How to convert NSEvent locationInWindow to window coordinate

Issue #822 Get active screen with mouse func activeScreen() -> NSScreen? { let mouseLocation = NSEvent.mouseLocation let screens = NSScreen.screens let screenWithMouse = (screens.first { NSMouseInRect(mouseLocation, $0.frame, false) }) return screenWithMouse } Reposition our NSWIndow if window.frame != screen.frame { window.setFrameOrigin(screen.frame.origin) window.setContentSize(screen.frame.size) } Flip y as AppKit has coordinate origin starting from bottom left of the screen, while our SwiftUI starts from top left var point = window.convertPoint(fromScreen: event.locationInWindow) point.y = window....

July 13, 2021 路 1 min 路 Khoa Pham

How to sync width for child views in SwiftUI

Issue #821 Suppose we have a 16:9 preview Image and we want the title Text to be the same width First we need PreferenceKey to store and sync size struct SizePreferenceKey: PreferenceKey { typealias Value = CGSize static var defaultValue: Value = .zero static func reduce(value: inout Value, nextValue: () -> Value) { value = nextValue() } } For our Image, we use a GeometryReader in the background with invisible View Color....

July 6, 2021 路 1 min 路 Khoa Pham

How to highlight link in Text in SwiftUI

Issue #820 Use NSDataDetector to detect links, and NSMutableAttributedString to mark link range. Then we enumerateAttributes and build our Text func attribute(string: String) -> Text { guard let detector = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue) else { return Text(string) } let stringRange = NSRange(location: 0, length: string.count) let matches = detector.matches( in: string, options: [], range: stringRange ) let attributedString = NSMutableAttributedString(string: string) for match in matches { attributedString.addAttribute(.underlineStyle, value: NSUnderlineStyle.single, range: match....

July 6, 2021 路 1 min 路 Khoa Pham

How to show custom context menu in SwiftUI

Issue #818 There鈥檚 a lot to do to imitate iOS ContextMenu look and feel vibrancy blur background haptics feedback targeted view position interaction dismiss gesture For now here鈥檚 a rough implementation of a custom context menu where we can show using .overlay import SwiftUI struct CustomContextMenu<Content: View>: View { @Binding var shows: Bool @ViewBuilder let content: Content var body: some View { ZStack { Color.black.opacity(0.1) .onTapGesture { shows = false } VStack(alignment: ....

July 2, 2021 路 1 min 路 Khoa Pham

How to declare View with ViewBuilder in SwiftUI

Issue #817 Thanks to resultBuilder and container type in Swift, the following are possible in SwiftUI Local variable struct ChartView { var body: some View { computation } @ViewBuilder var computation: some View { let left = 10 let right = 20 if left + right == 30 { Text("Correct") } } } if and switch statement struct ChartView: View { @State private var showsOverlay: Bool = false @State private var overlayKind: OverlayKind?...

July 2, 2021 路 2 min 路 Khoa Pham

How to make custom Menu in SwiftUI

Issue #816 SwiftUI supports Menu but the menu items only appear after the menu button is touched. We can initiate the look and feel of Menu with a custom implementation import SwiftUI struct CustomMenu<Content: View>: View { @ViewBuilder let content: Content var body: some View { VStack(spacing: 0) { content } .frame(width: 234) .background( Color(UIColor.systemBackground) .opacity(0.8) .blur(radius: 50) ) .cornerRadius(14) } } struct CustomMenuButtonStyle: ButtonStyle { let symbol: String let color: Color func makeBody(configuration: Configuration) -> some View { HStack { configuration....

July 1, 2021 路 1 min 路 Khoa Pham

How ObservableObject work in SwiftUI

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....

June 30, 2021 路 2 min 路 Khoa Pham

How to cancel vertical scrolling on paging TabView in SwiftUI

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鈥檚 hard to do lazy. Paging TabView in iOS 14 is built int and optimized for us. We just need to specify PageTabViewStyle, or just ....

June 29, 2021 路 3 min 路 Khoa Pham

How to make carousel pager view in SwiftUI

Issue #812 Use GeometryReader to set width and a DragGesture on LazyVStack CarouselView( pageCount: images.count, currentIndex: $selectedImageIndex ) { ForEach(0 ..< images) { image in // AsyncImage } } struct CarouselView<Content: View>: View { let pageCount: Int @Binding var currentIndex: Int @ViewBuilder let content: Content @GestureState private var translation: CGFloat = 0 var body: some View { GeometryReader { geometry in LazyHStack(spacing: 0) { self.content.frame(width: geometry.size.width) } .frame(width: geometry.size.width, alignment: ....

June 29, 2021 路 1 min 路 Khoa Pham

How to show context menu with custom preview in SwiftUI

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....

June 26, 2021 路 3 min 路 Khoa Pham

How to login with Apple in SwiftUI

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?...

June 25, 2021 路 3 min 路 Khoa Pham

How to use SwiftGen and LocalizedStringKey in SwiftUI

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 鈥 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....

April 27, 2021 路 2 min 路 Khoa Pham

How to use ForEach with indices in SwiftUI

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....

April 20, 2021 路 2 min 路 Khoa Pham

How to convert from paid to freemium in SwiftUI with RevenueCat

Issue #794 I鈥檝e been distributing my apps PastePal and Push Hero as a paid upfront apps on Appstore. I鈥檝e 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....

April 11, 2021 路 5 min 路 Khoa Pham

How to use View protocol in SwiftUI

Issue #791 SwiftUI has View protocol which represents part of your app鈥檚 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 ....

March 10, 2021 路 1 min 路 Khoa Pham

How to manage WindowGroup in SwiftUI for macOS

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鈥檙e 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...

March 7, 2021 路 6 min 路 Khoa Pham

How to use Core Data

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鈥檛 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....

February 26, 2021 路 5 min 路 Khoa Pham

How to force resolve Swift Package in Xcode

Issue #784 Every time I switch git branches, SPM packages seem to be invalidated and Xcode does not fetch again, no matter how many times I reopen. Running xcodebuild -resolvePackageDependencies does fetch but Xcode does not recognize the resolved packages and still reports missing packages. The good thing is under menu File -> Swift Packages there are options to reset and resolve packages

February 26, 2021 路 1 min 路 Khoa Pham

How to listen to Published outside of SwiftUI view

Issue #782 Use $ to access Publisher final class Store: ObservableObject { @Published var showsSideWindow: Bool = false } var anyCancellables = Set<AnyCancellable>() store.$showsSideWindow .removeDuplicates() .throttle(for: 0.2, scheduler: RunLoop.main, latest: true) .receive(on: RunLoop.main) .sink(receiveValue: { shows in preferenceManager.reloadPosition(shows: shows) }) .store(in: &anyCancellables)

February 25, 2021 路 1 min 路 Khoa Pham

How to build container view in SwiftUI

Issue #780 To make a container view that accepts child content, we use ViewBuilder struct ContainerView<Content: View>: View { let content: Content init(@ViewBuilder content: () -> Content) { self.content = content() } var body: some View { content } } From Swift 5.4, it can synthesize the init, so we can declare resultBuilder for stored property struct AwesomeContainerView<Content: View>: View { @ViewBuilder let content: Content var body: some View { content } }

February 24, 2021 路 1 min 路 Khoa Pham