[Bugfix] Fix UIHostingView update issue

Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift

@@ -167,12 +167,14 @@ open class _UIHostingView<Content>: UIView, XcodeViewDebugDataProvider where Con
         }
         // TODO
         super.init(frame: .zero)
-
-        initializeViewGraph()
+        // TODO
+        let base = base
+        if let host = base.host {
+            host.initializeViewGraph()
+            base.setupNotifications()
+        }
         // RepresentableContextValues.current =
 
-        renderer.host = self
-
         // TODO
         HostingViewRegistry.shared.add(self)
         Update.end()
@@ -465,7 +467,7 @@ extension _UIHostingView {
     }
 }
 
-extension _UIHostingView: ViewGraphDelegate {
+extension _UIHostingView: ViewRendererHost {
     package func `as`<T>(_ type: T.Type) -> T? {
         guard let value = base.as(type) else {
             // TODO
@@ -474,13 +476,6 @@ extension _UIHostingView: ViewGraphDelegate {
         return value
     }
 
-    package func requestUpdate(after: Double) {
-        // TODO
-        requestImmediateUpdate()
-    }
-}
-
-extension _UIHostingView: ViewRendererHost {
     package var renderingPhase: ViewRenderingPhase {
         get { base.renderingPhase }
         set { base.renderingPhase = newValue }
@@ -521,26 +516,20 @@ extension _UIHostingView: ViewRendererHost {
         viewGraph.setRootView(rootView)
     }
 
-    func requestImmediateUpdate() {
-        // FIXME
-        setNeedsLayout()
-    }
-
     package func outputsDidChange(outputs: ViewGraph.Outputs) {
-        // TODO
+        _openSwiftUIUnimplementedWarning()
     }
 
     package func focusDidChange() {
-        // TODO
-    }
-
-    package func rootTransform() -> ViewTransform {
         _openSwiftUIUnimplementedWarning()
-        return ViewTransform()
+    }
+
+    package func requestUpdate(after delay: Double) {
+        base.requestUpdate(after: delay)
     }
 
     public func preferencesDidChange() {
-        // TODO
+        _openSwiftUIUnimplementedWarning()
     }
 }
 

Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingViewBase.swift

@@ -265,7 +265,27 @@ package class UIHostingViewBase {
     }
 
     package func requestUpdate(after delay: Double) {
-        _openSwiftUIUnimplementedFailure()
+        Update.lock()
+        if delay != .zero || (viewGraph.mayDeferUpdate && displayLink?.willRender == true) {
+            let delay = Double(UIAnimationDragCoefficient()) * delay
+            if delay >= 0.25 {
+                startUpdateTimer(delay: delay)
+            } else {
+                startDisplayLink(delay: delay)
+            }
+        } else {
+            if Thread.isMainThread {
+                requestImmediateUpdate()
+            } else {
+                DispatchQueue.main.async { [weak self] in
+                    guard let self else {
+                        return
+                    }
+                    requestImmediateUpdate()
+                }
+            }
+        }
+        Update.unlock()
     }
 
     package func updateRemovedState(uiView: UIView?) {
@@ -296,7 +316,12 @@ package class UIHostingViewBase {
             return
         }
         guard updatesAtFullFidelity else {
-            // TODO:
+            cancelAsyncRendering()
+            clearDisplayLink()
+            clearUpdateTimer()
+            if uiView.layer.needsLayout() {
+                requestImmediateUpdate()
+            }
             return
         }
         uiView.setNeedsLayout()
@@ -469,6 +494,13 @@ package class UIHostingViewBase {
                 updateRemovedState(uiView: nil)
             }
         }
+        updateSceneNotifications()
+        updateWindowNotifications()
+        requestUpdateForFidelity()
+        if window == nil {
+            isRotatingWindow = false
+        }
+        host.invalidateProperties(.environment)
     }
 
     // MARK: - Notification