SwiftUI sample "closed"-command

Unity Engine
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1

Hi,

I noticed that in the Swift UI sample’s SwiftUIDriver, the CallbackFromNative method has this small if-statement:

 if (command == "closed") {
 self.m_SwiftUIWindowOpen = false;
 return;
}

But I don’t see anything in the native Swift code actually sending a “closed”-command. Hasn’t this been implemented? I would like to see an example of receiving a command when the native SwiftUI window is closed so I can react to that in Unity.

2

This looks like an oversight to me. Nothing currently sends the “closed” message, and SwiftUIDriver itself sets the m_SwiftUIWindowOpen state when it opens or closes the window via OpenSwiftUIWindow/CloseSwiftUIWindow. However, note that HelloWorldContentView.swift sends an “appeared” message in the onAppear handler. You could add the “closed” message in an onDisappear handler:

// ...

      VStack {
          // ...
      }
      .onAppear {
            // Call the public function that was defined in SwiftUISamplePlugin
            // inside UnityFramework
            CallCSharpCallback("appeared")
            // ...
        }
        .onDisappear {
            CallCSharpCallback("closed")
        }

We can add that to the sample for a future release.

3

After testing, it was found that .onDisappear is not triggered when the window is closed. Therefore, CallCSharpCallback(“closed”) is not called.

4

In my testing, I found that this works in PolySpatial 2.X/visionOS 2.0 beta, but not in PolySpatial 1.X/visionOS 1.0. So, we added it to that version only. I didn’t find any alternative means of getting a callback in 1.0, but if you find one, definitely let us know–and/or report the issue to Apple via their Feedback Assistant.