Enable OSUI ViewRenderer by default (#872)

Author: Kyle-Ye

.github/workflows/uitests.yml

@@ -168,6 +168,7 @@ jobs:
       OPENSWIFTUI_TARGET_RELEASE: ${{ matrix.release }}
       OPENSWIFTUI_USE_LOCAL_DEPS: 1
       OPENSWIFTUI_LINK_TESTING: 0
+      OPENSWIFTUI_SWIFTUI_RENDERER: 1 # TODO: Add render-off UI test coverage with OPENSWIFTUI_SWIFTUI_RENDERER=0.
       GH_TOKEN: ${{ github.token }}
     steps:
       - name: Mark PR status running
@@ -258,6 +259,7 @@ jobs:
       OPENSWIFTUI_SWIFT_CRYPTO: 0
       OPENSWIFTUI_TARGET_RELEASE: ${{ matrix.release }}
       OPENSWIFTUI_USE_LOCAL_DEPS: 1
+      OPENSWIFTUI_SWIFTUI_RENDERER: 1 # TODO: Add render-off UI test coverage with OPENSWIFTUI_SWIFTUI_RENDERER=0.
       GH_TOKEN: ${{ github.token }}
     steps:
       - name: Mark PR status running

INTEGRATION.md

@@ -6,7 +6,6 @@ This guide walks you through the steps to integrate OpenSwiftUI into your projec
 
 - Xcode 16.4
 - Swift 6.1.2+
-- macOS 15.5 (for macOS apps) or iOS 18.5 (for iOS apps)
 
 ## Important Notes
 
@@ -186,17 +185,17 @@ Currently, AttributeGraph is missing some symbols for iOS device. Until OpenAttr
 
 **Future resolution:** This limitation will be lifted when OpenAttributeGraph is ready, which will unlock iOS device platform support.
 
-### 2. ABI Compatibility Requirements
+### 2. Optional SwiftUI Renderer ABI Compatibility
 
-⚠️ **Important:** The current Render engine uses a private API of SwiftUI which does not guarantee ABI stability. Until OpenSwiftUI's ViewUpdater render engine is implemented, it is required to use the same ABI version.
+By default, OpenSwiftUI does not require a specific SwiftUI renderer ABI version.
 
-**Current supported ABI versions:**
-- **iOS 18.5**
-- **macOS 15.5**
+The ABI limitation only applies when you explicitly opt into the SwiftUI renderer by setting `OPENSWIFTUI_SWIFTUI_RENDERER=1`. That renderer uses private SwiftUI APIs which do not guarantee ABI stability.
 
-**Impact:** Your target platform deployment version must match these specific versions to avoid runtime compatibility issues.
+**Current supported SwiftUI renderer ABI versions:**
+- **iOS 18.5 to before iOS 26.0**
+- **macOS 15.5 to before macOS 26.0**
 
-**Future resolution:** This limitation will be lifted when OpenSwiftUI's own Render engine (ViewUpdater) is ready, which will remove the ABI version lock requirement and allow broader platform version support.
+**Impact:** If `OPENSWIFTUI_SWIFTUI_RENDERER=1` is enabled, your runtime platform version must be in the supported range to avoid runtime compatibility issues.
 
 ## Troubleshooting
 
@@ -214,4 +213,4 @@ Make sure you've added the AttributeGraph.xcframework to your target and set it
 If Xcode fails to resolve the package:
 1. Make sure you're using `branch: "main"` or a specific `revision:` instead of a version tag
 2. Try **File → Packages → Reset Package Caches**
-3. Clean the build folder (**Shift+Cmd+K**) and rebuild
+3. Clean the build folder (**Shift+Cmd+K**) and rebuild

Package.resolved

@@ -171,7 +171,7 @@ let swiftLogCondition = envBoolValue("SWIFT_LOG", default: !buildForDarwinPlatfo
 let swiftCryptoCondition = envBoolValue("SWIFT_CRYPTO", default: !buildForDarwinPlatform)
 let renderGTKCondition = envBoolValue("RENDER_GTK", default: !buildForDarwinPlatform)
 
-let swiftUIRenderCondition = envBoolValue("SWIFTUI_RENDER", default: buildForDarwinPlatform)
+let swiftUIRenderCondition = envBoolValue("SWIFTUI_RENDERER", default: false)
 
 let ignoreAvailability = envBoolValue("IGNORE_AVAILABILITY", default: !isSPIDocGenerationBuild && !compatibilityTestCondition)
 
@@ -291,9 +291,9 @@ if linkBacklightServices {
 }
 
 if swiftUIRenderCondition {
-    sharedCSettings.append(.define("_OPENSWIFTUI_SWIFTUI_RENDER"))
-    sharedCxxSettings.append(.define("_OPENSWIFTUI_SWIFTUI_RENDER"))
-    sharedSwiftSettings.append(.define("_OPENSWIFTUI_SWIFTUI_RENDER"))
+    sharedCSettings.append(.define("OPENSWIFTUI_SWIFTUI_RENDERER", .when(platforms: .darwinPlatforms)))
+    sharedCxxSettings.append(.define("OPENSWIFTUI_SWIFTUI_RENDERER", .when(platforms: .darwinPlatforms)))
+    sharedSwiftSettings.append(.define("OPENSWIFTUI_SWIFTUI_RENDERER", .when(platforms: .darwinPlatforms)))
 }
 
 if linkTesting {

Package.swift

@@ -104,9 +104,9 @@ for various platforms:
 | **Android** | None | Not supported yet | ❌ | ❌ | ❌ | |
 | **Windows** | None | Not supported yet | ❌ | ❌ | ❌ | |
 
-[^1]: AppKit intergration is partly implemented. Render is support via SwiftUI's render implementation. Other UI framework backend is not intergrated yet.
+[^1]: AppKit intergration is partly implemented. Other UI framework backend is not intergrated yet.
 
-[^2]: UIKit intergration is partly implemented. Render is support via SwiftUI's render implementation.
+[^2]: UIKit intergration is partly implemented.
 
 [^3]: Build and test is supported. But some feature is cut due to known Swift compiler issue.
 

README.md

@@ -4,8 +4,11 @@ set -e
 
 : "${OPENSWIFTUI_LIBRARY_TYPE:=dynamic}"
 : "${OPENSWIFTUI_USE_LOCAL_DEPS:=1}"
+: "${OPENSWIFTUI_SWIFTUI_RENDERER:=0}"
 export OPENSWIFTUI_LIBRARY_TYPE
 export OPENSWIFTUI_USE_LOCAL_DEPS
+export OPENSWIFTUI_SWIFTUI_RENDERER
+# TODO: replace AG with Compute or OAG by default
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd -P)"
 PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"

Scripts/build_xcframework.sh

@@ -12,7 +12,7 @@ import OpenAttributeGraphShims
 @_spi(ForOpenSwiftUIOnly)
 @_spi(Private)
 public import OpenSwiftUICore
-#if _OPENSWIFTUI_SWIFTUI_RENDER
+#if OPENSWIFTUI_SWIFTUI_RENDERER
 import OpenSwiftUISymbolDualTestsSupport
 #endif
 import COpenSwiftUI

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

@@ -11,7 +11,7 @@
 @_spi(DisplayList_ViewSystem)
 import OpenSwiftUICore
 import AppKit
-#if _OPENSWIFTUI_SWIFTUI_RENDER
+#if OPENSWIFTUI_SWIFTUI_RENDERER
 import OpenSwiftUISymbolDualTestsSupport
 #endif
 import COpenSwiftUI

Sources/OpenSwiftUI/Render/DisplayList/AppKitDisplayList.swift

@@ -10,7 +10,7 @@
 import COpenSwiftUI
 @_spi(DisplayList_ViewSystem) import OpenSwiftUICore
 import UIKit
-#if _OPENSWIFTUI_SWIFTUI_RENDER
+#if OPENSWIFTUI_SWIFTUI_RENDERER
 import OpenSwiftUISymbolDualTestsSupport
 #endif
 import QuartzCore_Private

Sources/OpenSwiftUI/Render/DisplayList/UIKitDisplayList.swift

@@ -523,13 +523,13 @@ public struct GraphicsContext {
 }
 
 extension GraphicsContext {
-    #if canImport(Darwin) && _OPENSWIFTUI_SWIFTUI_RENDER
+    #if OPENSWIFTUI_SWIFTUI_RENDERER
     @_silgen_name("OpenSwiftUITestStub_GraphicsContextDrawPathWithShadingAndStyle")
     private func swiftUI_draw(_ path: Path, with shading: GraphicsContext.ResolvedShading, style: PathDrawingStyle)
     #endif
 
     package func draw(_ path: Path, with shading: GraphicsContext.ResolvedShading, style: PathDrawingStyle) {
-        #if canImport(Darwin) && _OPENSWIFTUI_SWIFTUI_RENDER
+        #if OPENSWIFTUI_SWIFTUI_RENDERER
         swiftUI_draw(path, with: shading, style: style)
         #else
         _openSwiftUIUnimplementedWarning()