Implement openURL environment action

Author: stackotter

Sources/AppKitBackend/AppKitBackend.swift

@@ -117,6 +117,10 @@ public final class AppKitBackend: AppBackend {
         window.makeKeyAndOrderFront(nil)
     }
 
+    public func openExternalURL(_ url: URL) throws {
+        NSWorkspace.shared.open(url)
+    }
+
     private static func renderMenuItems(_ items: [ResolvedMenu.Item]) -> [NSMenuItem] {
         items.map { item in
             switch item {

Sources/Gtk3Backend/Gtk3Backend.swift

@@ -215,6 +215,11 @@ public final class Gtk3Backend: AppBackend {
         window.present()
     }
 
+    public func openExternalURL(_ url: URL) throws {
+        // Used instead of gtk_uri_launcher_launch to maintain <4.10 compatibility
+        gtk_show_uri(nil, url.absoluteString, GDK_CURRENT_TIME)
+    }
+
     class ThreadActionContext {
         var action: () -> Void
 

Sources/GtkBackend/GtkBackend.swift

@@ -157,6 +157,11 @@ public final class GtkBackend: AppBackend {
         window.present()
     }
 
+    public func openExternalURL(_ url: URL) throws {
+        // Used instead of gtk_uri_launcher_launch to maintain <4.10 compatibility
+        gtk_show_uri(nil, url.absoluteString, GDK_CURRENT_TIME)
+    }
+
     private func renderMenu(
         _ menu: ResolvedMenu,
         actionMap: any GActionMap,

Sources/SwiftCrossUI/Backend/AppBackend.swift

@@ -168,6 +168,10 @@ public protocol AppBackend {
     /// associated with a custom URL scheme).
     func setIncomingURLHandler(to action: @escaping (URL) -> Void)
 
+    /// Opens an external URL in the system browser or app registered for the
+    /// URL's protocol.
+    func openExternalURL(_ url: URL) throws
+
     /// Shows a widget after it has been created or updated (may be unnecessary
     /// for some backends). Predominantly used by ``ViewGraphNode`` after
     /// propagating updates.
@@ -501,6 +505,12 @@ extension AppBackend {
         Foundation.exit(1)
     }
 
+    // MARK: System
+
+    public func openExternalURL(_ url: URL) throws {
+        todo()
+    }
+
     // MARK: Application
 
     public func setApplicationMenu(_ submenus: [ResolvedMenu.Submenu]) {

Sources/SwiftCrossUI/Environment/Actions/OpenURLAction.swift

@@ -0,0 +1,21 @@
+import Foundation
+
+/// Opens a URL with the default application. May present an application picker
+/// if multiple applications are registered for the given URL protocol.
+public struct OpenURLAction {
+    let action: (URL) -> Void
+
+    init<Backend: AppBackend>(backend: Backend) {
+        action = { url in
+            do {
+                try backend.openExternalURL(url)
+            } catch {
+                print("warning: Failed to open external url: \(error)")
+            }
+        }
+    }
+
+    public func callAsFunction(_ url: URL) {
+        action(url)
+    }
+}

Sources/SwiftCrossUI/Environment/EnvironmentValues.swift

@@ -95,6 +95,15 @@ public struct EnvironmentValues {
         )
     }
 
+    /// Opens a URL with the default application. May present an application
+    /// picker if multiple applications are registered for the given URL
+    /// protocol.
+    public var openURL: OpenURLAction {
+        return OpenURLAction(
+            backend: backend
+        )
+    }
+
     /// Creates the default environment.
     init<Backend: AppBackend>(backend: Backend) {
         self.backend = backend

Sources/WinUIBackend/WinUIBackend.swift

@@ -195,6 +195,10 @@ public final class WinUIBackend: AppBackend {
         try! window.activate()
     }
 
+    public func openExternalURL(_ url: URL) throws {
+        UWP.Launcher.launchUriAsync(WindowsFoundation.Uri(url.absoluteString))
+    }
+
     public func runInMainThread(action: @escaping () -> Void) {
         _ = try! internalState.dispatcherQueue!.tryEnqueue(.normal) {
             action()