protected override UndoToken Redo(object parameter, bool creatingActionItem)
{
UndoToken token;
object index;
var modelNode = NodePath.GetSourceNode(out index);
if (modelNode == null)
{
throw new InvalidOperationException("Unable to retrieve the node on which to apply the redo operation.");
}
var currentValue = modelNode.GetValue(index);
var newValue = NodeCommand.Invoke(currentValue, parameter, out token);
modelNode.SetValue(newValue, index);
Refresh(modelNode, index);
var additionalToken = new UndoToken();
if (AdditionalCommand != null)
{
additionalToken = AdditionalCommand.ExecuteCommand(null, false);
}
return(new UndoToken(token.CanUndo, new ModelNodeToken(token, additionalToken)));
}
/// <inheritdoc/>
protected override void UndoAction()
{
object pathIndex;
var node = NodePath.GetSourceNode(out pathIndex);
if (node == null)
{
throw new InvalidOperationException("Unable to retrieve the node to modify in this undo process.");
}
var currentValue = node.GetValue(Index);
bool setByObservableNode = false;
var observableNode = service.ResolveObservableNode(identifier, ObservableNodePath) as SingleObservableNode;
if (observableNode != null)
{
observableNode.Value = PreviousValue;
setByObservableNode = true;
}
if (!setByObservableNode)
{
node.SetValue(PreviousValue, Index);
}
PreviousValue = currentValue;
}