single instance checker addition for MSW

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16180 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/snglinst.h

@@ -50,7 +50,16 @@ public:
 
     // is another copy of this program already running?
     bool IsAnotherRunning() const;
-
+    
+#ifdef __WXMSW__
+    // Activates Previous Instance if a window whose Title contains the search string is found
+    bool ActivatePrevInstance(const wxString & sSearch);
+    
+    // Activates Previous Instance and passes CommandLine to wxCommandLineEvent
+    // if a window with matching Title is found
+    bool PassCommandLineToPrevInstance(const wxString & sSearch, const wxString & sCmdLine);
+#endif
+    
     // dtor is not virtual, this class is not meant to be used polymorphically
     ~wxSingleInstanceChecker();
 

src/msw/snglinst.cpp

@@ -40,6 +40,37 @@
 
 #include "wx/msw/private.h"
 
+//variables held in common by the callback and wxSingleInstanceCheckerImpl
+static HWND FirsthWnd;
+static wxString s_Title;
+
+// callback to look for windows whose titles include the search string
+// BCC (at least) does not like the callback to be part of the class :-((
+bool CALLBACK EnumWindowsProc ( HWND hwnd, LPARAM lParam )
+{
+    // Get the title of this window
+    int iTitleLen = ::GetWindowTextLength(hwnd);
+    // possible UNICODE/ANSI bug here, see SDK documentation,
+    // so allow extra space
+    char * cTitle = new char [iTitleLen*2+10] ;
+    ::GetWindowText(hwnd, cTitle, iTitleLen*2+10);
+    
+    bool bSuccess = wxString(cTitle).Contains(s_Title) ;
+    delete [] cTitle ;
+    
+    if (bSuccess)
+    {
+        FirsthWnd = hwnd ;
+        return FALSE ;
+    }
+    else
+    {
+        //not this window
+        return TRUE;
+    }
+    
+}
+    
 // ----------------------------------------------------------------------------
 // wxSingleInstanceCheckerImpl: the real implementation class
 // ----------------------------------------------------------------------------
@@ -76,6 +107,54 @@ public:
                      _T("can't be called if mutex creation failed") );
 
         return m_wasOpened;
+    };
+    
+
+
+    // Activates Previous Instance if a window matching Title is found
+    bool ActivatePrevInstance(const wxString & sSearch)
+    {
+        //store search text and window handle for use by callback
+         s_Title = sSearch ;
+         FirsthWnd = 0;
+         
+         EnumWindows (WNDENUMPROC(&EnumWindowsProc), 0L);
+         if (FirsthWnd == 0)
+         {
+            //no matching window found
+            return FALSE;
+         }
+         
+         if (::IsIconic(FirsthWnd))
+         {
+             ::ShowWindow(FirsthWnd, SW_SHOWDEFAULT);
+         }
+         ::SetForegroundWindow(FirsthWnd);
+         
+         // now try to deal with any active children
+         // Handles to child of previous instance 
+         HWND FirstChildhWnd;
+         
+         FirstChildhWnd = ::GetLastActivePopup(FirsthWnd);
+         if (FirsthWnd != FirstChildhWnd)
+         {
+            // A pop-up is active so bring it to the top too.
+            ::BringWindowToTop(FirstChildhWnd); 
+         }
+        return TRUE;
+    }
+    
+    // Activates Previous Instance and passes CommandLine to wxCommandLineEvent
+    // if a window matching Title is found
+    bool PassCommandLineToPrevInstance(const wxString & sTitle, const wxString & sCmdLine)
+    {
+        // this stores a string of up to 255 bytes
+        //ATOM myAtom = GlobalAddAtom ( sCmdLine );
+
+        // this would create a call to wxWindow::OnCommandLine(wxCommandLineEvent & event)
+        // which should retrieve the commandline, and then delete the atom, GlobalDeleteAtom( myAtom );
+        //::SendMessage (FirsthWnd, wxCOMMANDLINE_MESSAGE, 0, myAtom) ;
+        return FALSE;
     }
 
     ~wxSingleInstanceCheckerImpl()
@@ -95,6 +174,7 @@ private:
 
     // the mutex handle, may be NULL
     HANDLE m_hMutex;
+    
 };
 
 // ============================================================================
@@ -124,6 +204,27 @@ bool wxSingleInstanceChecker::IsAnotherRunning() const
     return m_impl->WasOpened();
 }
 
+    // Activates Previous Instance if a window whose Title contains the search string is found
+bool wxSingleInstanceChecker::ActivatePrevInstance(const wxString & sSearch)
+{
+    if (!IsAnotherRunning())
+    {
+        return FALSE;
+    }
+    return m_impl->ActivatePrevInstance(sSearch) ;
+}
+    
+    // Activates Previous Instance and passes CommandLine to wxCommandLineEvent
+    // if a window matching Title is found
+bool wxSingleInstanceChecker::PassCommandLineToPrevInstance(const wxString & sSearch, const wxString & sCmdLine)
+{
+    if (!ActivatePrevInstance(sSearch))
+    {
+        return FALSE;
+    }
+    return m_impl->PassCommandLineToPrevInstance(sSearch, sCmdLine);
+}
+
 wxSingleInstanceChecker::~wxSingleInstanceChecker()
 {
     delete m_impl;