Support Copy/Paste keyboard shortcuts with Swift UI for Mac OS X

Thought this might be a great opportunity for my first post! 🎉

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Objectives:

• Add a paste command to your app menu (window commands) and a Cmd+V keyboard shortcut
• Make a copy button that you can add to your window commands

TL;DR:
Add the PasteButton system button in your window commands.
Find snippet for copy button action at the end.

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Setup

Create an ObservableObject to store and publish your clipboard content to the rest of the app.

// AppClipboard.swift

class AppClipboard: ObservableObject {
    @Published var content: URL?

    init(content: URL? = nil) {
        self.content = content
    }
}

Attach an instance in your app entry point:

// MyApp.swift

import SwiftUI

@main
struct MyApp: App {
    @StateObject var clipboard = AppClipboard() // <---- 1. //

    var body: some Scene {

        WindowGroup("My App Name") {
            ContentView()
                .environmentObject(clipboard) // <---- 2. //

        }

    }
}

And now you can access the object in child views:

import SwiftUI

struct MyView: View {
    @EnvironmentObject var clipboard: AppClipboard // <---- 1. //

    var body: some View {
      Text(clipboard.content) // <----- 2. //
    }
}

Next, create a FocusBinding by extending the FocusedValues struct and adding a key for the clipboard. This makes the ObservableObject we created earlier accessible from the window menu commands we will create later.

// FocusedValuesExtension.swift

private struct ClipboardContentKey: FocusedValueKey {
    typealias Value = Binding<String?>
}

extension FocusedValues {
    var clipboardContent: Binding<String?>? {
        get { self[ClipboardContentKey.self] }
        set { self[ClipboardContentKey.self] = newValue }
    }
}

Now in your window menu commands add the clipboard FocusedBinding like so:

// Commands.swift

import SwiftUI

struct MyWindowCommands: Commands {
    @FocusedBinding(\.clipboardContent) var clipboardContent // <--- 1. //

    var body: some Commands {
        // Option 1: Replace system pasteboard menu...
        CommandGroup(replacing: CommandGroupPlacement.pasteboard) {
            PasteButton(payloadType: String.self) { values in
                 guard let value = values.first else { return }
                 // make sure we updating on the main thread (or we get a warning)
                 DispatchQueue.main.async{
                     clipboardContent = value // <---- 2. //
                 }
                 return
            }
            .keyboardShortcut("V", modifiers: [.command]) // <--- shortcut 3. // 
        }

        // Option 2: Create custom menu
        CommandMenu("My Custom Menu") {
            PasteButton(payloadType: String.self) { values in
                 guard let value = values.first else { return }
                 DispatchQueue.main.async{
                     clipboardContent = value 
                 }
                 return
            }
            .keyboardShortcut("V", modifiers: [.command])  
        }
    }
}

If you build your app in XCode, you should now see a working paste under the Edit menu or your custom menu.

Making a copy button

This is a little trickier because it depends on how you plan to use the copy action in your app. But I will include here a simple button action snippet that lets you put content in the system clipboard.

Button(action: {
    NSPasteboard.general.declareTypes([.string], owner: nil)

    let pasteboard = NSPasteboard.general // <----- This is important! Do not convert to a one liner!
    pasteboard.setString(webURL.absoluteString, forType: .string)
}, label: {
    Image(systemName: "square.on.square")
})

You can incorporate this into your window commands like the paste button.

Hope you found this useful!

Resources

SwiftUI Mac Menus

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Photo by Jørgen Håland