Bug 166015 Refactor designer actions to eclipse command framework
Eclipse command framework provide a more explicit way to manage UI actions contributions, we can take it's advantage to make our actions code more clean and maintainable.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dnd/InsertInLayoutUtil.java
EditPart dropPart )
	{
		if ( dropPart.getParent( ) == null )
		{
			return false;
		}
		Object container = dropPart.getParent( ).getModel( );
		return ( container instanceof GridHandle
				|| container instanceof TableHandle
				|| container instanceof FreeFormHandle
				|| container instanceof ListHandle || dropPart.getModel( ) instanceof ModuleHandle );
	}
	/**
	 * Validates container of drop target from data set column in data view
	 * 
	 * @param dropPart
	 * @return validate result
	 */
	protected static boolean handleValidateDataSetColumnDropContainer(
			EditPart dropPart )
	{
		if ( dropPart.getParent( ) == null )
		{
			return false;
		}
		Object container = dropPart.getParent( ).getModel( );
		return ( container instanceof GridHandle
				|| container instanceof TableHandle
				|| container instanceof FreeFormHandle
				|| container instanceof ListHandle