In my SwiftUI app I have set in all my views .navigationBarBackButtonHidden(true) to have always a custom Back Button, so the iOS classic swipe to go back has been disabled everywhere, but I actually need it only in specific views.
I re enabled it using this code:
extension UINavigationController: UIGestureRecognizerDelegate {
override open func viewDidLoad() {
super.viewDidLoad()
interactivePopGestureRecognizer?.delegate = self
}
public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return viewControllers.count > 1
}
}
It works but unfortunately it re enables swipe to go back in the entire project, what should I do?
It can be managed via some global app state, like
class AppState {
static let shared = AppState()
var swipeEnabled = false // << by default
}
extension UINavigationController: UIGestureRecognizerDelegate {
// ...
public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return AppState.shared.swipeEnabled ?
viewControllers.count > 1 : false // << here !!
}
}
// ... and somewhere in view, for example
.onAppear {
AppState.shared.swipeEnabled = true
}
.onDisappear {
AppState.shared.swipeEnabled = false
}
Related
I create this basic tap gesture function for dismissing view and I added a delegate to override tap when the user taps on another custom sheet (container).
#objc func handleTapGesture() {
dismiss(animated: true, completion: nil)
}
private func tapGestureToDissmis() {
let tap = UITapGestureRecognizer()
tap.addTarget(self, action: #selector(handleTapGesture))
tap.delegate = self
view.addGestureRecognizer(tap)
}
extension TextConfigurationVC : UIGestureRecognizerDelegate {
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
if touch.view?.isDescendant(of: container) == true {
return false
}
return true
}
My problem is that I want to implement this for 8 screens and I don't want to repeat my self. i create in my UIViewcontroler extension file this tap function and I don't now how to pass this view :
extension UIViewController : UIGestureRecognizerDelegate {
public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
if touch.view?.isDescendant(of: **<UIView>)** == true {
return false
}
return true
}
when I created the global container, each time it was called, it was overlapping each other
(tap x 6)
Simple way to handle individual tap action for views
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")
}
}
Displaying a PDFDocument in a PDFView allows the user to select parts of the document and perform actions e.g. "copy" with the selection.
How can selection be disabled in a PDFView while preserving the possibility for the user to zoom in and out and scroll in the PDF?
PDFView itself does not seem to offer such a property nor does the PDFViewDelegate.
You have to subclass PDFView, as such:
class MyPDFView: PDFView {
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return false
}
override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
if gestureRecognizer is UILongPressGestureRecognizer {
gestureRecognizer.isEnabled = false
}
super.addGestureRecognizer(gestureRecognizer)
}
}
Just need to do is it will auto clear the selection and User will no longer long-press on PDF text.
class MyPDFView: PDFView {
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
self.currentSelection = nil
self.clearSelection()
return false
}
override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
if gestureRecognizer is UILongPressGestureRecognizer {
gestureRecognizer.isEnabled = false
}
super.addGestureRecognizer(gestureRecognizer)
}
}
This below 2 lines need to add in canPerformAction()
self.currentSelection = nil
self.clearSelection()
For iOS 13, the above solution no longer works. It looks like they've changed the internal implementation of PDFView and specifically how the gesture recognizers are set up. I think generally it's discouraged to do this kind of thing, but it can still be done without using any internal API, here's how:
1) Recursively gather all subviews of PDFView (see below for the helper function to do this)
let allSubviews = pdfView.allSubViewsOf(type: UIView.self)
2) Iterate over them and deactivate any UILongPressGestureRecognizers:
for gestureRec in allSubviews.compactMap({ $0.gestureRecognizers }).flatMap({ $0 }) {
if gestureRec is UILongPressGestureRecognizer {
gestureRec.isEnabled = false
}
}
Helper func to recursively get all subviews of a given type:
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
}
I'm calling the above code from the viewDidLoad method of the containing view controller.
I haven't yet found a good way to work this into a subclass of PDFView, which would be the preferred way for reusability and could just be an addition to the above NonSelectablePDFView. What I've tried so far is overriding didAddSubview and adding the above code after the call to super, but that didn't work as expected. It seems like the gesture recognizers are only being added at a later step, so figuring out when that is and if there's a way for the subclass to call some custom code after this happened would be a next step here.
With Swift 5 and iOS 12.3, you can solve your problem by overriding addGestureRecognizer(_:) method and canPerformAction(_:withSender:) method in a PDFView subclass.
import UIKit
import PDFKit
class NonSelectablePDFView: PDFView {
override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
(gestureRecognizer as? UILongPressGestureRecognizer)?.isEnabled = false
super.addGestureRecognizer(gestureRecognizer)
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return false
}
}
As an alternative to the previous implementation, you can simply toggle UILongPressGestureRecognizer isEnabled property to false in the initializer.
import UIKit
import PDFKit
class NonSelectablePDFView: PDFView {
override init(frame: CGRect) {
super.init(frame: frame)
if let gestureRecognizers = gestureRecognizers {
for gestureRecognizer in gestureRecognizers where gestureRecognizer is UILongPressGestureRecognizer {
gestureRecognizer.isEnabled = false
}
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
return false
}
}
You should note that this is not sufficient to disable text selecting, as there is a UITapAndHalfRecognizer as well – obviously a private Apple class - that also creates selections.
It is attached to the PDFDocumentView, which is another private implementation detail of PDFView, and which you can not replace with your own class implementation.
I have a table view with cells that the user can swipe to delete the row. I'm receiving a fatal error: Index out of range error whenever I swipe two rows at once (with two fingers, one on each row).
I've added these 4 lines in my OrdersViewController:
override func viewDidLoad() {
...
self.view.isMultipleTouchEnabled = false
self.view.isExclusiveTouch = true
self.ordersTable.isMultipleTouchEnabled = false
self.ordersTable.isExclusiveTouch = true
}
in an effort to try to change this behavior so that only one cell is swiped at a time, but nothing has changed. I can still use two fingers on two different rows to swipe back and forth at the same time.
Is there another way?
None of the IsExclusiveTouch and IsMultipleTouchEnabled is working regardless of where I put it. I wonder if it has anything to do with me using this library github.com/alikaragoz/MCSwipeTableViewCell
It could also be because I'm using Firebase?
First of all set delegates of gesture and then use this delegate, it could help you :
override func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return false;
}
I eventually did this, using the callbacks made available by the table cell pod i'm using:
class OrderTableManager {
static var swiping = false
}
class OrderPreparingTableViewCell: MCSwipeTableViewCell, MCSwipeTableViewCellDelegate {
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if !OrderTableManager.swiping {
OrderTableManager.swiping = true
return true
} else {
return false
}
}
// MARK: Public
func swipeTableViewCellDidEndSwiping(_ cell: MCSwipeTableViewCell!) {
OrderTableManager.swiping = false
}
func displayOrder(order: AppState.Order, clock: Clock, fDone: #escaping SwipeHandler, fDelete: #escaping SwipeHandler) -> OrderPreparingTableViewCell {
...
self.delegate = self
...
}
I'm facing problem when string in UILabel is displayed with delay in inputAccessoryView on UIViewController. I have attached gif demonstrating this problem. After pushing SecondViewController to navigation stack inputAccessoryView is missing text for short time. But I want text to be shown right away after opening screen.
Implementation demonstrating this problem is extremely simple.
class SecondViewController: UIViewController {
#IBOutlet var accessoryView: UIView!
override var inputAccessoryView: UIView {
return accessoryView
}
override func canBecomeFirstResponder() -> Bool {
return true
}
}
Does any one have solution for this problem?
I have come up with the solution which works on both iOS 8 and 9. Also it address retain cycle issue presented in iOS 9 which prevent view controller from being deallocated when use inputaccessoryview. Check github project for more details.
With lots of experimentation I have found quite hacky solution but works like a charm. Just subclass your implemantation accessory view from AccessoryView listed below.
class AccessoryView: UITextField {
override var canBecomeFirstResponder: Bool {
return true
}
override func awakeFromNib() {
super.awakeFromNib()
disableShowingKeyboard()
hideCursor()
}
}
extension AccessoryView {
private func disableShowingKeyboard() {
inputView = UIView()
}
private func hideCursor() {
tintColor = UIColor.clear
}
override func accessibilityActivate() -> Bool {
return false
}
override var isEditing: Bool {
return false
}
override func caretRect(for position: UITextPosition) -> CGRect {
return .zero
}
override func selectionRects(for range: UITextRange) -> [UITextSelectionRect] {
return []
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
if action == #selector(UIResponder.copy(_:)) || action == #selector(UIResponder.selectAll(_:)) || action == #selector(UIResponder.paste(_:)){
return false
}
return super.canPerformAction(action, withSender: sender)
}
override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
if gestureRecognizer is UILongPressGestureRecognizer {
gestureRecognizer.isEnabled = false
}
super.addGestureRecognizer(gestureRecognizer)
}
}
extension AccessoryView {
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
for view in subviews {
let _point = self.convert(point, to: view)
if !view.isHidden && view.isUserInteractionEnabled && view.alpha > 0.01 && view.point(inside: _point, with: event) {
if let _view = view.hitTest(_point, with: event){
return _view
}
}
}
return super.hitTest(point, with: event)
}
}
I'm trying to get a setup similar to what Facebook use (if they use a UITextView). I want links to be detected automatically however I don't want any other text in the UITextView selectable. So, the user can click on the link but is unable to select any other text.
Despite searching around, I've yet to come across a solution as for link selection to work it requires the whole of the text view to be selectable.
if your minimum deployment target is iOS 11.2 or newer
You can disable text selection by subclassing UITextView and forbidding the gestures that can select something.
The below solution is:
compatible with isEditable
compatible with isScrollEnabled
compatible with links
/// Class to allow links but no selection.
/// Basically, it disables unwanted UIGestureRecognizer from UITextView.
/// https://stackoverflow.com/a/49428307/1033581
class UnselectableTappableTextView: UITextView {
// required to prevent blue background selection from any situation
override var selectedTextRange: UITextRange? {
get { return nil }
set {}
}
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if gestureRecognizer is UIPanGestureRecognizer {
// required for compatibility with isScrollEnabled
return super.gestureRecognizerShouldBegin(gestureRecognizer)
}
if let tapGestureRecognizer = gestureRecognizer as? UITapGestureRecognizer,
tapGestureRecognizer.numberOfTapsRequired == 1 {
// required for compatibility with links
return super.gestureRecognizerShouldBegin(gestureRecognizer)
}
// allowing smallDelayRecognizer for links
// https://stackoverflow.com/questions/46143868/xcode-9-uitextview-links-no-longer-clickable
if let longPressGestureRecognizer = gestureRecognizer as? UILongPressGestureRecognizer,
// comparison value is used to distinguish between 0.12 (smallDelayRecognizer) and 0.5 (textSelectionForce and textLoupe)
longPressGestureRecognizer.minimumPressDuration < 0.325 {
return super.gestureRecognizerShouldBegin(gestureRecognizer)
}
// preventing selection from loupe/magnifier (_UITextSelectionForceGesture), multi tap, tap and a half, etc.
gestureRecognizer.isEnabled = false
return false
}
}
if your minimum deployment target is iOS 11.1 or older
Native UITextView links gesture recognizers are broken on iOS 11.0-11.1 and require a small delay long press instead of a tap: Xcode 9 UITextView links no longer clickable
You can properly support links with your own gesture recognizer and you can disable text selection by subclassing UITextView and forbidding the gestures that can select something or tap something.
The below solution will disallow selection and is:
compatible with isScrollEnabled
compatible with links
workaround limitations of iOS 11.0 and iOS 11.1, but loses the UI effect when tapping on text attachments
/// Class to support links and to disallow selection.
/// It disables most UIGestureRecognizer from UITextView and adds a UITapGestureRecognizer.
/// https://stackoverflow.com/a/49428307/1033581
class UnselectableTappableTextView: UITextView {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
// Native UITextView links gesture recognizers are broken on iOS 11.0-11.1:
// https://stackoverflow.com/questions/46143868/xcode-9-uitextview-links-no-longer-clickable
// So we add our own UITapGestureRecognizer.
linkGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(textTapped))
linkGestureRecognizer.numberOfTapsRequired = 1
addGestureRecognizer(linkGestureRecognizer)
linkGestureRecognizer.isEnabled = true
}
var linkGestureRecognizer: UITapGestureRecognizer!
// required to prevent blue background selection from any situation
override var selectedTextRange: UITextRange? {
get { return nil }
set {}
}
override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
// Prevents drag and drop gestures,
// but also prevents a crash with links on iOS 11.0 and 11.1.
// https://stackoverflow.com/a/49535011/1033581
gestureRecognizer.isEnabled = false
super.addGestureRecognizer(gestureRecognizer)
}
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if gestureRecognizer == linkGestureRecognizer {
// Supporting links correctly.
return super.gestureRecognizerShouldBegin(gestureRecognizer)
}
if gestureRecognizer is UIPanGestureRecognizer {
// Compatibility support with isScrollEnabled.
return super.gestureRecognizerShouldBegin(gestureRecognizer)
}
// Preventing selection gestures and disabling broken links support.
gestureRecognizer.isEnabled = false
return false
}
#objc func textTapped(recognizer: UITapGestureRecognizer) {
guard recognizer == linkGestureRecognizer else {
return
}
var location = recognizer.location(in: self)
location.x -= textContainerInset.left
location.y -= textContainerInset.top
let characterIndex = layoutManager.characterIndex(for: location, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
let characterRange = NSRange(location: characterIndex, length: 1)
if let attachment = attributedText?.attribute(.attachment, at: characterIndex, effectiveRange: nil) as? NSTextAttachment {
if #available(iOS 10.0, *) {
_ = delegate?.textView?(self, shouldInteractWith: attachment, in: characterRange, interaction: .invokeDefaultAction)
} else {
_ = delegate?.textView?(self, shouldInteractWith: attachment, in: characterRange)
}
}
if let url = attributedText?.attribute(.link, at: characterIndex, effectiveRange: nil) as? URL {
if #available(iOS 10.0, *) {
_ = delegate?.textView?(self, shouldInteractWith: url, in: characterRange, interaction: .invokeDefaultAction)
} else {
_ = delegate?.textView?(self, shouldInteractWith: url, in: characterRange)
}
}
}
}
You can subclass the UITextView overriding the method of selectedTextRange, setting it to nil. And the links will still be clickable, but you won't be able to select the rest of the text (even the link but you can click on it).
class CustomTextView: UITextView {
override public var selectedTextRange: UITextRange? {
get {
return nil
}
set { }
}
You need to subclass UITextView and override gestureRecognizerShouldBegin (_:) method like this:
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if isEditable == false {
if let gesture = gestureRecognizer as? UILongPressGestureRecognizer, gesture.minimumPressDuration == 0.5 {
return false
}
}
return true
}
this will prevent from textview being selected but link will work as expected
Edited:
It turned out that when double tap and hold you are still able to select text. As I figured out it happens after two taps(not the UITapGesture with property "minimalNumberOfTaps", but to different taps one after another), so the solution is to track time after first step (approx. 0.7 sec)
Full code:
var lastTapTime: TimeInterval = 0
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if isEditable == false {
if let gesture = gestureRecognizer as? UILongPressGestureRecognizer, gesture.minimumPressDuration == 0.5 {
return false
}
}
if Date().timeIntervalSince1970 >= lastTapTime + 0.7 {
lastTapTime = Date().timeIntervalSince1970
return true
} else {
return false
}
}
This is not the most elegant solution but it seems to work 🤷♂️
The selected answer doesn't work in my case, and I'm not comfortable with comparing unconfirmed values inside of internal UIGestureRecognizers.
My solution was to override point(inside:with:) and allow a tap-through when the user is not touching down on linked text: https://stackoverflow.com/a/44878203/1153630
This is what worked for me;
class LinkDetectingTextView: UITextView {
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if isEditable == false {
if let _ = gestureRecognizer as? UITapGestureRecognizer {
return false
}
if let longPressRecognizer = gestureRecognizer as? UILongPressGestureRecognizer,
longPressRecognizer.minimumPressDuration == 0.5 { // prevent to select text but allow certain functionality in application
return false
}
}
return true
}
}
In addition, set minimumPressDuration of the longPressGestureRecognizer in the application another value different than 0.5.
This answer is for iOS 10.3.x and below where your UIView is not embedded in a subview. For a more robust, modern answer, please see Cœur's answer below.
You need to prevent the UITextView from becoming first responder.
1. Subclass UITextView to your own custom class (MyTextView).
2. Override canBecomeFirstResponder(). Here's an example in Swift:
Swift 3:
class MyTextView: UITextView {
override func becomeFirstResponder() -> Bool {
return false
}
}
Swift 2:
class MyTextView: UITextView {
override func canBecomeFirstResponder() -> Bool {
return false
}
}
Any links detected will still be enabled. I tested this with a phone number.