public bool DoOperation(CustomOperation operation)
{
if (operation == null)
{
return(false);
}
bool result;
if (!operation.Redo())
{
Rollback();
result = false;
}
else
{
// cut off redo-items
int index = fCurrentIndex + 1;
if (index < fList.Count)
{
fList.RemoveRange(index, fList.Count - index);
}
// add new operation
IntPush(operation);
result = true;
}
return(result);
}
public void Rollback()
{
while (IntPeek() != TRANS_DELIMITER)
{
CustomOperation cmd = fList[fCurrentIndex];
fCurrentIndex--;
cmd.Undo();
}
Transaction(TransactionType.taRollback);
}
public void Undo()
{
if (fCurrentIndex >= 1)
{
if (IntPeek() == TRANS_DELIMITER)
{
fCurrentIndex--;
}
while (IntPeek() != TRANS_DELIMITER)
{
CustomOperation cmd = fList[fCurrentIndex];
fCurrentIndex--;
cmd.Undo();
}
Transaction(TransactionType.taCommitUndo);
}
}
public void Redo()
{
if (fCurrentIndex < fList.Count - 1)
{
if (fList[fCurrentIndex] == TRANS_DELIMITER)
{
fCurrentIndex++;
}
while (IntPeek() != TRANS_DELIMITER)
{
CustomOperation cmd = fList[fCurrentIndex];
fCurrentIndex++;
if (!cmd.Redo())
{
Rollback();
return;
}
}
Transaction(TransactionType.taCommitRedo);
}
}
private void IntPush(CustomOperation op)
{
fList.Add(op);
fCurrentIndex++;
}
