#ifndef TLessListBoxH

#define TLessListBoxH

//---------------------------------------------------------------------------

#include <SysUtils.hpp>

#include <Classes.hpp>

#include <Controls.hpp>

#include <StdCtrls.hpp>

#include <stdio.h>

#include <vector>

 

//---------------------------------------------------------------------------

 

class PACKAGE TLessListBox : public TCustomListBox

{

public:

    /* operation modes (with a File, with a COM Port) */

    enum mode_t { file_mode, port_mode };

 

private:

    /* default configuration values */

    static const size_t def_wnd_size = 10000;       // specifies a buffer size

    static const size_t def_frontier_size = 1000;   //specifies a frontier size

    static const size_t def_max_line_len = 256;

 

    size_t Fwnd_size;      // specifies a buffer size

    size_t Ffrontier_size; // specifies a frontier of a window

    size_t Fmax_line_len;

 

    int displayed_lines;        // number of lines displaying at the moment

 

    struct buf_t {

        size_t first_line;      // number of the first line of the buffer

        TStringList *pList;

 

        void copyto(buf_t *dest);

    };

 

    buf_t buf1, buf2;   //actual buffers to store wnd_size lines of the file

 

    buf_t *main_buf;    // pointer to a buffer which is primary now

    buf_t *hot_swap_buf;// pointer to a buffer which is hot swap now

 

    /* current operation modes */

    mode_t  mode;   // current operation mode

 

    FILE *fp;                   // pointer to a FILE of a file to display

    std::vector <long int> ovec;// vector of boundary points offsets

 

    /* Critical section to support COM operations with threads */

    TCriticalSection    *COM_Critical;

 

    bool reenter; // to prevent reenter in COM_Pause

 

    static const wchar_t *NotAvailStr;//denotes: line is not available online

 

protected:

    virtual void __fastcall Loaded(void);

 

    void __fastcall OnDataHandler(TWinControl *Control, int Index,

            UnicodeString &Data) throw (Exception);

 

    void __fastcall OnDataHelperFile(int Index, UnicodeString &line);

    void __fastcall LoadWnd(int wnd_idx, buf_t * pbuf) throw (Exception);

 

    void __fastcall OnDataHelperPort(int Index, UnicodeString &line)

            throw (Exception);

 

    void setup_displayed_lines() { displayed_lines = Height / ItemHeight; };

    void __fastcall OnResizeHandler(TObject* Sender);

 

public:

    __fastcall TLessListBox(TComponent* Owner) throw (Exception);

    virtual __fastcall ~TLessListBox();

 

    virtual void __fastcall Clear();

 

    enum wpos_t { wTop, wMiddle, wBottom};

    void __fastcall GoTo(int LineNum, wpos_t pos);

 

    void __fastcall DisplayFile(UnicodeString FileName) throw (Exception);

 

    void __fastcall DisplayPort();

    void __fastcall COM_Append(char *line) throw (Exception);

    void __fastcall COM_Update();

    void __fastcall COM_Pause() throw(Exception);

    void __fastcall COM_Resume() throw(Exception);

    bool __fastcall COM_Is_Paused() { return reenter; };

    static const wchar_t *GetNotAvailStr() { return NotAvailStr; };

 

    /* get current operation mode */

    mode_t get_mode() { return mode; };

 

    /* get delta between Integral Height and Non Integral Height */

    int __fastcall GetIntegralHeightDelta();

 

__published:

    __property size_t wnd_size =

    {

        read = Fwnd_size,

        write = Fwnd_size,

        default = def_wnd_size

    };

 

    __property size_t frontier_size =

    {

        read = Ffrontier_size,

        write = Ffrontier_size,

        default = def_frontier_size

    };

 

    __property size_t max_line_len =

    {

        read = Fmax_line_len,

        write = Fmax_line_len,

        default = def_max_line_len

    };

 

    /* specify default properties values */

    __property Align = {default=0};

    __property Anchors = { default=3};

    __property BevelEdges = { default=15};

    __property BevelInner = { index=0, default=2};

    __property BevelKind = {default=0};

    __property BevelOuter = { index=1, default=1};

    __property BevelWidth = { default=1};

    __property BorderStyle = { default=1};

    __property Color = { default=-16777211};

    __property Constraints;

    __property Enabled = { default=1};

    __property Font;

    __property ItemHeight;

    __property ParentColor = { default=0};

    __property ParentFont = { default=1};

    __property ParentShowHint = { default=1};

    __property ShowHint;

    __property TabOrder = { default=-1};

    __property TabStop = { default=1};

    __property TabWidth = { default=0};

    __property Visible = { default=1};

 

    __property OnClick;

    __property OnDblClick;

    __property OnDragDrop;

    __property OnDragOver;

    __property OnEndDock;

    __property OnEndDrag;

    __property OnEnter;

    __property OnExit;

    __property OnKeyDown;

    __property OnKeyPress;

    __property OnKeyUp;

    __property OnMeasureItem;

    __property OnMouseActivate;

    __property OnMouseDown;

    __property OnMouseEnter;

    __property OnMouseLeave;

    __property OnMouseMove;

    __property OnMouseUp;

    __property OnStartDock;

    __property OnStartDrag;

 

 };

//---------------------------------------------------------------------------

#endif

#include <vcl.h>

 

#pragma hdrstop

 

#include <vector>

#include <math.h>

#include "TLessListBox.h"

 

#pragma package(smart_init)

 

//---------------------------------------------------------------------------

// ValidCtrCheck is used to assure that the components created do not have

// any pure virtual functions.

//

 

static inline void ValidCtrCheck(TLessListBox *)

{

    new TLessListBox(NULL);

}

//---------------------------------------------------------------------------

 

const wchar_t *TLessListBox::NotAvailStr = L"    line is not available online";

 

__fastcall TLessListBox::TLessListBox(TComponent* Owner) throw (Exception)

        : TCustomListBox(Owner),

        Fwnd_size(def_wnd_size), Ffrontier_size(def_frontier_size),

        Fmax_line_len(def_max_line_len),

        reenter(false)

{

    try {

        /* allocate memory for buffers */

        buf1.pList = new TStringList;

        buf2.pList = new TStringList;

        COM_Critical = new TCriticalSection;

    } catch (std::bad_alloc) {

        delete buf1.pList;

        delete buf2.pList;

        delete COM_Critical;

        throw Exception(L"Cannot create TLessListBox");

    }

}

 

void __fastcall TLessListBox::Loaded(void)

{

    TCustomListBox::Loaded();  // call the inherited method

 

    /* set up the members which need the window handle of the object */

    IntegralHeight = true;

    Style = lbVirtual;

    OnData = OnDataHandler;

    setup_displayed_lines();

    OnResize = &OnResizeHandler; // set up the event handler

    if (!ScrollWidth) { //change only if there is default value

        ScrollWidth = (int) ((double) def_max_line_len *

                1.4L * abs(Font->Height));

    }

}

 

__fastcall TLessListBox::~TLessListBox()

{

    /* delete buffers */

    delete buf1.pList;

    delete buf2.pList;

    delete COM_Critical;

 

    /* close input file if open */

    if (fp) {

        fclose(fp);

    }

}

 

....

....

....

//---------------------------------------------------------------------------

namespace Tlesslistbox

{

    void __fastcall PACKAGE Register()

    {

         TComponentClass classes[1] = {__classid(TLessListBox)};

         RegisterComponents(L"NewComponents", classes, 0);

    }

}