Reimplement foregroundColor modifier under new layout system (much better now)

Author: stackotter

Examples/Sources/SplitExample/SplitApp.swift

@@ -127,7 +127,8 @@ struct SplitApp: App {
                     default:
                         Text("Select a subject")
                 }
-            }.padding(10)
+            }
+            .padding(10)
         }
     }
 }

Sources/AppKitBackend/AppKitBackend.swift

@@ -270,9 +270,16 @@ public struct AppKitBackend: AppBackend {
         return .view(textView)
     }
 
-    public func updateTextView(_ textView: Widget, content: String, shouldWrap: Bool) {
-        // TODO: Implement text wrap handling
-        (textView.view as! NSTextField).stringValue = content
+    public func updateTextView(_ textView: Widget, content: String, environment: Environment) {
+        let field = textView.view as! NSTextField
+        field.stringValue = content
+        let textColor = environment.foregroundColor
+        field.textColor = NSColor(
+            calibratedRed: CGFloat(textColor.red),
+            green: CGFloat(textColor.green),
+            blue: CGFloat(textColor.blue),
+            alpha: 1
+        )
     }
 
     public func createButton() -> Widget {

Sources/SwiftCrossUI/Backend/AppBackend.swift

@@ -174,9 +174,8 @@ public protocol AppBackend {
     /// Creates a non-editable text view with optional text wrapping. Predominantly used
     /// by ``Text``.`
     func createTextView() -> Widget
-    /// Sets the content and wrapping mode of a non-editable text view. If `shouldWrap`
-    /// is `false`, text shouldn't be wrapped onto multiple lines.
-    func updateTextView(_ textView: Widget, content: String, shouldWrap: Bool)
+    /// Sets the content and wrapping mode of a non-editable text view.
+    func updateTextView(_ textView: Widget, content: String, environment: Environment)
 
     /// Creates an image view from an image file (specified by path). Predominantly used
     /// by ``Image``.
@@ -307,7 +306,7 @@ extension AppBackend {
     public func createTextView(content: String, shouldWrap: Bool) -> Widget {
         todo()
     }
-    public func updateTextView(_ textView: Widget, content: String, shouldWrap: Bool) {
+    public func updateTextView(_ textView: Widget, content: String, environment: Environment) {
         todo()
     }
 

Sources/SwiftCrossUI/Modifiers/ForegroundColor.swift

@@ -1,38 +1,63 @@
-// extension View {
-//     /// Sets the color of the foreground elements displayed by this view.
-//     public func foregroundColor(_ color: Color) -> some View {
-//         return ForegroundView(
-//             self,
-//             color: color
-//         )
-//     }
-// }
+extension View {
+    /// Sets the color of the foreground elements displayed by this view.
+    public func foregroundColor(_ color: Color) -> some View {
+        return EnvironmentModifier(self) { environment in
+            print("Updating fg color")
+            return environment.with(\.foregroundColor, color)
+        }
+    }
+}
 
-// /// The implementation for the ``View/foregroundColor(_:)`` view modifier.
-// struct ForegroundView<Child: View>: TypeSafeView {
-//     var body: VariadicView1<Child>
+struct EnvironmentModifier<Child: View>: TypeSafeView {
+    typealias Children = VariadicView1<Child>.Children
 
-//     /// The foreground color to use.
-//     var color: Color
+    var body: VariadicView1<Child>
+    var modification: (Environment) -> Environment
 
-//     /// Wraps a child view and sets a specific foreground color.
-//     init(_ child: Child, color: Color) {
-//         self.body = VariadicView1(child)
-//         self.color = color
-//     }
+    init(_ child: Child, modification: @escaping (Environment) -> Environment) {
+        self.body = VariadicView1(child)
+        self.modification = modification
+    }
 
-//     func asWidget<Backend: AppBackend>(
-//         _ children: ViewGraphNodeChildren1<Child>,
-//         backend: Backend
-//     ) -> Backend.Widget {
-//         return backend.createStyleContainer(for: children.child0.widget.into())
-//     }
+    func children<Backend: AppBackend>(
+        backend: Backend,
+        snapshots: [ViewGraphSnapshotter.NodeSnapshot]?,
+        environment: Environment
+    ) -> Children {
+        body.children(
+            backend: backend,
+            snapshots: snapshots,
+            environment: modification(environment)
+        )
+    }
 
-//     func update<Backend: AppBackend>(
-//         _ widget: Backend.Widget,
-//         children: ViewGraphNodeChildren1<Child>,
-//         backend: Backend
-//     ) {
-//         backend.setForegroundColor(ofStyleContainer: widget, to: color)
-//     }
-// }
+    func layoutableChildren<Backend: AppBackend>(
+        backend: Backend,
+        children: Children
+    ) -> [LayoutSystem.LayoutableChild] {
+        []
+    }
+
+    func asWidget<Backend: AppBackend>(
+        _ children: Children,
+        backend: Backend
+    ) -> Backend.Widget {
+        return body.asWidget(children, backend: backend)
+    }
+
+    func update<Backend: AppBackend>(
+        _ widget: Backend.Widget,
+        children: Children,
+        proposedSize: SIMD2<Int>,
+        environment: Environment,
+        backend: Backend
+    ) -> ViewUpdateResult {
+        return body.update(
+            widget,
+            children: children,
+            proposedSize: proposedSize,
+            environment: modification(environment),
+            backend: backend
+        )
+    }
+}

Sources/SwiftCrossUI/ViewGraph/Environment.swift

@@ -1,14 +1,16 @@
 public struct Environment {
-    var onResize: (_ newSize: ViewUpdateResult) -> Void
-    var layoutOrientation: Orientation
-    var layoutAlignment: StackAlignment
-    var layoutSpacing: Int
+    public var onResize: (_ newSize: ViewUpdateResult) -> Void
+    public var layoutOrientation: Orientation
+    public var layoutAlignment: StackAlignment
+    public var layoutSpacing: Int
+    public var foregroundColor: Color
 
     init() {
         onResize = { _ in }
         layoutOrientation = .vertical
         layoutAlignment = .center
         layoutSpacing = 10
+        foregroundColor = .black
     }
 
     func with<T>(_ keyPath: WritableKeyPath<Self, T>, _ newValue: T) -> Self {

Sources/SwiftCrossUI/Views/Text.swift

@@ -25,7 +25,7 @@ public struct Text: ElementaryView, View {
         backend: Backend
     ) -> ViewUpdateResult {
         let size = backend.size(of: string, in: proposedSize)
-        backend.updateTextView(widget, content: string, shouldWrap: true)
+        backend.updateTextView(widget, content: string, environment: environment)
         backend.setSize(of: widget, to: size)
         // TODO: Query from backend
         let lineHeight = 12