Bug 197269 Cant set a series invisible per default
I have a line chart with several value series. I want to have some invisible as the default, so I set the "OnLoad" event for the series to "Toggle Visbility". But the onLoad event is triggered for every segment of the series so the result, wether the line is visible or not, depends on a odd or even number of datapoints. The same happens with "Toggle Datapoint Visibility"
chart/org.eclipse.birt.chart.device.svg/src/org/eclipse/birt/chart/device/svg/SVGInteractiveRenderer.java
|| ( getElementFromSource( sourceObject,
								StructureType.CHART_BLOCK ) != null )
						|| ( getElementFromSource( sourceObject,
								StructureType.PLOT ) != null ) )
				{
					svg_g2d.setDeferStrokColor( null );
					svg_g2d.popParent( );
				}
			}
		}
	}
	/**
	 * Helper function that will determine if the source object is a series
	 * component of the chart.
	 * 
	 * @param src
	 *            StructureSource that is stored in the primitive render event.
	 * @return true if the object or its parent is a series component.
	 */
	private Object getElementFromSource( StructureSource src, StructureType type )
	{
		if ( src instanceof WrappedStructureSource )
		{
			WrappedStructureSource wss = (WrappedStructureSource) src;
			while ( wss != null )
			{
				if ( wss.getType( ) == type )
				{
					return wss.getSource( );
				}