Branching Undo/Redo Mechanism Based on Variadic Parameter Command Pattern

Abstract

Traditional linear undo/redo mechanism cannot backtrack to some special history nodes. For example, the users undo to a previous state and then submit a new operation. In this case, the undone history node cannot be recovered anymore. To solve this problem, a branching undo/redo mechanism that can retain all the undone history nodes is proposed. Its undo/redo realization based on command pattern is detailed. Besides, a new universal variadic parameter command pattern is proposed to overcome the disadvantages of classic command pattern. The variadic parameter command pattern can be adapt to different command receivers and different receiver actions with different action arguments.