Bug 198031 Legend interactivity does not work correctly for drill-throughs
Under Value (Y) Series enable interactivity for the event "Mouse Click" Set action to Hyperlink The type of the hyperlink is Drill-through and the target is the a sub-report Pass parameter to sub-report as row["value_of_the_legend_item"] Suppose there are 3 values, x,y and z No matter which legend item you click (x, y or z), z gets passed as param to the subreport
chart/org.eclipse.birt.chart.ui/src/org/eclipse/birt/chart/ui/swt/interfaces/IUIServiceProvider.java
String sTitle ) throws ChartException;
	
	/**
	 * Returns whether all outside builder invokings are supported
	 * @since 2.1
	 */
	public boolean isInvokingSupported( );
	/**
	 * This method will be used by the Chart Builder UI to validate the model
	 * and show any error messages before the user leaves the dialog.
	 * 
	 * @param chartModel
	 *            the model to be validated
	 * @param oContext
	 *            the application-specific context associated with the extended
	 *            chart item
	 * @return an array of user-friendly messages indicating problems with the
	 *         model
	 */
	public String[] validate( Chart chartModel, Object oContext );
	/**
	 * Fetches the list of registered keys for externalizing chart content
	 * 
	 * @return List containing available keys for externalized content
	 */
	public List getRegisteredKeys( );
	/**
	 * Fetches the value for the specified key from the properties file
	 * appropriate for the current locale
	 *