Memo со свойствами Row и Col

unit C_rcmemo;

interface

uses

  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls;

type

  TRCMemo = class(TMemo)
  private
    { Private declarations }
    function GetRow: Integer;
    procedure SetRow(value: Integer);
    function GetCol: Integer;
    procedure SetCol(value: Integer);
    function GetPosn: LongInt;
    procedure SetPosn(value: LongInt);
  protected
    { Protected declarations }
  public
    { Public declarations }
  published
    { Published declarations }
    property Row: Integer read GetRow write SetRow;
    property Col: Integer read GetCol write SetCol;
    property Posn: LongInt read GetPosn write SetPosn;
  end;

procedure Register;

implementation

function TRCMemo.GetRow: Integer;
begin

  Result := Perform(EM_LINEFROMCHAR, $FFFF, 0);
end;

procedure TRCMemo.SetRow(value: Integer);
begin

  SelStart := GetCol + Perform(EM_LINEINDEX, Value, 0);
end;

function TRCMemo.GetCol: Integer;
begin

  Result := SelStart - Perform(EM_LINEINDEX, GetRow, 0);
end;

procedure TRCMemo.SetCol(value: Integer);
begin

  SelStart := Perform(EM_LINEINDEX, GetRow, 0) + Value;
end;

function TRCMemo.GetPosn: LongInt;
var
  ro, co: Integer;
begin

  ro := GetRow;
  co := SelStart - Perform(EM_LINEINDEX, ro, 0);
  Result := MakeLong(co, ro);
end;

procedure TRCMemo.SetPosn(value: LongInt);
begin

  SelStart := Perform(EM_LINEINDEX, HiWord(Value), 0) + LoWord(Value);
end;

procedure Register;
begin

  RegisterComponents('NJR', [TRCMemo]);
end;

end.