A "GraphAction" event is delivered when a mouse click event occurs on
a Graph's data-element. A GraphActionEvent object is sent as an argument
to the GraphActionListener's "actionUpdate" method.
GraphActionEvent objects will contain all the data associated with the subject
data-element in the form of an instance of a PickInfo class.
"Data-elements" are those chart graphics depicting the values found in
the data model. For example the bars in the BarChart are data-elements but
the axis, legend, titles, footnotes, etc. are not.
Usage
Use the PickInfo property to retrieve the associated data.