LazyVGrid onTapGesture navigate to next screen swiftUI - swiftui

I am quite new to swiftUI. I have created a grid view on tapping on which I want to go to next screen. But somehow I am not able to manage to push to next screen. I am doing like this:
var body: some View {
NavigationView {
ScrollView {
LazyVGrid(columns: gridItems, spacing: 16) {
ForEach(viewModel.pokemon) { pokemon in
PokemonCell(pokemon: pokemon, viewModel: viewModel)
.onTapGesture {
NavigationLink(destination: PokemonDetailView(pokemon: pokemon)) {
Text(pokemon.name)
}
}
}
}
}
.navigationTitle("Pokedex")
}
}
Upon doing like this, I am getting a warning stating
Result of 'NavigationLink<Label, Destination>' initializer is unused
Can someone please guide me, how to do this?

.onTapGesture adds an action to perform when the view recognizes a tap gesture. In your case you don't need to use .onTapGesture. If you want to go to another view when cell is tapped you need to write NavigationLink as below.
NavigationLink(destination: PokemonDetailView(pokemon: pokemon)) {
PokemonCell(pokemon: pokemon, viewModel: viewModel)
}
If you want to use .onTapGesture, another approach is creating #State for your tapped cell's pokemon and using NavigationLink's isActive binding. So when user tap the cell it will change the #State and toggle the isActive in .onTapGesture. You may need to add another Stack (ZStack etc.) for this.
NavigationView {
ZStack {
NavigationLink("", destination: PokemonDetailView(pokemon: pokemon), isActive: $isNavigationActive).hidden()
ScrollView {
// ...

Related

NavigationStack and TabView in Swiftui iOS 16: bug or improper usage?

[Xcode 14.1, iOS 16.1]
I have a NavigationStack with a navigationTitle and a TabView with 2 Views. Each View has a ScrollView (see image below):
NavigationStack and TabView problem image
When I tap on Tab1 (#1 in red on the image above), then swipe up, the behavior is as expected (#2), i.e. the big navigationTitle move to the center, and my view passes below and becomes blurry. Perfect.
However, when I tap ton Tab2 (#3) and then swipe up (#4), the big title stays big, and the view doesn't become blurry.
Then I tap on Tab1 again (#5) and it works as expected.
Please help!
Here is my code:
ContentView:
import SwiftUI
struct ContentView: View {
#State private var selection: Tab = .tab1
enum Tab {
case tab1
case tab2
}
#State private var mainTitle = "Tab1"
var body: some View {
NavigationStack {
TabView(selection: $selection) {
Tab1(mainTitle: $mainTitle)
.tabItem {
Label("Tab1", systemImage: "wrench.adjustable.fill")
}
.tag(Tab.tab1)
Tab2(mainTitle: $mainTitle)
.tabItem {
Label("Tab2", systemImage: "wrench.adjustable.fill")
}
.tag(Tab.tab2)
} .navigationTitle(mainTitle)
}
}
}
Tab1:
import SwiftUI
struct Tab1: View {
#Binding var mainTitle : String
var body: some View {
ScrollView {
Text("Text tab 1")
.padding(.all,100)
.background(.blue)
} .onAppear {
mainTitle = "Tab1"
}
}
}
Tab2:
import SwiftUI
struct Tab2: View {
#Binding var mainTitle : String
var body: some View {
ScrollView {
Text("Text tab 2")
.padding(.all,100)
.background(.green)
} .onAppear {
mainTitle = "Tab2"
}
}
}
I tried a hack that is supposed to fix the transparency bug for Tab bars, but it doesn't work.
.onAppear {
let tabBarAppearance = UITabBarAppearance()
tabBarAppearance.configureWithOpaqueBackground()
UITabBar.appearance().scrollEdgeAppearance = tabBarAppearance
}
TabViews are designed to sit at the top of the navigation hierarchy. They're intended to allow users to switch between independent sections of your app at any time.
You would generally put a separate navigation stack within each tab that then handles pushing and popping of views. And then, you can use the navigationTitle modifier to manage the screen's title.
So your structure (which might be split over multiple custom views) should look something like:
TabView {
NavigationStack {
ScrollView {
}
.navigationTitle("Tab 1")
}
.tabItem { Label("Tab1", ...) }
NavigationStack {
ScrollView {
}
.navigationTitle("Tab 2")
}
.tabItem { Label("Tab2", ...) }
}
This structure is by design, to align with Apple's Human Interface Guidelines. It's worth reading the HIG to get a handle on where Apple are coming from, and how working on the same principles can really help your app feel like it belongs on your users' device.

How to fix double back button in SwiftUI

I got 2 views. On the second view I have list of exercises and when I choose one of them and go inside I see double back. It's driving me crazy.
First one:
import SwiftUI
struct ProgrammView: View {
var body: some View {
NavigationView{
ScrollView(.vertical, showsIndicators: false) {
VStack {
Text("blabla")
.multilineTextAlignment(.center)
.font(.custom("AvenirNext-Bold", size: 30))
NavigationLink{
InsultHandProgram()
} label: {
Image("35")
.resizable()
.scaledToFit()
.padding(.horizontal)
.padding(.bottom, 7)
.shadow(radius: 5)
}
}
}
}
}
}
Second one:
import SwiftUI
struct InsultHandProgram: View {
let numbers = InsultProgram.getInsultProgram()
var body: some View {
NavigationStack {
List(numbers) { InsultProgram in
NavigationLink( InsultProgram.name, value: InsultProgram)
}
.navigationTitle("blabla")
.navigationDestination(for: InsultProgram.self) {
InsultProgram in InsultProgrammDetail(InsultProgram: InsultProgram)
}
}
}
I tried to change navigation stack. It's crushed.
If you use NavigationView, then it provides the navigation bars for all its child views. NavigationStack in your child view also wants to provide a navigation bar, and so you end up with two.
To remedy the situation you have some choices:
Remove the NavigationStack from your child view and let NavigationView manage everything.
Remove NavigationStack from you child view and replace NavigationView in your parent with a NavigationStack. This will work fine on iPhones, but doesn't adapt well to iPads.
Keep your navigation stack in the child view but replace NavigationView with NavigationSplitView. This came in with iOS16, as did NavigationStack. The two work well together so they don't step on each other's toes when it comes to setting up navigation bars.
Given you're already using other iOS 16 idioms such as navigationDestination I'd recommend approach 3.

Navigate to another screen in swiftUI

Below is the code i am trying to push to another swiftUI when button in swiftUI is pressed.
But it is not navigating to another screen
let controller = DestinationHostingController(rootView: AnotherSwiftUI())
pushViewController(controller, animated: animated)
In SwiftUI, the navigation has been improved,
You have to embed your view inside a NavigationView,
and after that you can use NavigationLink to redirect wherever you want
example:
struct ContentView: View {
var body: some View {
NavigationView {
VStack(spacing: 30) {
Text("You're going to flip a coin – do you want to choose heads or tails?")
NavigationLink(destination: ResultView(choice: "Heads")) {
Text("Choose Heads")
}
NavigationLink(destination: ResultView(choice: "Tails")) {
Text("Choose Tails")
}
}
.navigationTitle("Navigation")
}
}
}
(You can replace the NavigationLink content by whatever you want, Text -> Button)

SwiftUI Navigation bar items disappear on iOS 14

Discovered in my app that navigation bar items in some views disappear when orientation of the device changes. This seems to occur only in a view that is opened using NavigationLink, on main view navigation bar items work as expected. It appears that something has changed between iOS 13.7 and iOS 14.2 related to this. Also, it does not seem to matter whether using leading or trailing items, both disappear.
Example snippet where this occurs:
struct ContentView: View {
var detailView: some View {
Text("This is detail view")
.navigationBarTitle("Detail view title", displayMode: .inline)
.navigationBarItems(trailing: Button(action: {}, label: {
Image(systemName: "pencil.circle.fill")
}))
}
var body: some View {
NavigationView {
NavigationLink(
destination: detailView,
label: {
Text("Open detail view")
})
.navigationBarTitle("Main view")
}.navigationViewStyle(StackNavigationViewStyle())
}
}
The issue occurs only when running on a real device. (iPhone 11 in my case) On simulator everything works as expected.
Anyone else seen similar issues? Workarounds/fixes?
.navigationBarTitle and .navigationBarItems are being deprecated. I think that the best "fix" is to switch to .toolbar
It's a weird issue but I guess there is a hack to make it work.
SwiftUI doesn't call body property when rotations happen. So you can add #State UIDeviceOrientation property to your view and update it every time orientation changes. One tricky thing is to use that property somewhere in the body of the view since SwiftUI smart enough to ignore #State that is not used in the body.
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(
destination: DetailsView(),
label: {
Text("Open detail view")
}).navigationBarTitle("Main view")
}.navigationViewStyle(StackNavigationViewStyle())
}
}
struct DetailsView: View {
#State var orientation: UIDeviceOrientation = UIDevice.current.orientation
var body: some View {
Text("This is detail view")
.navigationBarTitle("Detail view title")
.navigationBarItems(trailing: button)
.onReceive(NotificationCenter.default.publisher(for: UIDevice.orientationDidChangeNotification)) { _ in
orientation = UIDevice.current.orientation
}.background(Text("\(orientation.rawValue)"))
}
var button: some View {
Button(action: { print("123") }, label: {
Image(systemName: "pencil.circle.fill")
}).id("123")
}
}
In my experience when I change a Button in the toolbar from disabled to enabled, they disappear. But if I scroll to the bottom of the View, they re-appear. If I am already at the end of the View when the button is enabled, it acts normally, until I then scroll away from the bottom, the button again disappears.
Try scrolling to the bottom of your view, if you use landscape.

Rename Cancel button on a modal sheet

I currently invoke an Example Sentence modal sheet by toggling $showingModal on a certain condition.
.sheet(isPresented: $showingModal) {
ExampleSentence()
}
According to the Human Interface Guidelines, I am able to rename Cancel to something more appropriate such as Dismiss. If I was using UIKit instead of SwiftUI, I'd be using the presentController function which then explains that I can rename the Cancel button using setTitle. https://developer.apple.com/documentation/watchkit/wkinterfacecontroller/1619560-presentcontroller
But if I'm using SwiftUI, is it possible to rename the Cancel button?
EDIT: Sorry I should have clarified that this is a watchOS app. By default it creates a Cancel button in the top left corner but I just want to rename it to dismiss.
You can do that by using a NavigationView within your ExampleSentences view and adding a toolbar to it, something like this.
struct ExampleSentence: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
NavigationView {
VStack {
Text("Hello View")
}
.navigationBarTitle("Example Sentences")
.navigationBarTitleDisplayMode(.inline)
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Text("Done")
}
}
}
}
}
}