- MGR: Check for a duplicate instance much earlier in the initialization

cycle, before any window or document creation.  Prevents rapid window
        creation and then destruction.
        
    clientgui/
        BOINCGUIApp.cpp, .h

svn path=/trunk/boinc/; revision=22504

checkin_notes

@@ -7317,3 +7317,11 @@ Charlie 14 Oct 2010
     
     client/
         cs_scheduler.cpp
+
+Rom    14 Oct 2010
+    - MGR: Check for a duplicate instance much earlier in the initialization
+        cycle, before any window or document creation.  Prevents rapid window
+        creation and then destruction.
+        
+    clientgui/
+        BOINCGUIApp.cpp, .h

clientgui/BOINCGUIApp.cpp

@@ -381,6 +381,13 @@ bool CBOINCGUIApp::OnInit() {
     }
 #endif
 
+    // Detect if BOINC Manager is already running, if so, bring it into the
+    // foreground and then exit.
+    if (!m_bMultipleInstancesOK) {
+        if (DetectDuplicateInstance()) {
+            return false;
+        }
+    }
 
     // Initialize the main document
     m_pDocument = new CMainDocument();
@@ -652,6 +659,23 @@ void CBOINCGUIApp::DetectAccessibilityEnabled() {
 }
 
 
+///
+/// Detect if another instance of this application is running.
+//  Returns true if there is, otherwise false
+///
+bool CBOINCGUIApp::DetectDuplicateInstance() {
+#ifdef __WXMSW__
+    HWND hWnd = ::FindWindow(NULL, m_pSkinManager->GetAdvanced()->GetApplicationName().c_str());
+    if (hWnd) {
+        ::ShowWindow(hWnd, SW_SHOW);
+        ::SetForegroundWindow(hWnd);
+        return true;
+    }
+#endif
+    return false;
+}
+
+
 ///
 /// Determines what name BOINC Manager is called.
 ///

clientgui/BOINCGUIApp.h

@@ -60,6 +60,7 @@ protected:
 
     void                DetectDisplayInfo();
     void                DetectAccessibilityEnabled();
+    bool                DetectDuplicateInstance();
     void                DetectExecutableName();
     void                DetectRootDirectory();
     void                DetectDataDirectory();