unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, Grids;

type
  TCellData = record
    Text: string;
    Value: Integer;
    Active: Boolean;
  end;
  TCellDataArray = array[0..127] of array[0..127] of TCellData;

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    DrawGrid1: TDrawGrid;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure DrawGrid1DrawCell(Sender: TObject; ACol, ARow: Integer; Rect: TRect;
      State: TGridDrawState);
    procedure DrawGrid1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X,
      Y: Integer);
  private
    FCellDataArray: TCellDataArray;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  X, Y: Integer;
begin
  Randomize;

  DrawGrid1.FixedCols := 0;
  DrawGrid1.FixedRows := 0;
  DrawGrid1.ColCount := 128;
  DrawGrid1.RowCount := 128;

  for Y := Low(FCellDataArray) to High(FCellDataArray) do
    for X := Low(FCellDataArray[Y]) to High(FCellDataArray[Y]) do
    begin
      FCellDataArray[Y][X].Text := Format('Cell [%d;%d]', [X, Y]);
      FCellDataArray[Y][X].Value := Random(1000);
      FCellDataArray[Y][X].Active := FCellDataArray[Y][X].Value >= 500;
    end;
end;

procedure TForm1.DrawGrid1DrawCell(Sender: TObject; ACol, ARow: Integer; Rect: TRect;
  State: TGridDrawState);
begin
  if FCellDataArray[ARow][ACol].Active then
    TDrawGrid(Sender).Canvas.Brush.Color := clGreen
  else
    TDrawGrid(Sender).Canvas.Brush.Color := $000080FF;
  TDrawGrid(Sender).Canvas.FillRect(Rect);
  TDrawGrid(Sender).Canvas.TextOut(Rect.Left + 8, Rect.Top + 5, FCellDataArray[ARow][ACol].Text);
end;

procedure TForm1.DrawGrid1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X,
  Y: Integer);
var
  Coords: TGridCoord;
begin
  Coords := TDrawGrid(Sender).MouseCoord(X, Y);
  if (Coords.X <> -1) and (Coords.Y <> -1) then
  begin
    FCellDataArray[Coords.Y][Coords.X].Active := not FCellDataArray[Coords.Y][Coords.X].Active;
    TDrawGrid(Sender).Invalidate;
  end;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  FCellDataArray[1][1].Active := not FCellDataArray[1][1].Active;
  DrawGrid1.Invalidate;
end;

end.