Add onClose to windows

Sources/Core/Model/Signals/SignalData.swift

@@ -11,7 +11,7 @@ import CAdw
 public class SignalData {
 
     /// The closure.
-    public var closure: ([Any?]) -> Void
+    public var closure: ([Any?]) -> Any?
     /// Destroy the class.
     public var selfDestruction: (() -> Void)?
 
@@ -62,11 +62,19 @@ public class SignalData {
         }
     }
 
+    /// The closure as a C handler with a return value.
+    var boolHandler: @convention(c) (UnsafeMutableRawPointer, UnsafeMutableRawPointer) -> Bool {
+        { _, data in
+            let data = unsafeBitCast(data, to: SignalData.self)
+            return data.closure([]) as? Bool ?? false
+        }
+    }
+
     /// Initialize the signal data.
     /// - Parameters:
     ///     - closure: The signal's closure.
     ///     - destroy: The self destruction.
-    public convenience init(closure: @escaping () -> Void, destroy: (() -> Void)? = nil) {
+    public convenience init(closure: @escaping () -> Any?, destroy: (() -> Void)? = nil) {
         self.init(closure: { _ in closure() }, destroy: destroy)
     }
 
@@ -74,19 +82,46 @@ public class SignalData {
     /// - Parameters:
     ///     - closure: The signal's closure.
     ///     - destroy: The self destruction.
-    public init(closure: @escaping ([Any]) -> Void, destroy: (() -> Void)? = nil) {
+    public convenience init(closure: @escaping () -> Void, destroy: (() -> Void)? = nil) {
+        self.init(closure: { _ in closure(); return nil }, destroy: destroy)
+    }
+
+    /// Initialize the signal data.
+    /// - Parameters:
+    ///     - closure: The signal's closure.
+    ///     - destroy: The self destruction.
+    public init(closure: @escaping ([Any]) -> Any?, destroy: (() -> Void)? = nil) {
         self.closure = closure
         self.selfDestruction = destroy
     }
 
+    /// The return type.
+    public enum ReturnType {
+
+        /// Returns a boolean.
+        case bool
+
+    }
+
     /// Connect the signal data to a signal.
     /// - Parameters:
     ///     - pointer: The pointer to the object which holds the signal.
     ///     - signal: The signal's name.
     ///     - argCount: The number of arguments.
-    public func connect(pointer: UnsafeMutableRawPointer?, signal: String, argCount: Int = 0) {
+    ///     - return: The return type.
+    public func connect(
+        pointer: UnsafeMutableRawPointer?,
+        signal: String,
+        argCount: Int = 0,
+        return: ReturnType? = nil
+    ) {
         let callback: GCallback
-        if argCount >= 3 {
+        if let `return` {
+            switch `return` {
+            case .bool:
+                callback = unsafeBitCast(boolHandler, to: GCallback.self)
+            }
+        } else if argCount >= 3 {
             callback = unsafeBitCast(fiveParamsHandler, to: GCallback.self)
         } else if argCount == 2 {
             callback = unsafeBitCast(fourParamsHandler, to: GCallback.self)

Sources/Core/Model/Storage.swift

@@ -48,7 +48,30 @@ extension Storage {
         pointer: OpaquePointer? = nil,
         handler: @escaping () -> Void
     ) {
-        connectSignal(name: name, id: id, argCount: argCount, pointer: pointer) { _ in
+        connectSignal(name: name, id: id, argCount: argCount, pointer: pointer) {
+            handler()
+            return nil
+        }
+    }
+
+    /// Connect a handler to a signal.
+    /// - Parameters:
+    ///     - name: The signal's name.
+    ///     - id: The handlers id to separate form others connecting to the signal.
+    ///     - connectFlags: The GConnectFlags.
+    ///     - argCount: The number of additional arguments (without the first and the last one).
+    ///     - return: The return type.
+    ///     - pointer: A custom pointer instead of the stored one.
+    ///     - handler: The signal's handler.
+    public func connectSignal(
+        name: String,
+        id: String = "",
+        argCount: Int = 0,
+        return: SignalData.ReturnType? = nil,
+        pointer: OpaquePointer? = nil,
+        handler: @escaping () -> Any?
+    ) {
+        connectSignal(name: name, id: id, argCount: argCount, return: `return`, pointer: pointer) { _ in
             handler()
         }
     }
@@ -66,13 +89,42 @@ extension Storage {
         argCount: Int = 0,
         pointer: OpaquePointer? = nil,
         handler: @escaping ([Any]) -> Void
+    ) {
+        connectSignal(name: name, id: id, argCount: argCount, pointer: pointer) { args in
+            handler(args)
+            return nil
+        }
+    }
+
+    /// Connect a handler to a signal.
+    /// - Parameters:
+    ///     - name: The signal's name.
+    ///     - id: The handlers id to separate form others connecting to the signal.
+    ///     - argCount: The number of additional arguments (without the first and the last one).
+    ///     - return: The return type.
+    ///     - pointer: A custom pointer instead of the stored one.
+    ///     - handler: The signal's handler.
+    public func connectSignal(
+        name: String,
+        id: String = "",
+        argCount: Int = 0,
+        return: SignalData.ReturnType? = nil,
+        pointer: OpaquePointer? = nil,
+        handler: @escaping ([Any]) -> Any?
     ) {
         if let data = fields[name + id] as? SignalData {
             data.closure = handler
         } else {
             let data = SignalData(closure: handler) { [self] in fields[name + id] = nil }
             fields[name + id] = data
-            data.connect(pointer: (pointer ?? opaquePointer)?.cast(), signal: name, argCount: argCount)
+            data.connect(
+                pointer: (
+                    pointer ?? opaquePointer ?? ((self as? SceneStorage)?.pointer as? AdwaitaWindow)?.pointer?.opaque()
+                )?.cast(),
+                signal: name,
+                argCount: argCount,
+                return: `return`
+            )
         }
     }
 

Sources/Core/Window/Window.swift

@@ -47,6 +47,9 @@ public struct Window: AdwaitaSceneElement {
     var maximized: Binding<Bool>?
     /// Whether the window uses the development style.
     var devel: Bool?
+    /// Run this function when the window should close.
+    /// Return true to stop the closing process.
+    var onClose: (() -> Bool)?
 
     /// Create a window type with a certain identifier and user interface.
     /// - Parameters:
@@ -136,6 +139,9 @@ public struct Window: AdwaitaSceneElement {
         if minWidth != nil || minHeight != nil {
             gtk_widget_set_size_request(window.pointer?.cast(), .init(minWidth ?? -1), .init(minHeight ?? -1))
         }
+        storage.connectSignal(name: "close-request", id: "on-close", return: .bool) {
+            (storage.fields["on-close"] as? (() -> Bool))?() ?? false
+        }
         update(storage, app: app, updateProperties: true)
         return storage
     }
@@ -246,6 +252,9 @@ public struct Window: AdwaitaSceneElement {
                 gtk_window_unmaximize(window.pointer?.cast())
             }
         }
+        if let onClose {
+            storage.fields["on-close"] = onClose
+        }
         storage.previousState = self
     }
 
@@ -373,9 +382,19 @@ public struct Window: AdwaitaSceneElement {
         return newSelf
     }
 
+    /// Run this closure when the window should be closed.
+    /// - Parameter onClose: The closure. Return true to cancel the closing process.
+    /// - Returns: The window.
+    ///
+    /// This does not get executed if the user quits the whole application.
+    public func onClose(onClose: @escaping () -> Bool) -> Self {
+        var newSelf = self
+        newSelf.onClose = onClose
+        return newSelf
+    }
+
 }
 
 // swiftlint:enable discouraged_optional_collection
-
 /// An AdwApplicationWindow.
 public typealias AdwaitaWindow = Window.AdwaitaWindow

Sources/Demo/Demo.swift

@@ -91,6 +91,8 @@ struct Demo: App {
         @State private var about = false
         @State private var preferences = false
         @State private var title: WindowName = .demo
+        @State private var closeAlert = false
+        @State private var destroy = false
         var window: AdwaitaWindow
         var app: AdwaitaApp!
         var pictureURL: URL?
@@ -172,6 +174,16 @@ struct Demo: App {
                             .title("Extra Action")
                     }
             }
+            .alertDialog(
+                visible: $closeAlert,
+                heading: "Close this Window?",
+                body: "Nothing will be lost. This is a demo."
+            )
+            .response("Cancel", role: .close) { }
+            .response("Close", appearance: .suggested, role: .default) {
+                destroy = true
+                window.close()
+            }
         }
 
         var menu: AnyView {
@@ -200,6 +212,7 @@ struct Demo: App {
             window
                 .size(width: $width, height: $height)
                 .maximized($maximized)
+                .onClose { closeAlert = !destroy; return !destroy }
         }
 
     }

io.github.AparokshaUI.Demo.json

@@ -1,7 +1,7 @@
 {
   "app-id": "io.github.AparokshaUI.Demo",
   "runtime": "org.gnome.Platform",
-  "runtime-version": "48",
+  "runtime-version": "49",
   "sdk": "org.gnome.Sdk",
   "sdk-extensions": [
     "org.freedesktop.Sdk.Extension.swift6"