Update DerivedLayout

Author: Kyle-Ye

Sources/OpenSwiftUICore/Layout/Layout.swift

@@ -680,24 +680,6 @@ extension Layout {
             )
         }
     }
-
-    static func makeDynamicView(
-        root: _GraphValue<Self>,
-        inputs: _ViewInputs,
-        properties: LayoutProperties,
-        list: Attribute<any ViewList>
-    ) -> _ViewOutputs {
-        preconditionFailure("TODO")
-    }
-
-    static func makeStaticView(
-        root: _GraphValue<Self>,
-        inputs: _ViewInputs,
-        properties: LayoutProperties,
-        list: ViewList.Elements
-    ) -> _ViewOutputs {
-        preconditionFailure("TODO")
-    }
 }
 
 extension Layout {

Sources/OpenSwiftUICore/Layout/UnaryLayout.swift

@@ -2,12 +2,13 @@
 //  UnaryLayout.swift
 //  OpenSwiftUICore
 //
-//  Audited for iOS 18.0
-//  Status: WIP
+//  Status: Blocked by makeStaticView and makeDynamicView
 
 package import Foundation
 package import OpenGraphShims
 
+// MARK: - UnaryLayout [6.4.41]
+
 package protocol UnaryLayout: Animatable, MultiViewModifier, PrimitiveViewModifier {
     associatedtype PlacementContextType = PlacementContext
 
@@ -50,12 +51,108 @@ extension UnaryLayout {
     }
 }
 
+// MARK: - DerivedLayout [6.4.41]
+
+package protocol DerivedLayout: Layout {
+    associatedtype Base: Layout where Cache == Base.Cache
+
+    var base: Base { get }
+}
+
+extension DerivedLayout {
+    public static var layoutProperties: LayoutProperties {
+        Base.layoutProperties
+    }
+
+    public func makeCache(subviews: Subviews) -> Base.Cache {
+        base.makeCache(subviews: subviews)
+    }
+
+    public func updateCache(_ cache: inout Base.Cache, subviews: Subviews) {
+        base.updateCache(&cache, subviews: subviews)
+    }
+
+    public func spacing(subviews: Subviews, cache: inout Base.Cache) -> ViewSpacing {
+        base.spacing(subviews: subviews, cache: &cache)
+    }
+
+    public func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout Base.Cache) -> CGSize {
+        base.sizeThatFits(proposal: proposal, subviews: subviews, cache: &cache)
+    }
+
+    public func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout Base.Cache) {
+        base.placeSubviews(in: bounds, proposal: proposal, subviews: subviews, cache: &cache)
+    }
+
+    public func explicitAlignment(of guide: HorizontalAlignment, in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout Base.Cache) -> CGFloat? {
+        base.explicitAlignment(of: guide, in: bounds, proposal: proposal, subviews: subviews, cache: &cache)
+    }
+
+    public func explicitAlignment(of guide: VerticalAlignment, in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout Base.Cache) -> CGFloat? {
+        base.explicitAlignment(of: guide, in: bounds, proposal: proposal, subviews: subviews, cache: &cache)
+    }
+}
+
+// MARK: - Layout + Static/Dynamic View Creation [6.4.41] [WIP]
+
+extension Layout {
+    package static func makeStaticView(
+        root: _GraphValue<Self>,
+        inputs: _ViewInputs,
+        properties: LayoutProperties,
+        list: any _ViewList_Elements
+    ) -> _ViewOutputs {
+        preconditionFailure("TODO")
+    }
+
+    static func makeDynamicView(
+        root: _GraphValue<Self>,
+        inputs: _ViewInputs,
+        properties: LayoutProperties,
+        list: Attribute<any ViewList>
+    ) -> _ViewOutputs {
+        preconditionFailure("TODO")
+    }
+}
+
+package struct LayoutChildGeometries: Rule, AsyncAttribute {
+    @Attribute
+    private var parentSize: ViewSize
+
+    @Attribute
+    private var parentPosition: PlatformPoint
+
+    @Attribute
+    private var layoutComputer: LayoutComputer
+
+    package init(parentSize: Attribute<ViewSize>, parentPosition: Attribute<PlatformPoint>, layoutComputer: Attribute<LayoutComputer>) {
+        _parentSize = parentSize
+        _parentPosition = parentPosition
+        _layoutComputer = layoutComputer
+    }
+
+    package var value: [ViewGeometry] {
+        layoutComputer.childGeometries(at: parentSize, origin: parentPosition)
+    }
+}
+
 extension StatefulRule where Value == LayoutComputer {
     package mutating func updateLayoutComputer<L>(
         layout: L,
         environment: Attribute<EnvironmentValues>,
         attributes: [LayoutProxyAttributes]
     ) where L: Layout {
-        preconditionFailure("TODO")
+        let context = AnyRuleContext(attribute: .current!)
+        layout.updateLayoutComputer(
+            rule: &self,
+            layoutContext: SizeAndSpacingContext(
+                context: context,
+                environment: environment
+            ),
+            children: LayoutProxyCollection(
+                context: context,
+                attributes: attributes
+            )
+        )
     }
 }