1.0.0

.gitignore

@@ -9,7 +9,6 @@ DerivedData/
 .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
 .netrc
 build.sh
-Sources/EnginePrivate
 Sources/EngineCore/EngineCore.xcframework
 Sources/EngineCore/EngineCore.xcframework.zip
 Sources/EngineCore/Example

Example/Example/ViewStyleExamples.swift

@@ -142,6 +142,27 @@ struct ViewStyleExamples: View {
                         Text("Label")
                     }
                     .labeledViewStyle(DoubleLabelStyle())
+
+                    Text("Multiple View Styling")
+                        .font(.headline)
+
+                    HStack {
+                        LabeledView {
+                            Text("Content")
+                        } label: {
+                            Text("Label")
+                        }
+                        .border(Color.blue)
+
+                        LabeledView {
+                            Text("Content")
+                        } label: {
+                            Text("Label")
+                        }
+                        .labeledViewStyle(PaddedLabeledViewStyle())
+                        .border(Color.blue)
+                    }
+                    .labeledViewStyle(BorderedLabeledViewStyle())
                 }
             }
             .frame(maxWidth: .infinity, alignment: .leading)

README.md

@@ -63,7 +63,7 @@ With the `@StyledView` macro nearly any `View` can be transformed into one that
 
 > Xcode's syntax highlighting currently does not work for types generated by a macro
 
-[Open ViewStyle.swift](https://github.com/nathantannar4/Engine/blob/main/Sources/Engine/Sources/StyledView.swift)
+[Open StyledView.swift](https://github.com/nathantannar4/Engine/blob/main/Sources/Engine/Sources/StyledView.swift)
 
 #### Examples
 
@@ -82,23 +82,26 @@ struct LabeledView<Label: View, Content: View>: StyledView {
     }
 }
 
-// 1. Define a custom style
-struct BorderedLabeledViewStyle: LabeledViewStyle {
-    func makeBody(configuration: Configuration) -> some View {
-        LabeledView(configuration)
-            .border(Color.red)
+extension View {
+    func labelViewStyle<Style: LabelViewStyle>(_ style: Style) -> some View {
+        modifier(LabelViewStyleModifier(style))
     }
 }
 
-// 2. Apply the style to the styled view
-struct ContentView: View {
-    var body: some View {
-        LabeledView {
-            Text("Label")
-        } content: {
-            Text("Content")
+struct VerticalLabeledViewStyle: LabeledViewStyle {
+    func makeBody(configuration: Configuration) -> some View {
+        VStack {
+            configuration.label
+
+            configuration.content
         }
-        .labelStyle(BorderedLabeledViewStyle())
+    }
+}
+
+struct BorderedLabeledViewStyle: LabeledViewStyle {
+    func makeBody(configuration: Configuration) -> some View {
+        LabeledView(configuration)
+            .border(Color.red)
     }
 }
 ```

Sources/Engine/Sources/StaticContent.swift

@@ -0,0 +1,140 @@
+//
+// Copyright (c) Nathan Tannar
+//
+
+import SwiftUI
+
+import EngineCore
+
+/// A static type-erased `View`.
+///
+/// > Warning: The ``TypeDescriptor/descriptor`` should match the type
+///  returned by `content`
+@frozen
+public struct StaticContent<Descriptor: TypeDescriptor>: View {
+
+    @usableFromInline
+    var content: Any
+
+    @inlinable
+    public init(
+        _ descriptor: Descriptor.Type = Descriptor.self,
+        content: () -> Any
+    ) {
+        self.content = content()
+    }
+
+    public var body: Never {
+        bodyError()
+    }
+
+    public static func _makeView(
+        view: _GraphValue<Self>,
+        inputs: _ViewInputs
+    ) -> _ViewOutputs {
+        func project<T>(_ type: T.Type) -> _ViewOutputs {
+            let conformance = ViewProtocolDescriptor.conformance(of: T.self)!
+            var visitor = ViewOutputsVisitor(view: view[\.content], inputs: inputs)
+            conformance.visit(visitor: &visitor)
+            return visitor.outputs
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+
+    public static func _makeViewList(
+        view: _GraphValue<Self>,
+        inputs: _ViewListInputs
+    ) -> _ViewListOutputs {
+        func project<T>(_ type: T.Type) -> _ViewListOutputs {
+            let conformance = ViewProtocolDescriptor.conformance(of: T.self)!
+            var visitor = ViewListOutputsVisitor(view: view[\.content], inputs: inputs)
+            conformance.visit(visitor: &visitor)
+            return visitor.outputs
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+
+    @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+    public static func _viewListCount(
+        inputs: _ViewListCountInputs
+    ) -> Int? {
+        func project<T>(_ type: T.Type) -> Int? {
+            let conformance = ViewProtocolDescriptor.conformance(of: T.self)!
+            var visitor = ViewListOutputsCountVisitor(inputs: inputs)
+            conformance.visit(visitor: &visitor)
+            return visitor.outputs
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+}
+
+private struct StaticContentBody<Content: View>: View {
+    var content: Any
+
+    var body: Content {
+        content as! Content
+    }
+}
+
+private struct ViewOutputsVisitor: ViewVisitor {
+    var view: _GraphValue<Any>
+    var inputs: _ViewInputs
+
+    var outputs: _ViewOutputs!
+
+    mutating func visit<Content>(type: Content.Type) where Content: View {
+        let view = unsafeBitCast(view, to: _GraphValue<StaticContentBody<Content>>.self)
+        outputs = StaticContentBody<Content>._makeView(view: view, inputs: inputs)
+    }
+}
+
+private struct ViewListOutputsVisitor: ViewVisitor {
+    var view: _GraphValue<Any>
+    var inputs: _ViewListInputs
+
+    var outputs: _ViewListOutputs!
+
+    mutating func visit<Content>(type: Content.Type) where Content: View {
+        let view = unsafeBitCast(view, to: _GraphValue<StaticContentBody<Content>>.self)
+        outputs = StaticContentBody<Content>._makeViewList(view: view, inputs: inputs)
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+private struct ViewListOutputsCountVisitor: ViewVisitor {
+    var inputs: _ViewListCountInputs
+
+    var outputs: Int?
+
+    mutating func visit<Content>(type: Content.Type) where Content: View {
+        outputs = StaticContentBody<Content>._viewListCount(inputs: inputs)
+    }
+}
+
+// MARK: - Previews
+
+struct StaticContent_Previews: PreviewProvider {
+
+    struct Content: View {
+        var body: some View {
+            Text("Hello, World")
+        }
+    }
+
+    struct Descriptor: TypeDescriptor {
+        static var descriptor: UnsafeRawPointer {
+            TypeIdentifier(Content.self).metadata
+        }
+    }
+
+    static var previews: some View {
+        VStack {
+            StaticContent<Descriptor> {
+                Content()
+            }
+        }
+    }
+}

Sources/Engine/Sources/StaticModifier.swift

@@ -0,0 +1,151 @@
+//
+// Copyright (c) Nathan Tannar
+//
+
+import SwiftUI
+
+import EngineCore
+
+/// A static type-erased `ViewModifier`.
+///
+/// > Warning: The ``TypeDescriptor/descriptor`` should match the type
+///  returned by `modifier`
+@frozen
+public struct StaticModifier<Descriptor: TypeDescriptor>: ViewModifier {
+
+    @usableFromInline
+    var modifier: Any
+
+    @inlinable
+    public init(
+        _ descriptor: Descriptor.Type = Descriptor.self,
+        modifier: () -> Any
+    ) {
+        self.modifier = modifier()
+    }
+
+    public func body(content: Content) -> Never {
+        bodyError()
+    }
+
+    public static func _makeView(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewInputs,
+        body: @escaping (_Graph, _ViewInputs) -> _ViewOutputs
+    ) -> _ViewOutputs {
+        func project<T>(_ type: T.Type) -> _ViewOutputs {
+            let conformance = ViewModifierProtocolDescriptor.conformance(of: T.self)!
+            var visitor = ViewOutputsVisitor(view: modifier[\.modifier], inputs: inputs, body: body)
+            conformance.visit(visitor: &visitor)
+            return visitor.outputs
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+
+    public static func _makeViewList(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewListInputs,
+        body: @escaping (_Graph, _ViewListInputs) -> _ViewListOutputs
+    ) -> _ViewListOutputs {
+        func project<T>(_ type: T.Type) -> _ViewListOutputs {
+            let conformance = ViewModifierProtocolDescriptor.conformance(of: T.self)!
+            var visitor = ViewListOutputsVisitor(view: modifier[\.modifier], inputs: inputs, body: body)
+            conformance.visit(visitor: &visitor)
+            return visitor.outputs
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+
+    @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+    public static func _viewListCount(
+        inputs: _ViewListCountInputs,
+        body: (_ViewListCountInputs) -> Int?
+    ) -> Int? {
+        func project<T>(_ type: T.Type) -> Int? {
+            withoutActuallyEscaping(body) { body in
+                let conformance = ViewModifierProtocolDescriptor.conformance(of: T.self)!
+                var visitor = ViewListOutputsCountVisitor(inputs: inputs, body: body)
+                conformance.visit(visitor: &visitor)
+                return visitor.outputs
+            }
+        }
+        let type = unsafeBitCast(Descriptor.descriptor, to: Any.Type.self)
+        return _openExistential(type, do: project)
+    }
+}
+
+private struct StaticModifierBody<Modifier: ViewModifier>: ViewModifier {
+    var modifier: Any
+
+    func body(content: Content) -> some View {
+        content.modifier(modifier as! Modifier)
+    }
+}
+
+private struct ViewOutputsVisitor: ViewModifierVisitor {
+    var view: _GraphValue<Any>
+    var inputs: _ViewInputs
+    var body: (_Graph, _ViewInputs) -> _ViewOutputs
+
+    var outputs: _ViewOutputs!
+
+    mutating func visit<Modifier>(type: Modifier.Type) where Modifier: ViewModifier {
+        let modifier = unsafeBitCast(view, to: _GraphValue<StaticModifierBody<Modifier>>.self)
+        outputs = StaticModifierBody<Modifier>._makeView(modifier: modifier, inputs: inputs, body: body)
+    }
+}
+
+private struct ViewListOutputsVisitor: ViewModifierVisitor {
+    var view: _GraphValue<Any>
+    var inputs: _ViewListInputs
+    var body: (_Graph, _ViewListInputs) -> _ViewListOutputs
+
+    var outputs: _ViewListOutputs!
+
+    mutating func visit<Modifier>(type: Modifier.Type) where Modifier: ViewModifier {
+        let modifier = unsafeBitCast(view, to: _GraphValue<StaticModifierBody<Modifier>>.self)
+        outputs = StaticModifierBody<Modifier>._makeViewList(modifier: modifier, inputs: inputs, body: body)
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+private struct ViewListOutputsCountVisitor: ViewModifierVisitor {
+    var inputs: _ViewListCountInputs
+    var body: (_ViewListCountInputs) -> Int?
+
+    var outputs: Int?
+
+    mutating func visit<Modifier>(type: Modifier.Type) where Modifier: ViewModifier {
+        outputs = StaticModifierBody<Modifier>._viewListCount(inputs: inputs, body: body)
+    }
+}
+
+// MARK: - Previews
+
+struct StaticModifier_Previews: PreviewProvider {
+
+    struct Modifier: ViewModifier {
+        func body(content: Content) -> some View {
+            content.border(Color.red)
+        }
+    }
+
+    struct Descriptor: TypeDescriptor {
+        static var descriptor: UnsafeRawPointer {
+            TypeIdentifier(Modifier.self).metadata
+        }
+    }
+
+    static var previews: some View {
+        VStack {
+            Text("Hello, World")
+                .modifier {
+                    StaticModifier<Descriptor> {
+                        Modifier()
+                    }
+                }
+        }
+    }
+}