public static TranScope CreateNewTransactionScope()
{
var microCommandProvider = new MicroCommandTransitionProvider();
var tranScope = new TranScope(microCommandProvider);
tranScope.Helper = new MicroCommandHelper(microCommandProvider);
return(tranScope);
}
public void Redo(int historyIndex)
{
if (!CanRedo())
{
throw new InvalidOperationException("Cannot redo!");
}
var curTran = _currentTransaction;
_currentTransaction = null; // no transaction at moment of redo
DestroyTransaction(curTran);
var nextNode = _currentNode.Children[historyIndex];
foreach (var oneTransition in nextNode.Transitions)
{
oneTransition.ExecuteForward();
}
_currentNode = nextNode;
CreateNewCurrentTransaction();
}
public void Undo()
{
if (!CanUndo())
{
throw new InvalidOperationException("Cannot undo!");
}
var curTran = _currentTransaction;
_currentTransaction = null; // no transaction at moment of undo
DestroyTransaction(curTran);
var transitions = _currentNode.Transitions;
for (int i = transitions.Count - 1; i >= 0; i--)
{
var oneTransition = transitions[i];
oneTransition.ExecuteBackward();
}
_currentNode = _currentNode.Parent;
CreateNewCurrentTransaction();
}
private void DestroyTransaction(TranScope tran)
{
tran.TransactionCompleted -= TransactionCompleted;
tran.Dispose();
}
private void CreateNewCurrentTransaction()
{
_currentTransaction = TransationFactory.CreateNewTransactionScope();
_currentTransaction.TransactionCompleted += TransactionCompleted;
}