protected override UndoToken Redo(object parameter, bool creatingActionItem)
{
UndoToken token;
var viewModelNode = nodePath.GetNode();
if (viewModelNode == null)
{
throw new InvalidOperationException("Unable to retrieve the node on which to apply the redo operation.");
}
var newValue = nodeCommand.Invoke(viewModelNode.Content.Value, viewModelNode.Content.Descriptor, parameter, out token);
Refresh(viewModelNode, newValue);
return(token);
}
/// <inheritdoc/>
protected override void UndoAction()
{
var node = nodePath.GetNode();
if (node == null)
{
throw new InvalidOperationException("Unable to retrieve the node to modify in this undo process.");
}
var currentValue = GetValue(node, index);
bool setByObservableNode = false;
var observableViewModel = service.ViewModelProvider != null?service.ViewModelProvider(identifier) : null;
if (observableViewModel != null && !observableViewModel.MatchRootNode(nodePath.RootNode))
{
observableViewModel = null;
}
if (observableViewModel != null)
{
SingleObservableNode observableNode = observableViewModel.ResolveObservableModelNode(observableNodePath, nodePath.RootNode);
if (observableNode != null)
{
observableNode.Value = previousValue;
setByObservableNode = true;
}
}
if (!setByObservableNode)
{
SetValue(node, index, previousValue);
// Update the view model nodes in case the graph of the object is modified by this value change
modelContainer.UpdateReferences(node);
}
previousValue = currentValue;
}
