabled in every way possible
I was struggling with this problem too, you should try to use methods of UIGestureRecognizerDelegate which allows you to handle simultaneous gestures.
Connect your gesture recognizers delegates e.g. tapGestureRecognizer.delegate = self
Make your ViewController conform this protocol e.g.
extension YourViewController: UIGestureRecognizerDelegate {}
Implement this function:
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool { return true }
I placed a small UIView inside a UITableViewCell.
In case of a tapping on such UIView, I would like to open a popup.
In case of a tapping outside such UIView, I would like to perform what it's defined in the UITableView "didSelectRowAtIndexPath" function.
What it's happening at the moment is that when I click on the view both things happen: the popup is opened and the "didSelectRowAtIndexPath" function is trigged.
How can I make sure that when I click on that UIView the "didSelectRowAtIndexPath" function is not triggered?
current implementation:
I defined a UITapGestureRecognizer for the UIView inside my custom UITableViewCell class.
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(MyCustomTableViewCell.clickOnHelp(_:)))
myClickAreaUIView.addGestureRecognizer(tapGesture)
The best solution I suggest is to change the UIView to a UIButton and handle the touch with a touchUpInside on the button.
This way you will reach your objective, as UIButton automatically prevents touch event forwarding to superview
Try setting the inner view's exclusiveTouch property to true.
cell.tapView.exclusiveTouch = true
You should use this method from UIGestureRecognizerDelegate
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return false
}
Create a customClass for your UIView lets say CustomView of type UIView
Connect your UIView's #IBOutlet conforming to tableViewCell of type CustomView
In CustomView class call this function
override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
super.pointInside(point, withEvent: event)
return CGRectContainsPoint(self.bounds, point)
}
This will tell you whether or not the location at which user tapped was contained inside that UIView bounds or not, if it returns true do pop up in your UIGestureRecognizer functions and follow https://stackoverflow.com/a/18606840/6297658 , if false do the opposite
I suggest to implement the following method of UIGestureRecognizerDelegate like below
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
print("in shouldReceiveTouch")
gestureRecognizer.delegate = self
if ([...]){ // touch location is in the UIView
print("touching UIView")
return false // prevent from forwarding touch to superview
} else {
println("touching elsewhere")
return true
}
}
just write this code inside cellForRowAtIndexPath() for did select prevent::
cell.selectionStyle = UITableViewCellSelectionStyle.None
I've got a tableView inside of a pageViewController and when swiping on a cell to bring up the option to delete the cell the gesture is only recognized under certain circumstances, say you swiped very quickly and aggressively.
I imagine this is happening because it's not sure whether the swiping gesture is meant for the pageView or the tableView. Is there a way to specifically determine where the swipe gesture is happening to enable a nice smooth display of the delete button?
Theory:
Both UIPageViewController and UITableView are implemented using UIScrollView, where UIPageViewController embeds UIScrollView and UITableView is a subclass of UIScrollView
UITableView also uses a couple of UIPanGestureRecognizers to bring in all the magic. One of these is UISwipeActionPanGestureRecognizer which handles the swipe to delete actions.
This issue is caused because UIPageViewControllers UIPanGestureRecognizer wins in the conflict with the UITableViews UISwipeActionPanGestureRecognizers.
So we have to some how tell UIPageViewController to ignore gestures if UITableViews UISwipeActionPanGestureRecognizer are in action.
Luckily there is something already provided by UIGestureRecognizer.
UIGestureRecognizer's require(toFail otherGestureRecognizer: UIGestureRecognizer) creates a relation between the two gesture recognizers that will prevent the gesture's actions being called until the other gesture recognizer fails.
So all we had to do is fail UIPageViewControllers embedded UIScrollviews panGestureRecognizer when UITableViews UISwipeActionPanGestureRecognizer are triggered.
There are two ways you could achieve this.
Solution 1: Add a new gesture recognizer to table view and Mimic UISwipeActionPanGestureRecognizer. And make UIPageViewController panGesture require to fail this new gestureRecognizer
Solution 2 (A bit dirty): Make a string comparision to the UITableView's UISwipeActionPanGestureRecognizer and make UIPageViewController panGesture require to fail this new gestureRecognizer
Code:
Solution 1
A helpful utility to get UIPageViewControllers embedded UIScrollView
extension UIPageViewController {
var scrollView: UIScrollView? {
return view.subviews.first { $0 is UIScrollView } as? UIScrollView
}
}
Add the below code to UIViewController holding the UITableView and call it from viewDidLoad()
func handleSwipeDelete() {
if let pageController = parent?.parent as? UIPageViewController {
let gestureRecognizer = UIPanGestureRecognizer(target: self, action: nil)
gestureRecognizer.delaysTouchesBegan = true
gestureRecognizer.cancelsTouchesInView = false
gestureRecognizer.delegate = self
tableView.addGestureRecognizer(gestureRecognizer)
pageController.scrollView?.canCancelContentTouches = false
pageController.scrollView?.panGestureRecognizer.require(toFail: gestureRecognizer)
}
}
And finally delegate methods
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
guard let panGesture = gestureRecognizer as? UIPanGestureRecognizer else {
return false
}
let translation = panGesture.translation(in: tableView)
// In my case I have only trailing actions, so I used below condition.
return translation.x < 0
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return otherGestureRecognizer.view == tableView
}
Solution 2 (A bit dirty)
A helpful utility to get UIPageViewControllers embedded UIScrollView
extension UIPageViewController {
var scrollView: UIScrollView? {
return view.subviews.first { $0 is UIScrollView } as? UIScrollView
}
}
Add the below code to UIViewController holding the UITableView and call it from viewDidLoad()
func handleSwipeDelete() {
guard let pageController = parent as? UIPageViewController else {
return
}
pageController.scrollView?.canCancelContentTouches = false
tableView.gestureRecognizers?.forEach { recognizer in
let name = String(describing: type(of: recognizer))
guard name == "_UISwipeActionPanGestureRecognizer" else {
return
}
pageController.scrollView?
.panGestureRecognizer
.require(toFail: recognizer)
}
}
I had the same problem. I found a solution that works well.
Put this in your UIPageViewController's viewDidLoad func.
if let myView = view?.subviews.first as? UIScrollView {
myView.canCancelContentTouches = false
}
PageViewControllers have an auto-generated subview that handles the gestures. We can prevent these subviews from cancelling content touches. The tableview will be able to capture swipes for the delete button, while still interpreting swipes that fail the tableview's gesture requirements as page swipes. The delete button will show in cases where you hold and swipe or swipe "aggressively."
You can set delaysContentTouches to false on the tableView itself as well. This solution worked for my collection view's UISlider elements.
See Swift 4.0 code below:
yourTableView.delaysContentTouches = false
I have found a working solution by reassigning UIScrollView's panGestureRecognizer's delegate to my class and ignoring the original delegate when a right-to-left pan is detected. I used method swizzling for that.
Please check my sample project: https://github.com/kambala-decapitator/SwipeToDeleteInsidePageVC
In case you have a tableView in the first or the last viewController inside of your UIPageViewController maybe think of disabling the bouncing at the end of your UIPageViewController first and then implement this solution.
In case you don't know how to disable the bounce of the UIPageViewController, check out my answer here.
I would like to assign a unique behaviour for two-finger swipe on WKWebView.
Referring to this site, I wrote codes as below. It worked, but scrolling on webview got extremely slow.
Is there any better way to do it by avoiding slow scrolling?
let doubleSwipeGestureRecognizer = UISwipeGestureRecognizer.init(target: self, action: "doubleSwiped2")
doubleSwipeGestureRecognizer.numberOfTouchesRequired = 2
doubleSwipeGestureRecognizer.direction = UISwipeGestureRecognizerDirection.Up
self.webView!.addGestureRecognizer(doubleSwipeGestureRecognizer)
for gesture in self.webView!.scrollView.gestureRecognizers!{
let gestureClass = gesture.classForCoder
let gestureName = NSStringFromClass(gestureClass)
print(gestureName)
if gestureName.containsString("Swipe"){
// do nothing
} else {
gesture.requireGestureRecognizerToFail(doubleSwipeGestureRecognizer)
}
}
Perhaps this codes suits for your demand.
First, you set self to delegate of recognizer.
doubleSwipeGestureRecognizer.delegate = self
Second, you writes a method of UIGestureRecognizerDelegate in self class.
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailByGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if otherGestureRecognizer is UIPanGestureRecognizer && otherGestureRecognizer.numberOfTouches() == 2 {
return true
}
return false
}
Third, you delete 'for' sentence.
for gesture in self.webView!.scrollView.gestureRecognizers! {
…
}
I have a uipageviewcontroller and the pages have an area on the screen where there is a uitableview. I want the user to only be able to swipe through pages outside of that uitableview.
I can't seem to find where these gesture recognizers are hiding. I am setting them up as delegates like this:
self.view.gestureRecognizers = self.pageViewController?.gestureRecognizers
for gesture in self.view.gestureRecognizers!{
// get the good one, i discover there are 2
if(gesture is UIPanGestureRecognizer)
{
println("ispan")
// replace delegate by yours (Do not forget to implement the gesture protocol)
(gesture as! UIPanGestureRecognizer).delegate = self
}
}
I am seeing ispan in the logs so it seems to find some uipangesturerecognizer but when I override the function like this:
func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
println("gesture should begin")
var point = gestureRecognizer.locationInView(self.view)
return true
}
it doesn't print out "gesture should begin" at all... I have the class set as a UIGestureRecognizerDelegate what am I doing wrong? I'm guessing I have the wrong gesture recognizers set as delegates how can I set the correct ones as delegates?
Could something like this work?
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
if(touch.view == <your tableView>){
return false
}else{
return true
}
}
You might need to also test which gestureRecognizer it is (the one from the pageView or the one from the tableView).