@mattpap should the linked issues be triaged as feature? As an aside, I'd make a pitch for colorbar to be the next target for this kind of treatment.

should the linked issues be triaged as feature?

Yes. I'm actually triaging issues that may be affected by this work.

As an aside, I'd make a pitch for colorbar to be the next target for this kind of treatment.

Axes and title will have to be next. Then it will be possible to work on color bars.

Legend with DOM (left) and canvas rendering (right) side-by-side:

I was hoping to finish this PR as a big feature for bokeh 3.6, but that's unrealistic given how much additional work needed to be done to support DOM rendering and how much more is needed to tweak and fine tune the implementation. What needs to be done is:

• fine tune CSS to cover all the corner cases (e.g. angled text)
• address CSS cross-browser compatibility issues (e.g. vertical text in FF)
• finalize support for positioning in side panels
• don't render and paint at the same time (new output backend?)
• address performance issues due to over-rendering (due to uncertainty when to update the legend)

There is still one regression to address, but otherwise this is ready for review. Note that great many changes to the internals are more or less temporary, and will get refined in future PRs touching the subject. These will include changes to axes, labels, title and text glyphs.

@mattpap one of the images at least seems to have an issue?

one of the images at least seems to have an issue?

It's fixed now.

Test failure is unrelated and reported in issue #14128. I'm going ahead and merge this. There is still a lot of temporary stuff in this PR or stuff that require generalization, that when refined in hopefully in smaller PRs, will be easier for reviewers to digest.

I see that this has been merged and I have only given it a cursory look so far.

I was asked to check this work in Safari specifically. So I built the js and the docs with this PR applied and the first plot that I opened (transform markers) I noticed a pretty big difference between Chrome versus Safari.

Chrome:

Safari:

@gabalafou, I can reproduce this in epiphany (webkit on Linux). Can you start an issue for this? Although I can reproduce the issue, that browser is insufferable and I can't inspect or debug anything in it at this point at least.

I've started an issue here: #14134

I added the plat: safari and type: bug labels but I'm not entirely sure how to title and label this issue.

Thanks.

I added the plat: safari and type: bug labels but I'm not entirely sure how to title and label this issue.

That's a good start.