Bug 179931 Provide new interface IStyle to let extension return the style properties values
Provide the IStyle interface to let extension user can return the style property value list for their extension elements.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/strategy/ExtendedItemPropSearchStrategy.java
/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.PropertySearchStrategy#getPropertyFromSelfSelector(org.eclipse.birt.report.model.core.Module,
	 *      org.eclipse.birt.report.model.core.DesignElement,
	 *      org.eclipse.birt.report.model.metadata.ElementPropertyDefn)
	 */
	protected Object getPropertyFromSelfSelector( Module module,
			DesignElement element, ElementPropertyDefn prop )
	{
		ExtendedItem extendedItem = (ExtendedItem) element;
		
		
		Object value = getPropertyFromPredefinedStyles( module, extendedItem,
				prop );
		if ( value != null )
			return value;
		
		IElementDefn elementDefn = extendedItem.getExtDefn( );
		if ( elementDefn != null )
		{
			String selector = extendedItem.getExtDefn( ).getSelector( );
			value = getPropertyFromSelector( module, prop, selector );
			if ( value != null )
				return value;
		}
		
		String selector = ( (ElementDefn) extendedItem.getDefaultDefn( ) )
				.getSelector( );
		return getPropertyFromSelector( module, prop, selector );