openswiftuiproject / openswiftui

[WIP] Open source implementation of Apple's SwiftUI.

OpenSwiftUI

OpenSwiftUI is an open source implementation of Apple's SwiftUI

The project is for the following purposes:

• Build GUI app on non-Apple platform (eg. Linux & Windows)
• Diagnose and debug SwiftUI issues on Apple platform

And the API design is to stay the same as the original SwiftUI API as possible.

Currently, this project is in early development.

You can find the API documentation here.

Warning

This package use a lot of hidden API and private framework on Apple platform.

Please DO NOT use this package in Apple's production environment(eg. App Store).

Otherwize it may break your build or crash your app at any future SDK/OS update.

Usage

See Example folder and try it with ExampleApp

Important

Clone OpenGraph in the same directory before running the example.

See Example/README.md for more detail.

Build

Build without testing framework

./Scripts/build

Build with Library Evolution

./Scripts/openswiftui_swiftinterface

Supported platforms

The table below describes the current level of support that OpenSwiftUI has for various platforms:

Platform	CI Status	Support Status	Build	Test	Deploy
SwiftUI Compatibility
macOS		⭐️⭐️⭐️ *1	✅	✅	✅
iOS		⭐️⭐️⭐️⭐️ *2	✅	✅	✅
Ubuntu 22.04		⭐️⭐️ *3	✅	✅	❌
Wasm		⭐️ *4	✅	❌	❌
Windows	None	Not supported yet	❌	❌	❌

Note

The cross-platform OpenGraph is not fully implemented.

It is only API compatible with AttributeGraph now.

So most of the core feature is only available on Apple platform built with AttributeGraph varient.

License

See LICENSE file - MIT

Related Projects

• https://github.com/Cosmo/OpenSwiftUI
• https://github.com/helbertgs/OpenSwiftUI

Star History

Footnotes

1. AppKit and other UI framework backend is not intergrated yet. ↩

2. UIKit intergration is partly implemented. No Render support yet. ↩

3. Build and test is supported. But some feature is cut due to known Swift compiler issue. ↩

4. Build is supported. Test is not supported yet dut to upstream issue. ↩

openswiftui's Issues

[Feature] onAppear and onDisappear implementation

constructing an object of class type 'Delegate' with a metatype value must use a 'required' initializer

class FallbackDelegateBox<Delegate: NSObject>: AnyFallbackDelegateBox {
    var storage: DelegateStorage
    
    enum DelegateStorage {
        case type(_ type: Delegate.Type)
        case instance(_ delegate: Delegate)
    }
   
    override var delegate: NSObject? {
        switch storage {
        case let .type(type):
            let delegate = type.init() // error: constructing an object of class type 'Delegate' with a metatype value must use a 'required' initializer
            ...
        }
        #endif
    }
}

Add AppGraph/AppAccessor support

Add NSHostingController and NSHostingView support

Cannot look up associated type for imported conformance

Compiler issue on non-Darwin platform(Linux and WASM).

Cannot look up associated type for imported conformance:
(struct_type decl=_OpenGraph.(file).OGAttribute)
(associated_type_decl "_ObjectiveCType" access=public overridden=)
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:

BodyAccessor crash for non empty View instance

Add any property (>=1) to our ContentView in HostingExample and it will crash.

Add DynamicBody Support

Add _printChanges implementation

Dependent on #64

Add other backend UI framework on non-Darwin platform

• Add AppKid as UIKit/AppKit alternative on Linux platform
• Take swift-cross-ui's code to use gtk4 as UIKit/AppKit alternative on Windows/Linux platform
• https://github.com/AparokshaUI/adwaita-swift

Will work on this when basic UIView/NSView support is ready.

How to run the Example by swift run?

Hi,

I can successfully run swift build for the project, but when I run swift run,

error: no executable product available

How can I run the examples?

Ubuntu 22, without Xcode.

Example and HostingExample code can't be built in Xcode 15.3

Hi Team,
I am trying to build the Example project in Xcode 15.3 and the simulator is 17.4
But I got a bunch of errors related to Multiple commands produce xxxxxxx
Is there any environment configuration that I set is wrong?

Here is the error message that I got, please check

Thank you

_UIHostingView deinit crash

@MainActor
@Test
func testDemo() throws {
    struct ContentView: View {
        var name = ""
        var body: some View {
            AnyView(EmptyView())
        }
    }
    let vc = UIHostingController(rootView: ContentView())
    vc.triggerLayout()
}
extension UIHostingController {
    func triggerLayout() {
        let window = UIWindow(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
        window.rootViewController = self
        window.makeKeyAndVisible()
        view.layoutSubviews()
    }
}

Commit Hash: a166851

Add State implementation

Thread and RunLoopMode.common in not available on WASM

Tracked via upstream issue: swiftwasm/swift#5581