Add ConditionalGraphicsView

Sources/OpenSwiftUICore/View/ConditionalGraphicsView.swift

@@ -0,0 +1,159 @@
+//
+//  ConditionalGraphicsView.swift
+//  OpenSwiftUICore
+//
+//  Audited for 6.5.4
+//  Status: Complete
+//  ID: EE189C0F837A6307D8FC8254E9B07A27 (SwiftUICore)
+
+import OpenAttributeGraphShims
+
+// MARK: - UsingGraphicsRenderer
+
+package struct UsingGraphicsRenderer: ViewInput {
+    package static let defaultValue: Bool = false
+}
+
+extension _GraphInputs {
+    @inline(__always)
+    var usingGraphicsRenderer: Bool {
+        get { self[UsingGraphicsRenderer.self] }
+        set { self[UsingGraphicsRenderer.self] = newValue }
+    }
+}
+
+extension _ViewInputs {
+    @inline(__always)
+    var usingGraphicsRenderer: Bool {
+        get { self[UsingGraphicsRenderer.self] }
+        set { self[UsingGraphicsRenderer.self] = newValue }
+    }
+}
+
+extension _ViewListInputs {
+    @inline(__always)
+    var usingGraphicsRenderer: Bool {
+        get { self[UsingGraphicsRenderer.self] }
+        set { self[UsingGraphicsRenderer.self] = newValue }
+    }
+}
+
+extension _ViewListCountInputs {
+    @inline(__always)
+    var usingGraphicsRenderer: Bool {
+        get { self[UsingGraphicsRenderer.self] }
+        set { self[UsingGraphicsRenderer.self] = newValue }
+    }
+}
+
+// MARK: - ConditionalGraphicsView
+
+@_spi(Private)
+@available(OpenSwiftUI_v6_0, *)
+public protocol ConditionalGraphicsView: View {
+    associatedtype GraphicsBody: View
+
+    @ViewBuilder
+    @MainActor
+    @preconcurrency
+    var graphicsBody: GraphicsBody { get }
+}
+
+@_spi(Private)
+extension ConditionalGraphicsView {
+    nonisolated public static func _makeView(
+        view: _GraphValue<Self>,
+        inputs: _ViewInputs
+    ) -> _ViewOutputs {
+        let fields = DynamicPropertyCache.fields(of: Self.self)
+        var newInputs = inputs
+        let (body, buffer) = makeBody(view: view, inputs: &newInputs.base, fields: fields)
+        let outputs = body.makeView(inputs: newInputs)
+        if let buffer {
+            buffer.traceMountedProperties(to: view, fields: fields)
+        }
+        return outputs
+    }
+
+    nonisolated public static func _makeViewList(
+        view: _GraphValue<Self>,
+        inputs: _ViewListInputs
+    ) -> _ViewListOutputs {
+        let fields = DynamicPropertyCache.fields(of: Self.self)
+        var newInputs = inputs
+        let (body, buffer) = makeBody(view: view, inputs: &newInputs.base, fields: fields)
+        let outputs = body.makeViewList(inputs: newInputs)
+        if let buffer {
+            buffer.traceMountedProperties(to: view, fields: fields)
+        }
+        return outputs
+    }
+
+    nonisolated public static func _viewListCount(
+        inputs: _ViewListCountInputs
+    ) -> Int? {
+        if inputs.usingGraphicsRenderer {
+            return GraphicsBody._viewListCount(inputs: inputs)
+        } else {
+            return Body._viewListCount(inputs: inputs)
+        }
+    }
+
+    nonisolated private static func makeBody(
+        view: _GraphValue<Self>,
+        inputs: inout _GraphInputs,
+        fields: DynamicPropertyCache.Fields
+    ) -> (ConditionalGraphValue<Body, GraphicsBody>, _DynamicPropertyBuffer?) {
+        precondition(
+            Metadata(Self.self).isValueType,
+            "views must be value types (either a struct or an enum); \(Self.self) is a class."
+        )
+        if inputs.usingGraphicsRenderer {
+            let accessor = GraphicsViewBodyAccessor<Self>()
+            let (body, buffer) = accessor.makeBody(container: view, inputs: &inputs, fields: fields)
+            return (.second(body), buffer)
+        } else {
+            let accessor = ViewBodyAccessor<Self>()
+            let (body, buffer) = accessor.makeBody(container: view, inputs: &inputs, fields: fields)
+            return (.first(body), buffer)
+        }
+    }
+}
+
+// MARK: - ConditionalGraphValue
+
+package enum ConditionalGraphValue<First, Second> {
+    case first(_GraphValue<First>)
+    case second(_GraphValue<Second>)
+}
+
+extension ConditionalGraphValue where First: View, Second: View {
+    package func makeView(inputs: _ViewInputs) -> _ViewOutputs {
+        switch self {
+        case let .first(view): First.makeDebuggableView(view: view, inputs: inputs)
+        case let .second(view): Second.makeDebuggableView(view: view, inputs: inputs)
+        }
+    }
+
+    package func makeViewList(inputs: _ViewListInputs) -> _ViewListOutputs {
+        switch self {
+        case let .first(view): First.makeDebuggableViewList(view: view, inputs: inputs)
+        case let .second(view): Second.makeDebuggableViewList(view: view, inputs: inputs)
+        }
+    }
+}
+
+// MARK: - GraphicsViewBodyAccessor
+
+private struct GraphicsViewBodyAccessor<V>: BodyAccessor where V: ConditionalGraphicsView {
+    typealias Container = V
+
+    typealias Body = V.GraphicsBody
+
+    func updateBody(of container: V, changed: Bool) {
+        guard changed else { return }
+        setBody {
+            container.graphicsBody
+        }
+    }
+}

Sources/OpenSwiftUICore/View/View.swift

@@ -86,7 +86,7 @@ public protocol View {
     @ViewBuilder
     @MainActor
     @preconcurrency
-    var body: Self.Body { get }
+    var body: Body { get }
 }
 
 // MARK: - PrimitiveView