I have a CustomSearchBar view that looks like this
However, when I wrap it with NavigationLink, the placeholder text will be centered. And user inputs will be centered too.
How do I maintain the leading alignment while using NavigationLink?
My code structure looks like this:
enum Tab {
case social
}
struct MainAppView: View {
#State var selection: Tab = .social
var body: some View {
TabView(selection: $selection) {
ZStack{
CustomButton()
NavigationView { SocialView() }
}.tabItem{Image(systemName: "person.2")}.tag(Tab.social)
// other tabs....
}
struct SocialView: View {
// ...
var body: some View {
GeometryReader{ geometry in
VStack{
NavigationLink(destination: Text("test")) {
CustomSearchBar()
//...
}.navigationBarHidden(true)
.navigationBarTitle(Text(""))
}
}
}
}
struct CustomSearchBar: View {
var body: some View {
VStack{
HStack {
SearchBarSymbols(// some binding arguments)
CustomTextField(// some binding arguments)
CancelButton(// some binding arguments)
}
.padding(.vertical, 8.0)
.padding(.horizontal, 10.0)
.background(Color("SearchBarBackgroundColor"))
.clipShape(Capsule())
}
.padding(.horizontal)
}
}
struct CustomTextField: View {
var body: some View {
TextField("friend name", text: $searchText)
.frame(alignment: .leading)
.onTapGesture {
// some actions
}
.foregroundColor(Color("SearchBarSymbolColor"))
.accentColor(Color("SearchBarSymbolColor"))
.disableAutocorrection(true)
}
}
The issues with your code are:
Your navigation view contains the search field. This means that any new view that gets pushed will cover the search field.
Your search field is inside of the navigation link. There are conflicting interactions here as it effectively turns the field into a button, ie tapping the search field vs tapping the navigation link.
Solution:
Move the navigation view below the text field, so that the new view will appear without covering it. Then change the navigation link so that it is activated via a binding that gets triggered when the search field is editing:
struct SocialView: View {
#State private var text: String = ""
#State private var isActive: Bool = false
var body: some View {
GeometryReader{ geometry in
VStack {
CustomTextField(searchText: $text, isActive: $isActive)
.padding(.vertical, 8.0)
.padding(.horizontal, 10.0)
.background(Color("SearchBarBackgroundColor"))
.clipShape(Capsule())
NavigationView {
NavigationLink(isActive: $isActive, destination: { Text("test") }, label: { EmptyView() })
}
}
}
}
}
struct CustomTextField: View {
#Binding var searchText: String
#Binding var isActive: Bool
var body: some View {
TextField("friend name", text: $searchText) { editing in
self.isActive = editing
} onCommit: {
}
.frame(alignment: .leading)
.disableAutocorrection(true)
}
}
Originally I was looking to make an extension on Text for example:
extension Text {
var headerText: Text {
self
.bold()
.foregroundColor(.blue)
.padding() //<-- Doesn't work
}
}
and it all worked except for padding
So I had the bright idea of writing an extension on View instead but then the .bold() wouldn't work..
Looking for a more swifty way of doing this. Thanks
If I'm understanding correctly, this seems like the perfect case for a custom view modifier...
struct HeaderText: ViewModifier {
func body(content: Content) -> some View {
content
.bold()
.foregroundColor(.blue)
.padding()
}
}
...which you could then use like this:
struct ContentView: View {
var body: some View {
Text("This is a header")
.modifier(HeaderText())
}
}
You could also put the modifier inside a view extension to make it cleaner, like so:
extension View {
func headerText() -> ModifiedContent<Self, HeaderText> {
return modifier(HeaderText())
}
}
That would enable you to use it like this:
struct ContentView: View {
var body: some View {
Text("This is a header")
.headerText()
}
}
I have a Text() view inside a HStack inside of a ForEach inside of a VStack. The text can be a string of any length, and I have no control of that is put inside of it. The problem is that when you run the program, the views in the VStack overlap resulting in this jumbled mess
What I want to do is have a view that resizes its height based on the height of the multi line text view, so that the views never overlap, and always displays the entirety of the string.
Here is some code that generates the view in question:
struct ScrollingChatView: View {
#State var model: WatchModel
#State var messages: [DisplayableMessage] = []
var body: some View {
ScrollView {
if (!messages.isEmpty) {
LazyVStack {
ForEach(messages, id: \.sortTimestamp) { message in
CompactChatView(message: message)
}
}.padding()
} else {
Text("Getting Chat...").padding()
}
}.onReceive(model.chatDriver.publisher) { m in
self.messages = m
}
}
}
struct CompactChatView: View {
#State var message: DisplayableMessage
#State var stringMessage: String? = nil
var body: some View {
VStack(alignment: .leading) {
HStack(alignment: .top) {
Text(message.displayAuthor)
.lineLimit(1)
.layoutPriority(1)
Group {
Text(getEmojiText(message))
.font(.headline)
.fixedSize(horizontal: false, vertical: true)
}
Spacer()
Text(message.displayTimestamp)
.font(.subheadline)
.foregroundColor(Color.gray)
.layoutPriority(1)
}.padding(.all, 6.0)
}
}
func getEmojiText(_ item: DisplayableMessage) -> String {
var fullMessage: String = ""
for m in item.displayMessage {
switch m {
case .text(let s):
fullMessage += s
case .emote(_):
print()
}
}
return fullMessage
}
}
I've tried removing .fixedSize(horizontal: false, vertical: true) from the text view, but it only makes the text cut off after one line, which is not what I want.
If you need more context, the entire project in located at: https://github.com/LiveTL/apple. We're looking at code in the macOS folder.
You may find it useful to instead use a List() with a trailing closure like this...
List(itemList) { item in
Text(item)
}
This should prevent the issue you are running into when trying to display messages. For more information on lists check this out: https://developer.apple.com/documentation/swiftui/list.
You can see an example of this at 25:11 here: https://developer.apple.com/videos/play/wwdc2019/216/
Lately started learning/developing apps with SwiftUI and seems pretty easy to build the UI components. However, struggling creating a BaseView in SwiftUI. My idea is to have the common UI controls like background , navigation , etc in BaseView and just subclass other SwiftUI views to have the base components automatically.
Usually you want to either have a common behaviour or a common style.
1) To have a common behaviour: composition with generics
Let's say we need to create a BgView which is a View with a full screen image as background. We want to reuse BgView whenever we want. You can design this situation this way:
struct BgView<Content>: View where Content: View {
private let bgImage = Image.init(systemName: "m.circle.fill")
let content: Content
var body : some View {
ZStack {
bgImage
.resizable()
.opacity(0.2)
content
}
}
}
You can use BgView wherever you need it and you can pass it all the content you want.
//1
struct ContentView: View {
var body: some View {
BgView(content: Text("Hello!"))
}
}
//2
struct ContentView: View {
var body: some View {
BgView(content:
VStack {
Text("Hello!")
Button(action: {
print("Clicked")
}) {
Text("Click me")
}
}
)
}
}
2) To have a common behaviour: composition with #ViewBuilder closures
This is probably the Apple preferred way to do things considering all the SwiftUI APIs. Let's try to design the example above in this different way
struct BgView<Content>: View where Content: View {
private let bgImage = Image.init(systemName: "m.circle.fill")
private let content: Content
public init(#ViewBuilder content: () -> Content) {
self.content = content()
}
var body : some View {
ZStack {
bgImage
.resizable()
.opacity(0.2)
content
}
}
}
struct ContentView: View {
var body: some View {
BgView {
Text("Hello!")
}
}
}
This way you can use BgView the same way you use a VStack or List or whatever.
3) To have a common style: create a view modifier
struct MyButtonStyle: ViewModifier {
func body(content: Content) -> some View {
content
.padding()
.background(Color.red)
.foregroundColor(Color.white)
.font(.largeTitle)
.cornerRadius(10)
.shadow(radius: 3)
}
}
struct ContentView: View {
var body: some View {
VStack(spacing: 20) {
Button(action: {
print("Button1 clicked")
}) {
Text("Button 1")
}
.modifier(MyButtonStyle())
Button(action: {
print("Button2 clicked")
}) {
Text("Button 2")
}
.modifier(MyButtonStyle())
Button(action: {
print("Button3 clicked")
}) {
Text("Button 3")
}
.modifier(MyButtonStyle())
}
}
}
These are just examples but usually you'll find yourself using one of the above design styles to do things.
EDIT: a very useful link about #functionBuilder (and therefore about #ViewBuilder) https://blog.vihan.org/swift-function-builders/
I got a idea about how to create a BaseView in SwiftUI for common usage in other screen
By the way
Step .1 create ViewModifier
struct BaseScene: ViewModifier {
/// Scene Title
var screenTitle: String
func body(content: Content) -> some View {
VStack {
HStack {
Spacer()
Text(screenTitle)
.font(.title)
.foregroundColor(.white)
Spacer()
}.padding()
.background(Color.blue.opacity(0.8))
content
}
}
}
Step .2 Use that ViewModifer in View
struct BaseSceneView: View {
var body: some View {
VStack {
Spacer()
Text("Home screen")
.font(.title)
Spacer()
}
.modifier(BaseScene(screenTitle: "Screen Title"))
}
}
struct BaseSceneView_Previews: PreviewProvider {
static var previews: some View {
Group {
BaseSceneView()
}
}
}
Your Output be like:
I'm implementing a very custom NavigationLink called MenuItem and would like to reuse it across the project. It's a struct that conforms to View and implements var body : some View which contains a NavigationLink.
I need to somehow store the view that shall be presented by NavigationLink in the body of MenuItem but have yet failed to do so.
I have defined destinationView in MenuItem's body as some View and tried two initializers:
This seemed too easy:
struct MenuItem: View {
private var destinationView: some View
init(destinationView: View) {
self.destinationView = destinationView
}
var body : some View {
// Here I'm passing destinationView to NavigationLink...
}
}
--> Error: Protocol 'View' can only be used as a generic constraint because it has Self or associated type requirements.
2nd try:
struct MenuItem: View {
private var destinationView: some View
init<V>(destinationView: V) where V: View {
self.destinationView = destinationView
}
var body : some View {
// Here I'm passing destinationView to NavigationLink...
}
}
--> Error: Cannot assign value of type 'V' to type 'some View'.
Final try:
struct MenuItem: View {
private var destinationView: some View
init<V>(destinationView: V) where V: View {
self.destinationView = destinationView as View
}
var body : some View {
// Here I'm passing destinationView to NavigationLink...
}
}
--> Error: Cannot assign value of type 'View' to type 'some View'.
I hope someone can help me. There must be a way if NavigationLink can accept some View as an argument.
Thanks ;D
To sum up everything I read here and the solution which worked for me:
struct ContainerView<Content: View>: View {
#ViewBuilder var content: Content
var body: some View {
content
}
}
This not only allows you to put simple Views inside, but also, thanks to #ViewBuilder, use if-else and switch-case blocks:
struct SimpleView: View {
var body: some View {
ContainerView {
Text("SimpleView Text")
}
}
}
struct IfElseView: View {
var flag = true
var body: some View {
ContainerView {
if flag {
Text("True text")
} else {
Text("False text")
}
}
}
}
struct SwitchCaseView: View {
var condition = 1
var body: some View {
ContainerView {
switch condition {
case 1:
Text("One")
case 2:
Text("Two")
default:
Text("Default")
}
}
}
}
Bonus:
If you want a greedy container, which will claim all the possible space (in contrary to the container above which claims only the space needed for its subviews) here it is:
struct GreedyContainerView<Content: View>: View {
#ViewBuilder let content: Content
var body: some View {
content
.frame(maxWidth: .infinity, maxHeight: .infinity)
}
}
If you need an initializer in your view then you can use #ViewBuilder for the parameter too. Even for multiple parameters if you will:
init(#ViewBuilder content: () -> Content) {…}
The way Apple does it is using function builders. There is a predefined one called ViewBuilder. Make it the last argument, or only argument, of your init method for MenuItem, like so:
..., #ViewBuilder builder: #escaping () -> Content)
Assign it to a property defined something like this:
let viewBuilder: () -> Content
Then, where you want to diplay your passed-in views, just call the function like this:
HStack {
viewBuilder()
}
You will be able to use your new view like this:
MenuItem {
Image("myImage")
Text("My Text")
}
This will let you pass up to 10 views and use if conditions etc. though if you want it to be more restrictive you will have to define your own function builder. I haven't done that so you will have to google that.
You should make the generic parameter part of MenuItem:
struct MenuItem<Content: View>: View {
private var destinationView: Content
init(destinationView: Content) {
self.destinationView = destinationView
}
var body : some View {
// ...
}
}
You can create your custom view like this:
struct ENavigationView<Content: View>: View {
let viewBuilder: () -> Content
var body: some View {
NavigationView {
VStack {
viewBuilder()
.navigationBarTitle("My App")
}
}
}
}
struct ENavigationView_Previews: PreviewProvider {
static var previews: some View {
ENavigationView {
Text("Preview")
}
}
}
Using:
struct ContentView: View {
var body: some View {
ENavigationView {
Text("My Text")
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
You can pass a NavigationLink (or any other view widget) as a variable to a subview as follows:
import SwiftUI
struct ParentView: View {
var body: some View {
NavigationView{
VStack(spacing: 8){
ChildView(destinationView: Text("View1"), title: "1st")
ChildView(destinationView: Text("View2"), title: "2nd")
ChildView(destinationView: ThirdView(), title: "3rd")
Spacer()
}
.padding(.all)
.navigationBarTitle("NavigationLinks")
}
}
}
struct ChildView<Content: View>: View {
var destinationView: Content
var title: String
init(destinationView: Content, title: String) {
self.destinationView = destinationView
self.title = title
}
var body: some View {
NavigationLink(destination: destinationView){
Text("This item opens the \(title) view").foregroundColor(Color.black)
}
}
}
struct ThirdView: View {
var body: some View {
VStack(spacing: 8){
ChildView(destinationView: Text("View1"), title: "1st")
ChildView(destinationView: Text("View2"), title: "2nd")
ChildView(destinationView: ThirdView(), title: "3rd")
Spacer()
}
.padding(.all)
.navigationBarTitle("NavigationLinks")
}
}
The accepted answer is nice and simple. The syntax got even cleaner with iOS 14 + macOS 11:
struct ContainerView<Content: View>: View {
#ViewBuilder var content: Content
var body: some View {
content
}
}
Then continue to use it like this:
ContainerView{
...
}
I really struggled to make mine work for an extension of View. Full details about how to call it are seen here.
The extension for View (using generics) - remember to import SwiftUI:
extension View {
/// Navigate to a new view.
/// - Parameters:
/// - view: View to navigate to.
/// - binding: Only navigates when this condition is `true`.
func navigate<SomeView: View>(to view: SomeView, when binding: Binding<Bool>) -> some View {
modifier(NavigateModifier(destination: view, binding: binding))
}
}
// MARK: - NavigateModifier
fileprivate struct NavigateModifier<SomeView: View>: ViewModifier {
// MARK: Private properties
fileprivate let destination: SomeView
#Binding fileprivate var binding: Bool
// MARK: - View body
fileprivate func body(content: Content) -> some View {
NavigationView {
ZStack {
content
.navigationBarTitle("")
.navigationBarHidden(true)
NavigationLink(destination: destination
.navigationBarTitle("")
.navigationBarHidden(true),
isActive: $binding) {
EmptyView()
}
}
}
}
}
Alternatively you can use a static function extension. For example, I make a titleBar extension to Text. This makes it very easy to reuse code.
In this case you can pass a #Viewbuilder wrapper with the view closure returning a custom type that conforms to view. For example:
import SwiftUI
extension Text{
static func titleBar<Content:View>(
titleString:String,
#ViewBuilder customIcon: ()-> Content
)->some View {
HStack{
customIcon()
Spacer()
Text(titleString)
.font(.title)
Spacer()
}
}
}
struct Text_Title_swift_Previews: PreviewProvider {
static var previews: some View {
Text.titleBar(titleString: "title",customIcon: {
Image(systemName: "arrowshape.turn.up.backward")
})
.previewLayout(.sizeThatFits)
}
}
If anyone is trying to pass two different views to other view, and can't do it because of this error:
Failed to produce diagnostic for expression; please submit a bug report...
Because we are using <Content: View>, the first view you passed, the view is going to store its type, and expect the second view you are passing be the same type, this way, if you want to pass a Text and an Image, you will not be able to.
The solution is simple, add another content view, and name it differently.
Example:
struct Collapsible<Title: View, Content: View>: View {
#State var title: () -> Title
#State var content: () -> Content
#State private var collapsed: Bool = true
var body: some View {
VStack {
Button(
action: { self.collapsed.toggle() },
label: {
HStack {
self.title()
Spacer()
Image(systemName: self.collapsed ? "chevron.down" : "chevron.up")
}
.padding(.bottom, 1)
.background(Color.white.opacity(0.01))
}
)
.buttonStyle(PlainButtonStyle())
VStack {
self.content()
}
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: collapsed ? 0 : .none)
.clipped()
.animation(.easeOut)
.transition(.slide)
}
}
}
Calling this View:
Collapsible {
Text("Collapsible")
} content: {
ForEach(1..<5) { index in
Text("\(index) test")
}
}
Syntax for 2 Views
struct PopOver<Content, PopView> : View where Content: View, PopView: View {
var isShowing: Bool
#ViewBuilder var content: () -> Content
#ViewBuilder var popover: () -> PopView
var body: some View {
ZStack(alignment: .center) {
self
.content()
.disabled(isShowing)
.blur(radius: isShowing ? 3 : 0)
ZStack {
self.popover()
}
.frame(width: 112, height: 112)
.opacity(isShowing ? 1 : 0)
.disabled(!isShowing)
}
}
}