Disable specific picker items - swift

Is there a way to disable specific picker items? In AppKit, you can disable NSPopUpButton items via the NSMenuValidation protocol, but disabling a label in the picker predictably does nothing. Just another API gap in SwiftUI?
I tried:
Picker(selection: $viewModel.providerSelection, label: Text("Try using:")) {
ForEach(0..<Provider.allCases.count) {
Text(Provider.allCases[$0].rawValue.capitalized)
.disabled(true)
}
}
and there was no visual or interaction difference between disabling and not here.

This seems currently not supported in pure SwiftUI. However, you can try wrapping NSPopUpButton in NSViewRepresentable, like this:
/// SwiftUI wrapper for NSPopUpButton which allows items to be disabled, which is currently not supported in SwiftUI's Picker
struct PopUpButtonPicker<Item: Equatable>: NSViewRepresentable {
final class Coordinator: NSObject {
private let parent: PopUpButtonPicker
init(parent: PopUpButtonPicker) {
self.parent = parent
}
#IBAction
func selectItem(_ sender: NSPopUpButton) {
let selectedItem = self.parent.items[sender.indexOfSelectedItem]
print("selected item \(selectedItem) at index=\(sender.indexOfSelectedItem)")
self.parent.selection = selectedItem
}
}
let items: [Item]
var isItemEnabled: (Item) -> Bool = { _ in true }
#Binding var selection: Item
let titleProvider: (Item) -> String
func makeCoordinator() -> Coordinator {
Coordinator(parent: self)
}
func makeNSView(context: Self.Context) -> NSPopUpButton {
let popUpButton = NSPopUpButton(frame: .zero, pullsDown: false)
popUpButton.autoenablesItems = false
popUpButton.target = context.coordinator
popUpButton.action = #selector(Coordinator.selectItem(_:))
for item in items.enumerated() {
popUpButton.addItem(withTitle: self.titleProvider(item.element))
// in order for this to work, autoenablesItems must be set to false
popUpButton.menu?.item(at: item.offset)?.isEnabled = self.isItemEnabled(item.element)
}
if let selectedIndex = self.items.firstIndex(where: { $0 == self.selection }) {
popUpButton.selectItem(at: selectedIndex)
}
return popUpButton
}
func updateNSView(_ view: NSPopUpButton, context: Self.Context) { }
}
// MARK: - Usage
struct ContentView: View {
private let items: [Int] = [1, 2, 3, 4, 5]
#State private var selectedValue: Int = 0
var body: some View {
PopUpButtonPicker(items: self.items, isItemEnabled: { $0 != 4 }, selection: self.$selectedValue, titleProvider: String.init)
}
}

Related

Array Binding in NSViewRepresentable Updating Incorrectly After Sorting

I have a ForEach binding to an array of items. Each item has an index (which represents how it should be sorted), and some text. Each row in the ForEach has an NSTextView in an NSViewRepresentable (I can't use TextEditor for various reasons), which uses the binding for the item's text. However, after sorting the list, if I update the NSTextView, one of the other views gets the update as well:
Here's my code:
struct ListItem: Hashable, Identifiable {
var index: Int
var text: String
var id = UUID()
static let initialItems: [ListItem] = [
.init(index: 2, text: "String 2"),
.init(index: 0, text: "String 0"),
.init(index: 1, text: "String 1"),
]
}
struct ContentView: View {
#State var items = ListItem.initialItems
var body: some View {
Form {
ForEach($items) { item in
HStack {
TextField("Index: ", value: item.index, format: .number)
.textFieldStyle(.roundedBorder)
TVRep(text: item.text)
}
}
Button("Sort!") {
items.sort(by: {$0.index < $1.index})
}
}
.padding()
}
}
struct TVRep: NSViewRepresentable {
#Binding var text: String
func makeNSView(context: Context) -> NSTextView {
let view = NSTextView()
view.string = text
view.delegate = context.coordinator
return view
}
func updateNSView(_ nsView: NSTextView, context: Context) {
nsView.string = text
}
func makeCoordinator() -> Coordinator {
Coordinator(parent: self)
}
class Coordinator: NSObject, NSTextViewDelegate {
var parent: TVRep!
init(parent: TVRep) {
super.init()
self.parent = parent
}
func textDidChange(_ notification: Notification) {
guard let tv = notification.object as? NSTextView else {return}
parent.text = tv.string
}
}
}
This doesn't occur when using SwiftUI's built-in TextEditor. Interestingly, this only seems to happen when I update the text binding's value within the Representable view - if I don't have the delegate method updating the binding value, this doesn't occur.
I do know that if I call sorted(by:) in the ForEach argument that it will update properly, but that means that the moment that the TextField for the index is updated, the views are sorted, while I want to be able to sort them manually.

SwiftUI Binding Edits Wrong TextField after Item Reordered

Xcode 13 beta 5, iOS 14, macOS 11.6
I have a parent SwiftUI view that lists some children. Each child is bound to an NSViewRepresentable. Everything works and I can edit the values as expected. But once I reorder the items in the list and edit a field, it edits the wrong field. It appears that the binding remains intact from the previous item order.
Here's what that looks like:
Here's the parent:
struct ParentView: View {
#StateObject var model = ThingModel.shared
var body: some View {
VStack{
ForEach($model.things){ $thing in
ChildView(thing: $thing)
//Reorder
.onDrag{
model.draggedThing = thing
return NSItemProvider(object: NSString())
}
}
Text("Value: \(model.value)").font(.title)
}
.frame(width:300, height: 200)
}
}
...and here's the child view:
struct ChildView: View {
#Binding var thing: Thing
#StateObject var model = ThingModel.shared
var body: some View{
HStack{
GrowingField(text: $thing.text, submit: {
model.value = thing.text
print(thing.text)
})
Text(" = ")
.opacity(0.4)
}
.padding(10)
.onDrop(of: [UTType.text], delegate: ThingReorderDelegate(hoveredThing: thing))
}
}
Last of all, here is the NSViewRepresentable which is called GrowingField. For simplicity, I have omitted the NSTextField subclass.
struct GrowingField: NSViewRepresentable{
#Binding var text: String
var submit:(() -> Void)? //Hit enter
func makeNSView(context: Context) -> NSTextField {
let textField = NSTextField()
textField.delegate = context.coordinator
textField.stringValue = text
return textField
}
func updateNSView(_ nsView: NSTextField, context: Context) {
nsView.stringValue = text
context.coordinator.textBinding = $text
}
//Delegates
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, NSTextFieldDelegate {
let parent: GrowingField
var textBinding : Binding<String>?
init(_ field: GrowingField) {
self.parent = field
}
func controlTextDidChange(_ obj: Notification) {
guard let textField = obj.object as? NSTextField else { return }
self.textBinding?.wrappedValue = textField.stringValue
}
//Listen for certain keyboard keys
func control(_ control: NSControl, textView: NSTextView, doCommandBy commandSelector: Selector) -> Bool {
switch commandSelector{
case #selector(NSStandardKeyBindingResponding.insertNewline(_:)):
//- Enter -
parent.submit?()
textView.window?.makeFirstResponder(nil) //Blur cursor
return true
default:
return false
}
}
}
}
Why does the binding to the NSViewRepresentable not follow the field after it is reordered?
Here is a sample project to download and try it out.
I believe the issue (bug?) is with the ForEach-generated binding.
If you forego the generated binding and create your own, everything seems to work as expected.
Added to the ThingModel:
func bindingForThing(id: String) -> Binding<Thing> {
.init {
self.things.first { $0.id == id }!
} set: { newThing in
self.things = self.things.map { $0.id == id ? newThing : $0 }
}
}
And the ParentView:
ForEach(model.things){ thing in
ChildView(thing: model.bindingForThing(id: thing.id))

SwiftUI: Custom UITextView UIViewRepresentable requires double tap on the first action to work, works fine with single taps thereafter

I've built this small demo view where I have two NoteRows and my goal is to be able to press the return key to create a new row and for it to become the first responder. This works, however, the first time around, the new row is created but it doesn't become the first responder. Subsequent taps of the return key both create the row and become first responder.
Any ideas what's going wrong here? Thanks!
import SwiftUI
import Combine
struct FirstResponderDemo: View {
#State private var rows: [NoteRow] = [
.init(parentNoteId: "1", text: "foo"),
.init(parentNoteId: "1", text: "bar"),
]
#State private var activeRowId: String?
var body: some View {
ScrollViewReader { proxy in
ScrollView {
VStack {
ForEach(rows, id: \.id) { row in
ResponderTextView(
row: row,
text: $login,
activeRowId: $activeRowId,
returnPressed: returnPressed
)
.frame(width: 300, height: 44)
}
}.padding(.horizontal, 12)
}
}
.onAppear {
self.activeRowId = rows[0].id
}
}
private func returnPressed() {
guard let id = activeRowId else { return }
let newRow = NoteRow(parentNoteId: "1", text: "")
print("new row id", newRow.id)
if let index = rows.firstIndex(where: { $0.id == id }) {
rows.insert(newRow, at: index + 1)
activeRowId = newRow.id
}
}
}
struct FirstResponderDemo_Previews: PreviewProvider {
static var previews: some View {
FirstResponderDemo()
}
}
struct ResponderView<View: UIView>: UIViewRepresentable {
let row: NoteRow
#Binding var activeRowId: String?
var configuration = { (view: View) in }
func makeUIView(context: Context) -> View { View() }
func makeCoordinator() -> Coordinator {
Coordinator(row: row, activeRowId: $activeRowId)
}
func updateUIView(_ uiView: View, context: Context) {
context.coordinator.view = uiView
// print(activeRowId)
_ = activeRowId == row.id ? uiView.becomeFirstResponder() : uiView.resignFirstResponder()
configuration(uiView)
}
}
// MARK: - Coordinator
extension ResponderView {
final class Coordinator {
#Binding private var activeRowId: String?
private var anyCancellable: AnyCancellable?
fileprivate weak var view: UIView?
init(row: NoteRow, activeRowId: Binding<String?>) {
_activeRowId = activeRowId
self.anyCancellable = Publishers.keyboardHeight.sink(receiveValue: { [weak self] keyboardHeight in
guard let view = self?.view, let self = self else { return }
DispatchQueue.main.async {
if view.isFirstResponder {
self.activeRowId = row.id
print("active row id is:", self.activeRowId)
}
}
})
}
}
}
// MARK: - keyboardHeight
extension Publishers {
static var keyboardHeight: AnyPublisher<CGFloat, Never> {
let willShow = NotificationCenter.default.publisher(for: UIApplication.keyboardWillShowNotification)
.map { ($0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect)?.height ?? 0 }
let willHide = NotificationCenter.default.publisher(for: UIApplication.keyboardWillHideNotification)
.map { _ in CGFloat(0) }
return MergeMany(willShow, willHide)
.eraseToAnyPublisher()
}
}
struct ResponderView_Previews: PreviewProvider {
static var previews: some View {
ResponderView<UITextView>.init(row: .init(parentNoteId: "1", text: "Hello world"), activeRowId: .constant(nil)) { _ in
}.previewLayout(.fixed(width: 300, height: 40))
}
}
struct ResponderTextView: View {
let row: NoteRow
#State var text: String
#Binding var activeRowId: String?
private var textViewDelegate: TextViewDelegate
init(row: NoteRow, text: Binding<String>, activeRowId: Binding<String?>, returnPressed: #escaping () -> Void) {
self.row = row
self._text = State(initialValue: row.text)
self._activeRowId = activeRowId
self.textViewDelegate = TextViewDelegate(text: text, returnPressed: returnPressed)
}
var body: some View {
ResponderView<UITextView>(row: row, activeRowId: $activeRowId) {
$0.text = self.text
$0.delegate = self.textViewDelegate
}
}
}
// MARK: - TextFieldDelegate
private extension ResponderTextView {
final class TextViewDelegate: NSObject, UITextViewDelegate {
#Binding private(set) var text: String
let returnPressed: () -> Void
init(text: Binding<String>, returnPressed: #escaping () -> Void) {
_text = text
self.returnPressed = returnPressed
}
func textViewDidChange(_ textView: UITextView) {
DispatchQueue.main.async {
self.text = textView.text
}
}
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
if (text == "\n") {
returnPressed()
return false
}
return true
}
}
}
And the definition of NoteRow:
final class NoteRow: ObservableObject, Identifiable {
let id: String = UUID().uuidString
let parentNoteId: String
let text: String
init(parentNoteId: String, text: String) {
self.parentNoteId = parentNoteId
self.text = text
}
}
extension NoteRow: Equatable {
static func == (lhs: NoteRow, rhs: NoteRow) -> Bool {
lhs.id == rhs.id &&
lhs.parentNoteId == rhs.parentNoteId
}
}
Edit: Debugging this more
active row id is: Optional("71D8839A-D046-4DC5-8E02-F124779309E6") // first default row
active row id is: Optional("5937B1D0-CBB0-4BE4-A235-4D57835D7B0F") // second default row
// I hit return key:
new row id F640D1F9-0708-4099-BDA4-2682AF82E3BD
active row id is: Optional("5937B1D0-CBB0-4BE4-A235-4D57835D7B0F") // ID for 2nd row is set as active for some reason
// After that, new row id and active row ID follow the expected path:
new row id 9FDEB548-E19F-4572-BAD3-00E6CBB951D1
active row id is: Optional("9FDEB548-E19F-4572-BAD3-00E6CBB951D1")
new row id 4B5C1AA3-15A1-4449-B1A2-9D834013496A
active row id is: Optional("4B5C1AA3-15A1-4449-B1A2-9D834013496A")
new row id 22A61BE8-1BAD-4209-B46B-15666FF82D9B
active row id is: Optional("22A61BE8-1BAD-4209-B46B-15666FF82D9B")
new row id 95DD6B33-4421-4A32-8478-DCCBCBB1824E
active row id is: Optional("95DD6B33-4421-4A32-8478-DCCBCBB1824E")
Ok, I did not get idea of this code, but the below fixes case in question (tested with Xcode 12b)
if (text == "\n") {
DispatchQueue.main.async { // << defer to next event !!
self.returnPressed()
}
return false
}
return true
}

#State updates view but #ObservedObject does not

I have a view:
struct Form: View {
#ObservedObject var model = FormInput()
var body: some View {
Form {
TextArea("Details", text: $model.details.value)
.validation(message: model.details.message)
}
}
}
Where TextArea is a custom view and .validation(message: model.details.message) is a custom view modifier. My FormInput looks as follows:
final class FormInput: ObservableObject {
#Published var details: TextInput
// ... other code
}
TextInput is a custom struct.
Now when I run the above code the validation never triggers because the Form never re-renders, but if I change the Form to:
struct MyForm: View {
#State var details = TextInput()
var body: some View {
Form {
TextArea("Details", text: $details.value)
.validation(message: details.message)
}
}
}
Then everything works as expected. Why would the view render for the second version of Form but not for the first? Shouldn't the Form in the first case update when details changes since details is #Published and the Form is observing the changes?
ADDITIONAL CONTEXT
Below is additional code for the above components
final class FormInput: ObservableObject {
#Published var details: TextInput
init(details: String = "") {
self.details = TextInput(value: details, isValid: false, validations: [.length(12)])
}
// other code
}
struct TextInput {
var value: String {
didSet {
self.validate()
}
}
var validations: [TextValidation] // this is just an enum of different types of validations
var isValid: Bool
var message: String
mutating func validate() {
for validation in validations {
// run validation
}
}
}
struct TextArea: View {
#Binding var text: String
#State var height: CGFloat = 12
init(text: Binding<String>) {
self._text = text
}
var body: some View {
TextAreaField(text: $text)
}
}
struct TextAreaField: UIViewRepresentable {
#Binding var text: String
#Binding var height: CGFloat
func makeUIView(context: Context) -> UITextView {
let textField = UITextView()
textField.isEditable = true
textField.isSelectable = true
textField.isUserInteractionEnabled = true
textField.isScrollEnabled = false
// ..other initializers removed for brevity
textField.delegate = context.coordinator
return textField
}
func updateUIView(_ uiView: UITextView, context: Context) {
calculateHeight(uiView)
}
func calculateHeight(_ uiView: UIView) {
let newSize = uiView.sizeThatFits(CGSize(width: uiView.frame.size.width, height: CGFloat.greatestFiniteMagnitude))
if self.height != newSize.height {
DispatchQueue.main.async {
self.height = newSize.height
}
}
}
func makeCoordinator() -> Coordinator {
return Coordinator(self)
}
final class Coordinator: NSObject, UITextViewDelegate {
var parent: TextAreaField
init(_ parent: TextAreaField) {
self.parent = parent
}
func textViewDidChange(_ uiView: UITextView) {
self.parent.text = uiView.text
self.parent.calculateHeight(uiView)
}
}
}
struct Validation: ViewModifier {
let message: String
func body(content: Content) -> some View {
let isValid = message == ""
print(message)
return VStack(alignment: .leading) {
content
if isValid == false {
Text(message)
.font(.footnote)
.italic()
.foregroundColor(Color.red)
.frame(height: 24)
}
}
.padding(.bottom, isValid ? 24 : 0)
}
}
extension View {
func validation(message: String) -> some View {
self.modifier(Validation(message: message))
}
}
I suppose the issue is in absent custom components. Because below simple demo replication of provided infrastructure works well with ObservableObject, actually as expected.
Tested with Xcode 11.4 / iOS 13.4. Comparing with below demo might be helpful to find what is missed in your code.
struct TextInput {
var value: String = "" {
didSet {
message = value // just duplication for demo
}
}
var message: String = ""
}
// simple validator highlighting text when too long
struct ValidationModifier: ViewModifier {
var text: String
func body(content: Content) -> some View {
content.foregroundColor(text.count > 5 ? Color.red : Color.primary)
}
}
extension View { // replicated
func validation(message: String) -> some View {
self.modifier(ValidationModifier(text: message))
}
}
struct MyForm: View { // avoid same names with standard views
#ObservedObject var model = FormInput()
var body: some View {
Form {
TextField("Details", text: $model.details.value) // used standard
.validation(message: model.details.message)
}
}
}
final class FormInput: ObservableObject {
#Published var details: TextInput = TextInput()
}
struct TestObservedInModifier: View {
var body: some View {
MyForm()
}
}

SwiftUI: How to make TextField become first responder?

Here's my SwiftUI code:
struct ContentView : View {
#State var showingTextField = false
#State var text = ""
var body: some View {
return VStack {
if showingTextField {
TextField($text)
}
Button(action: { self.showingTextField.toggle() }) {
Text ("Show")
}
}
}
}
What I want is when the text field becomes visible, to make the text field become the first responder (i.e. receive focus & have the keyboard pop up).
Using SwiftUI-Introspect, you can do:
TextField("", text: $value)
.introspectTextField { textField in
textField.becomeFirstResponder()
}
Swift UI 3
As of Xcode 13, you can use the focused modifier to make a view become first responder.
Swift UI 1/2
It doesn't seem to be possible at the moment, but you can implement something similar yourself.
You can create a custom text field and add a value to make it become first responder.
struct CustomTextField: UIViewRepresentable {
class Coordinator: NSObject, UITextFieldDelegate {
#Binding var text: String
var didBecomeFirstResponder = false
init(text: Binding<String>) {
_text = text
}
func textFieldDidChangeSelection(_ textField: UITextField) {
text = textField.text ?? ""
}
}
#Binding var text: String
var isFirstResponder: Bool = false
func makeUIView(context: UIViewRepresentableContext<CustomTextField>) -> UITextField {
let textField = UITextField(frame: .zero)
textField.delegate = context.coordinator
return textField
}
func makeCoordinator() -> CustomTextField.Coordinator {
return Coordinator(text: $text)
}
func updateUIView(_ uiView: UITextField, context: UIViewRepresentableContext<CustomTextField>) {
uiView.text = text
if isFirstResponder && !context.coordinator.didBecomeFirstResponder {
uiView.becomeFirstResponder()
context.coordinator.didBecomeFirstResponder = true
}
}
}
Note: didBecomeFirstResponder is needed to make sure the text field becomes first responder only once, not on every refresh by SwiftUI!
You would use it like this...
struct ContentView : View {
#State var text: String = ""
var body: some View {
CustomTextField(text: $text, isFirstResponder: true)
.frame(width: 300, height: 50)
.background(Color.red)
}
}
P.S. I added a frame as it doesn't behave like the stock TextField, meaning there's more stuff going on behind the scenes.
More on Coordinators in this excellent WWDC 19 talk:
Integrating SwiftUI
Tested on Xcode 11.4
iOS 15
There is a new wrapper called #FocusState that controls the state of the keyboard and the focused keyboard ('aka' firstResponder).
Become First Responder ( Focused )
If you use a focused modifier on the text fields, you can make them become focused:
Resign first responder ( Dismiss keyboard )
or dismiss the keyboard by setting the variable to nil:
iOS 13 and above: Old but working!
Simple wrapper struct - Works like a native:
Note that Text binding support added as requested in the comments
struct LegacyTextField: UIViewRepresentable {
#Binding public var isFirstResponder: Bool
#Binding public var text: String
public var configuration = { (view: UITextField) in }
public init(text: Binding<String>, isFirstResponder: Binding<Bool>, configuration: #escaping (UITextField) -> () = { _ in }) {
self.configuration = configuration
self._text = text
self._isFirstResponder = isFirstResponder
}
public func makeUIView(context: Context) -> UITextField {
let view = UITextField()
view.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
view.addTarget(context.coordinator, action: #selector(Coordinator.textViewDidChange), for: .editingChanged)
view.delegate = context.coordinator
return view
}
public func updateUIView(_ uiView: UITextField, context: Context) {
uiView.text = text
configuration(uiView)
switch isFirstResponder {
case true: uiView.becomeFirstResponder()
case false: uiView.resignFirstResponder()
}
}
public func makeCoordinator() -> Coordinator {
Coordinator($text, isFirstResponder: $isFirstResponder)
}
public class Coordinator: NSObject, UITextFieldDelegate {
var text: Binding<String>
var isFirstResponder: Binding<Bool>
init(_ text: Binding<String>, isFirstResponder: Binding<Bool>) {
self.text = text
self.isFirstResponder = isFirstResponder
}
#objc public func textViewDidChange(_ textField: UITextField) {
self.text.wrappedValue = textField.text ?? ""
}
public func textFieldDidBeginEditing(_ textField: UITextField) {
self.isFirstResponder.wrappedValue = true
}
public func textFieldDidEndEditing(_ textField: UITextField) {
self.isFirstResponder.wrappedValue = false
}
}
}
Usage:
struct ContentView: View {
#State var text = ""
#State var isFirstResponder = false
var body: some View {
LegacyTextField(text: $text, isFirstResponder: $isFirstResponder)
}
}
🎁 Bonus: Completely customizable
LegacyTextField(text: $text, isFirstResponder: $isFirstResponder) {
$0.textColor = .red
$0.tintColor = .blue
}
This method is fully adaptable. For example, you can see How to add an Activity indicator in SwiftUI with the same method here
iOS 15.0+
macOS 12.0+,
Mac Catalyst 15.0+,
tvOS 15.0+,
watchOS 8.0+
Use focused(_:) if you have a single TextField.
focused(_:)
Modifies this view by binding its focus state to the given Boolean state value.
struct NameForm: View {
#FocusState private var isFocused: Bool
#State private var name = ""
var body: some View {
TextField("Name", text: $name)
.focused($isFocused)
Button("Submit") {
if name.isEmpty {
isFocued = true
}
}
}
}
Use focused(_:equals:) should you have multiple TextFields.
focused(_:equals:)
Modifies this view by binding its focus state to the given state value.
struct LoginForm: View {
enum Field: Hashable {
case usernameField
case passwordField
}
#State private var username = ""
#State private var password = ""
#FocusState private var focusedField: Field?
var body: some View {
Form {
TextField("Username", text: $username)
.focused($focusedField, equals: .usernameField)
SecureField("Password", text: $password)
.focused($focusedField, equals: .passwordField)
Button("Sign In") {
if username.isEmpty {
focusedField = .usernameField
} else if password.isEmpty {
focusedField = .passwordField
} else {
handleLogin(username, password)
}
}
}
}
}
SwiftUI Documentation
focused(_:)
focused(_:equals:)
#FocusState
Update
I tested this in Xcode version 13.0 beta 5 (13A5212g). It works
For anyone who ended up here but faced crashed using #Matteo Pacini's answer, please be aware of this change in beta 4: Cannot assign to property: '$text' is immutable about this block:
init(text: Binding<String>) {
$text = text
}
should use:
init(text: Binding<String>) {
_text = text
}
And if you want to make the textfield become first responder in a sheet, please be aware that you cannot call becomeFirstResponder until the textfield is shown. In other words, putting #Matteo Pacini's textfield directly in sheet content causes crash.
To solve the issue, add an additional check uiView.window != nil for textfield's visibility. Only focus after it is in the view hierarchy:
struct AutoFocusTextField: UIViewRepresentable {
#Binding var text: String
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIView(context: UIViewRepresentableContext<AutoFocusTextField>) -> UITextField {
let textField = UITextField()
textField.delegate = context.coordinator
return textField
}
func updateUIView(_ uiView: UITextField, context:
UIViewRepresentableContext<AutoFocusTextField>) {
uiView.text = text
if uiView.window != nil, !uiView.isFirstResponder {
uiView.becomeFirstResponder()
}
}
class Coordinator: NSObject, UITextFieldDelegate {
var parent: AutoFocusTextField
init(_ autoFocusTextField: AutoFocusTextField) {
self.parent = autoFocusTextField
}
func textFieldDidChangeSelection(_ textField: UITextField) {
parent.text = textField.text ?? ""
}
}
}
📦 ResponderChain
I made this small package for cross-platform first responder handling without subclassing views or making custom ViewRepresentables in SwiftUI on iOS 13+
https://github.com/Amzd/ResponderChain
How to apply it to your problem
SceneDelegate.swift
...
// Set the ResponderChain as environmentObject
let rootView = ContentView().environmentObject(ResponderChain(forWindow: window))
...
ContentView.swift
struct ContentView: View {
#EnvironmentObject var chain: ResponderChain
#State var showingTextField = false
#State var text = ""
var body: some View {
return VStack {
if showingTextField {
TextField($text).responderTag("field1").onAppear {
DispatchQueue.main.async {
chain.firstResponder = "field1"
}
}
}
Button(action: { self.showingTextField.toggle() }) {
Text ("Show")
}
}
}
}
In my case I wanted to focused a textfield just right away I used .onappear function
struct MyView: View {
#FocusState private var isTitleTextFieldFocused: Bool
#State private var title = ""
var body: some View {
VStack {
TextField("Title", text: $title)
.focused($isTitleTextFieldFocused)
}
.padding()
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
self.isTitleTextFieldFocused = true
}
}
}
}
As others have noted (e.g. #kipelovets comment on the accepted answer, e.g. #Eonil's answer), I have also not found any of the accepted solutions to work on macOS. I've had some luck, however, using NSViewControllerRepresentable to get a NSSearchField to appear as the first responder in a SwiftUI view:
import Cocoa
import SwiftUI
class FirstResponderNSSearchFieldController: NSViewController {
#Binding var text: String
init(text: Binding<String>) {
self._text = text
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
let searchField = NSSearchField()
searchField.delegate = self
self.view = searchField
}
override func viewDidAppear() {
self.view.window?.makeFirstResponder(self.view)
}
}
extension FirstResponderNSSearchFieldController: NSSearchFieldDelegate {
func controlTextDidChange(_ obj: Notification) {
if let textField = obj.object as? NSTextField {
self.text = textField.stringValue
}
}
}
struct FirstResponderNSSearchFieldRepresentable: NSViewControllerRepresentable {
#Binding var text: String
func makeNSViewController(
context: NSViewControllerRepresentableContext<FirstResponderNSSearchFieldRepresentable>
) -> FirstResponderNSSearchFieldController {
return FirstResponderNSSearchFieldController(text: $text)
}
func updateNSViewController(
_ nsViewController: FirstResponderNSSearchFieldController,
context: NSViewControllerRepresentableContext<FirstResponderNSSearchFieldRepresentable>
) {
}
}
Sample SwiftUI view:
struct ContentView: View {
#State private var text: String = ""
var body: some View {
FirstResponderNSSearchFieldRepresentable(text: $text)
}
}
To fill in this missing functionality, you may install SwiftUIX using Swift Package Manager:
In Xcode, open your project and navigate to File → Swift Packages → Add Package Dependency...
Paste the repository URL (https://github.com/SwiftUIX/SwiftUIX) and click Next.
For Rules, select Branch (with branch set to master).
Click Finish.
Open the Project settings, add SwiftUI.framework to the Linked Frameworks and Libraries, set Status to Optional.
More Info: https://github.com/SwiftUIX/SwiftUIX
import SwiftUI
import SwiftUIX
struct ContentView : View {
#State var showingTextField = false
#State var text = ""
var body: some View {
return VStack {
if showingTextField {
CocoaTextField("Placeholder text", text: $text)
.isFirstResponder(true)
.frame(width: 300, height: 48, alignment: .center)
}
Button(action: { self.showingTextField.toggle() }) {
Text ("Show")
}
}
}
}
SwiftUI
struct ContentView: View {
enum Field {
case firstTextfield
case secondTextfield
case lastTextfield
}
#State private var firstTextfield = ""
#State private var secondTextfield = ""
#State private var lastTextfield = ""
#FocusState private var focusedField: Field?
var body: some View {
VStack {
TextField("Enter anything on first textfield", text: $firstTextfield)
.focused($focusedField, equals: .firstTextfield)
.submitLabel(.next)
TextField("Enter anything on second textfield", text: $secondTextfield)
.focused($focusedField, equals: .secondTextfield)
.submitLabel(.next)
TextField("Enter anything on last textfield", text: $lastTextfield)
.focused($focusedField, equals: .lastTextfield)
.submitLabel(.join)
}
.onSubmit {
switch focusedField {
case .firstTextfield:
focusedField = .secondTextfield
case .secondTextfield:
focusedField = .lastTextfield
default:
focusedField = nil
}
}
}
}
Description: Add an enum with textfields cases, and a property wrapped in a #FocusState with type of that enum. Add focused(_:equals:) modifier to have a binding value, equal to the enum cases. Now, you can change the focusedField to whichever textfield you want to have cursor on, or resign first responder by assigning nil to focusedField.
Not really an answer, just building on Casper's great solution with a convenient modifier -
struct StartInput: ViewModifier {
#EnvironmentObject var chain: ResponderChain
private let tag: String
init(tag: String) {
self.tag = tag
}
func body(content: Content) -> some View {
content.responderTag(tag).onAppear() {
DispatchQueue.main.async {
chain.firstResponder = tag
}
}
}
}
extension TextField {
func startInput(_ tag: String = "field") -> ModifiedContent<TextField<Label>, StartInput> {
self.modifier(StartInput(tag: tag))
}
}
Just use like -
TextField("Enter value:", text: $quantity)
.startInput()
This is a ViewModifier that works with introspect. It works for AppKit MacOS, Xcode 11.5
struct SetFirstResponderTextField: ViewModifier {
#State var isFirstResponderSet = false
func body(content: Content) -> some View {
content
.introspectTextField { textField in
if self.isFirstResponderSet == false {
textField.becomeFirstResponder()
self.isFirstResponderSet = true
}
}
}
}
We have a solution that makes controlling the first responder effortless.
https://github.com/mobilinked/MbSwiftUIFirstResponder
TextField("Name", text: $name)
.firstResponder(id: FirstResponders.name, firstResponder: $firstResponder, resignableUserOperations: .all)
TextEditor(text: $notes)
.firstResponder(id: FirstResponders.notes, firstResponder: $firstResponder, resignableUserOperations: .all)
Selected answer causes some infinite loop issue with AppKit. I don't know about UIKit case.
To avoid that issue, I recommend just sharing NSTextField instance directly.
import AppKit
import SwiftUI
struct Sample1: NSViewRepresentable {
var textField: NSTextField
func makeNSView(context:NSViewRepresentableContext<Sample1>) -> NSView { textField }
func updateNSView(_ x:NSView, context:NSViewRepresentableContext<Sample1>) {}
}
You can use that like this.
let win = NSWindow()
let txt = NSTextField()
win.setIsVisible(true)
win.setContentSize(NSSize(width: 256, height: 256))
win.center()
win.contentView = NSHostingView(rootView: Sample1(textField: txt))
win.makeFirstResponder(txt)
let app = NSApplication.shared
app.setActivationPolicy(.regular)
app.run()
This breaks pure value semantic, but depending on AppKit means you partially abandon pure value semantic and gonna afford some dirtiness. This is a magic hole we need right now for deal with lack of first-responder control in SwiftUI.
As we access NSTextField directly, setting first-responder is plain AppKit way, therefore no visible source of trouble.
You can download working source code here.
I took a little bit different approach - instead of UIViewRepresentable based on UITextField i made it based on UIView and and plug it in SwiftUI view hierarchy with background modifier. Inside UIView i added logic to find first view that canBecomeFirstResponder in subviews and parent views.
private struct FocusableUIView: UIViewRepresentable {
var isFirstResponder: Bool = false
class Coordinator: NSObject {
var didBecomeFirstResponder = false
}
func makeUIView(context: UIViewRepresentableContext<FocusableUIView>) -> UIView {
let view = UIView()
view.backgroundColor = .clear
return view
}
func makeCoordinator() -> FocusableUIView.Coordinator {
return Coordinator()
}
func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<FocusableUIView>) {
guard uiView.window != nil, isFirstResponder, !context.coordinator.didBecomeFirstResponder else {
return
}
var foundRepsonder: UIView?
var currentSuperview: UIView? = uiView
repeat {
foundRepsonder = currentSuperview?.subviewFirstPossibleResponder
currentSuperview = currentSuperview?.superview
} while foundRepsonder == nil && currentSuperview != nil
guard let responder = foundRepsonder else {
return
}
DispatchQueue.main.async {
responder.becomeFirstResponder()
context.coordinator.didBecomeFirstResponder = true
}
}
}
private extension UIView {
var subviewFirstPossibleResponder: UIView? {
guard !canBecomeFirstResponder else { return self }
for subview in subviews {
if let firstResponder = subview.subviewFirstPossibleResponder {
return firstResponder
}
}
return nil
}
}
Here is an example how to use it to make TextField to autofocus (+ bonus utilise #FocusState new iOS 15 api).
extension View {
#ViewBuilder
func autofocus() -> some View {
if #available(iOS 15, *) {
modifier(AutofocusedViewModifiers.Modern())
} else {
modifier(AutofocusedViewModifiers.Legacy())
}
}
}
private enum AutofocusedViewModifiers {
struct Legacy: ViewModifier {
func body(content: Content) -> some View {
content
.background(FocusableUIView(isFirstResponder: isFocused))
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
isFocused = true
}
}
}
#State private var isFocused = false
}
#available(iOS 15, *)
struct Modern: ViewModifier {
func body(content: Content) -> some View {
content
.focused($isFocused)
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
isFocused = true
}
}
}
#FocusState private var isFocused: Bool
}
}
Content view example:
struct ContentView: View {
#State private var text = ""
var body: some View {
VStack {
TextField("placeholder", text: $text)
Text("some text")
}
.autofocus()
}
}
Since Responder Chain is not available to be consumed via SwiftUI, so we have to consume it using UIViewRepresentable.
Do have a look at the below link as I have made a workaround that can work similarly to the way we use to do using UIKit.
https://stackoverflow.com/a/61121199/6445871
It is my variant of the implementation, based on #Mojtaba Hosseini and #Matteo Pacini solutions.
I am still new to SwiftUI, so I won't guarantee the absolute correctness of the code, but it works.
I hope it would be helpful to someone.
ResponderView: It is a generic-responder view, that could be used with any UIKit view.
struct ResponderView<View: UIView>: UIViewRepresentable {
#Binding var isFirstResponder: Bool
var configuration = { (view: View) in }
func makeUIView(context: UIViewRepresentableContext<Self>) -> View { View() }
func makeCoordinator() -> Coordinator {
Coordinator($isFirstResponder)
}
func updateUIView(_ uiView: View, context: UIViewRepresentableContext<Self>) {
context.coordinator.view = uiView
_ = isFirstResponder ? uiView.becomeFirstResponder() : uiView.resignFirstResponder()
configuration(uiView)
}
}
// MARK: - Coordinator
extension ResponderView {
final class Coordinator {
#Binding private var isFirstResponder: Bool
private var anyCancellable: AnyCancellable?
fileprivate weak var view: UIView?
init(_ isFirstResponder: Binding<Bool>) {
_isFirstResponder = isFirstResponder
self.anyCancellable = Publishers.keyboardHeight.sink(receiveValue: { [weak self] keyboardHeight in
guard let view = self?.view else { return }
DispatchQueue.main.async { self?.isFirstResponder = view.isFirstResponder }
})
}
}
}
// MARK: - keyboardHeight
extension Publishers {
static var keyboardHeight: AnyPublisher<CGFloat, Never> {
let willShow = NotificationCenter.default.publisher(for: UIApplication.keyboardWillShowNotification)
.map { ($0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect)?.height ?? 0 }
let willHide = NotificationCenter.default.publisher(for: UIApplication.keyboardWillHideNotification)
.map { _ in CGFloat(0) }
return MergeMany(willShow, willHide)
.eraseToAnyPublisher()
}
}
struct ResponderView_Previews: PreviewProvider {
static var previews: some View {
ResponderView<UITextField>.init(isFirstResponder: .constant(false)) {
$0.placeholder = "Placeholder"
}.previewLayout(.fixed(width: 300, height: 40))
}
}
ResponderTextField - It is a convenient text-field wrapper around ResponderView.
struct ResponderTextField: View {
var placeholder: String
#Binding var text: String
#Binding var isFirstResponder: Bool
private var textFieldDelegate: TextFieldDelegate
init(_ placeholder: String, text: Binding<String>, isFirstResponder: Binding<Bool>) {
self.placeholder = placeholder
self._text = text
self._isFirstResponder = isFirstResponder
self.textFieldDelegate = .init(text: text)
}
var body: some View {
ResponderView<UITextField>(isFirstResponder: $isFirstResponder) {
$0.text = self.text
$0.placeholder = self.placeholder
$0.delegate = self.textFieldDelegate
}
}
}
// MARK: - TextFieldDelegate
private extension ResponderTextField {
final class TextFieldDelegate: NSObject, UITextFieldDelegate {
#Binding private(set) var text: String
init(text: Binding<String>) {
_text = text
}
func textFieldDidChangeSelection(_ textField: UITextField) {
text = textField.text ?? ""
}
}
}
struct ResponderTextField_Previews: PreviewProvider {
static var previews: some View {
ResponderTextField("Placeholder",
text: .constant(""),
isFirstResponder: .constant(false))
.previewLayout(.fixed(width: 300, height: 40))
}
}
And way to use that.
struct SomeView: View {
#State private var login: String = ""
#State private var password: String = ""
#State private var isLoginFocused = false
#State private var isPasswordFocused = false
var body: some View {
VStack {
ResponderTextField("Login", text: $login, isFirstResponder: $isLoginFocused)
ResponderTextField("Password", text: $password, isFirstResponder: $isPasswordFocused)
}
}
}
Expanding on #JoshuaKifer answer's above, if you're dealing with the navigation animation being glitchy when using Introspect to make a text field first responder. Use this:
import SchafKit
#State var field: UITextField?
TextField("", text: $value)
.introspectTextField { textField in
field = textField
}
.onDidAppear {
field?.becomeFirstResponder()
}
More details on this solution here.
The correct SwiftUI way is to use #FocusState as mentioned above. However this API is available only for iOS 15. If you are using iOS 14 or iOS 13 you can use the Focuser library which is modelled to follow Apple API.
https://github.com/art-technologies/swift-focuser
Here's an example code. You will notice that API looks almost exactly as Apple, however Focuser also offers to use keyboard to move first responder down the chain which is pretty handy.
If you're having any problem with #JoshuaKifer or #ahaze 's response,
I've solved mine by using the modifier on the parent class, instead of on the TextField itself.
What I was doing:
TextField("Placeholder text...", text: $searchInput)
.introspectTextField { textField in
textField.becomeFirstResponder()
}
How I solved my problem:
YourParentStruct(searchInput: $searchInput)
.introspectTextField { textField in
textField.becomeFirstResponder()
}
I'll put the definition of the parent struct below just for clearness
struct YourParentStruct: View {
#Binding var searchInput: String
var body: some View {
HStack {
TextField("Placeholder text...", text: $searchInput)
.padding()
.background(Color.gray)
.cornerRadius(10)
}
}
}
At its Simplest form in iOS 13 ( without using any third party sdk/repo , or if you havent upgraded to iOS 14 to utilise the focus modifiers)
struct CustomTextField: UIViewRepresentable {
func makeUIView(context: Context) -> UITextField {
UITextField(frame: .zero)
}
func updateUIView(_ uiView: UITextField, context: Context) {
uiView.becomeFirstResponder()
}
}
Usage:
struct ContentView : View {
var body: some View {
CustomTextField()
.frame(width: 300, height: 50)
.background(Color.red)
}
}
I know its too late but if it helps anyone this is how I do it.
import SwiftUI
import Introspect
struct MyView: View {
#Binding var text1: String
#Binding var text2: String
#State private var toggleTF: Bool = false
var body: some View {
TextField("TextField 1", text: $text1)
.introspectTextField{ tF in
if toggleTF {
tF.becomeFirstResponder()
}
}
TextField("TextField 2", text: $text1)
.introspectTextField{ tF in
if !toggleTF {
tF.becomeFirstResponder()
}
}
Button("Toggle textfields") {
toggleTF.toggle()
}
}
}
As SwiftUI 2 doesn't support first responders yet I use this solution. It is dirty, but might work for some use cases when you only have 1 UITextField and 1 UIWindow.
import SwiftUI
struct MyView: View {
#Binding var text: String
var body: some View {
TextField("Hello world", text: $text)
.onAppear {
UIApplication.shared.windows.first?.rootViewController?.view.textField?.becomeFirstResponder()
}
}
}
private extension UIView {
var textField: UITextField? {
subviews.compactMap { $0 as? UITextField }.first ??
subviews.compactMap { $0.textField }.first
}
}