Initial Shaft render backend impl

.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+    "swift.path": "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin",
+    "swift.swiftEnvironmentVariables": {
+        "DEVELOPER_DIR": "/Applications/Xcode.app/Contents/Developer"
+    }
+}

Example/ShaftExample/.gitignore

@@ -0,0 +1 @@
+.build

Example/ShaftExample/Package.swift

@@ -0,0 +1,31 @@
+// swift-tools-version: 6.1
+
+import PackageDescription
+
+let package = Package(
+    name: "ShaftExample",
+    platforms: [
+        .macOS(.v15),
+        .iOS(.v18),
+    ],
+    products: [
+        .executable(name: "ShaftExample", targets: ["ShaftExample"]),
+    ],
+    dependencies: [
+        .package(path: "../../"),  // OpenSwiftUI
+    ],
+    targets: [
+        .executableTarget(
+            name: "ShaftExample",
+            dependencies: [
+                .product(name: "OpenSwiftUI", package: "OpenSwiftUI"),
+                .product(name: "OpenSwiftUIShaftBackend", package: "OpenSwiftUI"),
+            ],
+            swiftSettings: [
+                .interoperabilityMode(.Cxx),
+            ]
+        ),
+    ],
+    cxxLanguageStandard: .cxx17,
+)
+

Example/ShaftExample/Sources/ShaftExample/main.swift

@@ -0,0 +1,30 @@
+//
+//  main.swift
+//  ShaftExample
+//
+//  Example application demonstrating OpenSwiftUI rendering via Shaft
+//
+
+import Foundation
+import OpenSwiftUI
+import OpenSwiftUIShaftBackend
+
+// Define a simple OpenSwiftUI view
+struct ContentView: View {
+    var body: some View {
+        VStack {
+            Color.red
+                .frame(width: 100, height: 60)
+            Spacer()
+            Color.blue
+                .frame(width: 100, height: 60)
+                .rotationEffect(.degrees(45))
+            Spacer()
+            Color.green
+                .frame(width: 100, height: 60)
+        }
+    }
+}
+
+// Run the application
+ShaftHostingView.run(rootView: ContentView())

Package.swift

@@ -167,6 +167,7 @@ let openCombineCondition = envBoolValue("OPENCOMBINE", default: !buildForDarwinP
 let swiftLogCondition = envBoolValue("SWIFT_LOG", default: !buildForDarwinPlatform)
 let swiftCryptoCondition = envBoolValue("SWIFT_CRYPTO", default: !buildForDarwinPlatform)
 let renderGTKCondition = envBoolValue("RENDER_GTK", default: !buildForDarwinPlatform)
+let shaftBackendCondition = envBoolValue("SHAFT_BACKEND")
 
 let swiftUIRenderCondition = envBoolValue("SWIFTUI_RENDER", default: buildForDarwinPlatform)
 
@@ -678,6 +679,21 @@ let openSwiftUIBridgeTestTarget = Target.testTarget(
     swiftSettings: sharedSwiftSettings
 )
 
+// MARK: - OpenSwiftUIShaftBackend Target
+
+let openSwiftUIShaftBackendTarget = Target.target(
+    name: "OpenSwiftUIShaftBackend",
+    dependencies: [
+        "OpenSwiftUI",
+        "OpenSwiftUICore",
+        .product(name: "Shaft", package: "Shaft"),
+        .product(name: "ShaftSetup", package: "Shaft"),
+    ],
+    cSettings: sharedCSettings,
+    cxxSettings: sharedCxxSettings,
+    swiftSettings: sharedSwiftSettings + [.interoperabilityMode(.Cxx)]
+)
+
 // MARK: - OpenSwiftUISymbolDualTests Target
 
 let openSwiftUISymbolDualTestsSupportTarget = Target.target(
@@ -730,6 +746,9 @@ if supportMultiProducts {
         .library(name: "OpenSwiftUIBridge", targets: ["OpenSwiftUIBridge"])
     ]
 }
+if shaftBackendCondition {
+    products.append(.library(name: "OpenSwiftUIShaftBackend", targets: ["OpenSwiftUIShaftBackend"]))
+}
 
 // MARK: - Package
 
@@ -862,6 +881,13 @@ if useLocalDeps {
     package.dependencies += dependencies
 }
 
+if shaftBackendCondition {
+    // Use relative path for easier local development
+    // package.dependencies.append(.package(path: "../../ShaftUI/Shaft"))
+    package.dependencies.append(.package(url: "https://github.com/ShaftUI/Shaft", branch: "main"))
+    package.targets.append(openSwiftUIShaftBackendTarget)
+}
+
 if openCombineCondition {
     package.dependencies.append(
         .package(url: "https://github.com/OpenSwiftUIProject/OpenCombine.git", from: "0.15.0")
@@ -886,3 +912,5 @@ if swiftCryptoCondition {
     openSwiftUICoreTarget.addSwiftCryptoSettings()
     openSwiftUITarget.addSwiftCryptoSettings()
 }
+
+package.cxxLanguageStandard = .cxx17 // For building Shaft's Skia backend

Sources/OpenSwiftUICore/Render/DisplayList/DisplayListViewRenderer.swift

@@ -8,7 +8,7 @@
 
 package import Foundation
 
-protocol ViewRendererBase: AnyObject {
+package protocol ViewRendererBase: AnyObject {
     var platform: DisplayList.ViewUpdater.Platform { get }
     var exportedObject: AnyObject? { get }
     func render(rootView: AnyObject, from list: DisplayList, time: Time, version: DisplayList.Version, maxVersion: DisplayList.Version, environment: DisplayList.ViewRenderer.Environment) -> Time
@@ -193,11 +193,11 @@ extension DisplayList {
             _openSwiftUIBaseClassAbstractMethod()
         }
 
-        var exportedObject: AnyObject? {
+        package var exportedObject: AnyObject? {
             platform.definition.getRBLayer(drawingView: drawingView!)
         }
 
-        func render(rootView: AnyObject, from list: DisplayList, time: Time, version: DisplayList.Version, maxVersion: DisplayList.Version, environment: DisplayList.ViewRenderer.Environment) -> Time {
+        package func render(rootView: AnyObject, from list: DisplayList, time: Time, version: DisplayList.Version, maxVersion: DisplayList.Version, environment: DisplayList.ViewRenderer.Environment) -> Time {
             // _openSwiftUIUnimplementedFailure()
             if printTree == nil {
                 printTree = ProcessEnvironment.bool(forKey: "OPENSWIFTUI_PRINT_TREE")
@@ -208,15 +208,15 @@ extension DisplayList {
             return .zero
         }
 
-        func renderAsync(to list: DisplayList, time: Time, targetTimestamp: Time?, version: DisplayList.Version, maxVersion: DisplayList.Version) -> Time? {
+        package func renderAsync(to list: DisplayList, time: Time, targetTimestamp: Time?, version: DisplayList.Version, maxVersion: DisplayList.Version) -> Time? {
             _openSwiftUIUnimplementedFailure()
         }
 
-        func destroy(rootView: AnyObject) {
+        package func destroy(rootView: AnyObject) {
             _openSwiftUIUnimplementedFailure()
         }
 
-        var viewCacheIsEmpty: Bool {
+        package var viewCacheIsEmpty: Bool {
             _openSwiftUIUnimplementedFailure()
         }
     }

Sources/OpenSwiftUICore/Render/DisplayList/DisplayListViewUpdater.swift

@@ -31,7 +31,7 @@ extension DisplayList {
             _openSwiftUIUnimplementedFailure()
         }
 
-        func render(rootView: AnyObject, from list: DisplayList, time: Time, version: DisplayList.Version, maxVersion: DisplayList.Version, environment: DisplayList.ViewRenderer.Environment) -> Time {
+        package func render(rootView: AnyObject, from list: DisplayList, time: Time, version: DisplayList.Version, maxVersion: DisplayList.Version, environment: DisplayList.ViewRenderer.Environment) -> Time {
             // TODO
             if printTree == nil {
                 printTree = ProcessEnvironment.bool(forKey: "OPENSWIFTUI_PRINT_TREE")
@@ -42,24 +42,24 @@ extension DisplayList {
             return .zero
         }
 
-        func renderAsync(to list: DisplayList, time: Time, targetTimestamp: Time?, version: DisplayList.Version, maxVersion: DisplayList.Version) -> Time? {
+        package func renderAsync(to list: DisplayList, time: Time, targetTimestamp: Time?, version: DisplayList.Version, maxVersion: DisplayList.Version) -> Time? {
             nil
         }
 
-        func destroy(rootView: AnyObject) {
+        package func destroy(rootView: AnyObject) {
         }
 
-        var viewCacheIsEmpty: Bool {
+        package var viewCacheIsEmpty: Bool {
             // TODO
             false
         }
 
-        var platform: Platform {
+        package var platform: Platform {
             // TODO
             _openSwiftUIUnimplementedFailure()
         }
 
-        var exportedObject: AnyObject? {
+        package var exportedObject: AnyObject? {
             // TODO
             nil
         }