Add support for GtkDropDown

Sources/Core/View/DropDown+.swift

@@ -0,0 +1,68 @@
+//
+//  DropDown+.swift
+//  Adwaita
+//
+//  Created by david-swift on 09.04.25.
+//
+
+import CAdw
+import LevenshteinTransformations
+
+extension DropDown {
+
+    /// The identifier for the values.
+    static var values: String { "values" }
+    /// The identifier for the string list.
+    static var stringList: String { "string-list" }
+
+    /// Initialize a combo row.
+    /// - Parameters:
+    ///     - title: The row's title.
+    ///     - selection: The selected value.
+    ///     - values: The available values.
+    public init<Element>(
+        selection: Binding<Element.ID>,
+        values: [Element]
+    ) where Element: Identifiable, Element: CustomStringConvertible {
+        self.init()
+        self = self.selected(.init {
+            .init(values.firstIndex { $0.id == selection.wrappedValue } ?? 0)
+        } set: { index in
+            if let id = values[safe: .init(index)]?.id {
+                selection.wrappedValue = id
+            }
+        })
+        appearFunctions.append { storage, _ in
+            storage.fields[Self.stringList] = gtk_drop_down_get_model(storage.opaquePointer)
+            Self.updateContent(storage: storage, values: values, element: Element.self)
+        }
+        updateFunctions.append { storage, _, _ in
+            Self.updateContent(storage: storage, values: values, element: Element.self)
+        }
+    }
+
+    /// Update the combo row's content.
+    /// - Parameters:
+    ///     - storage: The view storage.
+    ///     - values: The elements.
+    ///     - element: The type of the elements.
+    static func updateContent<Element>(
+        storage: ViewStorage,
+        values: [Element],
+        element: Element.Type
+    ) where Element: Identifiable, Element: CustomStringConvertible {
+        if let list = storage.fields[Self.stringList] as? OpaquePointer {
+            let old = storage.fields[Self.values] as? [Element] ?? []
+            old.identifiableTransform(
+                to: values,
+                functions: .init { index in
+                    gtk_string_list_remove(list, .init(index))
+                } insert: { _, element in
+                    gtk_string_list_append(list, element.description)
+                }
+            )
+            storage.fields[Self.values] = values
+        }
+    }
+
+}

Sources/Core/View/Generated/DropDown.swift

@@ -0,0 +1,191 @@
+//
+//  DropDown.swift
+//  Adwaita
+//
+//  Created by auto-generation on 09.04.25.
+//
+
+import CAdw
+import LevenshteinTransformations
+
+/// Allows the user to choose an item from a list of options.
+/// 
+/// <picture><source srcset="drop-down-dark.png" media="(prefers-color-scheme: dark)"><img alt="An example GtkDropDown" src="drop-down.png"></picture>
+/// 
+/// The `GtkDropDown` displays the [selected][property@Gtk.DropDown:selected]
+/// choice.
+/// 
+/// The options are given to `GtkDropDown` in the form of `GListModel`
+/// and how the individual options are represented is determined by
+/// a [class@Gtk.ListItemFactory]. The default factory displays simple strings,
+/// and adds a checkmark to the selected item in the popup.
+/// 
+/// To set your own factory, use [method@Gtk.DropDown.set_factory]. It is
+/// possible to use a separate factory for the items in the popup, with
+/// [method@Gtk.DropDown.set_list_factory].
+/// 
+/// `GtkDropDown` knows how to obtain strings from the items in a
+/// [class@Gtk.StringList]; for other models, you have to provide an expression
+/// to find the strings via [method@Gtk.DropDown.set_expression].
+/// 
+/// `GtkDropDown` can optionally allow search in the popup, which is
+/// useful if the list of options is long. To enable the search entry,
+/// use [method@Gtk.DropDown.set_enable_search].
+/// 
+/// Here is a UI definition example for `GtkDropDown` with a simple model:
+/// 
+/// ```xml
+/// <object class="GtkDropDown"><property name="model"><object class="GtkStringList"><items><item translatable="yes">Factory</item><item translatable="yes">Home</item><item translatable="yes">Subway</item></items></object></property></object>
+/// ```
+/// 
+/// If a `GtkDropDown` is created in this manner, or with
+/// [ctor@Gtk.DropDown.new_from_strings], for instance, the object returned from
+/// [method@Gtk.DropDown.get_selected_item] will be a [class@Gtk.StringObject].
+/// 
+/// To learn more about the list widget framework, see the
+/// [overview](section-list-widget.html).
+/// 
+/// ## CSS nodes
+/// 
+/// `GtkDropDown` has a single CSS node with name dropdown,
+/// with the button and popover nodes as children.
+/// 
+/// ## Accessibility
+/// 
+/// `GtkDropDown` uses the [enum@Gtk.AccessibleRole.combo_box] role.
+public struct DropDown: AdwaitaWidget {
+
+    /// Additional update functions for type extensions.
+    var updateFunctions: [(ViewStorage, WidgetData, Bool) -> Void] = []
+    /// Additional appear functions for type extensions.
+    var appearFunctions: [(ViewStorage, WidgetData) -> Void] = []
+
+    /// The accessible role of the given `GtkAccessible` implementation.
+    /// 
+    /// The accessible role cannot be changed once set.
+    var accessibleRole: String?
+    /// Whether to show a search entry in the popup.
+    /// 
+    /// Note that search requires [property@Gtk.DropDown:expression]
+    /// to be set.
+    var enableSearch: Bool?
+    /// The position of the selected item.
+    /// 
+    /// If no item is selected, the property has the value
+    /// %GTK_INVALID_LIST_POSITION.
+    var selected: Binding<UInt>?
+    /// Whether to show an arrow within the GtkDropDown widget.
+    var showArrow: Bool?
+    /// Emitted to when the drop down is activated.
+    /// 
+    /// The `::activate` signal on `GtkDropDown` is an action signal and
+    /// emitting it causes the drop down to pop up its dropdown.
+    var activate: (() -> Void)?
+
+    /// Initialize `DropDown`.
+    public init() {
+    }
+
+    /// The view storage.
+    /// - Parameters:
+    ///     - modifiers: Modify views before being updated.
+    ///     - type: The view render data type.
+    /// - Returns: The view storage.
+    public func container<Data>(data: WidgetData, type: Data.Type) -> ViewStorage where Data: ViewRenderData {
+        let storage = ViewStorage(gtk_drop_down_new(gtk_string_list_new(nil), nil)?.opaque())
+        for function in appearFunctions {
+            function(storage, data)
+        }
+        update(storage, data: data, updateProperties: true, type: type)
+
+        return storage
+    }
+
+    /// Update the stored content.
+    /// - Parameters:
+    ///     - storage: The storage to update.
+    ///     - modifiers: Modify views before being updated
+    ///     - updateProperties: Whether to update the view's properties.
+    ///     - type: The view render data type.
+    public func update<Data>(_ storage: ViewStorage, data: WidgetData, updateProperties: Bool, type: Data.Type) where Data: ViewRenderData {
+        if let activate {
+            storage.connectSignal(name: "activate", argCount: 0) {
+                activate()
+            }
+        }
+        storage.modify { widget in
+
+        storage.notify(name: "selected") {
+            let newValue = UInt(gtk_drop_down_get_selected(storage.opaquePointer))
+if let selected, newValue != selected.wrappedValue {
+    selected.wrappedValue = newValue
+}
+        }
+            if let enableSearch, updateProperties, (storage.previousState as? Self)?.enableSearch != enableSearch {
+                gtk_drop_down_set_enable_search(widget, enableSearch.cBool)
+            }
+            if let selected, updateProperties, (UInt(gtk_drop_down_get_selected(storage.opaquePointer))) != selected.wrappedValue {
+                gtk_drop_down_set_selected(storage.opaquePointer, selected.wrappedValue.cInt)
+            }
+            if let showArrow, updateProperties, (storage.previousState as? Self)?.showArrow != showArrow {
+                gtk_drop_down_set_show_arrow(widget, showArrow.cBool)
+            }
+
+
+
+        }
+        for function in updateFunctions {
+            function(storage, data, updateProperties)
+        }
+        if updateProperties {
+            storage.previousState = self
+        }
+    }
+
+    /// The accessible role of the given `GtkAccessible` implementation.
+    /// 
+    /// The accessible role cannot be changed once set.
+    public func accessibleRole(_ accessibleRole: String?) -> Self {
+        var newSelf = self
+        newSelf.accessibleRole = accessibleRole
+        return newSelf
+    }
+
+    /// Whether to show a search entry in the popup.
+    /// 
+    /// Note that search requires [property@Gtk.DropDown:expression]
+    /// to be set.
+    public func enableSearch(_ enableSearch: Bool? = true) -> Self {
+        var newSelf = self
+        newSelf.enableSearch = enableSearch
+        return newSelf
+    }
+
+    /// The position of the selected item.
+    /// 
+    /// If no item is selected, the property has the value
+    /// %GTK_INVALID_LIST_POSITION.
+    public func selected(_ selected: Binding<UInt>?) -> Self {
+        var newSelf = self
+        newSelf.selected = selected
+        return newSelf
+    }
+
+    /// Whether to show an arrow within the GtkDropDown widget.
+    public func showArrow(_ showArrow: Bool? = true) -> Self {
+        var newSelf = self
+        newSelf.showArrow = showArrow
+        return newSelf
+    }
+
+    /// Emitted to when the drop down is activated.
+    /// 
+    /// The `::activate` signal on `GtkDropDown` is an action signal and
+    /// emitting it causes the drop down to pop up its dropdown.
+    public func activate(_ activate: @escaping () -> Void) -> Self {
+        var newSelf = self
+        newSelf.activate = activate
+        return newSelf
+    }
+
+}

Sources/Demo/Demo.swift

@@ -65,6 +65,19 @@ struct Demo: App {
         .title("Navigation View Demo")
     }
 
+    enum WindowName: String, CaseIterable, CustomStringConvertible, Identifiable {
+
+        case demo = "Demo"
+        case alternative = "Alternative"
+
+        var id: Self { self }
+
+        var description: String {
+            rawValue
+        }
+
+    }
+
     struct DemoContent: WindowView {
 
         @State("selection")
@@ -77,6 +90,7 @@ struct Demo: App {
         @State private var maximized = false
         @State private var about = false
         @State private var preferences = false
+        @State private var title: WindowName = .demo
         var window: AdwaitaWindow
         var app: AdwaitaApp!
         var pictureURL: URL?
@@ -98,7 +112,7 @@ struct Demo: App {
                         menu
                     }
                     .headerBarTitle {
-                        WindowTitle(subtitle: "", title: "Demo")
+                        WindowTitle(subtitle: "", title: title.description)
                     }
                 }
             } content: {
@@ -111,6 +125,7 @@ struct Demo: App {
                     HeaderBar {
                         Toggle(icon: .default(icon: .sidebarShow), isOn: $sidebarVisible)
                             .tooltip("Toggle Sidebar")
+                        DropDown(selection: $title, values: WindowName.allCases)
                     } end: {
                         if sidebarVisible {
                             Text("").transition(.crossfade)
@@ -123,7 +138,7 @@ struct Demo: App {
                             Text("")
                                 .transition(.crossfade)
                         } else {
-                            WindowTitle(subtitle: "Demo", title: selection.label)
+                            WindowTitle(subtitle: title.description, title: selection.label)
                                 .transition(.crossfade)
                         }
                     }

Sources/Generation/GenerationConfiguration.swift

@@ -292,7 +292,21 @@ struct GenerationConfiguration {
             initializer: "gtk_separator_new(GTK_ORIENTATION_VERTICAL)",
             excludeProperties: ["orientation"]
         ),
-        .init(class: "Fixed")
+        .init(class: "Fixed"),
+        .init(
+            class: "DropDown",
+            initializer: "gtk_drop_down_new(gtk_string_list_new(nil), nil)",
+            bindings: [.init(property: "selected")],
+            excludeProperties: [
+                "expression",
+                "factory",
+                "header-factory",
+                "list-factory",
+                "model",
+                "search-match-mode",
+                "selected-item"
+            ]
+        )
     ]
 
     /// The unshortening map.