Bug 134949 Themes nest in other library
Details: Themes nest in other library Step: 1. Library A use LibraryB, and Library B has a themes 2. Report design use Library A 3. I open the Library tree of A in library explorer and drop the themes from B into layout. Actual result: It pop up an error message and said that the library namespace "B" exists already. Exception result: I don't konw if I can use by this method. But I think it is a method user may be used.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/views/attributes/providers/ChoiceSetFactory.java
{
		IElementPropertyDefn propertyDefn = DesignEngine.getMetaDataDictionary( )
				.getElement( elementName )
				.getProperty( property );
		if ( propertyDefn.getTypeCode( ) == IPropertyType.DIMENSION_TYPE )
		{
			return propertyDefn.getAllowedChoices( );
		}
		return null;
	}
	/**
	 * Gets the collection that given structure property value can selected from
	 * them.
	 * 
	 * @param elementName
	 *            The name of the element.
	 * @param property
	 *            DE Property key.
	 * @return The ChoiceSet instance contains all the allowed values.
	 */
	public static IChoiceSet getStructChoiceSet( String structName,
			String property )
	{
		IPropertyDefn propertyDefn = DesignEngine.getMetaDataDictionary( )
				.getStructure( structName )
				.findProperty( property );
		return propertyDefn.getChoices( );
	}
	/**
	 * Gets all displayNames that a given ChoiceSet instance contained.