When I create a text view:
Text("Hello World")
I can't allow the user to select text when they long press.
I've looked at using a TextField but that doesn't seem to allow for turning off text editing.
I just want to be able to display a body of text and allow the user to highlight a selection using the system text selector.
Thanks!
You can use textField. inputView = UIView() and textField.
TextField in SwiftUI is a simple control that shows an editable text interface (equivalent to UITextField in UIKit). Because TextField allows a user to type text, it also needs a way of storing the entered text in a State variable which can then be used to read the input.
It contains text and an icon. A view that uses a label can choose whether to use it based on available space and environment. We have learn all of this in SwiftUI Label: A standard way to label user interface items post. At the end of the post, I told you that we should consider using a label when building a custom view.
In brief, data binding is a way for SwiftUI to communicate the data between the view and the one who uses it. It serves the same purpose as UITextFieldDelegate and the target-action mechanism in UITextField to report changes made during editing. There are many ways to create a text field.
Mayor: When a user selects some text he can tap in the context menu cut, paste and other items which can change the text regardless of using .constant (...) My solution to this problem involves subclassing UITextField and using UIViewRepresentable to bridge between UIKit and SwiftUI.
As of Xcode 13.0 beta 2
you can use
Text("Selectable text")
.textSelection(.enabled)
Text("Non selectable text")
.textSelection(.disabled)
// applying `textSelection` to a container
// enables text selection for all `Text` views inside it
VStack {
Text("Selectable text1")
Text("Selectable text2")
// disable selection only for this `Text` view
Text("Non selectable text")
.textSelection(.disabled)
}.textSelection(.enabled)
See also the textSelection Documentation.
Using TextField("", text: .constant("Some text"))
has two problems:
cut
, paste
and other items which can change the text regardless of using .constant(...)
My solution to this problem involves subclassing UITextField
and using UIViewRepresentable
to bridge between UIKit
and SwiftUI
.
At the end I provide the full code to copy and paste into a playground in Xcode 11.3 on macOS 10.14
Subclassing the UITextField
:
/// This subclass is needed since we want to customize the cursor and the context menu
class CustomUITextField: UITextField, UITextFieldDelegate {
/// (Not used for this workaround, see below for the full code) Binding from the `CustomTextField` so changes of the text can be observed by `SwiftUI`
fileprivate var _textBinding: Binding<String>!
/// If it is `true` the text field behaves normally.
/// If it is `false` the text cannot be modified only selected, copied and so on.
fileprivate var _isEditable = true {
didSet {
// set the input view so the keyboard does not show up if it is edited
self.inputView = self._isEditable ? nil : UIView()
// do not show autocorrection if it is not editable
self.autocorrectionType = self._isEditable ? .default : .no
}
}
// change the cursor to have zero size
override func caretRect(for position: UITextPosition) -> CGRect {
return self._isEditable ? super.caretRect(for: position) : .zero
}
// override this method to customize the displayed items of 'UIMenuController' (the context menu when selecting text)
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
// disable 'cut', 'delete', 'paste','_promptForReplace:'
// if it is not editable
if (!_isEditable) {
switch action {
case #selector(cut(_:)),
#selector(delete(_:)),
#selector(paste(_:)):
return false
default:
// do not show 'Replace...' which can also replace text
// Note: This selector is private and may change
if (action == Selector("_promptForReplace:")) {
return false
}
}
}
return super.canPerformAction(action, withSender: sender)
}
// === UITextFieldDelegate methods
func textFieldDidChangeSelection(_ textField: UITextField) {
// update the text of the binding
self._textBinding.wrappedValue = textField.text ?? ""
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Allow changing the text depending on `self._isEditable`
return self._isEditable
}
}
Using UIViewRepresentable
to implement SelectableText
struct SelectableText: UIViewRepresentable {
private var text: String
private var selectable: Bool
init(_ text: String, selectable: Bool = true) {
self.text = text
self.selectable = selectable
}
func makeUIView(context: Context) -> CustomUITextField {
let textField = CustomUITextField(frame: .zero)
textField.delegate = textField
textField.text = self.text
textField.setContentHuggingPriority(.defaultHigh, for: .vertical)
textField.setContentHuggingPriority(.defaultHigh, for: .horizontal)
return textField
}
func updateUIView(_ uiView: CustomUITextField, context: Context) {
uiView.text = self.text
uiView._textBinding = .constant(self.text)
uiView._isEditable = false
uiView.isEnabled = self.selectable
}
func selectable(_ selectable: Bool) -> SelectableText {
return SelectableText(self.text, selectable: selectable)
}
}
In the full code below I also implemented a CustomTextField
where editing can be turned off but still be selectable.
Playground view
Code
import PlaygroundSupport
import SwiftUI
/// This subclass is needed since we want to customize the cursor and the context menu
class CustomUITextField: UITextField, UITextFieldDelegate {
/// Binding from the `CustomTextField` so changes of the text can be observed by `SwiftUI`
fileprivate var _textBinding: Binding<String>!
/// If it is `true` the text field behaves normally.
/// If it is `false` the text cannot be modified only selected, copied and so on.
fileprivate var _isEditable = true {
didSet {
// set the input view so the keyboard does not show up if it is edited
self.inputView = self._isEditable ? nil : UIView()
// do not show autocorrection if it is not editable
self.autocorrectionType = self._isEditable ? .default : .no
}
}
// change the cursor to have zero size
override func caretRect(for position: UITextPosition) -> CGRect {
return self._isEditable ? super.caretRect(for: position) : .zero
}
// override this method to customize the displayed items of 'UIMenuController' (the context menu when selecting text)
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
// disable 'cut', 'delete', 'paste','_promptForReplace:'
// if it is not editable
if (!_isEditable) {
switch action {
case #selector(cut(_:)),
#selector(delete(_:)),
#selector(paste(_:)):
return false
default:
// do not show 'Replace...' which can also replace text
// Note: This selector is private and may change
if (action == Selector("_promptForReplace:")) {
return false
}
}
}
return super.canPerformAction(action, withSender: sender)
}
// === UITextFieldDelegate methods
func textFieldDidChangeSelection(_ textField: UITextField) {
// update the text of the binding
self._textBinding.wrappedValue = textField.text ?? ""
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Allow changing the text depending on `self._isEditable`
return self._isEditable
}
}
struct CustomTextField: UIViewRepresentable {
@Binding private var text: String
private var isEditable: Bool
init(text: Binding<String>, isEditable: Bool = true) {
self._text = text
self.isEditable = isEditable
}
func makeUIView(context: UIViewRepresentableContext<CustomTextField>) -> CustomUITextField {
let textField = CustomUITextField(frame: .zero)
textField.delegate = textField
textField.text = self.text
textField.setContentHuggingPriority(.defaultHigh, for: .vertical)
return textField
}
func updateUIView(_ uiView: CustomUITextField, context: UIViewRepresentableContext<CustomTextField>) {
uiView.text = self.text
uiView._textBinding = self.$text
uiView._isEditable = self.isEditable
}
func isEditable(editable: Bool) -> CustomTextField {
return CustomTextField(text: self.$text, isEditable: editable)
}
}
struct SelectableText: UIViewRepresentable {
private var text: String
private var selectable: Bool
init(_ text: String, selectable: Bool = true) {
self.text = text
self.selectable = selectable
}
func makeUIView(context: Context) -> CustomUITextField {
let textField = CustomUITextField(frame: .zero)
textField.delegate = textField
textField.text = self.text
textField.setContentHuggingPriority(.defaultHigh, for: .vertical)
textField.setContentHuggingPriority(.defaultHigh, for: .horizontal)
return textField
}
func updateUIView(_ uiView: CustomUITextField, context: Context) {
uiView.text = self.text
uiView._textBinding = .constant(self.text)
uiView._isEditable = false
uiView.isEnabled = self.selectable
}
func selectable(_ selectable: Bool) -> SelectableText {
return SelectableText(self.text, selectable: selectable)
}
}
struct TextTestView: View {
@State private var selectableText = true
var body: some View {
VStack {
// Even though the text should be constant, it is not because the user can select and e.g. 'cut' the text
TextField("", text: .constant("Test SwiftUI TextField"))
.background(Color(red: 0.5, green: 0.5, blue: 1))
// This view behaves like the `SelectableText` however the layout behaves like a `TextField`
CustomTextField(text: .constant("Test `CustomTextField`"))
.isEditable(editable: false)
.background(Color.green)
// A non selectable normal `Text`
Text("Test SwiftUI `Text`")
.background(Color.red)
// A selectable `text` where the selection ability can be changed by the button below
SelectableText("Test `SelectableText` maybe selectable")
.selectable(self.selectableText)
.background(Color.orange)
Button(action: {
self.selectableText.toggle()
}) {
Text("`SelectableText` can be selected: \(self.selectableText.description)")
}
// A selectable `text` which cannot be changed
SelectableText("Test `SelectableText` always selectable")
.background(Color.yellow)
}.padding()
}
}
let viewController = UIHostingController(rootView: TextTestView())
viewController.view.frame = CGRect(x: 0, y: 0, width: 400, height: 200)
PlaygroundPage.current.liveView = viewController.view
A simple workaround solution I found is to just use context menus instead:
Text($someText)
.contextMenu(ContextMenu(menuItems: {
Button("Copy", action: {
UIPasteboard.general.string = someText
})
}))
I ran into a similar problem, where I wanted in essence to select the text without allowing editing. In my case, I wanted to show the UIMenuController when the text was tapped on, without allowing editing of the text or showing the cursor or keyboard. Building on the prior answers:
import SwiftUI
import UIKit
struct SelectableText: UIViewRepresentable {
var text: String
@Binding var isSelected: Bool
func makeUIView(context: Context) -> SelectableLabel {
let label = SelectableLabel()
label.textColor = .white
label.font = .systemFont(ofSize: 60, weight: .light)
label.minimumScaleFactor = 0.6
label.adjustsFontSizeToFitWidth = true
label.textAlignment = .right
label.numberOfLines = 1
label.setContentHuggingPriority(.defaultHigh, for: .horizontal)
label.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
label.text = text
return label
}
func updateUIView(_ uiView: SelectableLabel, context: Context) {
uiView.text = text
if isSelected {
uiView.showMenu()
} else {
let _ = uiView.resignFirstResponder()
}
}
}
class SelectableLabel: UILabel {
override var canBecomeFirstResponder: Bool {
return true
}
override init(frame: CGRect) {
super.init(frame: .zero)
highlightedTextColor = .gray
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
switch action {
case #selector(copy(_:)), #selector(paste(_:)), #selector(delete(_:)):
return true
default:
return super.canPerformAction(action, withSender: sender)
}
}
override func copy(_ sender: Any?) {
UIPasteboard.general.string = self.stringValue
}
override func paste(_ sender: Any?) {
guard let string = UIPasteboard.general.string else { return }
NotificationCenter.default.post(name: Notification.Name.Paste, object: nil, userInfo: [Keys.PastedString: string])
}
override func delete(_ sender: Any?) {
NotificationCenter.default.post(name: Notification.Name.Delete, object: nil)
}
override func resignFirstResponder() -> Bool {
isHighlighted = false
return super.resignFirstResponder()
}
public func showMenu() {
becomeFirstResponder()
isHighlighted = true
let menu = UIMenuController.shared
menu.showMenu(from: self, rect: bounds)
}
}
I use custom paste and delete notifications to message my model object, where the paste and delete actions are processed to update the display appropriately, which works for my purposes. Bindings could also be used.
To use:
SelectableText(text: text, isSelected: self.$isSelected)
.onTapGesture {
self.isSelected.toggle()
}
.onReceive(NotificationCenter.default.publisher(for: UIMenuController.willHideMenuNotification)) { _ in
self.isSelected = false
}
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