Starting Ideas?

[laultman]

@maluoi Hi Nick, I know you haven't progressed this project and I know it's made for desktop. I would like to implement the project on HoloLens 2. Could you please give me your thoughts and ideas on a good approach to help me get going?

As always thanks for your insights and input.

[maluoi]

I'd take a look at WebView2! When I first wrote this, WebView2 wasn't compatible with UWP, so it wasn't a good route for HoloLens2. But since then WebView2 has gotten the necessary updates, and should be a good candidate now!

[laultman]

I got webview2 compiling in a test project with StereoKit ver 0.3.9 but still struggling with the getting actual page on the "screen" in HoloLens. All of the Microsoft samples use XAML page to render the browser. I'm going to look at your code and see if there are any hints there.

[maluoi]

There is a WebView2 plugin for Unity that could be interesting to peek at. Unfortunately the relevant texture work seems to dip into native code, which doesn't seem to have source available. It does look like you could repurpose those native libraries if you wanted to though, they don't appear to be Unity specific at first glance?

[laultman]

As I dig deeper into the WebView2 control, it turns out to be much more complex. Just getting it to instantiate in the StereoKit environment has so far been baffling. When I attempt to create a new instance of the control I get an error that the control is being marshaled on a different thread. I've tried creating it before calling anything SK all the way to using a stepper to call the instantiation after SK is running. The documentation says that there is an affinity to the UI thread and that it must be created on the main UI thread. It's like the control is looking for a window or a main Page that you would get in a UWP XAML app.
'''
var mainv = Windows.ApplicationModel.Core.CoreApplication.MainView; // test
var cur = Windows.ApplicationModel.Core.CoreApplication.GetCurrentView(); // test

		var dispatcher = Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher;
		await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async () =>
		{
			webView = new WebView();
			// Ensure all UI operations, including event subscriptions, are done here
			webView.NavigationCompleted += WebView_NavigationCompleted;
			webView.NavigationFailed += WebView_NavigationFailed;
			webViewerInitialized = true;
			webViewerInitializing = false;
		});

'''

Ideas??

[laultman]

@maluoi Hi Nick, I've been plowing through the Unity plugin and the Microsoft code. Under the covers the WebView2 code requires an HWND handle to initialize the control. The C# new WebView() method in the XMAL control is relying on the app to provide the HWND. The Unity plugin from Microsoft does not rely on the XMAL nuget and uses native calls much like you do with your native calls to the SK C backend.

How would we get the handle to the HWND for the StereoKit?

Here is the code from the plugin.
`

    [DllImport(DLL_NAME, CallingConvention = CallingConvention.StdCall)]
    
    public static extern WebViewInstancePtr InitializeWebView(int w, int h, string parentHWNDHint, ref int errorCode);

`

[laultman]

@maluoi Here is what I have learned so far... Unity implementation uses the WebView2 class's native code for a simple reason. The Microsoft.Web.WebView2 control nuget package is an implementation for winforms/WPF. It will not instantiate in a console app without a LOT of work that entirely defeats the purpose of using a "control".

I'm working on an implementation for StereoKit. I will use Unity as a pattern. There is so much code in the Unity implementation that is there just to manage the Unity framework, it will take some time to unravel.