When using the AreaSeries, the SeriesItemOverEvent has the wrong index and item properties.
The SeriesItemOverEvent index property has the same value for an entire YField in the AreaSeries, and does not account for the intervals in the TimeAxis. This makes it useless for determining what item to use for the tooltip. In fact, the values of the index range from 0 to 1 less than the total YFields in the AreaSeries. The index is always 0 for the first YField, always 1 for the second Yfield, always 2 for the third YField, and so on.
Likewise, the SeriesItemOverEvent item property has the same problem. The item is always the first item in the ListStore for the first YField, always the second item in the ListStore for the second YField, always the third item in the ListStore for the third YField, and so on. This makes event item useless for tooltip purposes where you want to include the date corresponding to the TimeAxis interval as well as one or more values from the item.
We are using a SeriesItemOverHandler so that we can use SafeHtml for the tooltip as the tooltip content needs to support multiple line breaks and custom formatting.
Occurs in when deployed to Tomcat (web mode), and when running under Eclipse (dev mode).
Steps to Reproduce
The attached file (ColumnChartAreaSeriesToolTipIssue.txt) can be used to demonstrate the problem. After launching the chart, just mouse over the area series and you will see the tooltip issues described above. The attached screen shot (ColumnChartAreaSeriesToolTipIssue.png) show an example of the problem as well.
The attached file (ColumnChartAreaSeriesToolTipIssueFixed.txt) contains a crude workaround to address this problem (see lines 146 through 158 and 183 through 214). After launching this fixed chart, just mouse over the area series and you will see the tooltips working properly. The attached screen shot (ColumnChartAreaSeriesToolTipIssueFixed.png) show an example of the fix as well.
Please let me know if I am doing anything wrong in the code in the attached file or if there is a work around.