Show/hide navigationBarItems when keyboard visible/non-visible | SwiftUI - xcode

I've spent a lot of time researching and playing with different codes to make this work but can't seem to figure it out. Below you'll see two pieces of code, one of me creating the "Done" bar button item and the other is checking to see if keyboard is present and to close it when the button is clicked. The one issue I'm having is, I only want the bar button to show when the keyboard is present. I want the bar button hidden once the keyboard is gone or prior to even opening up the keyboard in the first place. How do you do that nowadays with SwiftUI?
.navigationBarItems(trailing:
Button(action: {
if UIApplication.shared.isKeyboardPresented {
UIApplication.shared.endEditing()
}
}, label: {
Text("Done")
})
extension UIApplication {
func endEditing() {
sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
}
/// Checks if view hierarchy of application contains `UIRemoteKeyboardWindow` if it does, keyboard is presented
var isKeyboardPresented: Bool {
if let keyboardWindowClass = NSClassFromString("UIRemoteKeyboardWindow"),
self.windows.contains(where: { $0.isKind(of: keyboardWindowClass) }) {
return true
} else {
return false
}
}
}

As an option, you can define an object to listen to keyboard notifications:
class KeybordManager: ObservableObject {
static let shared = KeybordManager()
#Published var keyboardFrame: CGRect? = nil
init() {
let notificationCenter = NotificationCenter.default
notificationCenter.addObserver(self, selector: #selector(willHide), name: UIResponder.keyboardWillHideNotification, object: nil)
notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
}
#objc func willHide() {
self.keyboardFrame = .zero
}
#objc func adjustForKeyboard(notification: Notification) {
guard let keyboardValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
let keyboardScreenEndFrame = keyboardValue.cgRectValue
self.keyboardFrame = keyboardScreenEndFrame
}
}
Then inside your view subscribe to keyboardFrame updates and show and hide the Done button accordingly:
public struct ContentView: View {
#State private var showDoneButton = false
#State private var text = ""
public var body: some View {
NavigationView {
TextField("Some text", text: $text)
.navigationBarItems(trailing:
Group {
if self.showDoneButton {
Button(action: {
UIApplication.shared.endEditing()
}, label: {
Text("Done")
})
} else {
EmptyView()
}
}
)
.onReceive(KeybordManager.shared.$keyboardFrame) { keyboardFrame in
if let keyboardFrame = keyboardFrame, keyboardFrame != .zero {
self.showDoneButton = true
} else {
self.showDoneButton = false
}
}
}
}
}
extension UIApplication {
func endEditing() {
sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
}
}

Related

SwiftUI: Sharing NSSharingService on macOS not receiving share

I have a simple test application that attempts to share a CoreData record with another user using NSSharingService. I can create my share and that works,
but when I try to receive the share it opens up the application but doesn't do anything.
I have added CKSharingSupported to my plist.
I have also followed this link to no avail:
CloudKit CKShare userDidAcceptCloudKitShareWith Never Fires on Mac App
Here is my code:
SharingServiceApp:
final class AppDelegate: NSObject, NSApplicationDelegate
{
func application(_ application: NSApplication, userDidAcceptCloudKitShareWith metadata: CKShare.Metadata)
{
print ("userDidAcceptCloudKitShareWith")
let shareStore = persistenceController.sharedPersistentStore!
persistenceController.container.acceptShareInvitations(from: [metadata], into: shareStore)
{ _, error in
if let error = error
{
print("acceptShareInvitation error :\(error)")
}
}
}
}
ContentView:
import SwiftUI
import CoreData
import CloudKit
let persistenceController = PersistenceController()
struct ContentView: View {
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \Item.timestamp, ascending: true)],
animation: .default)
private var items: FetchedResults<Item>
var body: some View {
NavigationView {
List {
ForEach(items) { item in
NavigationLink {
VStack
{
Text("Item at \(item.timestamp!, formatter: itemFormatter)")
Button("Share")
{
shareRecord(item: item)
}
}
} label: {
Text(item.timestamp!, formatter: itemFormatter)
}
}
}
.toolbar {
ToolbarItem {
Button(action: addItem) {
Label("Add Item", systemImage: "plus")
}
}
}
Text("Select an item")
}
}
private func addItem() {
withAnimation {
let newItem = Item(context: viewContext)
newItem.timestamp = Date()
do {
try viewContext.save()
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
}
}
}
private let itemFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateStyle = .short
formatter.timeStyle = .medium
return formatter
}()
func shareRecord(item: Item)
{
Task
{
if let share = await createShare(item: item)
{
let container = CKContainer(identifier: "iCloud.com.xxxxxxxx.sharingservice")
let item = NSItemProvider()
item.registerCloudKitShare(share, container: container)
DispatchQueue.main.async
{
let sharingService = NSSharingService(named: .cloudSharing)
sharingService!.perform(withItems: [item])
}
}
}
}
private func createShare(item: Item) async -> CKShare?
{
do
{
let (_, share, _) = try await persistenceController.container.share([item], to: nil)
share[CKShare.SystemFieldKey.title] = "MyApp"
return share
}
catch
{
print("Failed to create share")
return nil
}
}
OK I have finally managed to get userDidAcceptCloudKitShareWith to be called.
You need to create the app delegate for your SwiftUI app using #NSApplicationDelegateAdaptor:
#main
struct Sharing_ServiceApp: App
{
#NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene
{
WindowGroup
{
ContentView()
.environment(\.managedObjectContext, persistenceController.container.viewContext)
}
}
}
I put that line in and my code instantly started receiving the share requests.

How to remove Top Safe Area in Zstack With ScrollView Image SwiftUI

I'm trying to remove top safe area. Is there any way to remove top safe area from top and image?
Code:-
struct ContentView22: View {
#State private var showDialog = false
var body: some View {
ZStack {
ScrollView {
VStack {
Image("CentrImg.jpeg")
.resizable()
.scaledToFill()
.frame(width:UIScreen.screenWidth,height: 180, alignment: .center)
.clipped()
.ignoresSafeArea()
.edgesIgnoringSafeArea(.top)
VStack(alignment:.leading,spacing:25) {
Text("Some text")
.onTapGesture {
showDialog = true
}
}
}
}
.alert(isPresented: $showDialog,TextAlert(title: "Title",message: "Message") { result in
print(result as Any)
if let _ = result {
} else {
}
})
}.edgesIgnoringSafeArea(.top)
.background(Color.red)
.foregroundColor(.white)
.navigationBarHidden(true)
.edgesIgnoringSafeArea(/*#START_MENU_TOKEN#*/.all/*#END_MENU_TOKEN#*/)
.navigationBarBackButtonHidden(true)
.navigationBarTitle("", displayMode: .inline)
}
}
Alert Control Class:-
import SwiftUI
import Combine
public struct TextAlert {
public var title: String // Title of the dialog
public var message: String // Dialog message
public var placeholder: String = "" // Placeholder text for the TextField
public var accept: String = "OK" // The left-most button label
public var cancel: String? = "Cancel" // The optional cancel (right-most) button label
public var secondaryActionTitle: String? = nil // The optional center button label
public var action: (String?) -> Void // Triggers when either of the two buttons closes the dialog
public var secondaryAction: (() -> Void)? = nil // Triggers when the optional center button is tapped
}
extension UIAlertController {
convenience init(alert: TextAlert) {
self.init(title: alert.title, message: alert.message, preferredStyle: .alert)
addTextField {
$0.placeholder = alert.placeholder
$0.returnKeyType = .done
}
if let cancel = alert.cancel {
addAction(UIAlertAction(title: cancel, style: .cancel) { _ in
alert.action(nil)
})
}
if let secondaryActionTitle = alert.secondaryActionTitle {
addAction(UIAlertAction(title: secondaryActionTitle, style: .default, handler: { _ in
alert.secondaryAction?()
}))
}
let textField = self.textFields?.first
addAction(UIAlertAction(title: alert.accept, style: .default) { _ in
alert.action(textField?.text)
})
}
}
struct AlertWrapper<Content: View>: UIViewControllerRepresentable {
#Binding var isPresented: Bool
let alert: TextAlert
let content: Content
func makeUIViewController(context: UIViewControllerRepresentableContext<AlertWrapper>) -> UIHostingController<Content> {
UIHostingController(rootView: content)
}
final class Coordinator {
var alertController: UIAlertController?
init(_ controller: UIAlertController? = nil) {
self.alertController = controller
}
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func updateUIViewController(_ uiViewController: UIHostingController<Content>, context: UIViewControllerRepresentableContext<AlertWrapper>) {
uiViewController.rootView = content
if isPresented && uiViewController.presentedViewController == nil {
var alert = self.alert
alert.action = {
self.isPresented = false
self.alert.action($0)
}
context.coordinator.alertController = UIAlertController(alert: alert)
uiViewController.present(context.coordinator.alertController!, animated: true)
}
if !isPresented && uiViewController.presentedViewController == context.coordinator.alertController {
uiViewController.dismiss(animated: true)
}
}
}
extension View {
public func alert(isPresented: Binding<Bool>, _ alert: TextAlert) -> some View {
AlertWrapper(isPresented: isPresented, alert: alert, content: self)
}
}
Output with alert code
Output without alert code:-
Can someone please explain to me how to remove top safe area from image with alert code, I've tried to implement by above but no results yet.
Any help would be greatly appreciated.
Thanks in advance.
I removed your Alert code. You can do the same with a much simpler function.
Value
#State var testText: String = ""
Alert Func
func alertView() {
let alert = UIAlertController(title: "Test", message: "Test Message", preferredStyle: .alert)
alert.addTextField { (testTextField) in
testTextField.placeholder = "Test TextField"
}
let okButton = UIAlertAction(title: "OK", style: .default) { (_) in
self.testText = alert.textFields?[0].text ?? ""
}
let cancellButton = UIAlertAction(title: "Cancel", style: .destructive) { (_) in
}
alert.addAction(okButton)
alert.addAction(cancellButton)
UIApplication.shared.windows.first?.rootViewController?.present(alert, animated: true, completion: {
})
}
Using:
Text("Some text")
.onTapGesture {
alertView()
}

SwitfUI: access the specific scene's ViewModel on macOS

In this simple example app, I have the following requirements:
have multiple windows, each having it's own ViewModel
toggling the Toggle in one window should not update the other window's
I want to also be able to toggle via menu
As it is right now, the first two points are not given, the last point works though. I do already know that when I move the ViewModel's single source of truth to the ContentView works for the first two points, but then I wouldn't have access at the WindowGroup level, where I inject the commands.
import SwiftUI
#main
struct ViewModelAndCommandsApp: App {
var body: some Scene {
ContentScene()
}
}
class ViewModel: ObservableObject {
#Published var toggleState = true
}
struct ContentScene: Scene {
#StateObject private var vm = ViewModel()// injecting here fulfills the last point only…
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(vm)
.frame(width: 200, height: 200)
}
.commands {
ContentCommands(vm: vm)
}
}
}
struct ContentCommands: Commands {
#ObservedObject var vm: ViewModel
var body: some Commands {
CommandGroup(before: .toolbar) {
Button("Toggle Some State") {
vm.toggleState.toggle()
}
}
}
}
struct ContentView: View {
#EnvironmentObject var vm: ViewModel//injecting here will result in window independant ViewModels, but make them unavailable in `ContactScene` and `ContentCommands`…
var body: some View {
Toggle(isOn: $vm.toggleState, label: {
Text("Some State")
})
}
}
How can I fulfill theses requirements–is there a SwiftUI solution to this or will I have to implement a SceneDelegate (is this the solution anyway?)?
Edit:
To be more specific: I'd like to know how I can go about instantiating a ViewModel for each individual scene and also be able to know from the menu bar which ViewModel is meant to be changed.
Long story short, see the code below. The project is called WindowSample this needs to match your app name in the URL registration.
import SwiftUI
#main
struct WindowSampleApp: App {
var body: some Scene {
ContentScene()
}
}
//This can be done several different ways. You just
//need somewhere to store multiple copies of the VM
class AStoragePlace {
private static var viewModels: [ViewModel] = []
static func getAViewModel(id: String?) -> ViewModel? {
var result: ViewModel? = nil
if id != nil{
result = viewModels.filter({$0.id == id}).first
if result == nil{
let newVm = ViewModel(id: id!)
viewModels.append(newVm)
result = newVm
}
}
return result
}
}
struct ContentCommands: Commands {
#ObservedObject var vm: ViewModel
var body: some Commands {
CommandGroup(before: .toolbar) {
Button("Toggle Some State \(vm.id)") {
vm.testMenu()
}
}
}
}
class ViewModel: ObservableObject, Identifiable {
let id: String
#Published var toggleState = true
init(id: String) {
self.id = id
}
func testMenu() {
toggleState.toggle()
}
}
struct ContentScene: Scene {
var body: some Scene {
//Trying to init from 1 windowGroup only makes a copy not a new scene
WindowGroup("1") {
ToggleView(vm: AStoragePlace.getAViewModel(id: "1")!)
.frame(width: 200, height: 200)
}
.commands {
ContentCommands(vm: AStoragePlace.getAViewModel(id: "1")!)
}.handlesExternalEvents(matching: Set(arrayLiteral: "1"))
//To open this go to File>New>New 2 Window
WindowGroup("2") {
ToggleView(vm: AStoragePlace.getAViewModel(id: "2")!)
.frame(width: 200, height: 200)
}
.commands {
ContentCommands(vm: AStoragePlace.getAViewModel(id: "2")!)
}.handlesExternalEvents(matching: Set(arrayLiteral: "2"))
}
}
struct ToggleView: View {
#Environment(\.openURL) var openURL
#ObservedObject var vm: ViewModel
var body: some View {
VStack{
//Makes copies of the window/scene
Button("new-window-of type \(vm.id)", action: {
//appname needs to be a registered url in info.plist
//Info Property List>Url types>url scheme>item 0 == appname
//Info Property List>Url types>url identifier == appname
if let url = URL(string: "WindowSample://\(vm.id)") {
openURL(url)
}
})
//Toggle the state
Toggle(isOn: $vm.toggleState, label: {
Text("Some State \(vm.id)")
})
}
}
}

exc_breakpoint while trying to load view in SwiftUI

I'm trying to make barcode scanner app. I want the scanner to load as the app first launches, like a background. Then when a barcode is scanned, load a view on top displaying the product.
In my ContentsView() I load this View, which starts the scanner and then navigates to FoundItemSheet() when a barcode has been found.
import Foundation
import SwiftUI
import CodeScanner
struct barcodeScannerView: View {
#State var isPresentingScanner = false
#State var scannedCode: String?
#State private var isShowingScanner = false
var body: some View {
NavigationView {
if self.scannedCode != nil {
NavigationLink("Next page", destination: FoundItemSheet(scannedCode: scannedCode!), isActive: .constant(true)).hidden()
}
}
.onAppear(perform: {
self.isPresentingScanner = true
})
.sheet(isPresented: $isShowingScanner) {
self.scannerSheet
}
}
var scannerSheet : some View {
CodeScannerView(
codeTypes: [.qr],
completion: { result in
if case let .success(code) = result {
self.scannedCode = code
self.isPresentingScanner = false
}
}
)
}
}
When navigation view is replaced with a button, like this:
VStack(spacing: 10) {
if self.scannedCode != nil {
NavigationLink("Next page", destination: FoundItemSheet(scannedCode: scannedCode!), isActive: .constant(true)).hidden()
}
Button("Scan Code") {
self.isPresentingScanner = true
}
.sheet(isPresented: $isPresentingScanner) {
self.scannerSheet
}
Text("Scan a QR code to begin")
It works with this solution, but I want the scanner to show when the app loads, not on a button press. I tried replacing the button with .onAppear with the same contents as the button, but it doesn't work.
This is foundItemSheet()
struct FoundItemSheet: View {
#State private var bottomSheetShown = false
#State var scannedCode: String?
var body: some View {
GeometryReader { geometry in
BottomSheetView(
scannedCode: self.$scannedCode,
isOpen: self.$bottomSheetShown,
maxHeight: geometry.size.height * 0.7
) {
Color.blue
}
}.edgesIgnoringSafeArea(.all)
}
}
struct FoundItemSheet_Previews: PreviewProvider {
static var previews: some View {
FoundItemSheet()
}
}
I'm getting exc_breakpoint I believe where CodeScanner is declared.
I've been stuck on this for hours, so I'll reply quick to any questions.
Couple of thoughts..
1) change order of modifiers
.sheet(isPresented: $isShowingScanner) {
self.scannerSheet
}
.onAppear(perform: {
self.isPresentingScanner = true
})
2) make delayed sheet activation (as view hierarchy might not ready for that custom scanner view)
.onAppear(perform: {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5)
self.isPresentingScanner = true
}
})

Scroll SwiftUI List to new selection

If you have a SwiftUI List with that allows single selection, you can change the selection by clicking the list (presumably this makes it the key responder) and then using the arrow keys. If that selection reaches the end of the visible area, it will scroll the whole list to keep the selection visible.
However, if the selection object is updated in some other way (e.g. using a button), the list will not be scrolled.
Is there any way to force the list to scroll to the new selection when set programmatically?
Example app:
import SwiftUI
struct ContentView: View {
#State var selection: Int? = 0
func changeSelection(_ by: Int) {
switch self.selection {
case .none:
self.selection = 0
case .some(let sel):
self.selection = max(min(sel + by, 20), 0)
}
}
var body: some View {
HStack {
List((0...20), selection: $selection) {
Text(String($0))
}
VStack {
Button(action: { self.changeSelection(-1) }) {
Text("Move Up")
}
Button(action: { self.changeSelection(1) }) {
Text("Move Down")
}
}
}
}
}
I tried several solutions, one of them I'm using in my project (I need horizontal paging for 3 lists). And here are my observations:
I didn't find any methods to scroll List in SwiftUI, there is no mention about it in documentation yet;
You may try ScrollView (my variant below, here is other solution), but these things might look monstroid;
Maybe the best way is to use UITableView: tutorial from Apple and try scrollToRowAtIndexPath method (like in this answer).
As I wrote, here is my example, which, of course, requires refinement. First of all ScrollView needs to be inside GeometryReader and you can understand the real size of content. The second thing is that you need to control your gestures, which might be difficult. And the last one: you need to calculate current offset of ScrollViews's content and it could be other than in my code (remember, I tried to give you example):
struct ScrollListView: View {
#State var selection: Int?
#State private var offset: CGFloat = 0
#State private var isGestureActive: Bool = false
func changeSelection(_ by: Int) {
switch self.selection {
case .none:
self.selection = 0
case .some(let sel):
self.selection = max(min(sel + by, 30), 0)
}
}
var body: some View {
HStack {
GeometryReader { geometry in
VStack {
ScrollView(.vertical, showsIndicators: false) {
ForEach(0...29, id: \.self) { line in
ListRow(line: line, selection: self.$selection)
.frame(height: 20)
}
}
.content.offset(y: self.isGestureActive ? self.offset : geometry.size.height / 4 - CGFloat((self.selection ?? 0) * 20))
.gesture(DragGesture()
.onChanged({ value in
self.isGestureActive = true
self.offset = value.translation.width + -geometry.size.width * CGFloat(self.selection ?? 1)
})
.onEnded({ value in
DispatchQueue.main.async { self.isGestureActive = false }
}))
}
}
VStack {
Button(action: { self.changeSelection(-1) }) {
Text("Move Up")
}
Spacer()
Button(action: { self.changeSelection(1) }) {
Text("Move Down")
}
}
}
}
}
of course you need to create your own "list row":
struct ListRow: View {
#State var line: Int
#Binding var selection: Int?
var body: some View {
HStack(alignment: .center, spacing: 2){
Image(systemName: line == self.selection ? "checkmark.square" : "square")
.padding(.horizontal, 3)
Text(String(line))
Spacer()
}
.onTapGesture {
self.selection = self.selection == self.line ? nil : self.line
}
}
}
hope it'll be helpful.
In the new relase of SwiftUI for iOs 14 and MacOs Big Sur they added the ability to programmatically scroll to a specific cell using the new ScrollViewReader:
struct ContentView: View {
let colors: [Color] = [.red, .green, .blue]
var body: some View {
ScrollView {
ScrollViewReader { value in
Button("Jump to #8") {
value.scrollTo(8)
}
ForEach(0..<10) { i in
Text("Example \(i)")
.frame(width: 300, height: 300)
.background(colors[i % colors.count])
.id(i)
}
}
}
}
}
Then you can use the method .scrollTo() like this
value.scrollTo(8, anchor: .top)
Credit: www.hackingwithswift.com
I am doing it this way:
1) Reusable copy-paste component:
import SwiftUI
struct TableViewConfigurator: UIViewControllerRepresentable {
var configure: (UITableView) -> Void = { _ in }
func makeUIViewController(context: UIViewControllerRepresentableContext<TableViewConfigurator>) -> UIViewController {
UIViewController()
}
func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<TableViewConfigurator>) {
//let tableViews = uiViewController.navigationController?.topViewController?.view.subviews(ofType: UITableView.self) ?? [UITableView]()
let tableViews = UIApplication.nonModalTopViewController()?.navigationController?.topViewController?.view.subviews(ofType: UITableView.self) ?? [UITableView]()
for tableView in tableViews {
self.configure(tableView)
}
}
}
2) Extension on UIApplication to find top view controller in hierarchy
extension UIApplication {
class var activeSceneRootViewController: UIViewController? {
if #available(iOS 13.0, *) {
for scene in UIApplication.shared.connectedScenes {
if scene.activationState == .foregroundActive {
return ((scene as? UIWindowScene)?.delegate as? UIWindowSceneDelegate)?.window??.rootViewController
}
}
} else {
// Fallback on earlier versions
return UIApplication.shared.keyWindow?.rootViewController
}
return nil
}
class func nonModalTopViewController(controller: UIViewController? = UIApplication.activeSceneRootViewController) -> UIViewController? {
print(controller ?? "nil")
if let navigationController = controller as? UINavigationController {
return nonModalTopViewController(controller: navigationController.topViewController ?? navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selected = tabController.selectedViewController {
return nonModalTopViewController(controller: selected)
}
}
if let presented = controller?.presentedViewController {
let top = nonModalTopViewController(controller: presented)
if top == presented { // just modal
return controller
} else {
print("Top:", top ?? "nil")
return top
}
}
if let navigationController = controller?.children.first as? UINavigationController {
return nonModalTopViewController(controller: navigationController.topViewController ?? navigationController.visibleViewController)
}
return controller
}
}
3) Custom part - Here you implement your solution for UITableView behind List like scrolling:
Use it like modifier on any view in List in View
.background(TableViewConfigurator(configure: { tableView in
if self.viewModel.statusChangeMessage != nil {
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(500)) {
let lastIndexPath = IndexPath(row: tableView.numberOfRows(inSection: 0) - 1, section: 0)
tableView.scrollToRow(at: lastIndexPath, at: .bottom, animated: true)
}
}
}))

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