Dual thumb mode in <sl-range>

[Kimi-Gao]

What issue are you having?

I found that <sl-range> doesn't support dual thumb mode that will be helpful to me, could you please consider about this feature?

Describe the solution you'd like

looks like:

Describe alternatives you've considered

No

[claviska]

This will require a refactor of <sl-range> since it uses <input type="range"> under the hood. I wouldn't discount it since that would make it easier to support vertical sliders and dual thumbs. It's also not currently possible to style the thumb since that requires vendor-prefixed pseudo selectors on an element buried in the shadow DOM.

Since this is going to be rewritten anyways, might as well add dual thumbs.

[claviska]

One challenge of this is making it work with the Constraint Validation API. Since the current control uses <input type="range"> under the hood, that's trivial. Dual mode means reimplementing the entire control, so we may need to wait for ElementInternals to be fully supported before taking this on.

[msvi]

It would be nice if a rewrite of <sl-range> could support not just two but an arbitrary number of values, similar to the MUI Slider.