As illustrated in the Charts demo app, crosshairs can be displayed on a chart, but they are a property of the Tooltip and are only drawn intersecting with the nearest data point. For the chart I am currently implementing, it would be nice to have the crosshair follow the mouse pointer independently rather than “sticking” to data points, as my users might be interested in the axis values between the points. I came across the following post about doing this in Highcharts:
http://highcharts.uservoice.com/forums/55896-general/suggestions/2716975-crosshair
Is this something that might end up being implemented in the Vaadin Charts API?