public IAction Undo()
{
if (undoStack.Count() > 0)
{
IUndoableAction action = null;
while (undoStack.Count > 0)
{
action = undoStack.Last();
Logger.Log(LOGKEY, "undo action: " + action.ToString());
if (BeforePerformAction != null)
{
var arg = new ActionEventArgs(action, ActionBehavior.Undo);
BeforePerformAction(this, new ActionEventArgs(action, ActionBehavior.Undo));
if (arg.Cancel) break;
}
undoStack.Remove(action);
action.Undo();
redoStack.Push(action);
if (AfterPerformAction != null) AfterPerformAction(this, new ActionEventArgs(action, ActionBehavior.Undo));
if (!(action is ISerialUndoAction)) break;
}
return action;
}
return null;
}
/*
* isCanUndo attribute specifies whether the action can be undo.
* sometimes an action doesn't need undo even it's a IUndoable action.
* the action will not be pushed in undo stack after performed immediately.
*/
private void Do(IAction action, bool perform, bool isCanUndo)
{
Logger.Log(LOGKEY, string.Format("{0} action: {1}[{2}]", perform ? "do" : "add", action.GetType().Name, action.GetName()));
if (BeforePerformAction != null)
{
var arg = new ActionEventArgs(action, ActionBehavior.Do);
BeforePerformAction(this, arg);
if (arg.Cancel) return;
}
if (perform) action.Do();
if (action is IUndoableAction && isCanUndo)
{
redoStack.Clear();
undoStack.Add(action as IUndoableAction);
if(undoStack.Count() > capacity)
{
undoStack.RemoveRange(0, undoStack.Count() - capacity);
Logger.Log(LOGKEY, "action stack full. remove " + (capacity - undoStack.Count()) + " action(s).");
}
}
if (AfterPerformAction != null) AfterPerformAction(this, new ActionEventArgs(action, ActionBehavior.Do));
}
public IAction Redo()
{
if (redoStack.Count > 0)
{
IUndoableAction action = null;
while (redoStack.Count > 0)
{
action = redoStack.Pop();
Logger.Log(LOGKEY, "redo action: " + action.ToString());
if (BeforePerformAction != null)
{
var arg = new ActionEventArgs(action, ActionBehavior.Redo);
BeforePerformAction(this, arg);
if (arg.Cancel) break;
}
action.Do();
undoStack.Add(action);
if (AfterPerformAction != null) AfterPerformAction(this, new ActionEventArgs(action, ActionBehavior.Redo));
if (!(action is ISerialUndoAction)) break;
}
return action;
}
else
return null;
}