private void ProduceHistoryNodes(List <ITransition> transitions)
{
var newNode = new HistoryTreeNode
{
Label = GetLabelForNode(transitions),
Parent = _currentNode,
Transitions = transitions
};
_currentNode.Children.Add(newNode);
_currentNode = newNode;
}
public void Init()
{
if (_initialized)
{
throw new InvalidOperationException("Already initialized.");
}
CreateNewCurrentTransaction();
_rootNode = new HistoryTreeNode {
Label = "Initial state"
};
_currentNode = _rootNode;
_initialized = true;
}
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();
}