src/msw/snglinst.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        msw/snglinst.cpp
   3 // Purpose:     implements wxSingleInstanceChecker class for Win32 using
   4 //              named mutexes
   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 // License:     wxWindows license
  11 ///////////////////////////////////////////////////////////////////////////////
  12
  13 // ============================================================================
  14 // declarations
  15 // ============================================================================
  16
  17 // ----------------------------------------------------------------------------
  18 // headers
  19 // ----------------------------------------------------------------------------
  20
  21 #ifdef __GNUG__
  22     #pragma implementation "snglinst.h"
  23 #endif
  24
  25 // For compilers that support precompilation, includes "wx.h".
  26 #include "wx/wxprec.h"
  27
  28 #ifdef __BORLANDC__
  29     #pragma hdrstop
  30 #endif
  31
  32 #if wxUSE_SNGLINST_CHECKER && defined(__WIN32__)
  33
  34 #ifndef WX_PRECOMP
  35     #include "wx/string.h"
  36     #include "wx/log.h"
  37 #endif //WX_PRECOMP
  38
  39 #include "wx/snglinst.h"
  40
  41 #include "wx/msw/private.h"
  42
  43 //variables held in common by the callback and wxSingleInstanceCheckerImpl
  44 static HWND FirsthWnd;
  45 static wxString s_Title;
  46
  47 // callback to look for windows whose titles include the search string
  48 // BCC (at least) does not like the callback to be part of the class :-((
  49 bool CALLBACK EnumWindowsProc ( HWND hwnd, LPARAM lParam )
  50 {
  51     // Get the title of this window
  52     int iTitleLen = ::GetWindowTextLength(hwnd);
  53     // possible UNICODE/ANSI bug here, see SDK documentation,
  54     // so allow extra space
  55     char * cTitle = new char [iTitleLen*2+10] ;
  56     ::GetWindowText(hwnd, cTitle, iTitleLen*2+10);
  57
  58     bool bSuccess = wxString(cTitle).Contains(s_Title) ;
  59     delete [] cTitle ;
  60
  61     if (bSuccess)
  62     {
  63         FirsthWnd = hwnd ;
  64         return FALSE ;
  65     }
  66     else
  67     {
  68         //not this window
  69         return TRUE;
  70     }
  71
  72 }
  73
  74 // ----------------------------------------------------------------------------
  75 // wxSingleInstanceCheckerImpl: the real implementation class
  76 // ----------------------------------------------------------------------------
  77
  78 class WXDLLEXPORT wxSingleInstanceCheckerImpl
  79 {
  80 public:
  81     wxSingleInstanceCheckerImpl()
  82     {
  83         // we don't care about m_wasOpened, it can't be accessed before being
  84         // initialized
  85         m_hMutex = NULL;
  86     }
  87
  88     bool Create(const wxString& name)
  89     {
  90         m_hMutex = ::CreateMutex(NULL, FALSE, name);
  91         if ( !m_hMutex )
  92         {
  93             wxLogLastError(_T("CreateMutex"));
  94
  95             return FALSE;
  96         }
  97
  98         // mutex was either created or opened - see what really happened
  99         m_wasOpened = ::GetLastError() == ERROR_ALREADY_EXISTS;
 100
 101         return TRUE;
 102     }
 103
 104     bool WasOpened() const
 105     {
 106         wxCHECK_MSG( m_hMutex, FALSE,
 107                      _T("can't be called if mutex creation failed") );
 108
 109         return m_wasOpened;
 110     };
 111
 112
 113
 114     // Activates Previous Instance if a window matching Title is found
 115     bool ActivatePrevInstance(const wxString & sSearch)
 116     {
 117         //store search text and window handle for use by callback
 118          s_Title = sSearch ;
 119          FirsthWnd = 0;
 120
 121          EnumWindows (WNDENUMPROC(&EnumWindowsProc), 0L);
 122          if (FirsthWnd == 0)
 123          {
 124             //no matching window found
 125             return FALSE;
 126          }
 127
 128          if (::IsIconic(FirsthWnd))
 129          {
 130              ::ShowWindow(FirsthWnd, SW_SHOWDEFAULT);
 131          }
 132          ::SetForegroundWindow(FirsthWnd);
 133
 134          // now try to deal with any active children
 135          // Handles to child of previous instance
 136          HWND FirstChildhWnd;
 137
 138          FirstChildhWnd = ::GetLastActivePopup(FirsthWnd);
 139          if (FirsthWnd != FirstChildhWnd)
 140          {
 141             // A pop-up is active so bring it to the top too.
 142             ::BringWindowToTop(FirstChildhWnd);
 143          }
 144         return TRUE;
 145     }
 146
 147     // Activates Previous Instance and passes CommandLine to wxCommandLineEvent
 148     // if a window matching Title is found
 149     bool PassCommandLineToPrevInstance(const wxString & sTitle, const wxString & sCmdLine)
 150     {
 151         // this stores a string of up to 255 bytes
 152         //ATOM myAtom = GlobalAddAtom ( sCmdLine );
 153
 154         // this would create a call to wxWindow::OnCommandLine(wxCommandLineEvent & event)
 155         // which should retrieve the commandline, and then delete the atom, GlobalDeleteAtom( myAtom );
 156         //::SendMessage (FirsthWnd, wxCOMMANDLINE_MESSAGE, 0, myAtom) ;
 157         return FALSE;
 158     }
 159
 160     ~wxSingleInstanceCheckerImpl()
 161     {
 162         if ( m_hMutex )
 163         {
 164             if ( !::CloseHandle(m_hMutex) )
 165             {
 166                 wxLogLastError(_T("CloseHandle(mutex)"));
 167             }
 168         }
 169     }
 170
 171 private:
 172     // the result of the CreateMutex() call
 173     bool m_wasOpened;
 174
 175     // the mutex handle, may be NULL
 176     HANDLE m_hMutex;
 177
 178 };
 179
 180 // ============================================================================
 181 // wxSingleInstanceChecker implementation
 182 // ============================================================================
 183
 184 bool wxSingleInstanceChecker::Create(const wxString& name,
 185                                      const wxString& WXUNUSED(path))
 186 {
 187     wxASSERT_MSG( !m_impl,
 188                   _T("calling wxSingleInstanceChecker::Create() twice?") );
 189
 190     // creating unnamed mutex doesn't have the same semantics!
 191     wxASSERT_MSG( !name.empty(), _T("mutex name can't be empty") );
 192
 193     m_impl = new wxSingleInstanceCheckerImpl;
 194
 195     return m_impl->Create(name);
 196 }
 197
 198 bool wxSingleInstanceChecker::IsAnotherRunning() const
 199 {
 200     wxCHECK_MSG( m_impl, FALSE, _T("must call Create() first") );
 201
 202     // if the mutex had been opened, another instance is running - otherwise we
 203     // would have created it
 204     return m_impl->WasOpened();
 205 }
 206
 207     // Activates Previous Instance if a window whose Title contains the search string is found
 208 bool wxSingleInstanceChecker::ActivatePrevInstance(const wxString & sSearch)
 209 {
 210     if (!IsAnotherRunning())
 211     {
 212         return FALSE;
 213     }
 214     return m_impl->ActivatePrevInstance(sSearch) ;
 215 }
 216
 217     // Activates Previous Instance and passes CommandLine to wxCommandLineEvent
 218     // if a window matching Title is found
 219 bool wxSingleInstanceChecker::PassCommandLineToPrevInstance(const wxString & sSearch, const wxString & sCmdLine)
 220 {
 221     if (!ActivatePrevInstance(sSearch))
 222     {
 223         return FALSE;
 224     }
 225     return m_impl->PassCommandLineToPrevInstance(sSearch, sCmdLine);
 226 }
 227
 228 wxSingleInstanceChecker::~wxSingleInstanceChecker()
 229 {
 230     delete m_impl;
 231 }
 232
 233 #endif // wxUSE_SNGLINST_CHECKER