internal override OperationResult UndoOperation()
{
/*
* forbid undo in those cases where elements couldn't be ordered
* in an ordering that would allow to put them back in the diagram
* safely
*/
if (CheckOrdering && !safeOrdering)
{
return(OperationResult.Failed);
}
foreach (Element element in DeletedElements)
{
if (IsInDiagram(element))
{
ErrorDescription = CommandError.CMDERR_REMOVED_ELEMENT_BEING_USED;
return(OperationResult.Failed);
}
}
foreach (Element element in _deletionOrder.Reverse())
{
if (DeletedElements.Contains(element))
{
element.PutMeBackToModel();
Diagram.AddModelElement(element, DeletedElementsViewHelpers[element]);
}
}
return(OperationResult.OK);
}
internal override void CommandOperation()
{
IList <Element> _deleted;
// try to order elements
if (PSMTree.ReturnElementsInPSMOrder(DeletedElements, out _deleted, true))
{
safeOrdering = true;
_deletionOrder = _deleted.Reverse();
}
else
{
// this will forbid undo
safeOrdering = false;
_deletionOrder = DeletedElements;
}
foreach (Element element in _deletionOrder)
{
if (DeletedElements.Contains(element))
{
DeletedElementsViewHelpers[element] = Diagram.DiagramElements[element];
element.RemoveMeFromModel();
Diagram.RemoveModelElement(element);
}
//AssociatedElements.Add(element);
}
}
