Bug 182076 Delete a style from a report item doesn't affect report xml source
Steps to reproduce: 1.Insert a label onto layout; 2.New a style, suppose named it "NewStyle"; 3.Right click the label and on the drop down list, choose Style->Apply Style->NewStyle; 4.Save the report design; 5.Right click the label and on the drop down list, choose Style->Delete Style->NewStyle; 6.Save the report design; Expected result: NewStyle is deleted from report design, and the label doesn't have the style property. Actual result: Switch to report xml source, a error mark indicate that the label still has a style property:<property name="style">NewStyle</property>
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/core/commands/DeleteCommand.java
return false;
		}
		else if ( source instanceof ReportElementHandle )
		{
			return ( (ReportElementHandle) source ).canDrop( );
		}
		else if ( source instanceof CssStyleSheetHandle )
		{
			DesignElementHandle elementHandle = ((CssStyleSheetHandle)source).getContainerHandle( );
			if(elementHandle instanceof ReportDesignHandle)
			{
				return ((ReportDesignHandle)elementHandle).canDropCssStyleSheet( (CssStyleSheetHandle )source);
			}else
			if(elementHandle instanceof ThemeHandle)
			{
				return ((ThemeHandle)elementHandle).canDropCssStyleSheet( (CssStyleSheetHandle )source);
			}else
			{
				return false;
			}
			
		}
		else
			return false;
		
		
		
		
	}
}