/// <summary>
/// Constructor which initializes the manager with up to 8 levels
/// of undo/redo.
/// </summary>
/// <param name="level">the undo level</param>
public UndoManager(int level)
{
undoLevel = level;
undoList = new UndoCollection();
redoStack = new StackBase <CommandInfo>();
// The following events are linked in the sense that when an item
// is popped from the stack it'll be put in the undo collection
// again. So, strictly speaking, you need only two of the four
// events to make the surface aware of the history changes, but
// we'll keep it as is. It depends on your own perception of the
// undo/reo process.
redoStack.OnItemPopped +=
new EventHandler <CollectionEventArgs <CommandInfo> >(
HistoryChanged);
redoStack.OnItemPushed +=
new EventHandler <CollectionEventArgs <CommandInfo> >(
HistoryChanged);
undoList.OnItemAdded +=
new EventHandler <CollectionEventArgs <CommandInfo> >(
HistoryChanged);
undoList.OnItemRemoved +=
new EventHandler <CollectionEventArgs <CommandInfo> >(
HistoryChanged);
}
public bool BeginAction(string actionName = "Many actions")
{
if (!this.UndoingRedoing)
{
this.actionsRecorded = new UndoCollection(actionName);
this.PerformingAction = true;
return true;
}
else
{
return false;
}
}
public void EndAction()
{
if (!this.UndoingRedoing)
{
this.undoStack.Push(this.actionsRecorded);
this.redoStack.Clear();
this.actionsRecorded = null;
this.PerformingAction = false;
}
}