Pasting text in the TextEditor no longer works

[maximlt]

Pasting text in the TextEditor no longer works. That's the error logged in the browser console when you try to paste in the widget:

quill.js:3065 Uncaught TypeError: Cannot read properties of null (reading 'offset')
    at quill.js:3065:26
    at Array.map (<anonymous>)
    at Selection.normalizedToRange (quill.js:3059:31)
    at Selection.getRange (quill.js:3042:24)
    at Selection.update (quill.js:3229:28)
    at HTMLDocument.<anonymous> (panel.min.js?v=c47f5b18b8a430e698b9fe15e51f6119984e78334bcf3f45e210d30c37ef2f9e:135:2379)

[maximlt]

The TextEditor widget is implemented based on QuillJS, which hasn't been updated in a while and doesn't yet support the shadow DOM. A good summary of this can be found in:

• Shadow DOM support - continued slab/quill#2961
• Feature/shadow dom robrez/quill#1

After Panel moved to Bokeh 3, the TextEditor widget was patched twice to improve its support in the shadow DOM:

• Update TextEditor for Bokeh 3 #4467
• Ensure Quill correctly detects selections and renders HTML #5511

Both patches were inspired from https://stackoverflow.com/questions/67914657/quill-editor-inside-shadow-dom/67944380#67944380, the author of this answer can also be found on Quill's Github slab/quill#2961 (comment).
A somewhat similar patch can be found here slab/quill#2021 (comment), it was suggested a few days after the other one.

The copy/paste issue has also been reported on Quill's issue tracker a few times:

• Support Shadow DOM v1 slab/quill#2021 (comment)
• Shadow DOM support - continued slab/quill#2961 (comment)

I haven't yet seen a solution that fixes the issue, I haven't tried them all though and I could easily miss it 🙃

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I've tried a few things to fix the issue, without luck so far. It seems the issue doesn't occur on Firefox.

[maximlt]

In my quest for finding a fix for this, I found this interesting PR nuxeo/quill#2 where they are patching Quill directly and replacing the shadow-selection-polyfill with an alternative. This branch slab/quill@develop...nuxeo:quill:2.0.0-NX, apparently built on top of the 2.0dev branch of Quill (that is a few years old) has a few commits to add support to the Shadow DOM. It's been last published two years ago https://www.npmjs.com/package/@nuxeo/quill.

I'm pretty sure we'll get hit back by some of these Shadow DOM issues with Quill, when that happens, trying out @nuxeo/quill might be an option.