unit StopWatch;
//***************************************************************************************
//  Description: StopWatch timer for counting minutes and seconds
//    File Name: StopWatch.pas
//
//---------------------------------------------------------------------------------------
//                          C O P Y R I G H T
//---------------------------------------------------------------------------------------
//   Copyright (c) 2011 by Feaser    http://www.feaser.com    All rights reserved
//
//   This software has been carefully tested, but is not guaranteed for any particular
// purpose. The author does not offer any warranties and does not guarantee the accuracy,
//   adequacy, or completeness of the software and is not responsible for any errors or
//              omissions or the results obtained from use of the software.
//
//---------------------------------------------------------------------------------------
//                            L I C E N S E
//---------------------------------------------------------------------------------------
// This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
// modify it under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option) any later
// version.
//
// OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with OpenBLT.
// If not, see <http://www.gnu.org/licenses/>.
//
// A special exception to the GPL is included to allow you to distribute a combined work
// that includes OpenBLT without being obliged to provide the source code for any
// proprietary components. The exception text is included at the bottom of the license
// file <license.html>.
//
//***************************************************************************************
interface


//***************************************************************************************
// Includes
//***************************************************************************************
uses
  Windows, Messages, SysUtils, Classes, ExtCtrls;


//***************************************************************************************
// Type Definitions
//***************************************************************************************
type
  TStopWatch = class(TObject)
  private
    FStartTime  : TDateTime;
    FRunning    : boolean;
  public
    constructor Create;
    procedure   Start;
    procedure   Stop;
    function    Interval : string;
  end;


implementation
//***************************************************************************************
// NAME:           Create
// PARAMETER:      none
// RETURN VALUE:   none
// DESCRIPTION:    Class constructor
//
//***************************************************************************************
constructor TStopWatch.Create;
begin
  // call inherited constructor
  inherited Create;

  // initialize variables
  FRunning := false;
end; //*** end of Create ***


//***************************************************************************************
// NAME:           Start
// PARAMETER:      none
// RETURN VALUE:   none
// DESCRIPTION:    Starts the stopwatch timer
//
//***************************************************************************************
procedure TStopWatch.Start;
begin
  // store the start time
  FStartTime := Time;

  // start the stopwatch
  FRunning := true;
end; //*** end of Start ***


//***************************************************************************************
// NAME:           Stop
// PARAMETER:      none
// RETURN VALUE:   none
// DESCRIPTION:    Stops the stopwatch timer
//
//***************************************************************************************
procedure TStopWatch.Stop;
begin
  // stop the stopwatch
  FRunning := false;
end; //*** end of Stop ***


//***************************************************************************************
// NAME:           Interval
// PARAMETER:      none
// RETURN VALUE:   stopwatch time as string in format [min]:[sec].
// DESCRIPTION:    Obtains the stopwatch time as a formatted string.
//
//***************************************************************************************
function TStopWatch.Interval : string;
var
  hr  : word;
  min : word;
  sec : word;
  ms  : word;
begin
  // decode the elased stopwatch time
  DecodeTime(Time-FStartTime, hr, min, sec, ms);

  // check if stopwatch is running
  if not FRunning then
  begin
    min := 0;
    sec := 0;
  end;

  // update the formatted stopwatch time string
  result := Format('%2.2d:%2.2d', [min, sec]);
end; //*** end of Interval ***


end.
//******************************** end of StopWatch.pas *********************************