Add Window scene, openWindow action, dismissWindow action, fix window close handling, and add multi-window support to WindowGroup

Examples/Sources/WindowingExample/WindowingApp.swift

@@ -157,6 +157,56 @@ struct SheetDemo: View {
     }
 }
 
+struct OpenWindowDemo: View {
+    @Environment(\.openWindow) private var openWindow
+    @Environment(\.supportsMultipleWindows) private var supportsMultipleWindows
+
+    var body: some View {
+        Text("Backend supports multi-window: \(supportsMultipleWindows)")
+
+        Button("Open singleton window") {
+            openWindow(id: "singleton-window")
+        }
+        Button("Open new tertiary window instance") {
+            openWindow(id: "tertiary-window")
+        }
+    }
+}
+
+struct TertiaryWindowView: View {
+    @Environment(\.dismissWindow) private var dismissWindow
+    @Environment(\.openWindow) private var openWindow
+
+    var body: some View {
+        VStack {
+            Text("This a tertiary window!")
+
+            Button("Close window") {
+                dismissWindow()
+            }
+            Button("Open new instance") {
+                openWindow(id: "tertiary-window")
+            }
+        }
+        .padding()
+    }
+}
+
+struct SingletonWindowView: View {
+    @Environment(\.dismissWindow) private var dismissWindow
+
+    var body: some View {
+        VStack {
+            Text("This a singleton window!")
+
+            Button("Close window") {
+                dismissWindow()
+            }
+        }
+        .padding()
+    }
+}
+
 @main
 @HotReloadable
 struct WindowingApp: App {
@@ -194,6 +244,10 @@ struct WindowingApp: App {
                     Divider()
 
                     SheetDemo()
+
+                    Divider()
+
+                    OpenWindowDemo()
                         .padding(.bottom, 20)
                 }
                 .padding(20)
@@ -213,20 +267,29 @@ struct WindowingApp: App {
                 }
             }
         }
+
         #if !(os(iOS) || os(tvOS) || os(Windows))
-            WindowGroup("Secondary window") {
+            WindowGroup("Secondary window", id: "secondary-window") {
                 #hotReloadable {
                     Text("This a secondary window!")
-                        .padding(10)
+                        .padding()
+                }
+            }
+            .defaultSize(width: 200, height: 200)
+            .windowResizability(.contentMinSize)
+
+            WindowGroup("Tertiary window (hidden)", id: "tertiary-window") {
+                #hotReloadable {
+                    TertiaryWindowView()
                 }
             }
             .defaultSize(width: 200, height: 200)
             .windowResizability(.contentMinSize)
+            .defaultLaunchBehavior(.suppressed)
 
-            WindowGroup("Tertiary window") {
+            Window("Singleton window", id: "singleton-window") {
                 #hotReloadable {
-                    Text("This a tertiary window!")
-                        .padding(10)
+                    SingletonWindowView()
                 }
             }
             .defaultSize(width: 200, height: 200)

Sources/AppKitBackend/AppKitBackend.swift

@@ -25,6 +25,7 @@ public final class AppKitBackend: AppBackend {
     public let requiresImageUpdateOnScaleFactorChange = false
     public let menuImplementationStyle = MenuImplementationStyle.dynamicPopover
     public let canRevealFiles = true
+    public let supportsMultipleWindows = true
     public let deviceClass = DeviceClass.desktop
 
     public var scrollBarWidth: Int {
@@ -68,6 +69,11 @@ public final class AppKitBackend: AppBackend {
         )
         window.delegate = window.customDelegate
 
+        // NB: If this isn't set, AppKit will crash within -[NSApplication run]
+        // the *second* time `openWindow` is called. I have absolutely no idea
+        // why.
+        window.isReleasedWhenClosed = false
+
         return window
     }
 
@@ -96,7 +102,7 @@ public final class AppKitBackend: AppBackend {
         ofWindow window: Window,
         to action: @escaping (SIMD2<Int>) -> Void
     ) {
-        window.customDelegate.setHandler(action)
+        window.customDelegate.setResizeHandler(action)
     }
 
     public func setTitle(ofWindow window: Window, to title: String) {
@@ -123,6 +129,17 @@ public final class AppKitBackend: AppBackend {
         window.makeKeyAndOrderFront(nil)
     }
 
+    public func close(window: Window) {
+        window.close()
+    }
+
+    public func setCloseHandler(
+        ofWindow window: Window,
+        to action: @escaping () -> Void
+    ) {
+        window.customDelegate.setCloseHandler(action)
+    }
+
     public func openExternalURL(_ url: URL) throws {
         NSWorkspace.shared.open(url)
     }
@@ -2253,11 +2270,16 @@ public class NSCustomWindow: NSWindow {
 
     class Delegate: NSObject, NSWindowDelegate {
         var resizeHandler: ((SIMD2<Int>) -> Void)?
+        var closeHandler: (() -> Void)?
 
-        func setHandler(_ resizeHandler: @escaping (SIMD2<Int>) -> Void) {
+        func setResizeHandler(_ resizeHandler: @escaping (SIMD2<Int>) -> Void) {
             self.resizeHandler = resizeHandler
         }
 
+        func setCloseHandler(_ closeHandler: @escaping () -> Void) {
+            self.closeHandler = closeHandler
+        }
+
         func windowWillResize(_ sender: NSWindow, to frameSize: NSSize) -> NSSize {
             guard let resizeHandler else {
                 return frameSize
@@ -2279,6 +2301,10 @@ public class NSCustomWindow: NSWindow {
             return frameSize
         }
 
+        func windowWillClose(_ notification: Notification) {
+            closeHandler?()
+        }
+
         func windowWillReturnUndoManager(_ window: NSWindow) -> UndoManager? {
             (window as! NSCustomWindow).persistentUndoManager
         }

Sources/DummyBackend/DummyBackend.swift

@@ -11,6 +11,7 @@ public final class DummyBackend: AppBackend {
         public var resizable = true
         public var content: Widget?
         public var resizeHandler: ((SIMD2<Int>) -> Void)?
+        public var closeHandler: (() -> Void)?
 
         public init(defaultSize: SIMD2<Int>?) {
             size = defaultSize ?? Self.defaultSize
@@ -247,6 +248,7 @@ public final class DummyBackend: AppBackend {
     public var menuImplementationStyle = MenuImplementationStyle.dynamicPopover
     public var deviceClass = DeviceClass.desktop
     public var canRevealFiles = false
+    public let supportsMultipleWindows = true
 
     public var incomingURLHandler: ((URL) -> Void)?
 
@@ -297,6 +299,14 @@ public final class DummyBackend: AppBackend {
 
     public func activate(window: Window) {}
 
+    public func close(window: Window) {
+        window.closeHandler?()
+    }
+
+    public func setCloseHandler(ofWindow window: Window, to action: @escaping () -> Void) {
+        window.closeHandler = action
+    }
+
     public func runInMainThread(action: @escaping @MainActor () -> Void) {
         DispatchQueue.main.async {
             action()

Sources/Gtk/Widgets/Window.swift

@@ -83,16 +83,10 @@ open class Window: Widget {
 
     public func present() {
         gtk_window_present(castedPointer())
+    }
 
-        addSignal(name: "close-request") { [weak self] () in
-            guard let self else { return }
-            self.onCloseRequest?(self)
-        }
-
-        addSignal(name: "destroy") { [weak self] () in
-            guard let self else { return }
-            self.onDestroy?(self)
-        }
+    public func close() {
+        gtk_window_close(castedPointer())
     }
 
     public func setEscapeKeyPressedHandler(to handler: (() -> Void)?) {
@@ -111,8 +105,24 @@ open class Window: Widget {
 
     private var escapeKeyEventController: EventControllerKey?
 
-    public var onCloseRequest: ((Window) -> Void)?
-    public var onDestroy: ((Window) -> Void)?
+    public var onCloseRequest: ((Window) -> Void)? {
+        didSet {
+            addSignal(name: "close-request") { [weak self] () in
+                guard let self else { return }
+                self.onCloseRequest?(self)
+            }
+        }
+    }
+
+    public var onDestroy: ((Window) -> Void)? {
+        didSet {
+            addSignal(name: "destroy") { [weak self] () in
+                guard let self else { return }
+                self.onDestroy?(self)
+            }
+        }
+    }
+
     public var escapeKeyPressed: (() -> Void)?
 }
 

Sources/Gtk3/Widgets/Window.swift

@@ -61,6 +61,10 @@ open class Window: Bin {
         gtk_window_present(castedPointer())
     }
 
+    public func close() {
+        gtk_window_close(castedPointer())
+    }
+
     public func setMinimumSize(to minimumSize: Size) {
         gtk_widget_set_size_request(
             castedPointer(),
@@ -72,4 +76,20 @@ open class Window: Bin {
     public func setPosition(to position: WindowPosition) {
         gtk_window_set_position(castedPointer(), position.toGtk())
     }
+
+    public var onCloseRequest: ((Window) -> Void)? {
+        didSet {
+            let handler:
+                @convention(c) (UnsafeMutableRawPointer, OpaquePointer, UnsafeMutableRawPointer) -> Void =
+                { _, value1, data in
+                    SignalBox1<OpaquePointer>.run(data, value1)
+                }
+
+            addSignal(name: "delete-event", handler: gCallback(handler)) {
+                [weak self] (_: OpaquePointer) in
+                guard let self else { return }
+                self.onCloseRequest?(self)
+            }
+        }
+    }
 }

Sources/Gtk3Backend/Gtk3Backend.swift

@@ -37,6 +37,7 @@ public final class Gtk3Backend: AppBackend {
     public let requiresImageUpdateOnScaleFactorChange = true
     public let menuImplementationStyle = MenuImplementationStyle.dynamicPopover
     public let canRevealFiles = true
+    public let supportsMultipleWindows = true
     public let deviceClass = DeviceClass.desktop
 
     var gtkApp: Application
@@ -297,6 +298,25 @@ public final class Gtk3Backend: AppBackend {
         window.present()
     }
 
+    public func close(window: Window) {
+        window.close()
+        window.destroy()
+
+        // NB: It seems GTK3 won't automatically signal `::delete-event` if
+        // the window is closed programmatically.
+        window.onCloseRequest?(window)
+    }
+
+    public func setCloseHandler(
+        ofWindow window: Window,
+        to action: @escaping () -> Void
+    ) {
+        window.onCloseRequest = { _ in
+            action()
+            window.destroy()
+        }
+    }
+
     public func openExternalURL(_ url: URL) throws {
         // Used instead of gtk_uri_launcher_launch to maintain <4.10 compatibility
         var error: UnsafeMutablePointer<GError>? = nil

Sources/GtkBackend/GtkBackend.swift

@@ -41,6 +41,7 @@
     public let requiresImageUpdateOnScaleFactorChange = false
     public let menuImplementationStyle = MenuImplementationStyle.dynamicPopover
     public let canRevealFiles = true
+    public let supportsMultipleWindows = true
     public let deviceClass = DeviceClass.desktop
     public let defaultSheetCornerRadius = 10
 
@@ -163,7 +164,7 @@
             return 0
         #else
             if window.showMenuBar {
                 // TODO: Don't hardcode this (if possible), because some Gtk
                 //   themes may affect the height of the menu bar.
                 25
             } else {
@@ -179,7 +180,7 @@
     }
 
     public func isWindowProgrammaticallyResizable(_ window: Window) -> Bool {
         // TODO: Detect whether window is fullscreen
         return true
     }
 
@@ -216,6 +217,21 @@
         window.present()
     }
 
+    public func close(window: Window) {
+        window.close()
+        window.destroy()
+    }
+
+    public func setCloseHandler(
+        ofWindow window: Window,
+        to action: @escaping () -> Void
+    ) {
+        window.onCloseRequest = { _ in
+            action()
+            window.destroy()
+        }
+    }
+
     public func openExternalURL(_ url: URL) throws {
         // Used instead of gtk_uri_launcher_launch to maintain <4.10 compatibility
         gtk_show_uri(nil, url.absoluteString, guint(GDK_CURRENT_TIME))
@@ -280,7 +296,7 @@
 
                     model.appendItem(label: label, actionName: "\(actionNamespace).\(actionName)")
                 case .toggle(let label, let value, let onChange):
                     // FIXME: Implement
                     logger.warning("menu toggles not implemented")
                 case .submenu(let submenu):
                     model.appendSubmenu(
@@ -386,14 +402,14 @@
     }
 
     public func setRootEnvironmentChangeHandler(to action: @escaping () -> Void) {
         // TODO: React to theme changes
     }
 
     public func computeWindowEnvironment(
         window: Window,
         rootEnvironment: EnvironmentValues
     ) -> EnvironmentValues {
         // TODO: Record window scale factor in here
         rootEnvironment
     }
 
@@ -401,7 +417,7 @@
         of window: Window,
         to action: @escaping () -> Void
     ) {
         // TODO: Notify when window scale factor changes
     }
 
     public func setIncomingURLHandler(to action: @escaping (URL) -> Void) {
@@ -686,7 +702,7 @@
 
     // private let tables = Tables()
 
     // TODO: Implement tables
     // public func createTable(rows: Int, columns: Int) -> Widget {
     //     let widget = Grid()
 
@@ -763,7 +779,7 @@
         environment: EnvironmentValues,
         action: @escaping () -> Void
     ) {
         // TODO: Update button label color using environment
         let button = button as! Gtk.Button
         button.sensitive = environment.isEnabled
         button.label = label
@@ -1179,7 +1195,7 @@
                 }
             },
             window: window ?? windows[0]
         ) { result in
             switch result {
                 case .success(let urls):
                     handleResult(.success(urls[0]))
@@ -1212,7 +1228,7 @@
         configure(chooser)
 
         chooser.registerSignals()
         chooser.response = { (_: NativeDialog, response: Int) -> Void in
             // Release our intentional retain cycle which ironically only exists
             // because of this line. The retain cycle keeps the file chooser
             // around long enough for the user to respond (it gets released

Sources/SwiftCrossUI/App.swift

@@ -107,7 +107,13 @@ extension App {
         label: String,
         metadataProvider: Logger.MetadataProvider?
     ) -> any LogHandler {
-        StreamLogHandler.standardError(label: label)
+        var logHandler = StreamLogHandler.standardError(label: label)
+        #if DEBUG
+            logHandler.logLevel = .debug
+        #else
+            logHandler.logLevel = .info
+        #endif
+        return logHandler
     }
 
     /// Runs the application.