Chart Tooltip on Mobile Browsers Doesn't Disappear

[wkatbey]

ng2-nvd3 version used: 2.0.0

Browser and OS used: Safari Mobile / Chrome Mobile, IOS

I’ve encountered a slight tooltip bug on mobile devices, primarily IOS (using an iPad Air), where if a tooltip appears for a particular chart, the tooltip never disappears, and as I scroll throughout the page, the tooltip stays in that same fixed position. The tooltip doesn't disappear unless I click on a chart that displays another tooltip. The tooltip only disappears upon page refresh.

A good reference would be the charts at http://nvd3.org, where the same issue occurs on mobile devices.