include/wx/snglinst.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/snglinst.h
   3 // Purpose:     wxSingleInstanceChecker can be used to restrict the number of
   4 //              simultaneously running copies of a program to one
   5 // Author:      Vadim Zeitlin
   6 // Modified by:
   7 // Created:     08.06.01
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
  10 // Licence:     wxWindows licence
  11 ///////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_SNGLINST_H_
  14 #define _WX_SNGLINST_H_
  15
  16 #if wxUSE_SNGLINST_CHECKER
  17
  18 #include "wx/app.h"
  19 #include "wx/utils.h"
  20
  21 // ----------------------------------------------------------------------------
  22 // wxSingleInstanceChecker
  23 // ----------------------------------------------------------------------------
  24
  25 class WXDLLIMPEXP_BASE wxSingleInstanceChecker
  26 {
  27 public:
  28     // default ctor, use Create() after it
  29     wxSingleInstanceChecker() { Init(); }
  30
  31     // like Create() but no error checking (dangerous!)
  32     wxSingleInstanceChecker(const wxString& name,
  33                             const wxString& path = wxEmptyString)
  34     {
  35         Init();
  36         Create(name, path);
  37     }
  38
  39     // notice that calling Create() is optional now, if you don't do it before
  40     // calling IsAnotherRunning(), CreateDefault() is used automatically
  41     //
  42     // name it is used as the mutex name under Win32 and the lock file name
  43     // under Unix so it should be as unique as possible and must be non-empty
  44     //
  45     // path is optional and is ignored under Win32 and used as the directory to
  46     // create the lock file in under Unix (default is wxGetHomeDir())
  47     //
  48     // returns false if initialization failed, it doesn't mean that another
  49     // instance is running - use IsAnotherRunning() to check it
  50     bool Create(const wxString& name, const wxString& path = wxEmptyString);
  51
  52     // use the default name, which is a combination of wxTheApp->GetAppName()
  53     // and wxGetUserId() for mutex/lock file
  54     //
  55     // this is called implicitly by IsAnotherRunning() if the checker hadn't
  56     // been created until then
  57     bool CreateDefault()
  58     {
  59         wxCHECK_MSG( wxTheApp, false, "must have application instance" );
  60         return Create(wxTheApp->GetAppName() + '-' + wxGetUserId());
  61     }
  62
  63     // is another copy of this program already running?
  64     bool IsAnotherRunning() const
  65     {
  66         if ( !m_impl )
  67         {
  68             if ( !const_cast<wxSingleInstanceChecker *>(this)->CreateDefault() )
  69             {
  70                 // if creation failed, return false as it's better to not
  71                 // prevent this instance from starting up if there is an error
  72                 return false;
  73             }
  74         }
  75
  76         return DoIsAnotherRunning();
  77     }
  78
  79     // dtor is not virtual, this class is not meant to be used polymorphically
  80     ~wxSingleInstanceChecker();
  81
  82 private:
  83     // common part of all ctors
  84     void Init() { m_impl = NULL; }
  85
  86     // do check if another instance is running, called only if m_impl != NULL
  87     bool DoIsAnotherRunning() const;
  88
  89     // the implementation details (platform specific)
  90     class WXDLLIMPEXP_FWD_BASE wxSingleInstanceCheckerImpl *m_impl;
  91
  92     wxDECLARE_NO_COPY_CLASS(wxSingleInstanceChecker);
  93 };
  94
  95 #endif // wxUSE_SNGLINST_CHECKER
  96
  97 #endif // _WX_SNGLINST_H_