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.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/ChartReportItemBuilderImpl.java
| SWT.RESIZE | SWT.APPLICATION_MODAL );
				ChartUIUtil.bindHelp( shell,
						ChartHelpContextIds.DIALOG_EXPRESSION_BUILDER );
				eb = new ExpressionBuilder( shell, value );
				ExpressionProvider ep = new ChartExpressionProvider( (ExtendedItemHandle) context,
						getExpressionBuilderStyle( command ) );
				eb.setExpressionProvier( ep );
				if ( sTitle != null )
				{
					eb.setDialogTitle( eb.getDialogTitle( ) + " - " + sTitle ); 
				}
				if ( eb.open( ) == Window.OK )
				{
					value = eb.getResult( );
				}
		}
		return value;
	}
	public boolean isInvokingSupported( )
	{
		return true;
	}
	
	public boolean isEclipseModeSupported( )
	{
		return true;
	}
	
	/**
	 * Returns the categories list in BIRT chart expression builder