Skip to content

Enable Preview examples on macOS #976

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Kyle-Ye merged 1 commit into from
Aug 2, 2026
Merged

Enable Preview examples on macOS #976

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion Docs/Preview.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@

## Current Status

OpenSwiftUI supports Xcode Preview rendering through the shim introduced in [PR #829](https://github.com/OpenSwiftUIProject/OpenSwiftUI/pull/829). Source builds and binary distributions must also satisfy the linkage requirements below.
OpenSwiftUI supports Xcode Preview rendering through the shim introduced in [PR #829](https://github.com/OpenSwiftUIProject/OpenSwiftUI/pull/829). macOS Preview support was enabled by the binary framework fixes in [PR #952](https://github.com/OpenSwiftUIProject/OpenSwiftUI/pull/952). Source builds and binary distributions must also satisfy the linkage requirements below.

### How It Works

Expand All @@ -17,6 +17,8 @@ Since OpenSwiftUI cannot use SwiftUI's `#Preview` macro directly (it targets `Sw
}
```

The same preview declaration works on both supported targets. Native macOS targets return an `NSViewController` backed by `NSHostingController`; iOS and Mac Catalyst targets return a `UIViewController` backed by `UIHostingController`.

### Binary XCFramework Requirements

Xcode Preview's XOJIT loading model requires both `OpenSwiftUI.framework` and `OpenSwiftUICore.framework` to be dynamic. Packaging `OpenSwiftUICore` as a static framework allows Preview to relink another copy of Core into the preview product, which can duplicate runtime metadata and crash the Preview process.
Expand Down
11 changes: 7 additions & 4 deletions Example/Shared/PreviewShims.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,18 +21,21 @@ extension SwiftUI.View {
}
#endif

#if canImport(UIKit)
// FIXME: Not working on macOS yet

#Preview("HostingVC") {
ContentView()
._previewVC()
}

#Preview("CAHostingLayerExample") {
#if canImport(AppKit) && !targetEnvironment(macCatalyst)
CAHostingLayerExample(
content: ContentView(),
size: CGSize(width: 500, height: 300)
).makeViewController()
#else
CAHostingLayerExample(
content: ContentView(),
size: UIScreen.main.bounds.size
).makeViewController()
#endif
}
#endif
Loading