[Slider] Implement variant prop

[david-ic3]

Material-UI : v5.0.0-beta.0 with Typescript

It's possible to add variants to Buttons as described in your documentation here.

Can't get this work with the Slider (compile error as variants is not a Slider prop).

Is this expected ?

[mnajdova]

The Slider component does not support the variant prop. This makes me think of a discussion we had when adding the theme.variants for allowing developers to extend the props.

Regarding the Slider, you may extend the color or size property. Can you please share what is the use-case you have in mind?

[david-ic3]

To have an overview of our application. It's dashboard editor, same concept as invision or photoshop. So we have a theme for the editor and one for the content (dashboard). We already have two different Themes with their variants but a single Theme type mapping. On top of that users can add new themes with their own variants dynamically.

We allow users to define variants for each of our components (some of them are MUI ones). We are using MUI Theme. Somehow we want to be able to extend Slider the same way we can do with Buttons. Defining for example the pretto.fr customization as a variant ( https://next.material-ui.com/components/slider/#customized-sliders ).

At run time we get the list of variants for each component.

Does it makes sense to have different slider variants in an 'application' ? I would say no, but eventually customers will decide if they want or not to use this flexibility.

It's a problem of consistency , nothing really important for us as what we are doing now is styling ( using styled ) Slider's parent div to allow variants (we could style directly Slider as well).

   const StyledSlider = styled('div',  ....

[paales]

@mnajdova Due to this line https://github.com/mui-org/material-ui/blob/v5.2.7/packages/mui-material/src/Slider/Slider.js#L657 it seems it isn't possible to actually possible to create a new size size

[mnajdova]

@paales looks like it wasn't updated as it is done with the other components, for example, the Button We also need to update the types for the props. Would you like to create a PR for this?