]> git.saurik.com Git - wxWidgets.git/blobdiff - src/motif/app.cpp
added some missing mac headers
[wxWidgets.git] / src / motif / app.cpp
index 94e652a549e893a503a77db586c21463b5ed71d1..30ddd80a6d13a551d773f0b145ea8195e5c123c7 100644 (file)
 // Created:     17/09/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Julian Smart
-// Licence:    wxWindows licence
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "app.h"
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
+    #pragma implementation "app.h"
+#endif
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __VMS
+#define XtParent XTPARENT
+#define XtDisplay XTDISPLAY
 #endif
 
-#include "wx/frame.h"
 #include "wx/app.h"
 #include "wx/utils.h"
-#include "wx/gdicmn.h"
-#include "wx/pen.h"
-#include "wx/brush.h"
-#include "wx/cursor.h"
-#include "wx/icon.h"
-#include "wx/palette.h"
-#include "wx/dc.h"
-#include "wx/dialog.h"
-#include "wx/msgdlg.h"
-#include "wx/log.h"
 #include "wx/module.h"
 #include "wx/memory.h"
+#include "wx/log.h"
+#include "wx/intl.h"
+#include "wx/evtloop.h"
+#include "wx/hash.h"
 
-#if wxUSE_WX_RESOURCES
-#include "wx/resource.h"
+#if wxUSE_THREADS
+    #include "wx/thread.h"
 #endif
 
+#ifdef __VMS__
+#pragma message disable nosimpint
+#endif
 #include <Xm/Xm.h>
+#include <Xm/Label.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/Xresource.h>
 #include <X11/Xatom.h>
+#ifdef __VMS__
+#pragma message enable nosimpint
+#endif
 
 #include "wx/motif/private.h"
 
 #include <string.h>
 
-extern char *wxBuffer;
-extern wxList wxPendingDelete;
+struct wxPerDisplayData
+{
+    wxPerDisplayData()
+    {
+        m_visualInfo = NULL;
+        m_topLevelWidget = NULL;
+        m_topLevelRealizedWidget = NULL;
+    }
 
-wxApp *wxTheApp = NULL;
+    wxXVisualInfo* m_visualInfo;
+    Widget         m_topLevelWidget, m_topLevelRealizedWidget;
+};
+
+static void wxTLWidgetDestroyCallback(Widget w, XtPointer clientData,
+                                      XtPointer ptr);
+static WXWidget wxCreateTopLevelWidget( WXDisplay* display );
+
+extern wxList wxPendingDelete;
+extern bool wxAddIdleCallback();
 
 wxHashTable *wxWidgetHashTable = NULL;
 
-#if !USE_SHARED_LIBRARY
 IMPLEMENT_DYNAMIC_CLASS(wxApp, wxEvtHandler)
+
 BEGIN_EVENT_TABLE(wxApp, wxEvtHandler)
-    EVT_IDLE(wxApp::OnIdle)
+    EVT_IDLE(wxAppBase::OnIdle)
 END_EVENT_TABLE()
-#endif
-
-long wxApp::sm_lastMessageTime = 0;
-
-bool wxApp::Initialize()
-{
-#ifdef __WXMSW__
-    wxBuffer = new char[1500];
-#else
-    wxBuffer = new char[BUFSIZ + 512];
-#endif
 
-#if (WXDEBUG && wxUSE_MEMORY_TRACING) || wxUSE_DEBUG_CONTEXT
+#ifdef __WXDEBUG__
+    typedef int (*XErrorHandlerFunc)(Display *, XErrorEvent *);
 
-    streambuf* sBuf = new wxDebugStreamBuf;
-    ostream* oStr = new ostream(sBuf) ;
-    wxDebugContext::SetStream(oStr, sBuf);
+    XErrorHandlerFunc gs_pfnXErrorHandler = 0;
 
-#endif
-  
-    wxClassInfo::InitializeClasses();
-
-    wxTheColourDatabase = new wxColourDatabase(wxKEY_STRING);
-    wxTheColourDatabase->Initialize();
-    wxInitializeStockObjects();
-
-#if wxUSE_WX_RESOURCES
-    wxInitializeResourceSystem();
-#endif
-
-  // For PostScript printing
-#if wxUSE_POSTSCRIPT
-/* Done using wxModule now
-    wxInitializePrintSetupData();
-    wxThePrintPaperDatabase = new wxPrintPaperDatabase;
-    wxThePrintPaperDatabase->CreateDatabase();
-*/
-#endif
+    static int wxXErrorHandler(Display *dpy, XErrorEvent *xevent)
+    {
+        // just forward to the default handler for now
+        return gs_pfnXErrorHandler(dpy, xevent);
+    }
+#endif // __WXDEBUG__
 
-    wxBitmap::InitStandardHandlers();
+bool wxApp::Initialize(int& argc, wxChar **argv)
+{
+    if ( !wxAppBase::Initialize(argc, argv) )
+        return false;
 
     wxWidgetHashTable = new wxHashTable(wxKEY_INTEGER);
 
-    wxModule::RegisterModules();
-    wxASSERT( wxModule::InitializeModules() == TRUE );
-
-    return TRUE;
+    return true;
 }
 
 void wxApp::CleanUp()
@@ -109,160 +106,53 @@ void wxApp::CleanUp()
     delete wxWidgetHashTable;
     wxWidgetHashTable = NULL;
 
-    wxModule::CleanUpModules();
-
-#if wxUSE_WX_RESOURCES
-    wxCleanUpResourceSystem();
-#endif
-
-    wxDeleteStockObjects() ;
-
-    // Destroy all GDI lists, etc.
-
-    delete wxTheBrushList;
-    wxTheBrushList = NULL;
-
-    delete wxThePenList;
-    wxThePenList = NULL;
-
-    delete wxTheFontList;
-    wxTheFontList = NULL;
-
-    delete wxTheBitmapList;
-    wxTheBitmapList = NULL;
-
-    delete wxTheColourDatabase;
-    wxTheColourDatabase = NULL;
-
-#if wxUSE_POSTSCRIPT
-/* Done using wxModule now
-    wxInitializePrintSetupData(FALSE);
-    delete wxThePrintPaperDatabase;
-    wxThePrintPaperDatabase = NULL;
-*/
-#endif
-
-    wxBitmap::CleanUpHandlers();
-
-    delete[] wxBuffer;
-    wxBuffer = NULL;
-
-    wxClassInfo::CleanUpClasses();
-
-    // do it as the very last thing because everything else can log messages
-    wxLog::DontCreateOnDemand();
-    // do it as the very last thing because everything else can log messages
-    delete wxLog::SetActiveTarget(NULL);
+    wxAppBase::CleanUp();
 }
 
-int wxEntry( int argc, char *argv[] )
+void wxApp::Exit()
 {
-    if (!wxApp::Initialize())
-      return FALSE;
-    if (!wxTheApp)
-    {
-      if (!wxApp::GetInitializerFunction())
-      {
-        printf( "wxWindows error: No initializer - use IMPLEMENT_APP macro.\n" );
-        return 0;
-      };
-    
-       wxTheApp = (wxApp*) (* wxApp::GetInitializerFunction()) ();
-    };
-  
-    if (!wxTheApp)
-    {
-      printf( "wxWindows error: wxTheApp == NULL\n" );
-      return 0;
-    };
-
-    wxTheApp->SetClassName(wxFileNameFromPath(argv[0]));
-    wxTheApp->SetAppName(wxFileNameFromPath(argv[0]));
-
-    wxTheApp->argc = argc;
-    wxTheApp->argv = argv;
-
-    // GUI-specific initialization, such as creating an app context.
-    wxTheApp->OnInitGui();
-
-    // Here frames insert themselves automatically
-    // into wxTopLevelWindows by getting created
-    // in OnInit().
-  
-    if (!wxTheApp->OnInit()) return 0;
-
-    int retValue = 0;
-  
-    if (wxTheApp->Initialized()) retValue = wxTheApp->OnRun();
-
-    if (wxTheApp->GetTopWindow())
-    {
-      delete wxTheApp->GetTopWindow();
-      wxTheApp->SetTopWindow(NULL);
-    }
-  
-    wxTheApp->DeletePendingObjects();
-  
-    wxTheApp->OnExit();
-  
     wxApp::CleanUp();
 
-    delete wxTheApp;
-    wxTheApp = NULL;
-  
-#if (WXDEBUG && wxUSE_MEMORY_TRACING) || wxUSE_DEBUG_CONTEXT
-    // At this point we want to check if there are any memory
-    // blocks that aren't part of the wxDebugContext itself,
-    // as a special case. Then when dumping we need to ignore
-    // wxDebugContext, too.
-    if (wxDebugContext::CountObjectsLeft() > 0)
-    {
-      wxTrace("There were memory leaks.\n");
-      wxDebugContext::Dump();
-      wxDebugContext::PrintStatistics();
-    }
-    wxDebugContext::SetStream(NULL, NULL);
-#endif
-  
-    return retValue;
-};
+    wxAppConsole::Exit();
+}
 
-// Static member initialization
-wxAppInitializerFunction wxApp::m_appInitFn = (wxAppInitializerFunction) NULL;
+// ============================================================================
+// wxApp
+// ============================================================================
 
 wxApp::wxApp()
 {
-    m_topWindow = NULL;
-    wxTheApp = this;
-    m_className = "";
-    m_wantDebugOutput = TRUE ;
-    m_appName = "";
     argc = 0;
     argv = NULL;
-    m_printMode = wxPRINT_POSTSCRIPT;
-    m_exitOnFrameDelete = TRUE;
-    m_auto3D = TRUE;
 
+    m_mainLoop = new wxEventLoop;
     m_mainColormap = (WXColormap) NULL;
     m_appContext = (WXAppContext) NULL;
-    m_topLevelWidget = (WXWidget) NULL;
-    m_maxRequestSize = 0;
     m_initialDisplay = (WXDisplay*) 0;
+    m_perDisplayData = new wxPerDisplayDataMap;
 }
 
-bool wxApp::Initialized()
+wxApp::~wxApp()
 {
-    if (GetTopWindow())
-      return TRUE;
-    else
-      return FALSE;
+    delete m_mainLoop;
+
+    for( wxPerDisplayDataMap::iterator it  = m_perDisplayData->begin(),
+                                       end = m_perDisplayData->end();
+         it != end; ++it )
+    {
+        delete it->second->m_visualInfo;
+        XtDestroyWidget( it->second->m_topLevelWidget );
+        delete it->second;
+    }
+
+    delete m_perDisplayData;
+
+    wxApp::SetInstance(NULL);
 }
 
 int wxApp::MainLoop()
 {
-    m_keepGoing = TRUE;
-
-   /*
+    /*
     * Sit around forever waiting to process X-events. Property Change
     * event are handled special, because they have to refer to
     * the root window rather than to a widget. therefore we can't
@@ -270,73 +160,14 @@ int wxApp::MainLoop()
     */
 
     XSelectInput(XtDisplay((Widget) wxTheApp->GetTopLevelWidget()),
-                 XDefaultRootWindow(XtDisplay((Widget) wxTheApp->GetTopLevelWidget())),
-                 PropertyChangeMask);
-
-    XEvent event;
-
-    // Use this flag to allow breaking the loop via wxApp::ExitMainLoop()
-    while (m_keepGoing)
-    {
-      XtAppNextEvent( (XtAppContext) wxTheApp->GetAppContext(), &event);
-      if(event.type == PropertyNotify)
-      {
-        HandlePropertyChange((WXEvent*) &event);
-      } else
-      {
-        // Terry Gitnick <terryg@scientech.com> - 1/21/98
-         /* if resize event, don't resize until the last resize event for this
-            window is recieved. Prevents flicker as windows are resized. */
-        if (event.type == ResizeRequest)
-        {
-           Display *disp = XtDisplay((Widget) wxTheApp->GetTopLevelWidget());
-           Window win = event.xany.window;
-           XEvent report;
-           //  to avoid flicker
-           report = event;
-           while( XCheckTypedWindowEvent (disp, win, ResizeRequest, &report));
-        }
-        // TODO: when implementing refresh optimization, we can use
-        // XtAddExposureToRegion to expand the window's paint region.
-
-        XtDispatchEvent(&event);
+        XDefaultRootWindow(XtDisplay((Widget) wxTheApp->GetTopLevelWidget())),
+        PropertyChangeMask);
 
-        DeletePendingObjects();
-      }
-    }
+    m_mainLoop->Run();
 
     return 0;
 }
 
-// Returns TRUE if more time is needed.
-bool wxApp::ProcessIdle()
-{
-    wxIdleEvent event;
-    event.SetEventObject(this);
-    ProcessEvent(event);
-
-    return event.MoreRequested();
-}
-
-void wxApp::ExitMainLoop()
-{
-    m_keepGoing = FALSE;
-}
-
-// Is a message/event pending?
-bool wxApp::Pending()
-{
-    XFlush(XtDisplay( (Widget) wxTheApp->GetTopLevelWidget() ));
-    return (XtAppPending( (XtAppContext) wxTheApp->GetAppContext() ) != 0) ;
-}
-
-// Dispatch a message.
-void wxApp::Dispatch()
-{
-    XtAppProcessEvent( (XtAppContext) wxTheApp->GetAppContext(), XtIMAll);
-}
-
 // This should be redefined in a derived class for
 // handling property change events for XAtom IPC.
 void wxApp::HandlePropertyChange(WXEvent *event)
@@ -345,174 +176,217 @@ void wxApp::HandlePropertyChange(WXEvent *event)
     XtDispatchEvent((XEvent*) event); /* let Motif do the work */
 }
 
-void wxApp::OnIdle(wxIdleEvent& event)
+static char *fallbackResources[] = {
+    "*menuBar.marginHeight: 0",
+    "*menuBar.shadowThickness: 1",
+    "*background: #c0c0c0",
+    "*foreground: black",
+    NULL
+};
+
+// Create an application context
+bool wxApp::OnInitGui()
 {
-    static bool inOnIdle = FALSE;
+    if( !wxAppBase::OnInitGui() )
+        return FALSE;
 
-    // Avoid recursion (via ProcessEvent default case)
-    if (inOnIdle)
-      return;
+    XtToolkitInitialize() ;
+    wxTheApp->m_appContext = (WXAppContext) XtCreateApplicationContext();
+    XtAppSetFallbackResources((XtAppContext) wxTheApp->m_appContext, fallbackResources);
 
-    inOnIdle = TRUE;
+    Display *dpy = XtOpenDisplay((XtAppContext) wxTheApp->m_appContext,(String)NULL,NULL,
+        wxTheApp->GetClassName().c_str(), NULL, 0,
+# if XtSpecificationRelease < 5
+        (Cardinal*) &argc,
+# else
+        &argc,
+# endif
+        argv);
 
-    // 'Garbage' collection of windows deleted with Close().
-    DeletePendingObjects();
+    if (!dpy) {
+         // if you don't log to stderr, nothing will be shown...
+        delete wxLog::SetActiveTarget(new wxLogStderr);
+        wxString className(wxTheApp->GetClassName());
+        wxLogError(_("wxWidgets could not open display for '%s': exiting."),
+                   className.c_str());
+        exit(-1);
+    }
+    m_initialDisplay = (WXDisplay*) dpy;
 
-    // flush the logged messages if any
-    wxLog *pLog = wxLog::GetActiveTarget();
-    if ( pLog != NULL && pLog->HasPendingMessages() )
-      pLog->Flush();
+#ifdef __WXDEBUG__
+    // install the X error handler
+    gs_pfnXErrorHandler = XSetErrorHandler(wxXErrorHandler);
+#endif // __WXDEBUG__
 
-    // Send OnIdle events to all windows
-    bool needMore = SendIdleEvents();
+    // Add general resize proc
+    XtActionsRec rec;
+    rec.string = "resize";
+    rec.proc = (XtActionProc)wxWidgetResizeProc;
+    XtAppAddActions((XtAppContext) wxTheApp->m_appContext, &rec, 1);
 
-    if (needMore)
-      event.RequestMore(TRUE);
+    GetMainColormap(dpy);
 
-    inOnIdle = FALSE;
-}
+    wxAddIdleCallback();
 
-// Send idle event to all top-level windows
-bool wxApp::SendIdleEvents()
-{
-    bool needMore = FALSE;
-       wxNode* node = wxTopLevelWindows.First();
-       while (node)
-       {
-               wxWindow* win = (wxWindow*) node->Data();
-               if (SendIdleEvents(win))
-            needMore = TRUE;
-
-               node = node->Next();
-       }
-    return needMore;
+    return TRUE;
 }
 
-// Send idle event to window and all subwindows
-bool wxApp::SendIdleEvents(wxWindow* win)
+WXColormap wxApp::GetMainColormap(WXDisplay* display)
 {
-    bool needMore = FALSE;
+    if (!display) /* Must be called first with non-NULL display */
+        return m_mainColormap;
 
-       wxIdleEvent event;
-       event.SetEventObject(win);
-       win->ProcessEvent(event);
+    int defaultScreen = DefaultScreen((Display*) display);
+    Screen* screen = XScreenOfDisplay((Display*) display, defaultScreen);
 
-    if (event.MoreRequested())
-        needMore = TRUE;
+    Colormap c = DefaultColormapOfScreen(screen);
 
-       wxNode* node = win->GetChildren()->First();
-       while (node)
-       {
-               wxWindow* win = (wxWindow*) node->Data();
-               if (SendIdleEvents(win))
-            needMore = TRUE;
+    if (!m_mainColormap)
+        m_mainColormap = (WXColormap) c;
 
-               node = node->Next();
-       }
-    return needMore ;
+    return (WXColormap) c;
 }
 
-void wxApp::DeletePendingObjects()
+static inline wxPerDisplayData& GetOrCreatePerDisplayData
+    ( wxPerDisplayDataMap& m, WXDisplay* display )
 {
-    wxNode *node = wxPendingDelete.First();
-    while (node)
-    {
-      wxObject *obj = (wxObject *)node->Data();
-    
-      delete obj;
+    wxPerDisplayDataMap::iterator it = m.find( display );
+    if( it != m.end() && it->second != NULL )
+        return *(it->second);
 
-      if (wxPendingDelete.Member(obj))
-        delete node;
+    wxPerDisplayData* nData = new wxPerDisplayData();
+    m[display] = nData;
 
-      // Deleting one object may have deleted other pending
-      // objects, so start from beginning of list again.
-      node = wxPendingDelete.First();
-    }
+    return *nData;
 }
 
-wxLog* wxApp::CreateLogTarget()
+wxXVisualInfo* wxApp::GetVisualInfo( WXDisplay* display )
 {
-    return new wxLogGui;
+    wxPerDisplayData& data = GetOrCreatePerDisplayData( *m_perDisplayData,
+                                                        display );
+    if( data.m_visualInfo )
+        return data.m_visualInfo;
+
+    wxXVisualInfo* vi = new wxXVisualInfo;
+    wxFillXVisualInfo( vi, (Display*)display );
+
+    data.m_visualInfo = vi;
+
+    return vi;
 }
 
-wxWindow* wxApp::GetTopWindow() const
+static void wxTLWidgetDestroyCallback(Widget w, XtPointer clientData,
+                                      XtPointer ptr)
 {
-    if (m_topWindow)
-        return m_topWindow;
-    else if (wxTopLevelWindows.Number() > 0)
-        return (wxWindow*) wxTopLevelWindows.First()->Data();
-    else
-        return NULL;
+    if( wxTheApp )
+    {
+        wxTheApp->SetTopLevelWidget( (WXDisplay*)XtDisplay(w),
+                                     (WXWidget)NULL );
+        wxTheApp->SetTopLevelRealizedWidget( (WXDisplay*)XtDisplay(w),
+                                             (WXWidget)NULL );
+    }
 }
 
-// Create an application context
-bool wxApp::OnInitGui()
+WXWidget wxCreateTopLevelWidget( WXDisplay* display )
 {
-    XtToolkitInitialize() ;
-    wxTheApp->m_appContext = (WXAppContext) XtCreateApplicationContext() ;
-    Display *dpy = XtOpenDisplay((XtAppContext) wxTheApp->m_appContext,(String)NULL,NULL,
-                            (const char*) wxTheApp->GetClassName(), NULL,
-# if XtSpecificationRelease < 5
-                            0,(Cardinal*) &argc,argv) ;
-# else
-                            0,&argc,argv) ;
-# endif
-    if (!dpy) {
-      cerr << "wxWindows could not open display for " << wxTheApp->GetClassName() << ": exiting.\n";
-      exit(-1);
-    }
-    m_initialDisplay = (WXDisplay*) dpy;
+    Widget tlw = XtAppCreateShell( (String)NULL,
+                                   wxTheApp->GetClassName().c_str(),
+                                   applicationShellWidgetClass,
+                                   (Display*)display,
+                                   NULL, 0 );
+    XtVaSetValues( tlw,
+                   XmNoverrideRedirect, True,
+                   NULL );
+
+    XtAddCallback( tlw, XmNdestroyCallback,
+                   (XtCallbackProc)wxTLWidgetDestroyCallback,
+                   (XtPointer)NULL );
+
+    return (WXWidget)tlw;
+}
 
-    wxTheApp->m_topLevelWidget = (WXWidget) XtAppCreateShell((String)NULL, (const char*) wxTheApp->GetClassName(),
-                                     applicationShellWidgetClass,dpy,
-                                     NULL,0) ;
+WXWidget wxCreateTopLevelRealizedWidget( WXDisplay* display )
+{
+    Widget rTlw = XtVaCreateWidget( "dummy_widget", xmLabelWidgetClass,
+                                    (Widget)wxTheApp->GetTopLevelWidget(),
+                                    NULL);
+    XtSetMappedWhenManaged( rTlw, False );
+    XtRealizeWidget( rTlw );
 
-    // Add general resize proc
-    XtActionsRec rec;
-    rec.string = "resize";
-    rec.proc = (XtActionProc)wxWidgetResizeProc;
-    XtAppAddActions((XtAppContext) wxTheApp->m_appContext, &rec, 1);
+    return (WXWidget)rTlw;
+}
 
-    GetMainColormap(dpy);
-    m_maxRequestSize = XMaxRequestSize((Display*) dpy);
+WXWidget wxApp::GetTopLevelWidget()
+{
+    WXDisplay* display = wxGetDisplay();
+    wxPerDisplayData& data = GetOrCreatePerDisplayData( *m_perDisplayData,
+                                                        display );
+    if( data.m_topLevelWidget )
+        return (WXWidget)data.m_topLevelWidget;
 
-    return TRUE;
+    WXWidget tlw = wxCreateTopLevelWidget( display );
+    SetTopLevelWidget( display, tlw );
+
+    return tlw;
 }
 
-WXColormap wxApp::GetMainColormap(WXDisplay* display)
+WXWidget wxApp::GetTopLevelRealizedWidget()
 {
-    if (!display) /* Must be called first with non-NULL display */
-      return m_mainColormap;
+    WXDisplay* display = wxGetDisplay();
+    wxPerDisplayDataMap::iterator it = m_perDisplayData->find( display );
 
-    Colormap c =
-      DefaultColormapOfScreen(XScreenOfDisplay((Display*) display,
-                                            DefaultScreen((Display*) display)));
+    if( it != m_perDisplayData->end() && it->second->m_topLevelRealizedWidget )
+        return (WXWidget)it->second->m_topLevelRealizedWidget;
 
-    if (!m_mainColormap)
-      m_mainColormap = (WXColormap) c;
+    WXWidget rTlw = wxCreateTopLevelRealizedWidget( display );
+    SetTopLevelRealizedWidget( display, rTlw );
 
-    return (WXColormap) c;
+    return rTlw;
 }
 
-void wxExit()
+void wxApp::SetTopLevelWidget(WXDisplay* display, WXWidget widget)
 {
-    int retValue = 0;
-    if (wxTheApp)
-      retValue = wxTheApp->OnExit();
+    GetOrCreatePerDisplayData( *m_perDisplayData, display )
+        .m_topLevelWidget = (Widget)widget;
+}
 
-    wxApp::CleanUp();
-    /*
-     * Exit in some platform-specific way. Not recommended that the app calls this:
-     * only for emergencies.
-     */
-    exit(retValue);
+void wxApp::SetTopLevelRealizedWidget(WXDisplay* display, WXWidget widget)
+{
+    GetOrCreatePerDisplayData( *m_perDisplayData, display )
+        .m_topLevelRealizedWidget = (Widget)widget;
 }
 
 // Yield to other processes
-bool wxYield()
+
+bool wxApp::Yield(bool onlyIfNeeded)
 {
+    static bool s_inYield = FALSE;
+
+    if ( s_inYield )
+    {
+        if ( !onlyIfNeeded )
+        {
+            wxFAIL_MSG( wxT("wxYield called recursively" ) );
+        }
+
+        return FALSE;
+    }
+
+    s_inYield = TRUE;
+
     while (wxTheApp && wxTheApp->Pending())
-      wxTheApp->Dispatch();
+        wxTheApp->Dispatch();
+
+    s_inYield = FALSE;
+
     return TRUE;
 }
 
+// ----------------------------------------------------------------------------
+// accessors for C modules
+// ----------------------------------------------------------------------------
+
+extern "C" XtAppContext wxGetAppContext()
+{
+    return (XtAppContext)wxTheApp->GetAppContext();
+}