How to Disable Multi Touch on UIBarButtonItems & UI Buttons? - swift

My app has quite a few buttons on each screen as well as a UIBarButtonItem back button and I have problems with people being able to multi click buttons. I need only 1 button to be clickable at a time.
Does anyone know how to make a UIBarButtonItem back button exclusive to touch?
I've managed to disable multi clicking the UIButtons by setting each one's view to isExclusiveTouch = true but this doesn't seem to count for the back button in the navigation bar.
The back button doesn't seem to adhere to isExclusiveTouch.
Does anyone have a simple work around that doesn't involve coding each and every buttons send events?
Many Thanks,
Krivvenz.

you can enable exclusive touch simply this will stop multiple touch until first touch is not done
buttton.exclusiveTouch = true

You could write an extension for UIBarButtonItem to add isExclusiveTouch?

you can simply disable the multi-touch property of the super view. You can also find this property in the storyboard.

you could try this for the scene where you want to disable multiple touch.
let skView = self.view as! SKView
skView.isMultipleTouchEnabled = false

I have found a solution to this. isExclusiveTouch is the solution in the end, but the reason why this property didn't do anything is because you need to set it also on all of the subviews of each button that you want to set as isExclusiveTouch = true. Then it works as expected :)

It's working fine in Swift
self.view.isMultipleTouchEnabled = false
buttonHistory.isExclusiveTouch = true

In addition of #Luky Lízal answer, you need pay attention that all subviews of a view you want disable multi-touching (exactly all in hierarchy, actually subviews of subviews) must be set as isExclusiveTouch = true.
You can run through all of them recursively like that:
extension UIView
{
func allSubViews() -> [UIView] {
var all: [UIView] = []
func getSubview(view: UIView) {
all.append(view)
guard view.subviews.count > 0 else { return }
view.subviews.forEach{ getSubview(view: $0) }
}
getSubview(view: self)
return all
}
}
// Call this method when all views in your parent view were set
func disableMultipleTouching() {
self.isMultipleTouchEnabled = false
self.allSubViews().forEach { $0.isExclusiveTouch = true }
}

Related

Swift - Programmatically refresh constraints

My VC starts with stackView attached with Align Bottom to Safe Area .
I have tabBar, but in the beginning is hidden tabBar.isHidden = true.
Later when the tabBar appears, it hides the stackView
So I need function that refresh constraints after tabBar.isHidden = false
When I start the app with tabBar.isHidden = false the stackView is shown properly.
Tried with every function like: stackView.needsUpdateConstraints() , updateConstraints() , setNeedsUpdateConstraints() without success.
Now I'm changing the bottom programatically, but when I switch the tabBarIndex and return to that one with changed bottom constraints it detects the tabBar and lifts the stackView under another view (which is not attached with constraints). Like is refreshing again the constraints. I'm hiding and showing this stackView with constrains on/off screen.
I need to refresh constraints after tabBar.isHidden = false, but the constraints don't detect the appearance of the tabBar.
As I mention switching between tabBars fixes the issue, so some code executes to detecting tabBar after the switch. Is anyone know this code? I tried with calling the methods viewDidLayoutSubviews and viewWillLayoutSubviews without success... Any suggestions?
This amateur approach fixed my bug... :D
tabBarController!.selectedIndex = 1
tabBarController!.selectedIndex = 0
Or with an extension
extension UITabBarController {
// Basically just toggles the tabs to fix layout issues
func forceConstraintRefresh() {
// Get the indices we need
let prevIndex = selectedIndex
var newIndex = 0
// Find an unused index
let items = viewControllers ?? []
find: for i in 0..<items.count {
if (i != prevIndex) {
newIndex = i
break find
}
}
// Toggle the tabs
selectedIndex = newIndex
selectedIndex = prevIndex
}
}
Usage (called when switching dark / light mode):
override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
super.traitCollectionDidChange(previousTraitCollection)
tabBarController?.forceConstraintRefresh()
}
If you want to update view's layout, you can try layoutIfNeeded() function.
after updating stackView constraints call this method:
stackView.superview?.layoutIfNeeded()
Apple's Human Interface Guidelines indicate that one should not mess around with the Tab Bar, which is why (I'm guessing) setting tabBar.isHidden doesn't properly update the rest of the view hierarchy.
Quick searching comes up with various UITabBarController extensions for showing / hiding the tab bar... but they all appear to push the tabBar down off-screen, rather than setting its .isHidden property. May or may not be suitable for your use.
I'm assuming from your comments that your VC in tab index 0 has a button (or some other action) to show / hide the tabBar?
If so, here is an approach that may do the job....
Add this enum in your project:
enum TabBarState {
case toggle, show, hide
}
and put this func in that view controller:
func showOrHideTabBar(state: TabBarState? = .toggle) {
if let tbc = self.tabBarController {
let b: Bool = (state == .toggle) ? !tbc.tabBar.isHidden : state == .hide
guard b != tbc.tabBar.isHidden else {
return
}
tbc.tabBar.isHidden = b
view.frame.size.height -= 0.1
view.setNeedsLayout()
view.frame.size.height += 0.1
}
}
You can call it with:
// default: toggles isHidden
showOrHideTabBar()
// toggles isHidden
showOrHideTabBar(state: .toggle)
// SHOW tabBar (if it's hidden)
showOrHideTabBar(state: .show)
// HIDE tabBar (if it's showing)
showOrHideTabBar(state: .hide)
I would expect that simply pairing .setNeedsLayout() with .layoutIfNeeded() after setting the tabBar's .isHidden property should do the job, but apparently not.
The quick frame height change (combined with .setNeedsLayout()) does trigger auto-layout, though, and the height change is not visible.
NOTE: This is the result of very brief testing, on one device and one iOS version. I expect it will work across devices and versions, but I have not done complete testing.

Prefer Large Titles and RefreshControl not working well

I am using this tutorial to implement a pull-to-refresh behavior with the RefreshControl. I am using a Navigation Bar. When using normal titles everything works good. But, when using "Prefer big titles" it doesn't work correctly as you can see in the following videos. Anyone knows why? The only change between videos is the storyboard check on "Prefer Large Titles".
I'm having the same problem, and none of the other answers worked for me.
I realised that changing the table view top constraint from the safe area to the superview fixed that strange spinning bug.
Also, make sure the constant value for this constraint is 0 🤯.
At the end what worked for me was:
In order to fix the RefreshControl progress bar disappearing bug with large titles:
self.extendedLayoutIncludesOpaqueBars = true
In order to fix the list offset after refreshcontrol.endRefreshing():
let top = self.tableView.adjustedContentInset.top
let y = self.refreshControl!.frame.maxY + top
self.tableView.setContentOffset(CGPoint(x: 0, y: -y), animated:true)
If you were using tableView.tableHeaderView = refreshControl or tableView.addSubView(refreshControl) you should try using tableView.refreshControl = refreshControl
It seems there are a lot of different causes that could make this happen, for me I had a TableView embedded within a ViewController. I set the top layout guide of the tableview to the superview with 0. After all of that still nothing until I wrapped my RefreshControl end editing in a delayed block:
DispatchQueue.main.async {
if self.refreshControl.isRefreshing {
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
self.refreshControl.endRefreshing()
})
}
}
The only working solution for me is combining Bruno's suggestion with this line of code:
tableView.contentInsetAdjustmentBehavior = .always
I've faced the same problem. Call refreshControl endRefreshing before calling further API.
refreshControl.addTarget(controller, action: #selector(refreshData(_:)), for: .valueChanged)
#objc func refreshData(_ refreshControl: UIRefreshControl) {
refreshControl.endRefreshing()
self.model.loadAPICall {
self.tableView.reloadData()
}
}
The only solution that worked for me using XIBs was Bruno's one:
https://stackoverflow.com/a/54629641/2178888
However I did not want to use a XIB. I struggled a lot trying to make this work by code using AutoLayout.
I finally found a solution that works:
override func loadView() {
super.loadView()
let tableView = UITableView()
//configure tableView
self.view = tableView
}
I had this issue too, and i fixed it by embedded my scrollView (or tableView \ collectionView) inside stackView, and it's important that this stackView's top constraint will not be attached to the safeArea view (all the other constraints can). the top constraint should be connect to it's superview or to other view.
I was facing the same issue for very long, the only working solution for me was adding refresh control to the background view of tableview.
tableView.backgroundView = refreshControl
Short Answer
I fixed this by delaying calling to API until my collection view ends decelerating
Long Answer
I notice that the issue happens when refresh control ends refreshing while the collection view is still moving up to its original position. Therefore, I delay making API call until my collection view stops moving a.k.a ends decelerating. Here's a step by step:
Follow Bruno's suggestion
If you set your navigation bar's translucent value to false (navigationBar.isTranslucent = false), then you will have to set extendedLayoutIncludesOpaqueBars = true on your view controller. Otherwise, skip this.
Delay api call. Since I'm using RxSwift, here's how I do it.
collectionView.rx.didEndDecelerating
.map { [unowned self] _ in self.refreshControl.isRefreshing }
.filter { $0 == true }
.subscribe(onNext: { _ in
// make api call
})
.disposed(by: disposeBag)
After API completes, call to
refreshControl.endRefreshing()
Caveat
Do note that since we delay API call, it means that this whole pull-to-refresh process is not as quick as it could have been done without the delay.
Unfortunately, no advice helped. But I found a solution that helped me. Setting the transparency of the navigation bar helped.enter image description here
Problem can be solved if add tableview or scroll view as root view in UIViewController hierarchy (like in UITableViewController)
override func loadView() {
view = customView
}
where customView is UITableView or UICollectionView

Tap gesture on UILabel beside a UIPageControl not working

I have a UILabel on both sides of a UIPageControl, as pictured below:
I found that tapping on the sides of the UIPageControl the dot would progress, ie not on my arrows and not triggering a method of mine. But nothing else would change, so I set isUserInteractionEnabled to false on the UIPageControl.
I connected (via UITapGestureRecognizer) another UILabel above and it launches a method fine.
However the UILabels, beside the UIPageControl, will not work. NOTE: I do have isUserInteractionEnabled set to true on this element. (I even temporarily changed the element to a UIButton and it wouldn't work either - so I reverted back to my UILabel.)
So, is there a way to add a UILabel to the side of a UIPageControl that gets triggered? Alternately, can the invisible objects (while tapping on the left or right of the UIPageControl - like in my second sentence) be connected to a custom method?
UPDATE:
I've added another separate modal (same title label, buttons, but no collection view and no page control). Again it won't respond when I press the label in the centre, but I temporarily am using the title label which responses and launches my method fine.
Can anyone say why?
I solved the issue!
I was declaring most variables - as well as the UILabel - in closures blocks, at the top of the class, like below:
let myLabel: UILabel = {
{
let view = UILabel()
view.translatesAutoresizingMaskIntoConstraints = false
view.isUserInteractionEnabled = true
view.textColor = UIColor.blue
return view
}
Within this closure I had view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(doMyLabelMethod(_:)))) and view.isUserInteractionEnabled = true, when I moved them out of the closure and placed them directly above addSubview(myLabel) it fired fine.
So variable-closures are good to contain many dressing, but not gesture recognizers!

Swift iOS -How to Add Subview to Window's Center?

I have an activity indicator that gets presented on an iPhone and iPad. In the iPad in split screen mode it gets presented to whichever side of the view that called it. I would instead like it to get presented in the middle/center the window's screen. If I do it this way wether on the iPhone in portrait or iPad in split screen mode it will always be in the center of the screen.
How do I do this?
MyView: UIViewController{
let actInd = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)
#IBAction fileprivate func buttonPressed(_ sender: UIButton) {
guard let window = UIApplication.shared.keyWindow else { return }
//how to add actInd as subview to the window' screen?
actInd.startAnimating()
}
}
It's pretty simple. Turn off the auto-resizing mask. Add the add actInd to window, then set the center anchors.
actInd.translatesAutoresizingMaskIntoConstraints = false
window.addSubview(actInd)
actInd.centerXAnchor.constraint(equalTo: window.centerXAnchor).isActive = true
actInd.centerYAnchor.constraint(equalTo: window.centerYAnchor).isActive = true
Window is subclass of UIView. Just add it as it's subview like you're adding a view to another view. But remember that window is shared throughout your app, so adding it every-time will consume memory, remove it after your job is done.
If you want to center it in the window, you can use autoResizingMask or add constraints to it.

Add custom recognizer delay

I've disabled delaysContentTouches in my tableview subclass using:
delaysContentTouches = false
subviews.forEach { ($0 as? UIScrollView)?.delaysContentTouches = false }
But in one of my sections, I still want to keep the delay. Is there a way to cancel the delay for certain sections or perhaps I can add a custom recognizer delay to a section?
Sections are not actual objects within a tableView, so my answer to your first question is no. The .delaysContentTouches applies to the entire tableView.
For your second inquiry, I believe that one way it could be possible is through setting a delay for desired cells' scrollView subview. In your tableView(cellForRowAt: indexPath) func, you could have something like this:
if indexPath.section == 3 { //or whatever your desired section is
for view in cell.subviews {
if view is UIScrollView {
let currentView = view as! UIScrollView
currentView.delaysContentTouches = true
}
}
}
This will find the UIScrollView in your cell's subviews in your desired section. It will then set the .delaysContentTouches property accordingly.
I have not personally executed this code, just researched it, so let me know if it works.
Edit
Apparently the UIScrollView in UITableViewCell has been deprecated, so the above method will not work anymore.
My next best suggestion to you is to use a UILongPressGuestureRecognizer. This will not be quite the same thing as delaying the touch, but could have a similar effect in real execution.
You could use it in the same tableView(cellForRowAt: indexPath) func as so:
let press = UILongPressGestureRecognizer(target: self, action: #selector(handlePress))
press.minimumPressDuration = 2.0 //however long you want
cell.addGestureRecognizer(press)
Whatever you are trying to achieve by selecting certain rows of your tableView could be placed in the handlePress func above which would be trigged upon the long press.