Add IdentifiedView

Sources/OpenSwiftUI/Integration/UIKit/UIHostingController.swift → Sources/OpenSwiftUI/Integration/Hosting/UIKit/UIHostingController.swift

@@ -47,10 +47,15 @@ open class UIHostingController<Content> : UIViewController where Content : View
         get { host.rootView }
         _modify { yield &host.rootView }
     }
+
+    public func _forEachIdentifiedView(body: (_IdentifiedViewProxy) -> Void) {
+        host._forEachIdentifiedView(body: body)
+    }
 }
 
 @available(macOS, unavailable)
 extension UIHostingController: _UIHostingViewable where Content == AnyView {
+
 }
 
 @available(macOS, unavailable)

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

@@ -7,7 +7,9 @@
 //  ID: FAF0B683EB49BE9BABC9009857940A1E
 
 #if os(iOS)
-@_spi(ForOpenSwiftUIOnly) public import OpenSwiftUICore
+@_spi(ForOpenSwiftUIOnly)
+@_spi(Private)
+public import OpenSwiftUICore
 public import UIKit
 
 @available(macOS, unavailable)
@@ -151,6 +153,19 @@ open class _UIHostingView<Content>: UIView where Content: View {
     // TODO
     func clearUpdateTimer() {
     }
+
+    func _forEachIdentifiedView(body: (_IdentifiedViewProxy) -> Void) {
+        let tree = preferenceValue(_IdentifiedViewsKey.self)
+        let adjustment = { [weak self](rect: inout CGRect) in
+            guard let self else { return }
+            rect = convert(rect, from: nil)
+        }
+        tree.forEach { proxy in
+            var proxy = proxy
+            proxy.adjustment = adjustment
+            body(proxy)
+        }
+    }
 }
 
 extension _UIHostingView: ViewRendererHost {

Sources/OpenSwiftUI/Integration/UIKit/UIHostingViewable.swift → Sources/OpenSwiftUI/Integration/Hosting/UIKit/UIHostingViewable.swift

@@ -13,7 +13,7 @@ import Foundation
 public protocol _UIHostingViewable: AnyObject {
 //    var rootView: AnyView { get set }
 //    func _render(seconds: Double)
-//    func _forEachIdentifiedView(body: (_IdentifiedViewProxy) -> Void)
+    func _forEachIdentifiedView(body: (_IdentifiedViewProxy) -> Void)
 //    func sizeThatFits(in size: CGSize) -> CGSize
 //    var _disableSafeArea: Bool { get set }
 ////    var _rendererConfiguration: _RendererConfiguration { get set }

Sources/OpenSwiftUI/Test/TestApp.swift

@@ -6,6 +6,9 @@
 //  Status: WIP
 //  ID: A519B5B95CA8FF4E3445832668F0B2D2
 
+@_spi(Testing)
+import OpenSwiftUICore
+
 public struct _TestApp {
     public init() {
         preconditionFailure("TODO")

Sources/OpenSwiftUI/View/IdentifiedView/IdentifiedViewTree.swift

@@ -0,0 +1,28 @@
+//
+//  IdentifiedViewTree.swift
+//  OpenSwiftUI
+//
+//  Audited for iOS 18.0
+//  Status: Complete
+
+public enum _IdentifiedViewTree {
+    case empty
+    case proxy(_IdentifiedViewProxy)
+    case array([_IdentifiedViewTree])
+
+    public func forEach(_ body: (_IdentifiedViewProxy) -> Void) {
+        switch self {
+            case .empty:
+                break
+            case let .proxy(proxy):
+                body(proxy)
+            case let .array(array):
+                for treeElement in array {
+                    treeElement.forEach(body)
+                }
+        }
+    }
+}
+
+@available(*, unavailable)
+extension _IdentifiedViewTree: Sendable {}

Sources/OpenSwiftUI/View/IdentifiedView/IdentifiedViewsKey.swift

@@ -0,0 +1,39 @@
+//
+//  IdentifiedViewsKey.swift
+//  OpenSwiftUI
+//
+//  Audited for iOS 18.0
+//  Status: Complete
+
+@_spi(Private)
+public import OpenSwiftUICore
+
+public struct _IdentifiedViewsKey {
+    public typealias Value = _IdentifiedViewTree
+
+    public static let defaultValue: _IdentifiedViewTree = .empty
+
+    public static func reduce(value: inout _IdentifiedViewTree, nextValue: () -> _IdentifiedViewTree) {
+        let newValue = nextValue()
+        switch (value, newValue) {
+            case (_, .empty):
+                break
+            case (.empty, _):
+                value = newValue
+            case let (.proxy(oldProxy), .proxy(newProxy)):
+                value = .array([.proxy(oldProxy)] + [.proxy(newProxy)])
+            case let (.array(oldArray), .proxy(newProxy)):
+                value = .array(oldArray + [.proxy(newProxy)])
+            case let (.proxy(oldProxy), .array(newArray)):
+                value = .array([.proxy(oldProxy)] + newArray)
+            case let (.array(oldArray), .array(newArray)):
+                value = .array(oldArray + newArray)
+        }
+    }
+}
+
+@available(*, unavailable)
+extension _IdentifiedViewsKey: Sendable {}
+
+@_spi(Private)
+extension _IdentifiedViewsKey: HostPreferenceKey {}

Sources/OpenSwiftUICore/Data/Preference/PreferenceKey.swift

@@ -36,12 +36,19 @@ public protocol PreferenceKey {
     ///   - nextValue: A closure that returns the next value in the sequence.
     static func reduce(value: inout Value, nextValue: () -> Value)
 
+    /// If true `reduce()` will also see preference values for views
+    /// that have active removal transitions. The default
+    /// implementation returns false.
     static var _includesRemovedValues: Bool { get }
 
+    /// If true the preference may be read via the renderer host API.
+    /// Defaults to false. If true `_includesRemovedValues` should be
+    /// false.
     static var _isReadableByHost: Bool { get }
 }
 
 extension PreferenceKey where Value: ExpressibleByNilLiteral {
+    /// Let nil-expressible values default-initialize to nil.
     public static var defaultValue: Value { Value(nilLiteral: ()) }
 }
 

Sources/OpenSwiftUICore/View/Graph/ViewRendererHost.swift

@@ -176,7 +176,9 @@ extension ViewRendererHost {
 
     @_spi(Private)
     public func preferenceValue<K>(_ key: K.Type) -> K.Value where K: HostPreferenceKey {
-        preconditionFailure("TODO")
+        updateViewGraph { graph in
+            graph.preferenceValue(key)
+        }
     }
 
     package func idealSize() -> CGSize { preconditionFailure("TODO") }

Sources/OpenSwiftUICore/View/IdentifiedView/IdentifiedViewProxy.swift

@@ -0,0 +1,51 @@
+//
+//  IdentifiedViewProxy.swift
+//  OpenSwiftUICore
+//
+//  Audited for iOS 18.0
+//  Status: Complete
+
+public import Foundation
+
+public struct _IdentifiedViewProxy {
+    public var identifier: AnyHashable
+    package var size: CGSize
+    package var position: CGPoint
+    package var transform: ViewTransform
+    package var adjustment: ((inout CGRect) -> ())?
+    package var accessibilityNodeStorage: Any?
+    package var platform: _IdentifiedViewProxy.Platform
+
+    package init(identifier: AnyHashable, size: CGSize, position: CGPoint, transform: ViewTransform, accessibilityNode: Any?, platform: _IdentifiedViewProxy.Platform) {
+        self.identifier = identifier
+        self.size = size
+        self.position = position
+        self.transform = transform
+        self.accessibilityNodeStorage = accessibilityNode
+        self.platform = platform
+    }
+
+    public var boundingRect: CGRect {
+        var rect = CGRect(origin: .zero, size: size)
+        rect.convert(to: .global, transform: transform.withPosition(position))
+        adjustment?(&rect)
+        return rect
+    }
+}
+
+@available(*, unavailable)
+extension _IdentifiedViewProxy: Sendable {}
+
+package struct IdentifiedViewPlatformInputs {
+    package init(inputs: _ViewInputs, outputs: _ViewOutputs) {}
+}
+
+extension _IdentifiedViewProxy {
+    package struct Platform {
+        package init(_ inputs: IdentifiedViewPlatformInputs) {}
+    }
+}
+
+package protocol IdentifierProvider {
+    func matchesIdentifier<I>(_ identifier: I) -> Bool where I: Hashable
+}

Sources/OpenSwiftUICore/View/Input/ViewOutputs.swift

@@ -13,7 +13,7 @@ public struct _ViewOutputs {
 
     private var _layoutComputer: OptionalAttribute<LayoutComputer>
 
-    init() {
+    package init() {
         preferences = PreferencesOutputs()
         _layoutComputer = OptionalAttribute()
     }

Sources/OpenSwiftUICore/View/Test/TestIDView.swift

@@ -0,0 +1,63 @@
+//
+//  TestIDView.swift
+//  OpenSwiftUICore
+//
+//  Audited for iOS 18.0
+//  Status: WIP
+//  ID: CC151E1A36B4405FF56CDABA5D46BF1E
+
+import OpenGraphShims
+
+@_spi(Testing)
+extension View {
+    nonisolated public func testID<ID>(_ id: ID) -> TestIDView<Self, ID> where ID : Hashable {
+        TestIDView(content: self, id: id)
+    }
+}
+
+@_spi(Testing)
+@MainActor
+@preconcurrency
+public struct TestIDView<Content, ID>: PrimitiveView, UnaryView where Content: View, ID: Hashable {
+    public var content: Content
+    public var id: ID
+
+    nonisolated public static func _makeView(view: _GraphValue<Self>, inputs: _ViewInputs) -> _ViewOutputs {
+        fatalError()
+    }
+
+    public typealias Body = Never
+
+    private struct IdentifiedView: StatefulRule, AsyncAttribute, IdentifierProvider, CustomStringConvertible {
+        @Attribute var view: TestIDView
+        var id: ID?
+
+        init(view: Attribute<TestIDView>, id: ID?) {
+            self._view = view
+            self.id = id
+        }
+
+        // TODO
+        typealias Value = TestIDView
+
+        mutating func updateValue() {
+            // TODO: id = view.id
+        }
+
+        func matchesIdentifier<I>(_ identifier: I) -> Bool where I: Hashable {
+            compareValues(id, identifier as? ID)
+        }
+
+        var description: String {
+            if let id {
+                "ID: \(id)"
+            } else {
+                "ID"
+            }
+        }
+    }
+}
+
+@_spi(Testing)
+@available(*, unavailable)
+extension TestIDView: Sendable {}

Tests/OpenSwiftUICompatibilityTests/SwiftUICore/View/IdentifiedView/IdentifiedViewProxyTests.swift

@@ -0,0 +1,26 @@
+//
+//  IdentifiedViewProxyTests.swift
+//  OpenSwiftUICompatibilityTests
+
+import Testing
+#if os(iOS)
+import UIKit
+#endif
+
+@MainActor
+struct IdentifiedViewProxyTests {
+    @Test
+    func boundingRect() async {
+        #if os(iOS) && OPENSWIFTUI_COMPATIBILITY_TEST // FIXME: add _identified modifier
+        let identifier = "Test"
+        let hosting = UIHostingController(rootView: AnyView(EmptyView())._identified(by: identifier))
+        await confirmation { @MainActor confirmation in
+            hosting._forEachIdentifiedView { proxy in
+                confirmation()
+                #expect(proxy.identifier == AnyHashable(identifier))
+                #expect(proxy.boundingRect == .zero)
+            }
+        }
+        #endif
+    }
+}

Tests/OpenSwiftUICompatibilityTests/SwiftUICore/View/IdentifiedView/IdentifiedViewTreeTests.swift

@@ -0,0 +1,17 @@
+//
+//  IdentifiedViewTreeTests.swift
+//  OpenSwiftUICompatibilityTests
+
+import Testing
+
+struct IdentifiedViewTreeTests {
+    @Test
+    func forEachEmpty() async {
+        let tree = _IdentifiedViewTree.empty
+        await confirmation(expectedCount: 0) { confirm in
+            tree.forEach { _ in
+                confirm()
+            }
+        }
+    }
+}