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 true if this is a style element, false otherwise.
	 */
	public boolean isStyle( )
	{
		return false;
	}
	/**
	 * Gets a property value given its internal name. This version checks only
	 * this one object. That is, it gets the "local" property value. The
	 * property name must also be valid for this object. The name can be a
	 * built-in property name, or a user-defined property name. The value is set
	 * without checking the name for validity.
	 * <p>
	 * Part of: Property value system.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            name of the property to set. Must be valid. Can be a
	 *            system-defined or user-defined property name.
	 * @return the property value, or null if no value is set
	 */
	public Object getLocalProperty( Module module, String propName )
	{
		ElementPropertyDefn prop = getPropertyDefn( propName );
		if ( prop == null )
			return null;
		return getLocalProperty( module, prop );
	}