Replace EitherView by the more powerful ViewStack

Documentation/Reference/README.md

@@ -20,7 +20,6 @@
 -   [Button](structs/Button.md)
 -   [Clamp](structs/Clamp.md)
 -   [ContentModifier](structs/ContentModifier.md)
--   [EitherView](structs/EitherView.md)
 -   [FileDialog](structs/FileDialog.md)
 -   [HStack](structs/HStack.md)
 -   [HeaderBar](structs/HeaderBar.md)
@@ -43,6 +42,7 @@
 -   [Toggle](structs/Toggle.md)
 -   [ToolbarView](structs/ToolbarView.md)
 -   [VStack](structs/VStack.md)
+-   [ViewStack](structs/ViewStack.md)
 -   [Window](structs/Window.md)
 
 ## Classes

Documentation/Reference/structs/ViewStack.md

@@ -0,0 +1,42 @@
+**STRUCT**
+
+# `ViewStack`
+
+A widget holding multiple children but only displaying one.
+
+## Properties
+### `content`
+
+The stack's active content.
+
+### `id`
+
+The stack's active identifier.
+
+## Methods
+### `init(id:view:)`
+
+Initialize the stack.
+- Parameters:
+    - id: The identifier of the current view.
+    - view: The current view.
+
+### `init(element:view:)`
+
+Initialize the stack.
+- Parameters:
+    - element: The current identifiable element.
+    - view: The current view.
+
+### `container(modifiers:)`
+
+Get a stack's view storage.
+- Parameter modifiers: Modify views before being updated.
+- Returns: The stack's view storage.
+
+### `update(_:modifiers:)`
+
+Update a stack's view storage.
+- Parameters:
+    - storage: The view storage.
+    - modifiers: Modify views before being updated.

Sources/Adwaita/Model/User Interface/View/ViewBuilder.swift

@@ -58,9 +58,9 @@ public enum ViewBuilder {
     /// - Returns: A nonoptional component.
     public static func buildOptional(_ component: Component?) -> Component {
         if let component {
-            return .element(EitherView(true, { buildFinalResult(component) }, else: nil))
+            return .element(ViewStack(id: true) { _ in buildFinalResult(component) })
         } else {
-            return .element(EitherView(false, nil) { [] })
+            return .element(ViewStack(id: false) { _ in [] })
         }
     }
 
@@ -68,14 +68,14 @@ public enum ViewBuilder {
     /// - Parameter component: A component.
     /// - Returns: The component.
     public static func buildEither(first component: Component) -> Component {
-        .element(EitherView(true, { buildFinalResult(component) }, else: nil))
+        .element(ViewStack(id: true) { _ in buildFinalResult(component) })
     }
 
     /// Enables support for `if`-`else` and `switch` statements.
     /// - Parameter component: A component.
     /// - Returns: The component.
     public static func buildEither(second component: Component) -> Component {
-        .element(EitherView(false, nil) { buildFinalResult(component) })
+        .element(ViewStack(id: false) { _ in buildFinalResult(component) })
     }
 
     /// Convert a component to an array of elements.

Sources/Adwaita/View/EitherView.swift

@@ -1,107 +0,0 @@
-//
-//  EitherView.swift
-//  Adwaita
-//
-//  Created by david-swift on 22.08.23.
-//
-
-import Libadwaita
-
-/// An equivalent to GtkStack for two views.
-public struct EitherView: Widget {
-
-    /// The view that is displayed when `isTrue` is true.
-    var trueView: Body?
-    /// The view that is displayed when `isTrue` is false.
-    var falseView: Body?
-    /// The state.
-    var isTrue: Bool
-
-    /// Initialize an `EitherView`.
-    /// - Parameters:
-    ///   - isTrue: The state.
-    ///   - _:  The view that is presented if `isTrue` is true.
-    ///   - else: The view that is presented if `isTrue` is false.
-    public init(
-        _ isTrue: Bool,
-        @ViewBuilder _ trueView: @escaping () -> Body,
-        @ViewBuilder else falseView: @escaping () -> Body
-    ) {
-        self.init(isTrue, .some(trueView), else: .some(falseView))
-    }
-
-    /// Initialize an `EitherView`.
-    /// - Parameters:
-    ///   - isTrue: The state.
-    ///   - trueView:  The view that is presented if `isTrue` is true.
-    ///   - falseView: The view that is presented if `isTrue` is false.
-    init(_ isTrue: Bool, _ trueView: (() -> Body)? = nil, else falseView: (() -> Body)? = nil) {
-        self.trueView = trueView?()
-        self.falseView = falseView?()
-        self.isTrue = isTrue
-    }
-
-    /// Update an `EitherView`'s storage.
-    /// - Parameters:
-    ///     - storage: The view storage.
-    ///     - modifiers: Modify views before being updated.
-    public func update(_ storage: ViewStorage, modifiers: [(View) -> View]) {
-        let stack = storage.view as? Stack
-        updateContent(storage, state: true, stack: stack, modifiers: modifiers)
-        updateContent(storage, state: false, stack: stack, modifiers: modifiers)
-        if isTrue, let trueView = storage.content["\(true)"]?.last?.view {
-            setVisible(stack, view: trueView)
-        } else if !isTrue, let falseView = storage.content["\(false)"]?.last?.view {
-            setVisible(stack, view: falseView)
-        }
-    }
-
-    /// Update the content of a view in the view storage.
-    /// - Parameters:
-    ///   - storage: The view storage.
-    ///   - state: Whether it is the true or false view.
-    ///   - stack: The stack.
-    ///   - modifiers: Modify views before being updated.
-    private func updateContent(_ storage: ViewStorage, state: Bool, stack: Stack?, modifiers: [(View) -> View]) {
-        let activeView = (state ? trueView : falseView)?.widget(modifiers: modifiers)
-        if let view = storage.content["\(state)"]?[safe: 0] {
-            activeView?.updateStorage(view, modifiers: modifiers)
-        } else if let view = activeView?.storage(modifiers: modifiers) {
-            _ = stack?.append(view.view)
-            storage.content["\(state)"] = [view]
-        }
-    }
-
-    /// Set the visible content page.
-    /// - Parameters:
-    ///   - stack: The stack.
-    ///   - view: The visible view.
-    private func setVisible(_ stack: Stack?, view: NativeWidgetPeer) {
-        stack?.setVisible(view, transition: view.fields[.transition] as? Transition)
-    }
-
-    /// Get a GtkStack view storage.
-    /// - Parameter modifiers: Modify views before being updated.
-    /// - Returns: The view storage.
-    public func container(modifiers: [(View) -> View]) -> ViewStorage {
-        let stack = Stack()
-        var content: [String: [ViewStorage]] = [:]
-        if let trueView {
-            let view = trueView.widget(modifiers: modifiers).storage(modifiers: modifiers)
-            _ = stack.append(view.view)
-            content["\(true)"] = [view]
-        }
-        if let falseView {
-            let view = falseView.widget(modifiers: modifiers).storage(modifiers: modifiers)
-            _ = stack.append(view.view)
-            content["\(false)"] = [view]
-        }
-        if isTrue, let trueView = content["\(true)"]?.last?.view {
-            stack.setVisible(trueView)
-        } else if let falseView = content["\(false)"]?.last?.view {
-            stack.setVisible(falseView)
-        }
-        return .init(stack, content: content)
-    }
-
-}

Sources/Adwaita/View/ViewStack.swift

@@ -0,0 +1,72 @@
+//
+//  ViewStack.swift
+//  Adwaita
+//
+//  Created by david-swift on 30.12.23.
+//
+
+import Libadwaita
+
+/// A widget holding multiple children but only displaying one.
+public struct ViewStack: Widget {
+
+    /// The stack's active content.
+    var content: Body
+    /// The stack's active identifier.
+    var id: CustomStringConvertible
+
+    /// Initialize the stack.
+    /// - Parameters:
+    ///     - id: The identifier of the current view.
+    ///     - view: The current view.
+    public init<Identifier>(
+        id: Identifier,
+        @ViewBuilder view: @escaping (Identifier) -> Body
+    ) where Identifier: CustomStringConvertible {
+        content = view(id)
+        self.id = id
+    }
+
+    /// Initialize the stack.
+    /// - Parameters:
+    ///     - element: The current identifiable element.
+    ///     - view: The current view.
+    public init<Element>(
+        element: Element,
+        @ViewBuilder view: @escaping (Element) -> Body
+    ) where Element: Identifiable, Element.ID: CustomStringConvertible {
+        content = view(element)
+        self.id = element.id
+    }
+
+    /// Get a stack's view storage.
+    /// - Parameter modifiers: Modify views before being updated.
+    /// - Returns: The stack's view storage.
+    public func container(modifiers: [(View) -> View]) -> ViewStorage {
+        let stack = Stack()
+        let storage = ViewStorage(stack)
+        update(storage, modifiers: modifiers)
+        return storage
+    }
+
+    /// Update a stack's view storage.
+    /// - Parameters:
+    ///     - storage: The view storage.
+    ///     - modifiers: Modify views before being updated.
+    public func update(_ storage: ViewStorage, modifiers: [(View) -> View]) {
+        if let stack = storage.view as? Stack {
+            let widget = content.widget(modifiers: modifiers)
+            if let view = storage.content[id.description]?.first {
+                widget.updateStorage(view, modifiers: modifiers)
+            } else {
+                let view = widget.storage(modifiers: modifiers)
+                _ = stack.append(view.view)
+                storage.content[id.description] = [view]
+            }
+            if let visibleView = storage.content[id.description]?.first?.view {
+                _ = stack.setVisible(visibleView, transition: visibleView.fields[.transition] as? Transition)
+            }
+        }
+    }
+
+}

user-manual/Information/Widgets.md

@@ -5,7 +5,7 @@ This is an overview of the available widgets and other components in _Adwaita_.
 | Name                 | Description                                                       | Widget                 |
 | -------------------- | ----------------------------------------------------------------- | ---------------------- |
 | Button               | A widget that triggers a function when being clicked.             | GtkButton              |
-| EitherView           | A widget that displays one of its child views based on a boolean. | GtkStack               |
+| ViewStack            | A widget that displays one of its child views based on an id.     | GtkStack               |
 | HeaderBar            | A widget for creating custom title bars for windows.              | GtkHeaderBar           |
 | Text                 | A widget for displaying a small amount of text.                   | GtkLabel               |
 | VStack               | A widget which arranges child widgets into a single column.       | GtkBox                 |