CodeSnip Old Code (SVN)

{
 * USystemInfo.pas
 *
 * Static class that provide information about the host system.
 *
 * Requires DelphiDabbler System information unit v3 or later.
 *
 * v0.1 of 07 Apr 2006  - Original version.
 * v1.0 of 24 May 2006  - Improved and corrected comments.
 *                      - Relocated and rationalised $WARN directives.
 * v1.1 of 02 Jun 2008  - Removed TComputerInfo.MACAddress routine: now in base
 *                        class.
 *                      - Added new TOSInfo.IsVistaOrLater method.
 * v1.2 of 15 Jun 2008  - Added new TOSInfo.IsXPOrLater method.
 *                      - Revised TOSInfo.IsVistaOrLater to call helper method
 *                        to check for required kernel function.
 * v1.3 of 24 Aug 2008  - Removed now unused TComputerInfo class.
 * v1.4 of 10 May 2009  - Added new TOSVer record.
 *                      - Made private section of TOSInfo strict.
 *                      - Added Win2K, WinXP and WinVista TOSVer constants and
 *                        CheckReportedOS method to TOSVer.
 *
 *
 * ***** BEGIN LICENSE BLOCK *****
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with the
 * License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
 * the specific language governing rights and limitations under the License.
 *
 * The Original Code is USystemInfo.pas
 *
 * The Initial Developer of the Original Code is Peter Johnson
 * (http://www.delphidabbler.com/).
 *
 * Portions created by the Initial Developer are Copyright (C) 2006-2009 Peter
 * Johnson. All Rights Reserved.
 *
 * ***** END LICENSE BLOCK *****
}


unit USystemInfo;


interface


uses
  // DelphiDabbler library
  PJSysInfo;


type

  {
  TOSVer:
    Record that records operation system major and minor version numbers.
  }
  TOSVer = packed record
    VerHi: Word;  // major OS version number
    VerLo: Word;  // minor OS version number
    constructor Create(const AVerHi, AVerLo: Word);
      {Record constructor. Sets initial field values.
        @param AVerHi [in] Major version number.
        @param AVerLo [in] Minor version number.
      }
    class operator GreaterThanOrEqual(const R1, R2: TOSVer): Boolean;
      {Overload for >= operator on TOSVer.
        @param R1 [in] First record to be checked.
        @param R2 [in] Second record to be checked.
        @return True in R1 >= R2, False otherwise.
      }
  end;

  {
  TOSInfo:
    Exposes TPJOSInfo class to rest of program under a new name and extends to
    add new methods.
  }
  TOSInfo = class(TPJOSInfo)
  private
    class function CheckForKernelFn(const FnName: string): Boolean;
      {Checks if a specified function exists in OSs kernel.
        @param FnName [in] Name of required function.
        @return True if function is present in kernel, false if not.
      }
  public
    const Win2K: TOSVer = (VerHi: 5; VerLo: 0);
      {Identifies Windows 2K}
    const WinXP: TOSVer = (VerHi: 5; VerLo: 1);
      {Identifies Windows XP}
    const WinVista: TOSVer = (VerHi: 6; VerLo: 0);
      {Identifies Windows Vista}
    class function IsVistaOrLater: Boolean;
      {Checks if the underlying operating system is Windows Vista or later.
      Ignores any OS emulation.
        @return True if OS is Vista or later, False if not.
      }
    class function IsXPOrLater: Boolean;
      {Checks if the underlying operating system is Windows XP or later. Ignores
      any OS emulation.
        @return True if OS is XP or later, False if not.
      }
    class function CheckReportedOS(const MinVer: TOSVer): Boolean;
      {Checks if the OS reported by Windows is the same as or later than a
      specified version number.
        @param MinVer [in] Minimum OS version required.
        @return True if OS reported by Windows is same as or later than MinVer.
      }
  end;


implementation


uses
  // Delphi
  Windows;


{ TOSInfo }

class function TOSInfo.CheckForKernelFn(const FnName: string): Boolean;
  {Checks if a specified function exists in OSs kernel.
    @param FnName [in] Name of required function.
    @return True if function is present in kernel, false if not.
  }
const
  cKernelDLL = 'kernel32.dll';  // name of kernel DLL
var
  PFunction: Pointer; // pointer to required function if exists
begin
  // Try to load GetProductInfo func from Kernel32: present if Vista
  PFunction := GetProcAddress(GetModuleHandle(cKernelDLL), PChar(FnName));
  Result := Assigned(PFunction);
end;

class function TOSInfo.CheckReportedOS(const MinVer: TOSVer): Boolean;
  {Checks if the OS reported by Windows is the same as or later than a specified
  version number.
    @param MinVer [in] Minimum OS version required.
    @return True if OS reported by Windows is same as or later than MinVer.
  }
begin
  Result := TOSVer.Create(TOSInfo.MajorVersion, TOSInfo.MinorVersion)
    >= MinVer;
end;

class function TOSInfo.IsVistaOrLater: Boolean;
  {Checks if the underlying operating system is Windows Vista or later. Ignores
  any OS emulation.
    @return True if OS is Vista or later, False if not.
  }
begin
  // The "GetProductInfo" API function only exists in the kernel of Vista and
  // Win 2008 server and later
  Result := CheckForKernelFn('GetProductInfo');
end;

class function TOSInfo.IsXPOrLater: Boolean;
  {Checks if the underlying operating system is Windows XP or later. Ignores
  any OS emulation.
    @return True if OS is XP or later, False if not.
  }
begin
  // The "ActivateActCtx" API function only exists in the kernel of XP and Win
  // 2003 server and later
  Result := CheckForKernelFn('ActivateActCtx');
end;

{ TOSVer }

constructor TOSVer.Create(const AVerHi, AVerLo: Word);
  {Record constructor. Sets initial field values.
    @param AVerHi [in] Major version number.
    @param AVerLo [in] Minor version number.
  }
begin
  VerHi := AVerHi;
  VerLo := AVerLo;
end;

class operator TOSVer.GreaterThanOrEqual(const R1, R2: TOSVer): Boolean;
  {Overload for >= operator on TOSVer.
    @param R1 [in] First record to be checked.
    @param R2 [in] Second record to be checked.
    @return True in R1 >= R2, False otherwise.
  }
begin
  Result := (R1.VerHi > R2.VerHi)
    or ((R1.VerHi = R2.VerHi) and (R1.VerLo >= R2.VerLo));
end;

end.