需要帮助编写文本编辑器程序的撤消/重做功能 [英] Need Help writing an undo/redo function for text editor program

问题描述

我在C ++中编写了一个文本编辑器程序，它有简单的命令：LEFT，RIGHT，HOME，END，BACKSPACE，DELETE，INSERT，现在我需要执行UNDO和REDO功能。在我的程序中，用户必须能够撤消不超过最后十个命令。我想使用一个向量实现来完成这一点，但我不知道如何设置。我不知道如何将光标位置和字符存储到向量中。有人可以提供一些帮助吗？

I have written a text editor program in C++ that has simple commands: LEFT, RIGHT, HOME, END, BACKSPACE, DELETE, INSERT, and now I need to perform the UNDO and REDO functions. In my program the user must be able to undo no more than the last ten commands. I would like to use a vector implementation to accomplish this, but I have no idea how to set this up. I'm not sure how to store the cursor position and the character into a vector. Can someone offer some help?

#ifndef CURSOR_H

#define CURSOR_H



#include <stdlib.h>
#include <iostream>

template <class Object>
class Cursor;
// Incomplete Declaration

template <class Object>
class CNode
{
        public:

                CNode( const Object & theElement = Object( ), CNode * n = NULL ) : element( theElement ), next( n ) { }
                Object  element;
                CNode *next;
                friend class Cursor<Object>;
};

template <class Object>
class Cursor
{
 public:
  Cursor( );
  bool isEmpty( ) const;
  void makeEmpty( );
  void left ( );
  void right ( );
  void del ( ); //This is the delete operation. I named it del instead of delete as delete conflicts with a C++ keyword.
  void back ( );
  void insert( const Object & x );
  void home ( );
  void end ( );
  void undo ( );


 private:

  void printText ( ) ;

  CNode<Object> *header;
  CNode<Object> *cursorPosition;

};
//#include "Cursor.cpp"
#endif

推荐答案

您要使用 deque ，以便可以从前面或后面添加和删除;当添加命令时，将其添加到后面，当撤消从后面删除它，当你达到11命令从前面删除一个。

You want to use a deque so that you can add and remove from the front or the back; when adding a command, add it to the back, when undoing remove it from the back, and when you reach 11 commands remove one from the front.

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