Listing 1: LBWE class definition

// ListBoxWithExtras.h 

#ifndef LISTBOXWITHEXTRAS_H
#define LISTBOXWITHEXTRAS_H

// stop some useless STL verbosity
#pragma warning (disable : 4146 4018)

#include <new.h>
#include <fstream.h>
namespace std {
#include <stack.h>
#include <deque.h>
}

#include "EditBox.h"
#include "LbweRep.h"

//This next structure will hold the list box previous states
//so they can be undone.  Since we are going to add these
//objects themselves to an STL container, we MUST define
//a constructor.  

enum Action {DELETE_STRING, EDIT_STRING, INSERT_STRING};

struct ListBoxState
{
    ListBoxState() {}
    int positionLBS;
    CString valueLBS;
    Action actionLBS;
    CWnd* boxInFocus;
};

class ListBoxWithExtras : public CListBox
{
public:
    ListBoxWithExtras();
    ~ListBoxWithExtras();

//Now come extensions to the CListBox control
    void EditEntry();
    void InsertEntry();
    void DeleteEntry();
    void AppendEntry();
    void Undo();        //Undoes last change
    void ResetUndo();   //Clears the Undo Buffer
    void SortList();    //Useless for sorted box

//Data transfer available via lbweBuffer
    LbweRep lbweBuffer;

    // ClassWizard generated virtual function overrides
    //{{AFX_VIRTUAL(ListBoxWithExtras)
    protected:
    virtual LRESULT DefWindowProc(UINT message, WPARAM wParam,
                                  LPARAM lParam);
    //}}AFX_VIRTUAL

protected:
    //{{AFX_MSG(ListBoxWithExtras)
    afx_msg void OnDblclk();
    afx_msg void OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags);
    afx_msg void OnParentNotify(UINT message, LPARAM lParam);
    afx_msg void OnChar(UINT nChar, UINT nRepCnt, UINT nFlags);
    //}}AFX_MSG
    DECLARE_MESSAGE_MAP()

private:
    EditBox* pEditBox;  
    BOOL IsSortedBox();
    void CrankUpTheEdit(int position, Action action);
    std::stack<std::deque<ListBoxState> > undoStack;
    ListBoxState currentState;
    BOOL lbweInitialized;

    //next private structure is for a "function object"
    //for std::sort()
    //MFC less than for CStrings isn't understood by STL.
    
    struct CompareCStrings {
        operator() (const CString& a, const CString& b)
            {return a < b;}
    };
};

#endif
// End of File