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.engine/src/org/eclipse/birt/chart/model/attribute/util/AttributeValidator.java
Map context )
	{
		boolean result = validateRGBValue_Min( rgbValue, diagnostics, context );
		if ( result || diagnostics != null )
			result &= validateRGBValue_Max( rgbValue, diagnostics, context );
		return result;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 * @see #validateRGBValue_Min
	 */
	public static final int RGB_VALUE__MIN__VALUE = 0;
	/**
	 * Validates the Min constraint of '<em>RGB Value</em>'. <!--
	 * begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @generated
	 */
	public boolean validateRGBValue_Min( int rgbValue,
			DiagnosticChain diagnostics, Map context )
	{
		boolean result = rgbValue >= RGB_VALUE__MIN__VALUE;
		if ( !result && diagnostics != null )
			reportMinViolation( AttributePackage.eINSTANCE.getRGBValue( ),
					new Integer( rgbValue ),
					new Integer( RGB_VALUE__MIN__VALUE ),
					true,
					diagnostics,
					context );