timer jam (delphi 7)

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    lblJam: TLabel;
    btnStart: TButton;
    btnStop: TButton;
    procedure btnStartClick(Sender: TObject);

    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure btnStopClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  StartTime, StopTime: TDateTime;

implementation

{$R *.dfm}

procedure TForm1.btnStartClick(Sender: TObject);
begin
  timer1.Enabled := true;
  btnStart.Enabled := false;
  btnStart.Font.Color := clGray;//clWindowText
  btnStop.Enabled := true;
  btnStop.Font.Color := clWindowText;
  lblJam.Caption:='Memulai perhitungan';
end;

//procedure TForm1.btnStopClick(Sender: TObject);
//begin
//  timer1.Enabled := false;
//  btnStart.Enabled := TRUE;
//  btnStart.Font.Color := clWindowText;//clWindowText
//  btnStop.Enabled := false;
//  btnStop.Font.Color := clGray;
//  StartTime := 0;
//end;

function waktu(wkt: double): string;
var
  //dTime: double;
  iHari, iJam, iMenit: integer;
  iDetik: double;

  //sResult: Text;
begin
  if int(wkt) > 0 then
    iHari := 0
  else
    iHari := Trunc(wkt);

  wkt := Frac(wkt) * 24; // untuk jam
  iJam := Trunc(wkt);
  wkt := frac(wkt) * 60; // untuk Menit
  iMenit := Trunc(wkt);
  iDetik := frac(wkt) * 60; // untuk detik
  result := IntToStr(iHari) + ' Hari, ' + IntToStr(iJam) + ' Jam, ';
  result := result + IntToStr(iMenit) + ' menit, ';
  result := result + FloatToStrF(iDetik, ffFixed, 15, 0) + ' detik';

  //return Result;

end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
  CTime: TDateTime;
  dTime: double;
begin
  if StartTime = 0 then
    StartTime := now;
  CTime := now;
  dTime := CTime - StartTime;
  lblJam.Caption := waktu(dTime);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  StartTime := 0;
  lblJam.Caption := '';
end;

procedure TForm1.btnStopClick(Sender: TObject);
begin
  timer1.Enabled := false;
  btnStart.Enabled := true;
  btnStart.Font.Color := clWindowText;//clWindowText
  btnStop.Enabled := false;
  btnStop.Font.Color := clGray;
  StartTime := 0;
end;

end.