Bug 104986 Backgound image uses an absolute path
Currently Chart uses an absolute path to indicate a backgournd image, that may cause the design unusable on other environments. Expected the background image can be definded in multiple ways like in report designer. e.g. URI(absolute path), File(relative path), Embedded Image(Encoded Image Data).
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/swing/SwingRendererImpl.java
/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.chart.event.IDeviceRenderer#getXServer()
	 */
	public IDisplayServer getDisplayServer( )
	{
		return _ids;
	}
	/**
	 * Returns the triggers associated with current renderer.
	 * 
	 * @return
	 */
	protected Map getTriggers( )
	{
		return _lhmAllTriggers;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.chart.device.IPrimitiveRenderer#applyTransformation(org.eclipse.birt.chart.event.TransformationEvent)
	 */
	public void applyTransformation( TransformationEvent tev )
			throws ChartException
	{
		switch ( tev.getTransform( ) )
		{
			case TransformationEvent.TRANSLATE :
				_g2d.translate( tev.getTranslateX( ), tev.getTranslateY( ) );