swift

Issue #815 When ever a property marked with @Published change, ObservableObject will emit objectWillChange.send hence telling the View that observes it to reinvalidate. In WWDC 2021 session Discover concurrency in SwiftUI they mention how objectWillChange is used to grab before-change data to diff the changes. In the below example, we have 2 ObservableObject Store with just count value being used in the View, while flag is not used Store2 with count not being used But since the View observes these 2 objects, whenever any @Publish property changes, SwiftUI thinks that the data changes, then invalidates the body again to see if it needs to redraw....

Issue #814 From iOS 14, TabView has the PageTabViewStyle that turns TabView into the equivalent UIPageViewController. We can of course implement our own Pager but the simple DragGesture does not bring the true experience of a paging UIScrollView or paging TabView. We can also use UIPageViewController under the hood but it’s hard to do lazy. Paging TabView in iOS 14 is built int and optimized for us. We just need to specify PageTabViewStyle, or just ....

Issue #810 struct User { var createdAt: Date var name: Sttring var locked: Bool } extension KeyPath where Root == User { var keyPathString: String { switch self { case \User.createdAt: return "createdAt" case \User.name: return "name" case \User.locked: return "locked" default: return "" } } } Then we can call reference .collection("users") .document(user.id) .updateData([ (\User.locked).keyPathString:. true ])

Issue #809 Add a hidden overlay UIContextMenuInteraction. Provide preview in previewProvider and actions in actionProvider. Use @ViewBuilder to make declaring preview easy. extension View { func contextMenuWithPreview<Content: View>( actions: [UIAction], @ViewBuilder preview: @escaping () -> Content ) -> some View { self.overlay( InteractionView( preview: preview, menu: UIMenu(title: "", children: actions), didTapPreview: {} ) ) } } private struct InteractionView<Content: View>: UIViewRepresentable { @ViewBuilder let preview: () -> Content let menu: UIMenu let didTapPreview: () -> Void func makeUIView(context: Context) -> UIView { let view = UIView() view....

Issue #808 Make SignInWithAppleButton Wrap ASAuthorizationAppleIDButton inside UIViewRepresentable import SwiftUI import UIKit import AuthenticationServices struct SignInWithAppleButton: View { @Environment(\.colorScheme) private var colorScheme: ColorScheme var body: some View { ButtonInside(colorScheme: colorScheme) .frame(width: 280, height: 45) } } private struct ButtonInside: UIViewRepresentable { let colorScheme: ColorScheme func makeUIView(context: Context) -> ASAuthorizationAppleIDButton { switch colorScheme { case .dark: return ASAuthorizationAppleIDButton(type: .signIn, style: .white) default: return ASAuthorizationAppleIDButton(type: .signIn, style: .black) } } func updateUIView(_ uiView: ASAuthorizationAppleIDButton, context: Context) { // No op } } struct SignInWithAppleButton_Previews: PreviewProvider { static var previews: some View { SignInWithAppleButton() } } Handle logic in ViewModel import SwiftUI import AuthenticationServices import Resolver import Firebase import FirebaseAuth final class AuthViewModel: NSObject, ObservableObject { enum RequestState: String { case signIn case link case reauth } let firebaseService: FirebaseService var window: UIWindow?...

Issue #806 Use runModal https://developer.apple.com/documentation/appkit/nsapplication/1428590-runmodalsession Blocks main queue A loop that uses this method is similar in some ways to a modal event loop run with runModal(for:), except with this method your code can do some additional work between method invocations. When you invoke this method, events for the NSWindow object of this session are dispatched as normal. This method returns when there are no more events. You must invoke this method frequently enough in your loop that the window remains responsive to events....

Issue #805 Use LongPressGesture to detect when long-press gesture has been recognized, and chain with DragGesture to check when pressing still occurs Image(systemName: SFSymbol.deleteLeft.rawValue) .imageScale(.medium) .onTapGesture { onKeyCommand(.backspace) } .gesture( LongPressGesture() .onEnded { _ in self.timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { _ in self.onKeyCommand(.backspace) } } .sequenced( before: DragGesture(minimumDistance: 0) .onEnded { _ in self.timer?.invalidate() self.timer = nil } ) )

Issue #798 swiftgen.yml strings: inputs: PastePal/Resources/Localizable/en.lproj outputs: - templatePath: swiftgen-swiftui-template.stencil output: PastePal/Resources/Strings.swift Template from https://github.com/SwiftGen/SwiftGen/issues/685 swiftgen-swiftui-template.stencil // Generated using SwiftGen — https://github.com/SwiftGen/SwiftGen {% if tables.count > 0 %} import SwiftUI // MARK: - Strings {% macro parametersBlock types %}{% filter removeNewlines:"leading" %} {% for type in types %} {% if type == "String" %} _ p{{forloop.counter}}: Any {% else %} _ p{{forloop.counter}}: {{type}} {% endif %} {{ ", " if not forloop....

Issue #796 One seemingly obvious way to use ForEach on array with indices is using enumerated struct Book: Hashable, Identifiable { let id: UUID let name: String } struct BooksView: View { let books: [Book] var body: some View { List { ForEach(Array(books.enumerated()), id: \.element) { index, book in Text(book.name) .background(index % 2 == 0 ? Color.green : Color.orange) } } } } Reading the documentation for enumerated closely When you enumerate a collection, the integer part of each pair is a counter for the enumeration, but is not necessarily the index of the paired value....

Issue #795 extension NSImage { func resize(width: CGFloat, height: CGFloat, padding: CGFloat) -> NSImage { let img = NSImage(size: CGSize(width: width, height: height)) img.lockFocus() let ctx = NSGraphicsContext.current ctx?.imageInterpolation = .high self.draw( in: NSMakeRect(0, 0, width, height), from: NSMakeRect(0, -padding, size.width, size.height - padding), operation: .copy, fraction: 1 ) img.unlockFocus() return img } } So we can use like button.image = NSImage(named: NSImage.Name("pastePal"))?.resize(width: 22, height: 22, padding: -4)

Issue #794 I’ve been distributing my apps PastePal and Push Hero as a paid upfront apps on Appstore. I’ve quickly come to realize the importance of trials since many have requested a tryout before purchasing. Manual sending out trials comes with its own problem. I need to notarize and package the app as a dmg file, and not to even mention implement my own trial mechanism to check and notify of expired builds....

Issue #793 To create array containing number of repeated value in Swift, we can use Array.init(repeating:count:) let fiveZs = Array(repeating: "Z", count: 5) print(fiveZs) // Prints "["Z", "Z", "Z", "Z", "Z"]" However, if we read Collection Types guide about Creating an Array with a Default Value Swift’s Array type also provides an initializer for creating an array of a certain size with all of its values set to the same default value....

Issue #792 iOS 13 introduced Dark Mode with User Interface Style that makes it easy to support dark and light theme in our apps. Before we dive in, here are some official resources WWDC 2019 Implementing Dark Mode on iOS Supporting Dark Mode in Your Interface Choosing a Specific Interface Style for Your iOS App Adaptive color Like adaptive layout that adapts to different screen sizes, adaptive colors adapt to different user interface styles, for now they are light and dark mode....

Issue #791 SwiftUI has View protocol which represents part of your app’s user interface and provides modifiers that you use to configure views. You create custom views by declaring types that conform to the View protocol. Implement the required body computed property to provide the content for your custom view. A typical example of View is using struct enum HeroType { case melee case range } struct ContentView: View { let heroType: HeroType var body: some View { switch heroType { case ....

Issue #790 Use UIImageWriteToSavedPhotosAlbum Adds the specified image to the user’s Camera Roll album. Let’s make an NSObject delegate class so we can perform target action to notify about completion import UIKit struct ImageService { final class Delegate: NSObject { let completion: (Error?) -> Void init(completion: @escaping (Error?) -> Void) { self.completion = completion } @objc func savedImage( _ im: UIImage, error: Error?, context: UnsafeMutableRawPointer? ) { DispatchQueue.main.async { self....

Issue #789 Using WindowGroup New in SwiftUI 2.0 for iOS 14 and macOS 11.0 is WindwGroup which is used in App protocol. WindowGroup is ideal for document based applications where you can open multiple windows for different content or files. For example if you’re developing a text editor or drawing apps, you can show multiple windows for different text file or drawing. All is handled automatically for you if you use WindowGroup...

Issue #787 In Swift, property, especially for Boolean flagging, uses the regular verb form for the third person. There are few exceptions, such as enable NSManagedObjectContext.automaticallyMergesChangesFromParent UIView.clipsToBounds UIView.translatesAutoresizingMaskIntoConstraints SwiftUI.Transaction.disablesAnimations UIScrollView.scrollsToTop NSView.isHidden UndoManager.enableUndoRegistration

Issue #786 Sometimes we need to update some properties between objects, for example book.name = updatedBook.name book.page = updatedBook.page book.publishedAt = updatedBook.publishedAt Repeating the caller book is tedious and error-prone. In Kotlin, there is with block which is handy to access the receiver properties and methods without referring to it. with(book) { name = updatedBook.name page = updatedBook.page publishedAt = updatedBook.publishedAt } In Swift, there are no such thing, we can write some extension like...

Issue #785 Core Data Responding to changes in a managed object context Calling mergeChanges on a managed object context will automatically refresh any managed objects that have changed. This ensures that your context always contains all the latest information. Note that you don’t have to call mergeChanges on a viewContext when you set its automaticallyMergesChangesFromParent property to true. In that case, Core Data will handle the merge on your behalf....

Issue #783 Remove chane notification Read Consuming Relevant Store Changes If the import happens through a batch operation, the save to the store doesn’t generate an NSManagedObjectContextDidSave notification, and the view misses these relevant updates. Alternatively, the background context may save changes to the store that don’t affect the current view—for example, inserting, modifying, or deleting Shape objects. These changes do generate context save events, so your view context processes them even though it doesn’t need to....