Add ViewGraphFeature and update ViewGraphDelegate

Author: Kyle-Ye

Sources/OpenSwiftUICore/View/ViewGraph.swift renamed to Sources/OpenSwiftUICore/View/Graph/ViewGraph.swift

@@ -144,11 +144,11 @@ package final class ViewGraph: GraphHost {
                 sizeThatFitsObserver?.callback(oldCachedSizeThatFits, self.cachedSizeThatFits)
             }
             if !requestedOutputs.isEmpty {
-                delegate?.outputsDidChange(outputs: updatedOutputs)
+//                delegate?.outputsDidChange(outputs: updatedOutputs)
             }
             if needsFocusUpdate {
                 needsFocusUpdate = false
-                delegate?.focusDidChange()
+//                delegate?.focusDidChange()
             }
         } else {
             fatalError("TODO")

Sources/OpenSwiftUICore/View/Graph/ViewGraphDelegate.swift

@@ -0,0 +1,27 @@
+//
+//  ViewGraphDelegate.swift
+//  OpenSwiftUICore
+//
+//  Audited for RELEASE_2024
+//  Status: Complete
+
+package protocol ViewGraphDelegate: GraphDelegate {
+    func `as`<T>(_ type: T.Type) -> T?
+    func modifyViewInputs(_ inputs: inout _ViewInputs)
+    func updateViewGraph<T>(body: (ViewGraph) -> T) -> T
+    func rootTransform() -> ViewTransform
+}
+
+@_spi(ForOpenSwiftUIOnly)
+extension ViewGraphDelegate {
+    package func `as`<T>(_ type: T.Type) -> T? { nil }
+    package func modifyViewInputs(_ inputs: inout _ViewInputs) {}
+    
+    public func updateGraph<T>(body: (GraphHost) -> T) -> T {
+        updateViewGraph { body($0) }
+    }
+    
+    package func rootTransform() -> ViewTransform {
+        ViewTransform()
+    }
+}

Sources/OpenSwiftUICore/View/Graph/ViewGraphFeature.swift

@@ -0,0 +1,26 @@
+//
+//  ViewGraphFeature.swift
+//  OpenSwiftUICore
+//
+//  Audited for RELEASE_2024
+//  Status: Complete
+
+package protocol ViewGraphFeature {
+    mutating func modifyViewInputs(inputs: inout _ViewInputs, graph: ViewGraph)
+    mutating func modifyViewOutputs(outputs: inout _ViewOutputs, inputs: _ViewInputs, graph: ViewGraph)
+    mutating func uninstantiate(graph: ViewGraph)
+    mutating func isHiddenForReuseDidChange(graph: ViewGraph)
+    mutating func allowsAsyncUpdate(graph: ViewGraph) -> Bool?
+    mutating func needsUpdate(graph: ViewGraph) -> Bool
+    mutating func update(graph: ViewGraph)
+}
+
+extension ViewGraphFeature {
+    package mutating func modifyViewInputs(inputs: inout _ViewInputs, graph: ViewGraph) {}
+    package mutating func modifyViewOutputs(outputs: inout _ViewOutputs, inputs: _ViewInputs, graph: ViewGraph) {}
+    package mutating func uninstantiate(graph: ViewGraph) {}
+    package mutating func isHiddenForReuseDidChange(graph: ViewGraph) {}
+    package mutating func allowsAsyncUpdate(graph: ViewGraph) -> Bool? { true }
+    package mutating func needsUpdate(graph: ViewGraph) -> Bool { false }
+    package mutating func update(graph: ViewGraph) {}
+}