private void OnTransactionStackCompleted(BasicUndoTransaction transaction)
{
Debug.Assert(_openTransactionStack.Count == 0);
ITextUndoTransaction eventArgument = transaction;
var result = TextUndoTransactionCompletionResult.TransactionAdded;
if (_undoStack.Count > 0)
{
var previous = _undoStack.Peek();
if (transaction.MergePolicy != null &&
previous.MergePolicy != null &&
previous.MergePolicy.TestCompatiblePolicy(transaction.MergePolicy) &&
previous.MergePolicy.CanMerge(newerTransaction: transaction, olderTransaction: previous))
{
eventArgument = previous;
previous.MergePolicy.PerformTransactionMerge(existingTransaction: previous, newTransaction: transaction);
}
else
{
_undoStack.Push(transaction);
}
}
else
{
_undoStack.Push(transaction);
}
var list = _undoTransactionCompleted;
if (list != null)
{
list(this, new TextUndoTransactionCompletedEventArgs(eventArgument, result));
}
}
internal void OnTransactionClosed(BasicUndoTransaction transaction, bool didComplete)
{
if (_openTransactionStack.Count == 0 || transaction != _openTransactionStack.Peek())
{
// Happens in dispose after complete / cancel
return;
}
_openTransactionStack.Pop();
if (!didComplete)
{
return;
}
if (_openTransactionStack.Count == 0)
{
OnTransactionStackCompleted(transaction);
}
else
{
var top = _openTransactionStack.Peek();
foreach (var cur in transaction.UndoPrimitives)
{
top.AddUndo(cur);
}
transaction.UndoPrimitives.Clear();
}
}
