Pie chart wedge itemRollOver

Question

I need help with creating a custom pie chart class that will allow a function call on pie wedge rollOver.
Right now I can get a function call on rollover using itemRollOver using;
import mx.charts.events.ChartItemEvent;
-in the <mx:PieChart>;
itemRollOver="pieChart_itemRoll(event);"
-which calls this function
private function pieChart_itemRoll(evt:ChartItemEvent):void {
                var psi:PieSeriesItem = evt.hitData.chartItem as PieSeriesItem;
                trace(psi.item.target);
Please advise on how can I put this into a custom PieChart .as that extends PieChart?
Currently itemRollOver in my custom class throws an undefined property error.
Thanks.

Answer 1

OK, now I get it. So you would need to place your two PieCharts in a s:Group or mx:Canvas. On top of the pie charts, lay another s:Group on which you will do some drawing on its graphics:Graphics object.
In your case, you need to use dataToLocal() (will give you pixel coordinates in your chart) then localToGlobal()  (convert to Application coordinates) then globalToLocal() (convert to the Top Group or Canvas coordinates you want to draw in) :
Using the dataToLocal() method
The dataToLocal() method converts a set of values to x  and y coordinates on the screen. The values you give the method are in  the "data space" of the chart; this method converts these values to  coordinates. The data space is the collection of all possible combinations of data values that a chart can represent.
The number and meaning of arguments passed to the dataToLocal() method depend on the chart type. For CartesianChart controls, such as the BarChart and ColumnChart controls, the first value is used to map along the x axis, and the second value is used to map along the y axis.
For PolarChart controls, such as the PieChart control, the first value maps to the angle around the center of the  chart, and the second value maps to the distance from the center of the  chart along the radius.
The coordinates returned are based on 0,0  being the upper-left corner of the chart. For a ColumnChart control, for  example, the height of the column is inversely related to the x  coordinate that is returned.
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/DisplayOb ject.html#localToGlobal%28%29
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/DisplayOb ject.html#globalToLocal%28%29