ARK-OS/arkos/arkrt/ark.ui.basic/Sources/SwiftCrossUI.docc/Backends/DefaultBackend.md

DefaultBackend

An adaptive backend which uses different backends under the hood depending on the target operating system.

@Metadata {

@TitleHeading("Backend")

}

Overview

The beauty of SwiftCrossUI is that you can write your app once and have it look native everywhere. For this reason we recommend using DefaultBackend unless you have particular constraints. It uses doc:AppKitBackend on macOS, doc:WinUIBackend on Window, doc:GtkBackend on Linux, and doc:UIKitBackend on iOS/tvOS.

Tip: If you're using DefaultBackend, you can override the underlying backend during compilation by setting the SCUI_DEFAULT_BACKEND environment variable to the name of the desired backend. This is useful when you e.g. want to test the Gtk version of your app while using a Mac.

Note that this only works for built-in backends and requires the chosen backend to be compatible with your machine.

Note: When using SCUI_DEFAULT_BACKEND to switch underlying backends, you may encounter some linker-related missing symbol errors. These are caused by a SwiftPM bug and usually disappear if you run swift package clean before attempting to build your app again.

Usage

@TabNavigator {

@Tab("Package.swift") {
    ```swift
    // ...
    let package = Package(
        // ...
        targets: [
            // ...
            .executableTarget(
                name: "YourApp",
                dependencies: [
                    .product(name: "SwiftCrossUI", package: "swift-cross-ui"),
                    .product(name: "DefaultBackend", package: "swift-cross-ui"),
                ]
            ),
            // ...
        ],
        // ...
    )
    ```
}
@Tab("YourApp.swift") {
    ```swift
    import SwiftCrossUI
    import DefaultBackend

    @main
    struct YourApp: App {
        // You can explicitly initialize your app's chosen backend if you desire.
        // This happens automatically when you import any of the built-in backends.
        //
        // var backend = DefaultBackend()

        var body: some Scene {
            WindowGroup {
                Text("Hello, World!")
                    .padding()
            }
        }
    }
    ```
}

}