[Slider] New Slider components and hook

[mj12albert]

Closes #216
Closes #76
Closes #77

Preview

https://deploy-preview-373--base-ui.netlify.app/base-ui/react-slider/

Major changes

• Thumbs can no longer swap positions/be dragged past each other. The related disableSwap prop has been dropped as well.
• A new Control subcomponent is added to represent the click/touch area of the slider. Previously this was combined with the root, but Slider.Root in the new API is expected to contain the Output element and a label as well
• The rail slot/component previously referred to the full length of the slider. This is now renamed to instead be the Track
• The previous track component referred to the filled portion of the slider "bar". This is now renamed to instead be the Indicator
• The API does not expose the thumb's input element anymore, it's automatically wired to the corresponding thumb (a span by default), and allows for styling the thumb directly with :focus-visible
• The Mark component/slot, and the marks prop will be dropped. Marks will be reintroduced with a new API in [Slider] Support for marks #462
• The step prop defaults to 1 and can no longer be null.
• The ValueLabel slot/component and related features have been dropped. This can be implemented using Tooltip as in this demo
• The restricted values feature will be redesigned, and decoupled from any props related to the visual marks: [Slider] Arbitrarily restrict the possible values of the slider #412
• The isRtl prop is replaced with direction: 'ltr' | 'rtl' for consistency
• A new minStepsBetweenValues prop (default 0) is added to prevent thumb overlap
• The scale prop is deprecated

Summary

• All relevant tests from material-ui have been ported over, a few new ones were added
• The render prop for the Thumb component is a special case that does not use standard utils, because we need to render a "hidden" <input> element. As a function it provides an additional inputProps argument, and it also supports the shorthand syntax. Documented here.
• On the final location of the input - it's kept as a child of the thumb (for now) because we could solve [Slider] Issues with adding focus-visible styles to the thumb slot #77 without actually having to move the input

Demos

The first 4 are also in the docs

• Basic/Range: https://deploy-preview-373--base-ui.netlify.app/experiments/slider/
• With DIY <label> & aria-labelledby: https://deploy-preview-373--base-ui.netlify.app/experiments/slider/#with-labels
• Vertical: https://deploy-preview-373--base-ui.netlify.app/experiments/slider/#vertical
• RTL: https://deploy-preview-373--base-ui.netlify.app/experiments/slider/#rtl
• Old landing page temperature slider with new API: https://deploy-preview-373--base-ui.netlify.app/experiments/slider-marks/
• Joy Design slider that integrates Slider and Tooltip: https://deploy-preview-373--base-ui.netlify.app/experiments/slider-tooltip

[mui-bot]

Netlify deploy preview

https://deploy-preview-373--base-ui.netlify.app/

Generated by 🚫 dangerJS against 37059b8

[colmtuite]

@mj12albert

• When you focus a single thumb slider, VO announces “[label], group, [value], group”. I think it should announce “[label], slider, [value], group” or “[value], [label], slider, [label], group”?
• In a range slider, when you move focus from the first thumb to the second thumb, VO announces “end range, [value], group”. I think it should announce “[value], end range, slider”.
• What is the scale prop on Root?

[mj12albert]

In a range slider, when you move focus from the first thumb to the second thumb, VO announces “end range, [value], group”. I think it should announce “[value], end range, slider”.

I've updated this so it announces "value" before "start/end range", it's announcing correctly as "slider" for me and not group though, I think this is just a VO quirk:

range.mov

When you focus a single thumb slider, VO announces “[label], group, [value], group”. I think it should announce “[label], slider, [value], group” or “[value], [label], slider, [label], group”?

You mean when VO focuses on the Root and not the Thumb right? I don't think it's possible to get it to announce "slider" unless it explicitly has the slider role (which is obviously incorrect). It also doesn't announce "group" like that for me, it could also be a VO issue:

single.mov

What is the scale prop on Root?

The scale prop enables a non-linear scale (a feature from Material UI): https://mui.com/material-ui/react-slider/#non-linear-scale
We could add a demo for this, unless you want to get rid of it? (Or are you just asking)

@colmtuite

[colmtuite]

@mj12albert Ok on the a11y stuff 👍

On scale, I was just asking what it was. I read the MUI docs just now and still not sure what it does? 😅

[michaldudak]

tabIndex seems unused

[mj12albert]

@michaldudak tabIndex in the return value here gets put into context and is used by the Thumb like this:

base-ui/packages/mui-base/src/Slider/Root/SliderRoot.test.tsx

Lines 1587 to 1590 in 55a30f7

	it('can be removed from the tab sequence', () => {
	render(<TestSlider tabIndex={-1} value={30} />);
	expect(screen.getByRole('slider')).to.have.property('tabIndex', -1);
	});

I suppose it could be passed straight from the SliderRoot component into the context without going through the hook, what do you think?

[michaldudak]

Yup, if it's not used by the hook, it shouldn't go there.

[michaldudak]

Is there any specific reason this is returned by the hook and not defined as a static function that takes two parameters to compare?

[mj12albert]

@michaldudak The 2nd parameter (the "old" value to be compared against) would be the internal valueState which is internal to useSliderRoot, I opted to pass this function through the hook instead of passing valueState as it seemed messier to pass 3 "values" through the hook - values, percentageValues, and valueState

[michaldudak]

It should be possible anyway with the standard useComponentRenderer, right?
render={(props) => <CustomThumb {...props}><SomeOtherComponent />{props.children}</SomeOtherComponent></CustomThumb>}.
I suppose it would just require some changes to the short form of the render prop (render={<CustomThumb><SomeOtherComponent /></CustomThumb}), to merge the children with internal children.

[mj12albert]

I read the MUI docs just now and still not sure what it does? 😅

Not sure if I can explain it better than the docs but let me try 😓 :

First set up a slider like this: (omitted subcomponents for simplicity)

<Slider.Root min={5} step={1} max={10} defaultValue={5} />

The possible values are: 5, 6, 7, 8,9, 10

Now we add the scale prop, which is a function that can transform the slider value.

<Slider.Root min={5} step={1} max={10} defaultValue={5} scale={(value) => 2 ** value } />

So now the default value of 5 will become 2^5 = 32
And the possible values of the slider become 2^5, 2^6, 2^7... 2^10 instead, for example to make a slider that lets you pick values among: 32kb, 64kb, 128kb, 256kb, 512kb like the Material UI demo

Does this make sense? Maybe it's the name scale that is unclear 🤔 @colmtuite

[colmtuite]

@mj12albert I understand now, thanks for explaining. Let's remove this functionality+prop for now.

[mj12albert]

@mj12albert I understand now, thanks for explaining. Let's remove this functionality+prop for now.

OK I've removed it

[oliviertassinari]

We might want to change the naming convention in the codebase for this, but for now since it's one of the only variations we have in the codebase, it's simpler to stick to it (it's simpler to do a mass codebase update all at once if we want to change this).

Suggested change

	const { children, ...rest } = props;
	const { children, ...other } = props;

Done in 89821a4

(I found this variation from reading the docs in MUI X Charts initially, I then did a quick search in VS Code where my environment has all the codebase of the organization in the VS Code workspace, to see the codebase patterns, and I found this in Base UI too).