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