Implement view updating system

Sources/Model/Extensions/Array.swift

@@ -15,9 +15,9 @@ extension Array: AnyView where Element == AnyView {
     /// Get the debug tree for an array of views.
     /// - Parameter parameters: Whether the widget parameters should be visible in the tree.
     /// - Returns: The tree.
-    public func getBodyDebugTree<ViewType>(parameters: Bool, type: ViewType.Type) -> String {
+    public func getBodyDebugTree<WidgetType>(parameters: Bool, type: WidgetType.Type) -> String {
         var description = ""
-        for view in self where view as? ViewType != nil {
+        for view in self where view.renderable(type: type) {
             let viewDescription: String
             if let widget = view as? Widget {
                 viewDescription = widget.getViewDescription(parameters: parameters, type: type)
@@ -45,7 +45,6 @@ extension Array: AnyView where Element == AnyView {
                     modified[safe: index] = modifier(view)
                 }
             }
-            // TODO: Is wrapper correct choice?
             return Wrapper { modified }
         }
     }
@@ -55,12 +54,13 @@ extension Array: AnyView where Element == AnyView {
     ///     - storage: The collection of view storages.
     ///     - modifiers: Modify views before being updated.
     ///     - updateProperties: Whether to update properties.
-    public func update(_ storage: [ViewStorage], modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+    ///     - type: The type of the widgets.
-        for (index, element) in enumerated() {
+    public func update<WidgetType>(_ storage: [ViewStorage], modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
+        for (index, element) in enumerated() where element.renderable(type: type) {
             if let storage = storage[safe: index] {
                 element
                     .widget(modifiers: modifiers)
-                    .updateStorage(storage, modifiers: modifiers, updateProperties: updateProperties)
+                    .updateStorage(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
             }
         }
     }

Sources/Model/User Interface/View/AnyView.swift

@@ -18,7 +18,7 @@ extension AnyView {
     /// Get the view's debug tree.
     /// - Parameter parameters: Whether the widget parameters should be included in the debug tree.
     /// - Returns: A textual description.
-    public func getDebugTree<ViewType>(parameters: Bool, type: ViewType.Type) -> String {
+    public func getDebugTree<WidgetType>(parameters: Bool, type: WidgetType.Type) -> String {
         if let body = self as? Body {
             return body.getBodyDebugTree(parameters: parameters, type: type)
         }
@@ -42,21 +42,24 @@ extension AnyView {
     ///     - storage: The storage.
     ///     - modifiers: Modify views before being updated.
     ///     - updateProperties: Whether to update properties.
-    public func updateStorage(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+    ///     - type: The type of the widgets.
+    public func updateStorage<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
         let modified = getModified(modifiers: modifiers)
         if let widget = modified as? Widget {
-            widget.update(storage, modifiers: modifiers, updateProperties: updateProperties)
+            widget.update(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
         } else {
             Wrapper { viewContent }
-                .update(storage, modifiers: modifiers, updateProperties: updateProperties)
+                .update(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
         }
     }
 
     /// Get a storage.
-    /// - Parameter modifiers: Modify views before being updated.
+    /// - Parameters:
+    ///     - modifiers: Modify views before being updated.
+    ///     - type: The widget types.
     /// - Returns: The storage.
-    public func storage(modifiers: [(AnyView) -> AnyView]) -> ViewStorage {
+    public func storage<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-        widget(modifiers: modifiers).container(modifiers: modifiers)
+        widget(modifiers: modifiers).container(modifiers: modifiers, type: type)
     }
 
     /// Wrap the view into a widget.
@@ -70,6 +73,11 @@ extension AnyView {
         return Wrapper { viewContent }
     }
 
+    /// Whether the view can be rendered in a certain environment.
+    func renderable<WidgetType>(type: WidgetType.Type) -> Bool {
+        self as? WidgetType != nil || self as? SimpleView != nil || self as? View != nil
+    }
+
 }
 
 /// `Body` is an array of views.

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

@@ -53,40 +53,6 @@ public enum ViewBuilder {
         component
     }
 
-    // TODO: Add support for optionals, building either
-    /*
-    /// Enables support for `if` statements without an `else`.
-    /// - Parameter component: An optional component.
-    /// - Returns: A nonoptional component.
-    public static func buildOptional(_ component: Component?) -> Component {
-        .element(
-            Bin()
-                .child {
-                    if let component {
-                        buildFinalResult(component)
-                    } else {
-                        []
-                    }
-                }
-                .visible(component != nil)
-        )
-    }
-
-    /// Enables support for `if`-`else` and `switch` statements.
-    /// - Parameter component: A component.
-    /// - Returns: The component.
-    public static func buildEither(first component: Component) -> Component {
-        .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(ViewStack(id: false) { _ in buildFinalResult(component) })
-    }
-    */
-
     /// Convert a component to an array of elements.
     /// - Parameter component: The component to convert.
     /// - Returns: The generated array of elements.

Sources/Model/User Interface/View/Widget.swift

@@ -13,14 +13,17 @@ public protocol Widget: AnyView {
     /// The debug tree's content.
     var debugTreeContent: [(String, body: Body)] { get }
     /// The view storage.
-    /// - Parameter modifiers: Modify views before being updated.
+    /// - Parameters:
-    func container(modifiers: [(AnyView) -> AnyView]) -> ViewStorage
+    ///     - modifiers: Modify views before being updated.
+    ///     - type: The type of the widgets.
+    func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage
     /// Update the stored content.
     /// - Parameters:
     ///     - storage: The storage to update.
     ///     - modifiers: Modify views before being updated
     ///     - updateProperties: Whether to update the view's properties.
-    func update(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool)
+    ///     - type: The type of the widgets.
+    func update<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type)
 
 }
 
@@ -30,7 +33,7 @@ extension Widget {
     public var viewContent: Body { [] }
 
     /// A description of the view.
-    public func getViewDescription<ViewType>(parameters: Bool, type: ViewType.Type) -> String {
+    public func getViewDescription<WidgetType>(parameters: Bool, type: WidgetType.Type) -> String {
         var content = ""
         for element in debugTreeContent {
             if content.isEmpty {

Sources/View/StateWrapper.swift

@@ -50,7 +50,8 @@ public struct StateWrapper: Widget {
     ///     - storage: The view storage.
     ///     - modifiers: Modify views before being updated.
     ///     - updateProperties: Whether to update properties.
-    public func update(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+    ///     - type: The type of the widgets.
+    public func update<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
         var updateProperties = storage.fields[updateID] as? Bool ?? false
         storage.fields[updateID] = false
         for property in state {
@@ -65,15 +66,17 @@ public struct StateWrapper: Widget {
         if let storage = storage.content[.mainContent]?.first {
             content()
                 .widget(modifiers: modifiers)
-                .update(storage, modifiers: modifiers, updateProperties: updateProperties)
+                .update(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
         }
     }
 
     /// Get a view storage.
-    /// - Parameter modifiers: Modify views before being updated.
+    /// - Parameters:
+    ///     - modifiers: Modify views before being updated.
+    ///     - type: The type of the widgets.
     /// - Returns: The view storage.
-    public func container(modifiers: [(AnyView) -> AnyView]) -> ViewStorage {
+    public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-        let content = content().widget(modifiers: modifiers).container(modifiers: modifiers)
+        let content = content().storage(modifiers: modifiers, type: type)
         let storage = ViewStorage(content.pointer, content: [.mainContent: [content]])
         storage.state = state
         observe(storage: storage)

Sources/View/Wrapper.swift

@@ -32,20 +32,21 @@ public struct Wrapper: Widget {
     ///     - storage: The view storage.
     ///     - modifiers: Modify views before being updated.
     ///     - updateProperties: Whether to update properties.
-    public func update(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+    ///     - type: The widget types.
-        if let storage = storage.content[.mainContent]?.first {
+    public func update<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
-            content
+        guard let storages = storage.content[.mainContent] else {
-                .widget(modifiers: modifiers)
+            return
-                .update(storage, modifiers: modifiers, updateProperties: updateProperties)
         }
+        content.update(storages, modifiers: modifiers, updateProperties: updateProperties, type: type)
     }
 
     /// Get a view storage.
-    /// - Parameter modifiers: Modify views before being updated.
+    /// - Parameters:
+    ///     - modifiers: Modify views before being updated.
+    ///     - type: The type of the widgets.
     /// - Returns: The view storage.
-    public func container(modifiers: [(AnyView) -> AnyView]) -> ViewStorage {
+    public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-        let content = content.widget(modifiers: modifiers).container(modifiers: modifiers)
+        ViewStorage(nil, content: [.mainContent: content.map { $0.storage(modifiers: [], type: type) }])
-        return .init(content.pointer, content: [.mainContent: [content]])
     }
 
 }

Tests/DemoApp/DemoApp.swift

@@ -4,17 +4,31 @@ import SampleBackends
 struct DemoView: SimpleView {
 
      var view: Body {
-        Backend1.TestWidget()
+        Backend1.TestWidget1()
+        TestView()
         testContent
      }
 
      @ViewBuilder
      var testContent: Body {
-        Backend2.TestWidget()
+        Backend2.TestWidget2()
-        Backend1.TestWidget()
+        Backend1.TestWidget1()
      }
 
 }
 
-print(DemoView().getDebugTree(parameters: true, type: Backend1.BackendView.self))
+struct TestView: SimpleView {
-print(DemoView().getDebugTree(parameters: true, type: Backend2.BackendView.self))
+
+    var view: Body {
+        []
+    }
+
+}
+
+print(DemoView().getDebugTree(parameters: true, type: Backend1.BackendWidget.self))
+print(DemoView().getDebugTree(parameters: true, type: Backend2.BackendWidget.self))
+
+let storage = DemoView().storage(modifiers: [], type: Backend1.BackendWidget.self)
+for _ in 0...2 {
+    DemoView().updateStorage(storage, modifiers: [], updateProperties: true, type: Backend2.BackendWidget.self)
+}

Tests/SampleBackends/Backend1.swift

@@ -2,33 +2,32 @@ import Meta
 
 public enum Backend1 {
 
-    public struct TestWidget: BackendWidget {
+    public struct TestWidget1: BackendWidget {
     
         public init() { }
     
         public var debugTreeContent: [(String, body: Body)] {
             []
         }
-        
+
         public var debugTreeParameters: [(String, value: CustomStringConvertible)] {
             []
         }
     
-        public func container(modifiers: [(AnyView) -> AnyView]) -> ViewStorage {
+        public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-            print("Init Content")
+            print("Init test widget 1")
             let storage = ViewStorage(nil)
             storage.fields["test"] = 0
             return storage
         }
 
-        public func update(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+        public func update<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
-            storage.fields["test"] = storage.fields["tests"] as? Int ?? 0 + 1
+            print("Update test widget 1 (#\(storage.fields["test"] ?? ""))")
+            storage.fields["test"] = (storage.fields["test"] as? Int ?? 0) + 1
         }
     
     }
     
-    public protocol BackendView: AnyView { }
+    public protocol BackendWidget: Widget { }
-    
-    public protocol BackendWidget: BackendView, Widget { }
 
-}
+}

Tests/SampleBackends/Backend2.swift

@@ -2,7 +2,7 @@ import Meta
 
 public enum Backend2 {
 
-    public struct TestWidget: BackendWidget {
+    public struct TestWidget2: BackendWidget {
     
         public init() { }
     
@@ -14,21 +14,20 @@ public enum Backend2 {
             []
         }
     
-        public func container(modifiers: [(AnyView) -> AnyView]) -> ViewStorage {
+        public func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage {
-            print("Init Content")
+            print("Init test widget 2")
             let storage = ViewStorage(nil)
             storage.fields["test"] = 0
             return storage
         }
 
-        public func update(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool) {
+        public func update<WidgetType>(_ storage: ViewStorage, modifiers: [(AnyView) -> AnyView], updateProperties: Bool, type: WidgetType.Type) {
-            storage.fields["test"] = storage.fields["tests"] as? Int ?? 0 + 1
+            print("Update test widget 2 (#\(storage.fields["test"] ?? ""))")
+            storage.fields["test"] = (storage.fields["test"] as? Int ?? 0) + 1
         }
     
     }
     
-    public protocol BackendView: AnyView { }
+    public protocol BackendWidget: Widget { }
-    
-    public protocol BackendWidget: BackendView, Widget { }
 
-}
+}