Allow tabIndex to be set explicitly on Handle

[gvincentlh]

Basic implementation of tabIndex prop on the Handle component. Both Slider.js and Range.js also implement tabIndex, but in both cases it's simply passed through to the Handle. I've also updated the test suite with some simple checks to make sure tabIndex gets set properly on Handle from its parent. I've updated the README doc as well.

The default value for tabIndex is preserved (it's still "0"), so this change should not break any existing uses.

This is a fix for #353

cc: @paranoidjk

[coveralls]

Coverage remained the same at 72.941% when pulling be3d775 on gvincentlh:gvincentlh/add-tabindex-prop into db32618 on react-component:master.

[gvincentlh]

Thanks @paranoidjk and @yesmeck ! When can we expect a new release?

[gvincentlh]

@paranoidjk @yesmeck could we get another release with that change in it please?

[yesmeck]

Released [email protected]

[gvincentlh]

Thanks!

[gvincentlh]

@yesmeck I'm not seeing my changes reflected in the 8.6.0 dist files. Were they regenerated?

[yesmeck]

Yes, search tabIndex || 0 in this file https://unpkg.com/[email protected]/dist/rc-slider.js

[Shardendu-kantha]

I updated to 8.6.0 version, but passing tabIndex={-1} is still not setting tabindex=-1 for handles for Range.

<Range value={[minPrice, maxPrice]} min={this.minPriceRange} max={this.maxPriceRange} onChange={this._onPriceChange} onAfterChange={this._onPriceAfterChange} step={null} marks={this.state.priceSliderMarksObj} tabIndex={-1} />

[Robin-front]

@Shardendu-kantha
<Range> expect an array for tabIndex prop. Different from <Slider>

slider/src/Range.jsx

Line 23 in 7a021d4

tabIndex: PropTypes.arrayOf(PropTypes.number),

[Shardendu-kantha]

@Robin-front thank you so much. Got the solution. cheers