Webview via Extensions

[notpeter]

Description

A number of VSCode plugins are implemented as shim atop a webview.

This can be used to support simple things like Preview panes (e.g. image/PDF/SVG preview) up through through full interactive web applications which dynamically edit an underlying file.

Example requests which could potentially implement with this extension interface:

• support for Typst language #12088
• Excalidraw integration #21197

[huacnlee]

I have made this change for WebView support. And we are already used those changes to integration WebView in our application.

huacnlee#6

There still have a big problem:

• The WebView will always render on top of the GPUI elements.
  • So we are limited our UI, to let the WebView render in a Drawer or a Modal to make sure no other GPUI elements render on top of it (e.g.: PopupMenu, Tooltip ...).
• On Linux with Wayland, the Wry can't be as a child window to use.
  • So ... we disable it in our application on Linux.

[notpeter]

There will definitely need to be significant work as for how to expose this the API in a platform agnostic way (e.g. bundle Chromium everywhere? Use native Safari WebView on Mac, Edge WebView2 on Windows, ?? on Linux) as well as the specific ergonomics/safety of the Extension API so that extensions can leverage it and Zed can support this as a stable API in the long-term.

Thanks for the link @huacnlee, it's exciting to see a proof-of-concept.
But I want to manage expectations -- there is still significant work to be done here and it's likely still a ways off.

[mocenigo]

Something like skia-canvas would be good to get a nt
Html canvas. Since the backend is separated I think it could be ported atop of GPUI. With JS and TS also compiling to wasm, I think this could allow fast porting of several VSCode extensions (imagine having draw.io).