Incubator-echarts: Legend scroll using mouse wheel

[jarben]

Version: 4.0.4

Would be great if legend can be scrolled using mouse wheel:)

[ghost]

+1. Same for the dataZoom slider.

[guylando]

Also legend scroll on mobile using swipe would be great

[pedroviniv]

I think this would be a great improvement too, mainly for using in a mobile device with a larger dataset. But since the legends is rendered using canvas, I think implement it wouldn't be so easy as it appears. As a workaround it could be implemented a feature where the legend is rendered as a SVG rather a canvas. Then, in the chart option we'd set the legend type as 'plain', define a max width (static or inherited from parent) and then, with css, use overflow-x: scroll.