Remove View and Reference in Array - ios

Currently working on an video conferencing app where we add/remove subviews that have a video/OpenGL display when users join or leave. We keep track of the views in an array in the class. We're getting a BAD_ACCESS in GL ASM code when we remove the subview and also the array reference. Commenting out the self.streams.remove(at: index) will cause it to work.
func add(stream: StreamType, withView streamView: StreamViewType? = nil) -> Bool {
if !self.has(streamId: stream.streamId) {
let view = streamView ?? StreamViewType(stream: stream, userId: self.userId, delegate: self)
let insertAt = view.stream.isLocal ? self.streams.count : 0
self.streams.append(view)
self.streamViews.insertSubview(view as! UIView, at: insertAt)
self.delegate?.layoutManager(layoutOnly: true)
return true
}
return false
}
func remove(streamId: String?) -> StreamViewType? {
if let index = self.indexOf(streamId: streamId) {
let streamView = self.streams[index]
streamView.removeFromSuperview()
self.streams.remove(at: index)
self.delegate?.layoutManager(layoutOnly: true)
return streamView
}
return nil
}
It seems to be a race condition of some sort. Any ideas?

Its seems to be an error in you openGL code when deallocating your view.
How is StreamViewType implemented?
Did you tear down the EAGLContext when deallocating your view?

Related

RxSwift subscriptions after didBecomeActive

I've written module based on RxSwift with Viewcontroller and ViewModel. ViewModel contains gesture's observers and images observables. Everything works well, except situation when application didBecameActive directly to mentioned module. Subscriptions of gestures don't work and imageView become blank.
They are set inside subscription to observable based on BehaviorSubjects, inside view:
func subscribePhotos(observerable: Observable<[(Int, UIImage?)]>) {
disposeBag = DisposeBag()
observerable.subscribeOnNext { [weak self] array in
array.forEach { identifier, image in
if let pictureView = self?.subviews.first(where: { view -> Bool in
guard let view = view as? PictureView else {
return false
}
return view.identifier == identifier
}) as? PictureView {
pictureView.set(image)
}
}
}.disposed(by: disposeBag)
}
In viewModel I set Observable:
var imagesObservable: Observable<[(Int, UIImage?)]> {
do {
let collection = try photosSubject.value()
if let photosObservables = collectionCreator?.getPhotosDetailsObservables(identifiers: collection.photoIdentifiers) {
let photosObservable = Observable.combineLatest(photosObservables)
return Observable.combineLatest(photosSubject, photosObservable,
resultSelector: { collection, currentArray -> [(Int, UIImage?)] in
var newArray = [(Int, UIImage?)]()
currentArray.forEach { stringIdentifier, image in
if let picture = grid.pictures.first(where: { $0. stringIdentifier == stringIdentifier }) {
newArray.append((picture.identifier, image))
}
}
return newArray
})
}
} catch { }
return Observable<[(Int, UIImage?)]>.never()
}
}
photosSubject is initialized in viewModel's init
photosSubject = BehaviorSubject<PictureCollection>(value: collection)
photosObservale
func createImageObservableForAsset(asset: PHAsset, size: CGSize) -> Observable<UIImage?> {
return Observable.create { obs in
PHImageManager.default().requestImage(for: asset,
targetSize: size,
contentMode: .aspectFit,
options: nil,
resultHandler: { image, _ in
obs.onNext(image)
})
return Disposables.create()
}
}
And in ViewController I connect them by calling method of view:
myView.pictureView.subscribePhotos(observerable: viewModel.imagesObservable)
After didBecameActive pictureView's property image of type UIImage isn't nil, but they disappear. I could listen notification didBecameActive and invoke onNext on observer, but I’m not sure is it correct way to figure out problem. Any idea what's reason of that?
Finally, I solved out this issue. Reason wasn't connected with Rx. Method drawing pictures draw(_:CGRect) was called after didBecomeActive and cleared myView. I changed method's body and now everything works well :)

Why does data returned from coredata become nil after tableview scroll in swift?

Update Note: This question does not seem to be a duplicate of How can I fix crash when tap to select row after scrolling the tableview? because my issue is specifically about one of my CoreData objects going nil after the table scrolls. But the cell returns data as long as the app doesnt crash due to the nil from the topic object.
Basically this part fails: let estimatedSkills = topic.topicEstimatedSkill and let topic = self.topics!.object(at: indexPath.row) as! Topic even though at first, a debugprint shows that the object is not nil, after scroll, self.topic becomes nil.
Original:
I hope you can help me because I am a beginner in Swift and apple development in general.
I inherited an ios app that didnt work because the structure of data returned from our server changed. The previous developers cant be reached, so I am trying to make out what to do here. On top of that, in the middle of development, apple forced me to update to swift3 and xcode8 changing the gamerules making everything even more confusing.
So basically I have a tableview that gets data from an object fetched from CoreData. It fills out the cells when initiated, but scrolling makes the data from the object return nil.
The object in question is named Topic
and the code fails at:
//TODO - this sometimes gives nil but shouldnt
if let estimatedSkills = topic.topicEstimatedSkill {
value = estimatedSkills.doubleValue * Double(cell.starViewContainer.subviews.count);
debugPrint("success getting estimated skills!" , indexPath, estimatedSkills)
} else {
debugPrint("Didnt get estimated skills :(")
}
Then when I return to the original cells, the info in those are gone too.
Here's the tableview function:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: Identifiers.cells.superTrainer.rawValue, for: indexPath) as! SuperTrainerOverViewCell;
cell.backgroundColor = UIColor.clear;
let topic = self.topics!.object(at: indexPath.row) as! Topic;
cell.titleLabel.text = topic.topicName;
var value = 0.0
//TODO - this sometimes gives nil but shouldnt
if let estimatedSkills = topic.topicEstimatedSkill {
value = estimatedSkills.doubleValue * Double(cell.starViewContainer.subviews.count);
debugPrint("success getting estimated skills!" , indexPath, estimatedSkills)
} else {
debugPrint("Didnt get estimated skills :(")
}
let wholeStar = Int(floor(value));
for index in (0..<wholeStar) {
let imageView = cell.starViewContainer.subviews[index] as! UIImageView;
imageView.image = UIImage(named: "icon-star-100");
}
if(wholeStar < cell.starViewContainer.subviews.count) {
let decimal = fmod(value, 1);
var image = UIImage(named: "icon-star-100");
if(decimal < 0.15) {
image = UIImage(named: "icon-star-0");
}else if(decimal >= 0.15 && decimal < 0.4) {
image = UIImage(named: "icon-star-25");
}else if(decimal >= 0.4 && decimal < 0.65) {
image = UIImage(named: "icon-star-50");
}else if(decimal >= 0.65 && decimal < 0.80) {
image = UIImage(named: "icon-star-75");
}
let imageView = cell.starViewContainer.subviews[wholeStar] as! UIImageView;
imageView.image = image;
}
return cell;
}
The class has a topics property which gets set at:
override func viewDidLoad() {
self.navigationItem.title = "SUPERTRAINER".localized;
self.tableView.backgroundColor = UIColor.init(rgba: hexColors.gray.rawValue);
if(Utility.isConnectedToNetwork()) {
self.getSuperTrainerData(student: self.student!);
} else {
self.topics = Topic.getTopics(student: self.student!, context: NetworkService.sharedInstance.coreDataHandler.context!);
Utility.showNoConnectionAlertView();
}
self.tableView.tableFooterView = UIView(frame: CGRect.zero);
}
// MARK: Custom Methods
func getSuperTrainerData(student: Student) {
_ = SwiftSpinner.show("FETCHING_DATA".localized);
Utility.backgroundThread( background: { () -> Void in
self.networkService.getSuperTrainerData(student: student) { (complet, returnDics, errorMessage) -> Void in
if(complet) {
self.removeSuperTrainerData();
self.createSuperTrainerData(dics: returnDics!);
} else {
Utility.showAlertView(title: "LOGIN_FAILED_TITLE".localized, message: errorMessage);
}
}
}) { () -> Void in
self.networkService.coreDataHandler.saveContext();
self.topics = Topic.getTopics(student: self.student!, context:self.networkService.coreDataHandler.context!)!;
SwiftSpinner.hide();
self.tableView.reloadData();
}
}
Anyone have any ideas? :) Im too new at swift to figure out all of this quickly right now, so any help is super appreciated!
I found out eventually that it was actually a threading(concurrence) problem.
Basically, in the getSuperTrainerData function, a bunch of objects were supposed to be created. Given that they returned nill all the time, the ViewController would of course refuse to create the rows.. however, entering the same view twice would have given the app time to store and cache the objects returned from a network call.
I make a call to Utility.backgroundThread which is just a wrapper for dispatchQueue. This means that networkService was placed inside a background thread. But inside networkService there is a call to urlSession. Call to servers create their own background threads, so even though I called my server call throuhg a background thread, it created its own background thread and never returned to the main call.
The solution that I used was to just make a server call, and place the background-object-creation call in the completion handler like so:
self.networkService.getSuperTrainerData(student: student) { (complet, returnDics, errorMessage) -> Void in
if(complet) {
DispatchQueue.global(qos: DispatchQoS.userInitiated.qosClass ).async {
self.removeSuperTrainerData();
self.createSuperTrainerData(dics: returnDics!);
DispatchQueue.main.async( execute: {
print("main queue without completion")
self.networkService.coreDataHandler.saveContext();
self.topics = Topic.getTopics(student: self.student!, context:self.networkService.coreDataHandler.context!)!;
SwiftSpinner.hide();
self.tableView.reloadData();
})
}
} else {
Utility.showAlertView(title: "LOGIN_FAILED_TITLE".localized, message: errorMessage);
}
}
Hope this helps someone :)

How to stop viewWillAppear from completing until a function has finished

I'm pretty new to IOS Application Development.
I'm trying to stop viewWillAppear from finishing until after my function has finished working. How do I do that?
Here's viewWillAppear:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
checkFacts()
if reset != 0 {
print("removing all bird facts")
birdFacts.removeAll()
}
}
func checkFacts() {
let date = getDate()
var x: Bool = true
var ind: Int = 0
print("count is ", birdFacts.count)
while ind < birdFacts.count {
print("accessing each bird fact in checkFacts")
let imageAsset: CKAsset = birdFacts[ind].valueForKey("birdPicture") as! CKAsset
let image = UIImage(contentsOfFile: imageAsset.fileURL.path!)
print(image)
if image == nil {
if (birdFacts[ind].valueForKey("sortingDate") != nil){
print("replacing fact")
print("accessing the sortingDate of current fact in checkFacts")
let sdate = birdFacts[ind].valueForKey("sortingDate") as! NSNumber
replaceFact(sdate, index: ind)
}
/*else {
birdFacts.removeAll()
print("removing all bird facts")
}*/
}
ind = ind + 1
print(ind)
}
self.saveFacts()
let y = checkRepeatingFacts()
if y {
print("removing all facts")
birdFacts.removeAll()
//allprevFacts(date, olddate: 0)
}
}
checkFacts references 2 others functions, but I'm not sure they're relevant here (but I will add them in if they are and I'm mistaken)
Instead of trying to alter or halt the application's actual lifecycle, why don't you try using a closure?
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
checkFacts(){ Void in
if self.reset != 0 {
print("removing all bird facts")
birdFacts.removeAll()
}
}
}
func checkFacts(block: (()->Void)? = nil) {
let date = getDate()
var x: Bool = true
var ind: Int = 0
print("count is ", birdFacts.count)
while ind < birdFacts.count {
print("accessing each bird fact in checkFacts")
let imageAsset: CKAsset = birdFacts[ind].valueForKey("birdPicture") as! CKAsset
let image = UIImage(contentsOfFile: imageAsset.fileURL.path!)
print(image)
if image == nil {
if (birdFacts[ind].valueForKey("sortingDate") != nil){
print("replacing fact")
print("accessing the sortingDate of current fact in checkFacts")
let sdate = birdFacts[ind].valueForKey("sortingDate") as! NSNumber
replaceFact(sdate, index: ind)
}
/*else {
birdFacts.removeAll()
print("removing all bird facts")
}*/
}
ind = ind + 1
print(ind)
}
self.saveFacts()
let y = checkRepeatingFacts()
if y {
print("removing all facts")
birdFacts.removeAll()
//allprevFacts(date, olddate: 0)
}
// CALL CODE IN CLOSURE LAST //
if let block = block {
block()
}
}
According to Apple Documentation:
Closures are self-contained blocks of functionality that can be passed around and used in your code.
Closures can capture and store references to any constants and variables from the context in which they are defined.
So by defining checkFacts() as: func checkFacts(block: (()->Void)? = nil){...} we can optionally pass in a block of code to be executed within the checkFacts() function.
The syntax block: (()->Void)? = nil means that we can take in a block of code that will return void, but if nothing is passed in, block will simply be nil. This allows us to call the function with or without the use of a closure.
By using:
if let block = block {
block()
}
we can safely call block(). If block comes back as nil, we pass over it and pretend like nothing happened. If block is not nil, we can execute the code contained within it, and go on our way.
One way we can pass our closure code into checkFacts() is by means of a trailing closure. A trailing closure looks like this:
checkFacts(){ Void in
if self.reset != 0 {
print("removing all bird facts")
birdFacts.removeAll()
}
}
Edit: Added syntax explanation.
So based on the comments, checkFacts is calling asynchronous iCloud operations that if they are not complete will result in null data that your view cannot manage.
Holding up viewWillAppear is not the way to manage this - that will just result in a user interface delay that will irritate your users.
Firstly, your view should be able to manage null data without crashing. Even when you solve this problem there may be other occasions when the data becomes bad and users hate crashes. So I recommend you fix that.
To fix the original problem: allow the view to load with unchecked data. Then trigger the checkData process and when it completes post an NSNotification. Make your view watch for that notification and redraw its contents when it occurs. Optionally, if you don't want your users to interact with unchecked data: disable appropriate controls and display an activity indicator until the notification occurs.

How Can I Filtering Using NSMutableArray and UISearchController

I'm working on an iOS application using Swift and I'm using NSMutableArray, and when I try to add UISearchController to my UITableViewController It give me this error
1.1 click here, please
But when I try to do it with NSArray it works great.
If you wondering about Why am I using NSMutableArray?
Because I need it to pass the object of the NSMutableArray that is in the selected row from the UITableViewController to another UIViewController like this:
1.2 click here, please
What I have to do now, how can I adding search bar?
Thanks in advance.
You can hack it by converting the mutable array to a nsarray and then using that.
Where your doing the stuff in 1.1 just add before the the self.businessNamesArray line add this line
var regArray = self.businessNamesArray as NSArray as! [String]
then change the self.businessNamesArray line to regArray.filter{ rest of your code here
If you use regular Swift arrays, which I think is the right idea since you're using Swift, you can get it working if you change your array variable type and fix your array filtering syntax. First, change the array declaration to this:
var BusinessNamesArray:[String]?
The filter function your are using on your self.BusinessNamesArray returns a filtered array rather than filtering the array in place (which is what it seems like you want). If you want to replace the content of your self.BusinessNamesArray, you would need to do something like this:
func updateSearchResultsForSearchController(searchController: UISearchController) {
self.BusinessNamesArray = self.BusinessNamesArray.filter { (business:String) -> Bool in
return true
// You probably want to compare strings here like this instead:
// guard let searchText = searchController.searchBar.text else {
// return false
// }
// return business.hasPrefix(searchText)
}
// You probably also need to reload your table view at this point:
self.tableView.reloadData()
}
Keep in mind though that your BusinessNamesArray is now filtered and you can't un-filter it. Instead, you should probably keep a second array of your Strings called something like searchResults. Then you can use that for filtering and maintain your original list of business names in the original array. So you would add a class variable called var searchResults:[String]? and the search filtering code would change to.
func updateSearchResultsForSearchController(searchController: UISearchController) {
self.searchResults = self.BusinessNamesArray.filter { (business:String) -> Bool in
guard let searchText = searchController.searchBar.text else {
return false
}
return business.hasPrefix(searchText)
}
self.tableView.reloadData()
}
When you call reloadData on your table view at this point, you will probably want to check and see if your search controller is active in the table view delegate's numberOfSectionsInTableView as well other delegate functions and use the searchResults array if it is active and the BusinessNamesArray if its not--something like:
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
if (self.resultSearchController.active) {
return self.searchResults.count ?? 0
} else {
return self.BusinessNamesArray.count ?? 0
}
}
(The self.resultSearchController variable is a local instance of UISearchController. I'm not sure what you've named yours.)
You'll then use similar code to decide which items to grab for your prepareForSegue: code:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Guard your variables here so you can return early if they're
// not valid
guard let upcoming = segue.destinationViewController as? DetailsViewController,
myindexpath = self.tableView.indexPathForSelectedRow else {
return
}
var titleString = ""
if (self.resultSearchController.active) {
if let searchResults = self.searchResults {
titleString = searchResults[myindexpath.row]
}
} else {
if let businessNames = self.BusinessNamesArray {
titleString = businessNames[myindexpath.row]
}
}
upcoming.titleString = titleString
self.deselectRowAtIndexPath(myindexpath, animated: true)
}

Swift: Get all subviews of a specific type and add to an array

I have a custom class of buttons in a UIView that I'd like to add to an array so that they're easily accessible. Is there a way to get all subviews of a specific class and add it to an array in Swift?
The filter function using the is operator can filter items of a specific class.
let myViews = view.subviews.filter{$0 is MyButtonClass}
MyButtonClass is the custom class to be filtered for.
To filter and cast the view to the custom type use compactMap
let myViews = view.subviews.compactMap{$0 as? MyButtonClass}
Here you go
extension UIView {
/** This is the function to get subViews of a view of a particular type
*/
func subViews<T : UIView>(type : T.Type) -> [T]{
var all = [T]()
for view in self.subviews {
if let aView = view as? T{
all.append(aView)
}
}
return all
}
/** This is a function to get subViews of a particular type from view recursively. It would look recursively in all subviews and return back the subviews of the type T */
func allSubViewsOf<T : UIView>(type : T.Type) -> [T]{
var all = [T]()
func getSubview(view: UIView) {
if let aView = view as? T{
all.append(aView)
}
guard view.subviews.count>0 else { return }
view.subviews.forEach{ getSubview(view: $0) }
}
getSubview(view: self)
return all
}
}
You can call it like
let allSubviews = view.allSubViewsOf(type: UIView.self)
let allLabels = view.allSubViewsOf(type: UILabel.self)
So many of the answers here are unnecessarily verbose or insufficiently general. Here's how to get all subviews of a view, at any depth, that are of any desired class:
extension UIView {
func subviews<T:UIView>(ofType WhatType:T.Type) -> [T] {
var result = self.subviews.compactMap {$0 as? T}
for sub in self.subviews {
result.append(contentsOf: sub.subviews(ofType:WhatType))
}
return result
}
}
How to use:
let arr = myView.subviews(ofType: MyButtonClass.self)
To do this recursively (I.e. fetching all subview's views aswell), you can use this generic function:
private func getSubviewsOf<T : UIView>(view:UIView) -> [T] {
var subviews = [T]()
for subview in view.subviews {
subviews += getSubviewsOf(view: subview) as [T]
if let subview = subview as? T {
subviews.append(subview)
}
}
return subviews
}
To fetch all UILabel's in a view hierarchy, just do this:
let allLabels : [UILabel] = getSubviewsOf(view: theView)
I can't test it right now but this should work in Swift 2:
view.subviews.flatMap{ $0 as? YourView }
Which returns an array of YourView
Here's a tested, typical example, to get a count:
countDots = allDots!.view.subviews.flatMap{$0 as? Dot}.count
From Swift 4.1, you can use new compactMap (flatMap is now depcrecated): https://developer.apple.com/documentation/swift/sequence/2950916-compactmap
(see examples inside)
In your case, you can use:
let buttons:[UIButton] = stackView.subviews.compactMap{ $0 as? UIButton }
And you can execute actions to all buttons using map:
let _ = stackView.subviews.compactMap{ $0 as? UIButton }.map { $0.isSelected = false }
If you want to update/access those specific subviews then use this,
for (index,button) in (view.subviews.filter{$0 is UIButton}).enumerated(){
button.isHidden = false
}
func allSubViews(views: [UIView]) {
for view in views {
if let tf = view as? UITextField {
// Do Something
}
self.allSubViews(views: view.subviews)
}
}
self.allSubViews(views: self.view.subviews)
For this case, I think we could use Swift's first.where syntax, which is more efficient than filter.count, filter.isEmpty.
Because when we use filter, it will create a underlying array, thus not effective, imagine we have a large collection.
So just check if a view's subViews collection contains a specific kind of class, we can use this
let containsBannerViewKind = view.subviews.first(where: { $0 is BannerView }) != nil
which equivalent to: find me the first match to BannerView class in this view's subViews collection. So if this is true, we can carry out our further logic.
Reference: https://github.com/realm/SwiftLint/blob/master/Rules.md#first-where
Let me post my variation of this) but this, finds the first of T
extension UIView {
func firstSubView<T: UIView>(ofType type: T.Type) -> T? {
var resultView: T?
for view in subviews {
if let view = view as? T {
resultView = view
break
}
else {
if let foundView = view.firstSubView(ofType: T.self) {
resultView = foundView
break
}
}
}
return resultView
}
}
Swift 5
func findViewInside<T>(views: [UIView]?, findView: [T] = [], findType: T.Type = T.self) -> [T] {
var findView = findView
let views = views ?? []
guard views.count > .zero else { return findView }
let firstView = views[0]
var loopViews = views.dropFirst()
if let typeView = firstView as? T {
findView = findView + [typeView]
return findViewInside(views: Array(loopViews), findView: findView)
} else if firstView.subviews.count > .zero {
firstView.subviews.forEach { loopViews.append($0) }
return findViewInside(views: Array(loopViews), findView: findView)
} else {
return findViewInside(views: Array(loopViews), findView: findView)
}
}
How to use:
findViewInside(views: (YourViews), findType: (YourType).self)
I've gone through all the answers above, they cover the scenario where the views are currently displayed in the window, but don't provide those views which are in view controllers not shown in the window.
Based on #matt answers, I wrote the following function which recursively go through all the views, including the non visible view controllers, child view controllers, navigation controller view controllers, using the next responders
(Note: It can be definitively improved, as it adds more complexity on top of the recursion function. consider it as a proof of concept)
/// Returns the array of subviews in the view hierarchy which match the provided type, including any hidden
/// - Parameter type: the type filter
/// - Returns: the resulting array of elements matching the given type
func allSubviews<T:UIView>(of type:T.Type) -> [T] {
var result = self.subviews.compactMap({$0 as? T})
var subviews = self.subviews
// *********** Start looking for non-visible view into view controllers ***********
// Inspect also the non visible views on the same level
var notVisibleViews = [UIView]()
subviews.forEach { (v) in
if let vc = v.next as? UIViewController {
let childVCViews = vc.children.filter({$0.isViewLoaded && $0.view.window == nil }).compactMap({$0.view})
notVisibleViews.append(contentsOf: childVCViews)
}
if let vc = v.next as? UINavigationController {
let nvNavVC = vc.viewControllers.filter({$0.isViewLoaded && $0.view.window == nil })
let navVCViews = nvNavVC.compactMap({$0.view})
notVisibleViews.append(contentsOf: navVCViews)
// detect child vc in not visible vc in the nav controller
let childInNvNavVC = nvNavVC.compactMap({$0.children}).reduce([],+).compactMap({$0.view})
notVisibleViews.append(contentsOf: childInNvNavVC)
}
if let vc = v.next as? UITabBarController {
let tabViewControllers = vc.viewControllers?.filter({$0.isViewLoaded && $0.view.window == nil }) ?? [UIViewController]()
// detect navigation controller in the hidden tab bar view controllers
let vc1 = tabViewControllers.compactMap({$0 as? UINavigationController})
vc1.forEach { (vc) in
let nvNavVC = vc.viewControllers.filter({$0.isViewLoaded && $0.view.window == nil })
let navVCViews = nvNavVC.compactMap({$0.view})
notVisibleViews.append(contentsOf: navVCViews)
// detect child vc in not visible vc in the nav controller
let childInNvNavVC = nvNavVC.compactMap({$0.children}).reduce([],+).compactMap({$0.view})
notVisibleViews.append(contentsOf: childInNvNavVC)
}
// ad non-navigation controller in the hidden tab bar view controllers
let tabVCViews = tabViewControllers.compactMap({($0 as? UINavigationController) == nil ? $0.view : nil})
notVisibleViews.append(contentsOf: tabVCViews)
}
}
subviews.append(contentsOf: notVisibleViews.removingDuplicates())
// *********** End looking for non-visible view into view controllers ***********
subviews.forEach({result.append(contentsOf: $0.allSubviews(of: type))})
return result.removingDuplicates()
}
extension Array where Element: Hashable {
func removingDuplicates() -> [Element] {
var dict = [Element: Bool]()
return filter { dict.updateValue(true, forKey: $0) == nil }
}
}
Sample usage:
let allButtons = keyWindow.allSubviews(of: UIButton.self)
Note: If a modal view controller is currently presented, the above script does not find views which are contained in the presentingViewController. (Can be expanded for that, but I could not find an elegant way to achieve it, as this code is already not elegant by itself :/ )
Probably is not common to have this need, but maybe helps someone out there :)

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