Bug 151959 inappropriate screen operation
steps to reproduce: - create a report - add a grid item (3x3) - switch to Outline view - expand the grid item to see its rows and cells - select the grid item, and drag it into any of its own cell expected behavior: - is it an invalid screen operation? if it is, it should be banned actual behavior: - the grid item was disappeared surprisingly
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
return prop.validateValue( module, value );
		}
		catch ( PropertyValueException e )
		{
			
			e.setElement( this );
			e.setPropertyName( propName );
			throw e;
		}
	}
	/**
	 * Returns the shared style referenced by this element. This method will try
	 * to resolve the style element if the value is un-resolved.
	 * <p>
	 * Part of: Style system.
	 * 
	 * @param module
	 *            module
	 * @return the shared style, or null if this element does not explicitly
	 *         reference a shared style.
	 */
	public StyleElement getStyle( Module module )
	{
		return null;
	}
	/**
	 * Returns the shared style referenced by this element. This method will not
	 * try to resolve the style element if the value is un-resolved.
	 * <p>
	 * Part of: Style system.