public void BeginSession()
{
if (CurrentSession != null)
throw new InvalidOperationException("A session is still in progress. End the active session before beginning a new session.");
CurrentSession = new HistorySession();
}
public void EndSession()
{
if (CurrentSession != null)
{
CurrentSession.Close();
_RedoSessions.Clear();
_UndoSessions.Add(CurrentSession);
while (_UndoSessions.Count > MaxSessionCount)
_UndoSessions.RemoveAt(0);
CurrentSession = null;
}
}
public void Redo()
{
if (_RedoSessions.Count == 0)
return;
var lastSession = _RedoSessions.Pop();
var undoSession = new HistorySession();
_UndoSessions.Add(undoSession);
while (lastSession.Entries.Count > 0)
{
var currentEntry = lastSession.Entries.Pop();
if (currentEntry.Action == HistoryAction.PropertiesChanged)
{
var entity = EntityService.Instance.GetEntity(currentEntry.ChangedEntityId);
if (entity != null)
{
undoSession.SaveOldPropertyValues(entity.EntityId, entity.GetPropertyValues());
entity.SetPropertyValues(currentEntry.ChangedPropertyValues);
}
}
else if (currentEntry.Action == HistoryAction.EntityDeleted)
{
EntityService.Instance.ReInsert(currentEntry.DeletedEntity, undoSession);
}
else if (currentEntry.Action == HistoryAction.EntityInserted)
{
EntityService.Instance.ReInsert(currentEntry.InsertedEntity, undoSession);
}
}
undoSession.Close();
}