Ensure that validators work even in presence of pushed event handlers.

[wxWidgets.git] / src / gtk / utilsgtk.cpp

diff --git a/src/gtk/utilsgtk.cpp b/src/gtk/utilsgtk.cpp
index 56a3f820cb5e32b707dc1ac3322285db14dd1d7c..e337be979235751aa3babba287ad8da657318ec6 100644 (file)
--- a/src/gtk/utilsgtk.cpp
+++ b/src/gtk/utilsgtk.cpp
@@ -1,336 +1,524 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        utils.cpp
+// Name:        src/gtk/utilsgtk.cpp

 // Purpose:
 // Author:      Robert Roebling
 // Purpose:
 // Author:      Robert Roebling

-// Created:     01/02/97

 // Id:          $Id$
 // Id:          $Id$

-// Copyright:   (c) 1998 Robert Roebling, Julian Smart and Markus Holzem
-// Licence:           wxWindows licence
+// Copyright:   (c) 1998 Robert Roebling
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 

-
-//#ifdef __GNUG__
-//#pragma implementation "utils.h"
-//#endif
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"

 
 #include "wx/utils.h"
 
 #include "wx/utils.h"

-#include "wx/string.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/string.h"
+    #include "wx/intl.h"
+    #include "wx/log.h"
+#endif
+
+#include "wx/apptrait.h"
+#include "wx/process.h"
+#include "wx/sysopt.h"
+#include "wx/unix/execute.h"
+
+#include "wx/gtk/private/timer.h"
+#include "wx/evtloop.h"
+
+#if wxDEBUG_LEVEL
+    #include "wx/gtk/assertdlg_gtk.h"
+    #if wxUSE_STACKWALKER
+        #include "wx/stackwalk.h"
+    #endif // wxUSE_STACKWALKER
+#endif // wxDEBUG_LEVEL

 
 #include <stdarg.h>
 
 #include <stdarg.h>

-#include <dirent.h>

 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>

+#include <sys/wait.h>   // for WNOHANG

 #include <unistd.h>
 #include <unistd.h>

-#include <sys/wait.h>
-#include <pwd.h>
-#include <errno.h>
-#include <netdb.h>
-#include <signal.h>

 
 

+#include "glib.h"
+#include "gdk/gdk.h"
+#include "gtk/gtk.h"
+#include "gdk/gdkx.h"

 
 

-#ifdef __SVR4__
-#include <sys/systeminfo.h>
+#if wxUSE_DETECT_SM
+    #include "X11/Xlib.h"
+    #include "X11/SM/SMlib.h"

 #endif
 
 #endif
 

-//------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+// data
+//-----------------------------------------------------------------------------
+
+extern GtkWidget *wxGetRootWindow();
+
+//----------------------------------------------------------------------------

 // misc.
 // misc.

-//------------------------------------------------------------------------
+//----------------------------------------------------------------------------
+#ifndef __EMX__
+// on OS/2, we use the wxBell from wxBase library

 
 

-void wxBell(void)
+void wxBell()

 {
 {

-  gdk_beep();
-};
+    gdk_beep();
+}
+#endif

 
 

-void wxSleep(int nSecs)
-{
-  sleep(nSecs);
-};
+// ----------------------------------------------------------------------------
+// display characterstics
+// ----------------------------------------------------------------------------

 
 

-int wxKill(long pid, int sig)
+void *wxGetDisplay()

 {
 {

-  return kill(pid, sig);
-};
+    return GDK_DISPLAY();
+}

 
 void wxDisplaySize( int *width, int *height )
 {
 
 void wxDisplaySize( int *width, int *height )
 {

-  if (width) *width = gdk_screen_width();
-  if (height) *height = gdk_screen_height();
+    if (width) *width = gdk_screen_width();
+    if (height) *height = gdk_screen_height();

 }
 
 }
 

-void wxGetMousePosition( int* x, int* y )
+void wxDisplaySizeMM( int *width, int *height )

 {
 {

-  wxFAIL_MSG( "GetMousePosition not yet implemented" );
-  if (x) *x = 0;
-  if (y) *y = 0;
-};
+    if (width) *width = gdk_screen_width_mm();
+    if (height) *height = gdk_screen_height_mm();
+}

 
 

-bool wxColourDisplay(void)
+void wxGetMousePosition( int* x, int* y )

 {
 {

-  wxFAIL_MSG( "wxColourDisplay always returns TRUE" );
-  return TRUE;
+    gdk_window_get_pointer( NULL, x, y, NULL );

 }
 
 }
 

-int wxDisplayDepth(void)
+bool wxColourDisplay()

 {
 {

-  wxFAIL_MSG( "wxDisplayDepth always returns 8" );
-  return 8;
+    return true;

 }
 
 }
 

-//------------------------------------------------------------------------
-// user and home routines
-//------------------------------------------------------------------------
+int wxDisplayDepth()
+{
+    return gdk_drawable_get_visual( wxGetRootWindow()->window )->depth;
+}

 
 

-const char* wxGetHomeDir( wxString *home  )
+wxWindow* wxFindWindowAtPoint(const wxPoint& pt)

 {
 {

-  *home = wxGetUserHome( wxString() );
-  if (home->IsNull()) *home = "/";
-  return *home;
-};
+    return wxGenericFindWindowAtPoint(pt);
+}
+
+#if !wxUSE_UNICODE

 
 

-char *wxGetUserHome( const wxString &user )
+WXDLLIMPEXP_CORE wxCharBuffer
+wxConvertToGTK(const wxString& s, wxFontEncoding enc)

 {
 {

-  struct passwd *who = (struct passwd *) NULL;
+    wxWCharBuffer wbuf;
+    if ( enc == wxFONTENCODING_SYSTEM || enc == wxFONTENCODING_DEFAULT )
+    {
+        wbuf = wxConvUI->cMB2WC(s.c_str());
+    }
+    else // another encoding, use generic conversion class
+    {
+        wbuf = wxCSConv(enc).cMB2WC(s.c_str());
+    }

 
 

-  if (user.IsNull() || (user== ""))
-  {
-        register char *ptr;
+    if ( !wbuf && !s.empty() )
+    {
+        // conversion failed, but we still want to show something to the user
+        // even if it's going to be wrong it is better than nothing
+        //
+        // we choose ISO8859-1 here arbitrarily, it's just the most common
+        // encoding probably and, also importantly here, conversion from it
+        // never fails as it's done internally by wxCSConv
+        wbuf = wxCSConv(wxFONTENCODING_ISO8859_1).cMB2WC(s.c_str());
+    }

 
 

-        if ((ptr = getenv("HOME")) != NULL)
-            return ptr;
-        if ((ptr = getenv("USER")) != NULL
-        || (ptr = getenv("LOGNAME")) != NULL) {
-            who = getpwnam(ptr);
-        }
-        // We now make sure the the user exists!
-        if (who == NULL)
-            who = getpwuid(getuid());
-  }
-  else
-    who = getpwnam (user);
-
-  return who ? who->pw_dir : (char*)NULL;
-};
+    return wxConvUTF8.cWC2MB(wbuf);
+}
+
+WXDLLIMPEXP_CORE wxCharBuffer
+wxConvertFromGTK(const wxString& s, wxFontEncoding enc)
+{
+    // this conversion should never fail as GTK+ always uses UTF-8 internally
+    // so there are no complications here
+    const wxWCharBuffer wbuf(wxConvUTF8.cMB2WC(s.c_str()));
+    if ( enc == wxFONTENCODING_SYSTEM )
+        return wxConvUI->cWC2MB(wbuf);
+
+    return wxCSConv(enc).cWC2MB(wbuf);
+}

 
 

-//------------------------------------------------------------------------
-// id routines
-//------------------------------------------------------------------------
+#endif // !wxUSE_UNICODE

 
 

-bool wxGetHostName(char *buf, int sz)
+// Returns NULL if version is certainly greater or equal than major.minor.micro
+// Returns string describing the error if version is lower than
+// major.minor.micro OR it cannot be determined and one should not rely on the
+// availability of pango version major.minor.micro, nor the non-availability
+const gchar *wx_pango_version_check (int major, int minor, int micro)

 {
 {

-    *buf = '\0';
-#if defined(__SVR4__) && !defined(__sgi)
-    //KB: does this return the fully qualified host.domain name?
-    return (sysinfo(SI_HOSTNAME, buf, sz) != -1);
-#else /* BSD Sockets */
-    char name[255], domain[255];
-    //struct hostent *h;
-    // Get hostname
-    if (gethostname(name, sizeof(name)/sizeof(char)-1) == -1)
-        return FALSE;
-    if (getdomainname(domain, sizeof(domain)/sizeof(char)-1) == -1)
-        return FALSE;
-    // Get official full name of host
-    // doesn't return the full qualified name, replaced by following
-    // code (KB)
-    // strncpy(buf, (h=gethostbyname(name))!=NULL ? h->h_name : name, sz-1);
-    if((unsigned)sz > strlen(name)+strlen(domain)+1)
+    // NOTE: you don't need to use this macro to check for Pango features
+    //       added in pango-1.4 or earlier since GTK 2.4 (our minimum requirement
+    //       for GTK lib) required pango 1.4...
+
+#ifdef PANGO_VERSION_MAJOR
+    if (!gtk_check_version (2,11,0))

     {
     {

-       strcpy(buf, name);
-       if(strcmp(domain,"(none)") == 0) // standalone machine
-       {
-         strcat(buf,".");
-         strcat(buf,domain);
-       }
+        // GTK+ 2.11 requires Pango >= 1.15.3 and pango_version_check
+        // was added in Pango 1.15.2 thus we know for sure the pango lib we're
+        // using has the pango_version_check function:
+        return pango_version_check (major, minor, micro);

     }
     }

-    else
-       return FALSE;
-    return TRUE;
+
+    return "can't check";
+#else // !PANGO_VERSION_MAJOR
+    wxUnusedVar(major);
+    wxUnusedVar(minor);
+    wxUnusedVar(micro);
+
+    return "too old headers";

 #endif
 }
 
 #endif
 }
 

-bool wxGetUserId(char *buf, int sz)
+
+// ----------------------------------------------------------------------------
+// subprocess routines
+// ----------------------------------------------------------------------------
+
+extern "C" {
+static
+void GTK_EndProcessDetector(gpointer data, gint source,
+                            GdkInputCondition WXUNUSED(condition))

 {
 {

-    struct passwd *who;
+    wxEndProcessData * const
+        proc_data = static_cast<wxEndProcessData *>(data);

 
 

-    *buf = '\0';
-    if ((who = getpwuid(getuid ())) != NULL) {
-        strncpy (buf, who->pw_name, sz-1);
-        return TRUE;
-    }
-    return FALSE;
+    // child exited, end waiting
+    close(source);
+
+    // don't call us again!
+    gdk_input_remove(proc_data->tag);
+
+    wxHandleProcessTermination(proc_data);
+}

 }
 
 }
 

-bool wxGetUserName(char *buf, int sz)
+int wxGUIAppTraits::AddProcessCallback(wxEndProcessData *proc_data, int fd)

 {
 {

-    struct passwd *who;
-    char *comma;
-
-    *buf = '\0';
-    if ((who = getpwuid (getuid ())) != NULL) {
-       comma = strchr(who->pw_gecos,'c');
-       if(comma) *comma = '\0'; // cut off non-name comment fields
-       strncpy (buf, who->pw_gecos, sz - 1);
-        return TRUE;
-    }
-    return FALSE;
+    int tag = gdk_input_add(fd,
+                            GDK_INPUT_READ,
+                            GTK_EndProcessDetector,
+                            (gpointer)proc_data);
+
+    return tag;

 }
 
 }
 

-//------------------------------------------------------------------------
-// error and debug output routines
-//------------------------------------------------------------------------

 
 

-void wxDebugMsg( const char *format, ... )
-{
-  va_list ap;
-  va_start( ap, format );
-  vfprintf( stderr, format, ap );
-  fflush( stderr );
-  va_end(ap);
-};

 
 

-void wxError( const wxString &msg, const wxString &title )
+// ----------------------------------------------------------------------------
+// wxPlatformInfo-related
+// ----------------------------------------------------------------------------
+
+wxPortId wxGUIAppTraits::GetToolkitVersion(int *verMaj, int *verMin) const

 {
 {

-  fprintf( stderr, "Error " );
-  if (!title.IsNull()) fprintf( stderr, "%s ", WXSTRINGCAST(title) );
-  if (!msg.IsNull()) fprintf( stderr, ": %s", WXSTRINGCAST(msg) );
-  fprintf( stderr, ".\n" );
-};
+    if ( verMaj )
+        *verMaj = gtk_major_version;
+    if ( verMin )
+        *verMin = gtk_minor_version;
+
+    return wxPORT_GTK;
+}
+
+#if wxUSE_TIMER

 
 

-void wxFatalError( const wxString &msg, const wxString &title )
+wxTimerImpl *wxGUIAppTraits::CreateTimerImpl(wxTimer *timer)

 {
 {

-  fprintf( stderr, "Error " );
-  if (!title.IsNull()) fprintf( stderr, "%s ", WXSTRINGCAST(title) );
-  if (!msg.IsNull()) fprintf( stderr, ": %s", WXSTRINGCAST(msg) );
-  fprintf( stderr, ".\n" );
-  exit(1);
-};
+    return new wxGTKTimerImpl(timer);
+}

 
 

-//------------------------------------------------------------------------
-// directory routines
-//------------------------------------------------------------------------
+#endif // wxUSE_TIMER

 
 

-bool wxDirExists( const wxString& dir )
+#if wxUSE_DETECT_SM
+static wxString GetSM()

 {
 {

-  char buf[500];
-  strcpy( buf, WXSTRINGCAST(dir) );
-  struct stat sbuf;
-  return ((stat(buf, &sbuf) != -1) && S_ISDIR(sbuf.st_mode) ? TRUE : FALSE);
-};
+    class Dpy
+    {
+    public:
+        Dpy() { m_dpy = XOpenDisplay(NULL); }
+        ~Dpy() { if ( m_dpy ) XCloseDisplay(m_dpy); }
+
+        operator Display *() const { return m_dpy; }
+    private:
+        Display *m_dpy;
+    } dpy;
+
+    if ( !dpy )
+        return wxEmptyString;
+
+    char smerr[256];
+    char *client_id;
+    SmcConn smc_conn = SmcOpenConnection(NULL, NULL,
+                                         999, 999,
+                                         0 /* mask */, NULL /* callbacks */,
+                                         NULL, &client_id,
+                                         WXSIZEOF(smerr), smerr);
+
+    if ( !smc_conn )
+    {
+        wxLogDebug("Failed to connect to session manager: %s", smerr);
+        return wxEmptyString;
+    }

 
 

-//------------------------------------------------------------------------
-// subprocess routines
-//------------------------------------------------------------------------
+    char *vendor = SmcVendor(smc_conn);
+    wxString ret = wxString::FromAscii( vendor );
+    free(vendor);

 
 

-typedef struct {
-  gint pid, tag;
-  wxProcess *process;
-} wxEndProcessData;
+    SmcCloseConnection(smc_conn, 0, NULL);
+    free(client_id);

 
 

-static void GTK_EndProcessDetector(gpointer data, gint source,
-                                   GdkInputCondition WXUNUSED(condition) )
+    return ret;
+}
+#endif // wxUSE_DETECT_SM
+
+
+//-----------------------------------------------------------------------------
+// wxGUIAppTraits
+//-----------------------------------------------------------------------------
+
+wxEventLoopBase *wxGUIAppTraits::CreateEventLoop()

 {
 {

-  wxEndProcessData *proc_data = (wxEndProcessData *)data;
-  int pid;
+    return new wxEventLoop();
+}

 
 

-  pid = (proc_data->pid > 0) ? proc_data->pid : -(proc_data->pid);

 
 

-  /* wait4 is not part of any standard, use at own risk
-   * not sure what wait4 does, but wait3 seems to be closest, whats a digit ;-)
-   * --- offer@sgi.com */
-#if !defined(__sgi)
-  wait4(proc_data->pid, NULL, 0, NULL);
-#else
-  wait3((int *) NULL, 0, (rusage *) NULL);
+#if wxUSE_INTL
+void wxGUIAppTraits::SetLocale()
+{
+    gtk_set_locale();
+    wxUpdateLocaleIsUtf8();
+}

 #endif
 
 #endif
 

-  close(source);
-  gdk_input_remove(proc_data->tag);
+#if wxDEBUG_LEVEL && wxUSE_STACKWALKER

 
 

-  if (proc_data->process)
-    proc_data->process->OnTerminate(proc_data->pid);
+// private helper class
+class StackDump : public wxStackWalker
+{
+public:
+    StackDump(GtkAssertDialog *dlg) { m_dlg=dlg; }
+
+protected:
+    virtual void OnStackFrame(const wxStackFrame& frame)
+    {
+        wxString fncname = frame.GetName();
+        wxString fncargs = fncname;
+
+        size_t n = fncname.find(wxT('('));
+        if (n != wxString::npos)
+        {
+            // remove arguments from function name
+            fncname.erase(n);
+
+            // remove function name and brackets from arguments
+            fncargs = fncargs.substr(n+1, fncargs.length()-n-2);
+        }
+        else
+            fncargs = wxEmptyString;
+
+        // append this stack frame's info in the dialog
+        if (!frame.GetFileName().empty() || !fncname.empty())
+            gtk_assert_dialog_append_stack_frame(m_dlg,
+                                                fncname.mb_str(),
+                                                fncargs.mb_str(),
+                                                frame.GetFileName().mb_str(),
+                                                frame.GetLine());
+    }

 
 

-  if (proc_data->pid > 0)
-    delete proc_data;
-  else
-    proc_data->pid = 0;
+private:
+    GtkAssertDialog *m_dlg;

 };
 
 };
 

-long wxExecute( char **argv, bool sync, wxProcess *process )
+// the callback functions must be extern "C" to comply with GTK+ declarations
+extern "C"

 {
 {

-    wxEndProcessData *data = new wxEndProcessData;
-    int end_proc_detect[2];
+    void get_stackframe_callback(StackDump *dump)
+    {
+        // skip over frames up to including wxOnAssert()
+        dump->ProcessFrames(3);
+    }
+}

 
 

-    if (*argv == NULL)
-        return 0;
+#endif // wxDEBUG_LEVEL && wxUSE_STACKWALKER

 
 

-    /* Create pipes */
-    if (pipe(end_proc_detect) == -1) {
-      perror("pipe failed");
-      return 0;
-    }
+bool wxGUIAppTraits::ShowAssertDialog(const wxString& msg)
+{
+#if wxDEBUG_LEVEL
+    // we can't show the dialog from another thread
+    if ( wxIsMainThread() )
+    {
+        // under GTK2 we prefer to use a dialog widget written using directly
+        // in GTK+ as use a dialog written using wxWidgets would need the
+        // wxWidgets idle processing to work correctly which might not be the
+        // case when assert happens
+        GtkWidget *dialog = gtk_assert_dialog_new();
+        gtk_assert_dialog_set_message(GTK_ASSERT_DIALOG(dialog), msg.mb_str());
+
+#if wxUSE_STACKWALKER
+        // save the current stack ow...
+        StackDump dump(GTK_ASSERT_DIALOG(dialog));
+        dump.SaveStack(100); // showing more than 100 frames is not very useful
+
+        // ...but process it only if the user needs it
+        gtk_assert_dialog_set_backtrace_callback
+        (
+            GTK_ASSERT_DIALOG(dialog),
+            (GtkAssertDialogStackFrameCallback)get_stackframe_callback,
+            &dump
+        );
+#endif // wxUSE_STACKWALKER
+
+        gint result = gtk_dialog_run(GTK_DIALOG (dialog));
+        bool returnCode = false;
+        switch (result)
+        {
+            case GTK_ASSERT_DIALOG_STOP:
+                wxTrap();
+                break;
+            case GTK_ASSERT_DIALOG_CONTINUE:
+                // nothing to do
+                break;
+            case GTK_ASSERT_DIALOG_CONTINUE_SUPPRESSING:
+                // no more asserts
+                returnCode = true;
+                break;
+
+            default:
+                wxFAIL_MSG( wxT("unexpected return code from GtkAssertDialog") );
+        }

 
 

-    /* fork the process */
-#if defined(sun) || defined(__ultrix) || defined(__bsdi__)
-    pid_t pid = vfork();
-#else
-    pid_t pid = fork();
-#endif
-    if (pid == -1) {
-        perror ("fork failed");
-        return 0;
-    } else if (pid == 0) {
-        /* Close fd not useful */
-        close(end_proc_detect[0]); // close reading side
-
-        /* child */
-#ifdef _AIX
-        execvp ((const char *)*argv, (const char **)argv);
-#else
-        execvp (*argv, argv);
-#endif
-        if (errno == ENOENT)
-            wxError("command not found", *argv);
-        else
-            perror (*argv);
-        wxError("could not execute", *argv);
-        _exit (-1);
+        gtk_widget_destroy(dialog);
+        return returnCode;

     }
     }

+#endif // wxDEBUG_LEVEL

 
 

-    close(end_proc_detect[1]); // close writing side
-    data->tag = gdk_input_add(end_proc_detect[0], GDK_INPUT_READ,
-                              GTK_EndProcessDetector, (gpointer)data);
-    data->pid = pid;
-    if (!sync) {
-      data->process = process;
-    } else {
-      data->process = (wxProcess *) NULL;
-      data->pid = -(data->pid);
+    return wxAppTraitsBase::ShowAssertDialog(msg);
+}

 
 

-      while (data->pid != 0)
-        wxYield();
+wxString wxGUIAppTraits::GetDesktopEnvironment() const
+{
+    wxString de = wxSystemOptions::GetOption(wxT("gtk.desktop"));
+#if wxUSE_DETECT_SM
+    if ( de.empty() )
+    {
+        static const wxString s_SM = GetSM();

 
 

-      delete data;
+        if (s_SM == wxT("GnomeSM"))
+            de = wxT("GNOME");
+        else if (s_SM == wxT("KDE"))
+            de = wxT("KDE");

     }
     }

+#endif // wxUSE_DETECT_SM

 
 

-    return pid;
-};
+    return de;
+}

 
 

-long wxExecute( const wxString& command, bool sync, wxProcess *process )
+#ifdef __WXGTK26__
+
+// see the hack below in wxCmdLineParser::GetUsageString().
+// TODO: replace this hack with a g_option_group_get_entries()
+//       call as soon as such function exists;
+//       see http://bugzilla.gnome.org/show_bug.cgi?id=431021 for the relative
+//       feature request
+struct _GOptionGroup

 {
 {

-    if (command.IsNull() || command == "") return FALSE;
-
-    int argc = 0;
-    char *argv[127];
-    char tmp[1024];
-    const char *IFS = " \t\n";
-
-    strncpy (tmp, command, sizeof(tmp) / sizeof(char) - 1);
-    tmp[sizeof (tmp) / sizeof (char) - 1] = '\0';
-    argv[argc++] = strtok (tmp, IFS);
-    while ((argv[argc++] = strtok((char *) NULL, IFS)) != NULL)
-        /* loop */ ;
-    return wxExecute(argv, sync, process);
+  gchar           *name;
+  gchar           *description;
+  gchar           *help_description;
+
+  GDestroyNotify   destroy_notify;
+  gpointer         user_data;
+
+  GTranslateFunc   translate_func;
+  GDestroyNotify   translate_notify;
+  gpointer     translate_data;
+
+  GOptionEntry    *entries;
+  gint             n_entries;
+
+  GOptionParseFunc pre_parse_func;
+  GOptionParseFunc post_parse_func;
+  GOptionErrorFunc error_func;

 };
 
 };
 

+wxString wxGetNameFromGtkOptionEntry(const GOptionEntry *opt)
+{
+    wxString ret;
+
+    if (opt->short_name)
+        ret << wxT("-") << opt->short_name;
+    if (opt->long_name)
+    {
+        if (!ret.empty())
+            ret << wxT(", ");
+        ret << wxT("--") << opt->long_name;
+
+        if (opt->arg_description)
+            ret << wxT("=") << opt->arg_description;
+    }
+
+    return wxT("  ") + ret;
+}
+
+#endif // __WXGTK26__
+
+wxString
+wxGUIAppTraits::GetStandardCmdLineOptions(wxArrayString& names,
+                                          wxArrayString& desc) const
+{
+    wxString usage;
+
+#ifdef __WXGTK26__
+    if (!gtk_check_version(2,6,0))
+    {
+        // since GTK>=2.6, we can use the glib_check_version() symbol...
+
+        // check whether GLib version is greater than 2.6 but also lower than 2.19
+        // because, as we use the undocumented _GOptionGroup struct, we don't want
+        // to run this code with future versions which might change it (2.19 is the
+        // latest one at the time of this writing)
+        if (!glib_check_version(2,6,0) && glib_check_version(2,20,0))
+        {
+            usage << _("The following standard GTK+ options are also supported:\n");
+
+            // passing true here means that the function can open the default
+            // display while parsing (not really used here anyhow)
+            GOptionGroup *gtkOpts = gtk_get_option_group(true);
+
+            // WARNING: here we access the internals of GOptionGroup:
+            GOptionEntry *entries = ((_GOptionGroup*)gtkOpts)->entries;
+            unsigned int n_entries = ((_GOptionGroup*)gtkOpts)->n_entries;
+            wxArrayString namesOptions, descOptions;
+
+            for ( size_t n = 0; n < n_entries; n++ )
+            {
+                if ( entries[n].flags & G_OPTION_FLAG_HIDDEN )
+                    continue;       // skip
+
+                names.push_back(wxGetNameFromGtkOptionEntry(&entries[n]));
+
+                const gchar * const entryDesc = entries[n].description;
+                desc.push_back(wxString(entryDesc));
+            }
+
+            g_option_group_free (gtkOpts);
+        }
+    }
+#else
+    wxUnusedVar(names);
+    wxUnusedVar(desc);
+#endif // __WXGTK26__
+
+    return usage;
+}