SwiftUI #FocusState when view appears - swiftui

How can I focus on a specific text field when the view appears? I have a basic form where I want the title field is be focused when the modal displays. I have the following code which achieves this but there has to be a cleaner/better way. Can I set the initial value of a #FocusState var to a field or a boolean that then selects the text field when the view appears?
var body: some View {
NavigationView {
VStack {
Form {
TextField("Title", text: $viewModel.title)
.focused($titleIsFocused)
}
}
.navigationBarTitle("New List")
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.6) {
titleIsFocused = true
}
}
}
}
}

Related

How to make a reusable TextPopUp in SwiftUI?

I am having trouble building a reusable SwiftUI text pop up view. I think the problem is the binding but I not sure. It is supposed to be a ContextMenu, but the reason I am not using ContextMenu is it does not show enough lines of text.
So far I have this...
struct TextPopUpView: View {
#EnvironmentObject var oracleViewModel: OracleViewModel
#Binding var showPopover: Bool
var displayedText: String
var popUpText: String
var body: some View {
Text("\(displayedText)")
.font(.title)
.fontWeight(.bold)
.onLongPressGesture {
self.showPopover = true
}
.popover(isPresented: $showPopover) {
Text("\(self.popUpText)")
.frame(width: 250.0)
.onTapGesture {
self.showPopover = false
}
}
}
}
And than I implement it for a particular view like so...
TextPopUpView(showPopover: $showPopover, displayedText: oracleViewModel.***someElement***, popUpText: oracleViewModel.getDescriptionFor***SomeElement***()).environmentObject(oracleViewModel)
where 'someElement' is the particular element text and popup text I want to show.
The problem is when I use TextPopUpView more than once in a view, the Popup view only displays the text for the last implementation on the said page.
I am guessing I am doing something wrong in the implementations of a reusable view, but I am not sure what. Any suggestions?
EDIT: (Example Used in code)
struct TopView: View {
#EnvironmentObject var oracleViewModel: OracleViewModel
#State private var showPopover: Bool = false
***Blarg Blarg Blarg***
VStack{
VStack {
Text("RUNE")
.font(.system(size:10))
.padding(.bottom, 5.0)
TextPopUpView(showPopover: $showPopover,
displayedText: oracleViewModel.rune,
popUpText: oracleViewModel.getDescriptionForRune()).environmentObject(oracleViewModel)
}
.padding(.bottom)
VStack {
Text("ELEMENT")
.font(.system(size:10))
.padding(.bottom, 5.0)
TextPopUpView(showPopover: $showPopover,
displayedText: oracleViewModel.element,
popUpText: oracleViewModel.getDescriptionForElement())
.environmentObject(oracleViewModel)
}
}
***Blarg Blarg Blarg***
}
(For some reason I only get the description for the Element, when I long press either view the TextPopUp is attached to)

Set initial value for a TextField in SwiftUI - compare new and old value

I have seen a lot of examples and tutorial of how to use an empty TextField for collecting new values, but none that shows how to use a TextField to edit a value.
In my use-case, I want the TextField to be prepopulated/prefilled with data from my viewmodel, then as user edits the data, a Save button should be enabled. In my form, I also have a navigationlink that leads to a sub-page where the user can select something from a list, and then be routed back to the form.
It behaves as described as long I use an empty field; the user can type something temporary in the field, navigate to the sub page, and the temp value is still like it was when he left.
struct TextFieldDemo: View {
var model:String // Actual a more complex view model
#State var editedValue:String = ""
var body: some View {
VStack(alignment: .leading, spacing: 20) {
Group{
Text("Some label")
TextField("Placeholder text", text: $editedValue)
}
Divider()
Text("Some navigation link to push in a page where " +
"the user can select something from a list and click back...")
// If the user starts to edit the textfield - follows a navigation link and comes back
// he should be able to continue edit the field where he left of - the text field should
// not have been reset to the original value.
Button(action: {
// Call some save function in the ViewModel
},label: {
Text("SAVE")
}
).disabled(model == editedValue)
}.onAppear(){
// I could have done something like:
// self.editedValue = model
// but it seems like this will fire if the user navigates into the described page and reset
// the TextField to the model value.
}
}
}
struct TextFieldDemo_Previews: PreviewProvider {
static var previews: some View {
TextFieldDemo(model: "The old value")
}
}
To initialize the text field with the value from your model, you need to define your own initializer and use the State(wrappedValue:) initializer for #State vars:
struct TextFieldDemo: View {
var model:String // Actual a more complex view model
#State var editedValue: String
init(model: String) {
self.model = model
self._editedValue = State(wrappedValue: model) // _editedValue is State<String>
}
var body: some View {
VStack(alignment: .leading, spacing: 20) {
Group{
Text("Some label")
TextField("Placeholder text", text: $editedValue)
}
Divider()
Text("Some navigation link to push in a page where " +
"the user can select something from a list and click back...")
// If the user starts to edit the textfield - follows a navigation link and comes back
// he should be able to continue edit the field where he left of - the text field should
// not have been reset to the original value.
Button(action: {
// Call some save function in the ViewModel
},label: {
Text("SAVE")
}
).disabled(model == editedValue)
}.onAppear(){
// I could have done something like:
// self.editedValue = model
// but it seems like this will fire if the user navigates into the described page and reset
// the TextField to the model value.
}
}
}
struct TextFieldDemo_Previews: PreviewProvider {
static var previews: some View {
TextFieldDemo(model: "The old value")
}
}
how about something like this test code. The key is to use the "ObservableObject":
import SwiftUI
class MyModel: ObservableObject {
#Published var model = "model1"
}
struct ContentView: View {
#ObservedObject var myModel = MyModel()
#State var editedValue = ""
var body: some View {
NavigationView {
VStack(alignment: .leading, spacing: 20) {
Group{
Text("Some label")
TextField("Placeholder text", text: Binding<String>(
get: { self.editedValue },
set: {
self.editedValue = $0
self.myModel.model = self.editedValue
})).onAppear(perform: loadData)
}
Divider()
NavigationLink(destination: Text("the nex page")) {
Text("Click Me To Display The next View")
}
// If the user starts to edit the textfield - follows a navigation link and comes back
// he should be able to continue edit the field where he left of - the text field should
// not have been reset to the original value.
Button(action: {
// Call some save function in the ViewModel
self.myModel.model = self.editedValue
},label: {
Text("SAVE")
})
}
}.navigationViewStyle(StackNavigationViewStyle())
}
func loadData() {
self.editedValue = myModel.model
}
}

Unable to repeat Picker Selection

Scenario:
I have a simple picker within a form.
I select a picker item (with chevron) from the form row.
I choose an item (row) from a list of items in the result panel.
The result panel slides away to reveal the original panel.
I am NOT able to repeat this procedure.
Here's my code:
class ChosenView: ObservableObject {
static let choices = ["Modal", "PopOver", "Circle", "CircleImage", "Scroll", "Segment", "Tab", "Multi-Line"]
#Published
var type = 0
}
struct ContentView: View {
#ObservedObject var chosenView = ChosenView()
#State private var isPresented = false
var body: some View {
VStack {
NavigationView {
Form {
Picker(selection: $chosenView.type, label: Text("The Panels")) {
ForEach(0..<ChosenView.choices.count) {
Text(ChosenView.choices[$0]).tag($0)
}
}
}.navigationBarTitle(Text("Available Views"))
.actionSheet(isPresented: $isPresented, content: {
ActionSheet(title: Text("Hello"))
})
}
Section {
Button(action: launchView) {
Text("Select: \(ChosenView.choices[chosenView.type])")
}
}
Spacer()
}
}
private func launchView() {
isPresented = true
}
}
What am I missing?
Why can't I repeat picker selection rather than having to reboot?

SwiftUI: Add ClearButton to TextField

I am trying to add a ClearButton to TextField in SwiftUI when the particular TextField is selected.
The closest I got was creating a ClearButton ViewModifier and adding it to the TextField using .modifer()
The only problem is ClearButton is permanent and does not disappear when TextField is deselected
TextField("Some Text" , text: $someBinding).modifier(ClearButton(text: $someBinding))
struct ClearButton: ViewModifier {
#Binding var text: String
public func body(content: Content) -> some View {
HStack {
content
Button(action: {
self.text = ""
}) {
Image(systemName: "multiply.circle.fill")
.foregroundColor(.secondary)
}
}
}
}
Use ZStack to position the clear button appear inside the TextField.
TextField("Some Text" , text: $someBinding).modifier(ClearButton(text: $someBinding))
struct ClearButton: ViewModifier
{
#Binding var text: String
public func body(content: Content) -> some View
{
ZStack(alignment: .trailing)
{
content
if !text.isEmpty
{
Button(action:
{
self.text = ""
})
{
Image(systemName: "delete.left")
.foregroundColor(Color(UIColor.opaqueSeparator))
}
.padding(.trailing, 8)
}
}
}
}
Use .appearance() to activate the button
var body: some View {
UITextField.appearance().clearButtonMode = .whileEditing
return TextField(...)
}
For reuse try with this:
func TextFieldUIKit(text: Binding<String>) -> some View{
UITextField.appearance().clearButtonMode = .whileEditing
return TextField("Nombre", text: text)
}
=== solution 1(best): Introspect https://github.com/siteline/SwiftUI-Introspect
import Introspect
TextField("", text: $text)
.introspectTextField(customize: {
$0.clearButtonMode = .whileEditing
})
=== solution 2: ViewModifier
public struct ClearButton: ViewModifier {
#Binding var text: String
public init(text: Binding<String>) {
self._text = text
}
public func body(content: Content) -> some View {
HStack {
content
Spacer()
Image(systemName: "multiply.circle.fill")
.foregroundColor(.secondary)
.opacity(text == "" ? 0 : 1)
.onTapGesture { self.text = "" } // onTapGesture or plainStyle button
}
}
}
Usage:
#State private var name: String
...
Form {
Section() {
TextField("NAME", text: $name).modifier(ClearButton(text: $name))
}
}
=== solution 3: global appearance
UITextField.appearance().clearButtonMode = .whileEditing
You can add another Binding in your modifier:
#Binding var visible: Bool
then bind it to opacity of the button:
.opacity(visible ? 1 : 0)
then add another State for checking textField:
#State var showClearButton = true
And lastly update the textfield:
TextField("Some Text", text: $someBinding, onEditingChanged: { editing in
self.showClearButton = editing
}, onCommit: {
self.showClearButton = false
})
.modifier( ClearButton(text: $someBinding, visible: $showClearButton))
Not exactly what you're looking for, but this will let you show/hide the button based on the text contents:
HStack {
if !text.isEmpty {
Button(action: {
self.text = ""
}) {
Image(systemName: "multiply.circle")
}
}
}
After initializing a new project we need to create a simple view modifier which we will apply later to our text field. The view modifier has the tasks to check for content in the text field element and display a clear button inside of it, if content is available. It also handles taps on the button and clears the content.
Let’s have a look at that view modifier:
import SwiftUI
struct TextFieldClearButton: ViewModifier {
#Binding var text: String
func body(content: Content) -> some View {
HStack {
content
if !text.isEmpty {
Button(
action: { self.text = "" },
label: {
Image(systemName: "delete.left")
.foregroundColor(Color(UIColor.opaqueSeparator))
}
)
}
}
}
}
The code itself should be self explanatory and easy to understand as there is no fancy logic included in our tasks.
We just wrap the textfield inside a HStack and add the button, if the text field is not empty. The button itself has a single action of deleting the value of the text field.
For the clear icon we use the delete.left icon from the SF Symbols 2 library by Apple, but you could also use another one or even your own custom one.
The binding of the modifier is the same as the one we apply to the text field. Without it we would not be able to check for content or clear the field itself.
Inside the ContentView.swift we now simply add a TextField element and apply our modifier to it — that’s all!
import SwiftUI
struct ContentView: View {
#State var exampleText: String = ""
var body: some View {
NavigationView {
Form {
Section {
TextField("Type in your Text here...", text: $exampleText)
.modifier(TextFieldClearButton(text: $exampleText))
.multilineTextAlignment(.leading)
}
}
.navigationTitle("Clear button example")
}
}
}
The navigation view and form inside of the ContentView are not required. You could also just add the TextField inside the body, but with a form it’s much clearer and beautiful. 🙈
And so our final result looks like this:
I found this answer from #NigelGee on "Hacking with Swift".
.onAppear {
UITextField.appearance().clearButtonMode = .whileEditing
}
It really helped me out.
Simplest solution I came up with
//
// ClearableTextField.swift
//
// Created by Fred on 21.11.22.
//
import SwiftUI
struct ClearableTextField: View {
var title: String
#Binding var text: String
init(_ title: String, text: Binding<String>) {
self.title = title
_text = text
}
var body: some View {
ZStack(alignment: .trailing) {
TextField(title, text: $text)
Image(systemName: "xmark.circle.fill")
.foregroundColor(.secondary)
.onTapGesture {
text = ""
}
}
}
}
struct ClearableTextField_Previews: PreviewProvider {
#State static var text = "some value"
static var previews: some View {
Form {
// replace TextField("Original", text: $text) with
ClearableTextField("Clear me", text: $text)
}
}
}

Is it possible for a NavigationLink to perform an action in addition to navigating to another view?

I'm trying to create a button that not only navigates to another view, but also run a function at the same time. I tried embedding both a NavigationLink and a Button into a Stack, but I'm only able to click on the Button.
ZStack {
NavigationLink(destination: TradeView(trade: trade)) {
TradeButton()
}
Button(action: {
print("Hello world!") //this is the only thing that runs
}) {
TradeButton()
}
}
You can use .simultaneousGesture to do that. The NavigationLink will navigate and at the same time perform an action exactly like you want:
NavigationLink(destination: TradeView(trade: trade)) {
Text("Trade View Link")
}.simultaneousGesture(TapGesture().onEnded{
print("Hello world!")
})
You can use NavigationLink(destination:isActive:label:). Use the setter on the binding to know when the link is tapped. I've noticed that the NavigationLink could be tapped outside of the content area, and this approach captures those taps as well.
struct Sidebar: View {
#State var isTapped = false
var body: some View {
NavigationLink(destination: ViewToPresent(),
isActive: Binding<Bool>(get: { isTapped },
set: { isTapped = $0; print("Tapped") }),
label: { Text("Link") })
}
}
struct ViewToPresent: View {
var body: some View {
print("View Presented")
return Text("View Presented")
}
}
The only thing I notice is that setter fires three times, one of which is after it's presented. Here's the output:
Tapped
Tapped
View Presented
Tapped
NavigationLink + isActive + onChange(of:)
// part 1
#State private var isPushed = false
// part 2
NavigationLink(destination: EmptyView(), isActive: $isPushed, label: {
Text("")
})
// part 3
.onChange(of: isPushed) { (newValue) in
if newValue {
// do what you want
}
}
This works for me atm:
#State private var isActive = false
NavigationLink(destination: MyView(), isActive: $isActive) {
Button {
// run your code
// then set
isActive = true
} label: {
Text("My Link")
}
}
Use NavigationLink(_:destination:tag:selection:) initializer and pass your model's property as a selection parameter. Because it is a two-way binding, you can define didset observer for this property, and call your function there.
struct ContentView: View {
#EnvironmentObject var navigationModel: NavigationModel
var body: some View {
NavigationView {
List(0 ..< 10, id: \.self) { row in
NavigationLink(destination: DetailView(id: row),
tag: row,
selection: self.$navigationModel.linkSelection) {
Text("Link \(row)")
}
}
}
}
}
struct DetailView: View {
var id: Int;
var body: some View {
Text("DetailView\(id)")
}
}
class NavigationModel: ObservableObject {
#Published var linkSelection: Int? = nil {
didSet {
if let linkSelection = linkSelection {
// action
print("selected: \(String(describing: linkSelection))")
}
}
}
}
It this example you need to pass in your model to ContentView as an environment object:
ContentView().environmentObject(NavigationModel())
in the SceneDelegate and SwiftUI Previews.
The model conforms to ObservableObject protocol and the property must have a #Published attribute.
(it works within a List)
I also just used:
NavigationLink(destination: View()....) {
Text("Demo")
}.task { do your stuff here }
iOS 15.3 deployment target.