]> git.saurik.com Git - wxWidgets.git/blobdiff - src/gtk1/settings.cpp
Correction to previous commit
[wxWidgets.git] / src / gtk1 / settings.cpp
index 76a1b0565d67c2ba023a5d2f886d3c758109a4fa..5efb1a3ebc7cca4cea9398b60e5b1a68cda9c825 100644 (file)
@@ -2,98 +2,54 @@
 // Name:        gtk/settings.cpp
 // Purpose:
 // Author:      Robert Roebling
+// Modified by: Mart Raudsepp (GetMetric)
 // Id:          $Id$
 // Copyright:   (c) 1998 Robert Roebling
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 
-#ifdef __GNUG__
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
 #pragma implementation "settings.h"
 #endif
 
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
 #include "wx/settings.h"
 #include "wx/debug.h"
-#include "wx/module.h"
 #include "wx/cmndata.h"
+#include "wx/fontutil.h"
+#include "wx/toplevel.h"
 
 #include <gdk/gdk.h>
+#include <gdk/gdkx.h>
 #include <gdk/gdkprivate.h>
 #include <gtk/gtk.h>
 
-/*
-#define wxSYS_COLOUR_SCROLLBAR         0
-#define wxSYS_COLOUR_BACKGROUND        1
-#define wxSYS_COLOUR_ACTIVECAPTION     2
-#define wxSYS_COLOUR_INACTIVECAPTION   3
-#define wxSYS_COLOUR_MENU              4
-#define wxSYS_COLOUR_WINDOW            5
-#define wxSYS_COLOUR_WINDOWFRAME       6
-#define wxSYS_COLOUR_MENUTEXT          7
-#define wxSYS_COLOUR_WINDOWTEXT        8
-#define wxSYS_COLOUR_CAPTIONTEXT       9
-#define wxSYS_COLOUR_ACTIVEBORDER      10
-#define wxSYS_COLOUR_INACTIVEBORDER    11
-#define wxSYS_COLOUR_APPWORKSPACE      12
-#define wxSYS_COLOUR_HIGHLIGHT         13
-#define wxSYS_COLOUR_HIGHLIGHTTEXT     14
-#define wxSYS_COLOUR_BTNFACE           15
-#define wxSYS_COLOUR_BTNSHADOW         16
-#define wxSYS_COLOUR_GRAYTEXT          17
-#define wxSYS_COLOUR_BTNTEXT           18
-#define wxSYS_COLOUR_INACTIVECAPTIONTEXT 19
-#define wxSYS_COLOUR_BTNHIGHLIGHT      20
-
-#define wxSYS_COLOUR_3DDKSHADOW        21
-#define wxSYS_COLOUR_3DLIGHT           22
-#define wxSYS_COLOUR_INFOTEXT          23
-#define wxSYS_COLOUR_INFOBK            24
-
-#define wxSYS_COLOUR_DESKTOP           wxSYS_COLOUR_BACKGROUND
-#define wxSYS_COLOUR_3DFACE            wxSYS_COLOUR_BTNFACE
-#define wxSYS_COLOUR_3DSHADOW          wxSYS_COLOUR_BTNSHADOW
-#define wxSYS_COLOUR_3DHIGHLIGHT       wxSYS_COLOUR_BTNHIGHLIGHT
-#define wxSYS_COLOUR_3DHILIGHT         wxSYS_COLOUR_BTNHIGHLIGHT
-#define wxSYS_COLOUR_BTNHILIGHT        wxSYS_COLOUR_BTNHIGHLIGHT
-*/
+#include <X11/Xatom.h>
 
 #define SHIFT (8*(sizeof(short int)-sizeof(char)))
 
-//wxColour *g_systemWinColour          = (wxColour *) NULL;
-wxColour *g_systemBtnFaceColour       = (wxColour *) NULL;
-wxColour *g_systemBtnShadowColour     = (wxColour *) NULL;
-wxColour *g_systemBtnHighlightColour  = (wxColour *) NULL;
-wxColour *g_systemHighlightColour     = (wxColour *) NULL;
-wxColour *g_systemHighlightTextColour = (wxColour *) NULL;
-wxColour *g_systemListBoxColour       = (wxColour *) NULL;
-wxColour *g_systemBtnTextColour       = (wxColour *) NULL;
-
-wxFont *g_systemFont = (wxFont *) NULL;
-
 // ----------------------------------------------------------------------------
-// wxSystemSettingsModule
+// wxSystemObjects
 // ----------------------------------------------------------------------------
 
-class wxSystemSettingsModule : public wxModule
+struct wxSystemObjects
 {
-public:
-    bool OnInit() { return TRUE; }
-    void OnExit()
-    {
-        //delete g_systemWinColour;
-        delete g_systemBtnFaceColour;
-        delete g_systemBtnShadowColour;
-        delete g_systemBtnHighlightColour;
-        delete g_systemHighlightColour;
-        delete g_systemHighlightTextColour;
-        delete g_systemListBoxColour;
-        delete g_systemFont;
-        delete g_systemBtnTextColour;
-    }
-    DECLARE_DYNAMIC_CLASS(wxSystemSettingsModule)
+    wxColour m_colBtnFace,
+             m_colBtnShadow,
+             m_colBtnHighlight,
+             m_colHighlight,
+             m_colHighlightText,
+             m_colListBox,
+             m_colBtnText,
+             m_colMenuItemHighlight;
+
+    wxFont m_fontSystem;
 };
 
-IMPLEMENT_DYNAMIC_CLASS(wxSystemSettingsModule, wxModule)
+static wxSystemObjects gs_objects;
 
 // ----------------------------------------------------------------------------
 // wxSystemSettings implementation
@@ -103,7 +59,8 @@ IMPLEMENT_DYNAMIC_CLASS(wxSystemSettingsModule, wxModule)
 enum wxGtkWidgetType
 {
     wxGTK_BUTTON,
-    wxGTK_LIST
+    wxGTK_LIST,
+    wxGTK_MENUITEM
 };
 
 // the colour we need
@@ -134,6 +91,10 @@ static bool GetColourFromGTKWidget(int& red, int& green, int& blue,
 
         case wxGTK_LIST:
             widget = gtk_list_new();
+            break;
+
+        case wxGTK_MENUITEM:
+            widget = gtk_menu_item_new();
     }
 
     GtkStyle *def = gtk_rc_get_style( widget );
@@ -185,15 +146,15 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
     {
         case wxSYS_COLOUR_SCROLLBAR:
         case wxSYS_COLOUR_BACKGROUND:
-        case wxSYS_COLOUR_ACTIVECAPTION:
         case wxSYS_COLOUR_INACTIVECAPTION:
         case wxSYS_COLOUR_MENU:
         case wxSYS_COLOUR_WINDOWFRAME:
         case wxSYS_COLOUR_ACTIVEBORDER:
         case wxSYS_COLOUR_INACTIVEBORDER:
         case wxSYS_COLOUR_BTNFACE:
+        case wxSYS_COLOUR_MENUBAR:
         case wxSYS_COLOUR_3DLIGHT:
-            if (!g_systemBtnFaceColour)
+            if (!gs_objects.m_colBtnFace.Ok())
             {
                 int red, green, blue;
                 if ( !GetColourFromGTKWidget(red, green, blue) )
@@ -203,11 +164,11 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
                     blue = 0x9c40;
                 }
 
-                g_systemBtnFaceColour = new wxColour( red   >> SHIFT,
-                                                      green >> SHIFT,
-                                                      blue  >> SHIFT );
+                gs_objects.m_colBtnFace = wxColour( red   >> SHIFT,
+                                                   green >> SHIFT,
+                                                   blue  >> SHIFT );
             }
-            return *g_systemBtnFaceColour;
+            return gs_objects.m_colBtnFace;
 
         case wxSYS_COLOUR_WINDOW:
             return *wxWHITE;
@@ -218,35 +179,23 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
         case wxSYS_COLOUR_GRAYTEXT:
         case wxSYS_COLOUR_BTNSHADOW:
         //case wxSYS_COLOUR_3DSHADOW:
-            if (!g_systemBtnShadowColour)
+            if (!gs_objects.m_colBtnShadow.Ok())
             {
                 wxColour faceColour(GetColour(wxSYS_COLOUR_3DFACE));
-                g_systemBtnShadowColour =
-                   new wxColour((unsigned char) (faceColour.Red() * 0.666),
-                                (unsigned char) (faceColour.Green() * 0.666),
-                                (unsigned char) (faceColour.Blue() * 0.666));
+                gs_objects.m_colBtnShadow =
+                   wxColour((unsigned char) (faceColour.Red() * 0.666),
+                            (unsigned char) (faceColour.Green() * 0.666),
+                            (unsigned char) (faceColour.Blue() * 0.666));
             }
 
-            return *g_systemBtnShadowColour;
+            return gs_objects.m_colBtnShadow;
 
         case wxSYS_COLOUR_3DHIGHLIGHT:
         //case wxSYS_COLOUR_BTNHIGHLIGHT:
             return * wxWHITE;
-/* I think this should normally be white (JACS 8/2000)
-
-   Hmm, I'm quite sure it shouldn't ... (VZ 20.08.01)
-            if (!g_systemBtnHighlightColour)
-            {
-                g_systemBtnHighlightColour =
-                    new wxColour( 0xea60 >> SHIFT,
-                                  0xea60 >> SHIFT,
-                                  0xea60 >> SHIFT );
-            }
-            return *g_systemBtnHighlightColour;
-*/
 
         case wxSYS_COLOUR_HIGHLIGHT:
-            if (!g_systemHighlightColour)
+            if (!gs_objects.m_colHighlight.Ok())
             {
                 int red, green, blue;
                 if ( !GetColourFromGTKWidget(red, green, blue,
@@ -258,14 +207,14 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
                     blue = 0x9c40;
                 }
 
-                g_systemHighlightColour = new wxColour( red   >> SHIFT,
+                gs_objects.m_colHighlight = wxColour( red   >> SHIFT,
                                                         green >> SHIFT,
                                                         blue  >> SHIFT );
             }
-            return *g_systemHighlightColour;
+            return gs_objects.m_colHighlight;
 
         case wxSYS_COLOUR_LISTBOX:
-            if (!g_systemListBoxColour)
+            if (!gs_objects.m_colListBox.Ok())
             {
                 int red, green, blue;
                 if ( GetColourFromGTKWidget(red, green, blue,
@@ -273,16 +222,16 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
                                             GTK_STATE_NORMAL,
                                             wxGTK_BASE) )
                 {
-                    g_systemListBoxColour = new wxColour( red   >> SHIFT,
+                    gs_objects.m_colListBox = wxColour( red   >> SHIFT,
                                                           green >> SHIFT,
                                                           blue  >> SHIFT );
                 }
                 else
                 {
-                    g_systemListBoxColour = new wxColour(*wxWHITE);
+                    gs_objects.m_colListBox = wxColour(*wxWHITE);
                 }
             }
-            return *g_systemListBoxColour;
+            return gs_objects.m_colListBox;
 
         case wxSYS_COLOUR_MENUTEXT:
         case wxSYS_COLOUR_WINDOWTEXT:
@@ -290,7 +239,7 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
         case wxSYS_COLOUR_INACTIVECAPTIONTEXT:
         case wxSYS_COLOUR_BTNTEXT:
         case wxSYS_COLOUR_INFOTEXT:
-            if (!g_systemBtnTextColour)
+            if (!gs_objects.m_colBtnText.Ok())
             {
                 int red, green, blue;
                 if ( !GetColourFromGTKWidget(red, green, blue,
@@ -303,29 +252,65 @@ wxColour wxSystemSettingsNative::GetColour( wxSystemColour index )
                     blue = 0;
                 }
 
-                g_systemBtnTextColour = new wxColour( red   >> SHIFT,
+                gs_objects.m_colBtnText = wxColour( red   >> SHIFT,
                                                       green >> SHIFT,
                                                       blue  >> SHIFT );
             }
-            return *g_systemBtnTextColour;
+            return gs_objects.m_colBtnText;
+
+            // this (as well as wxSYS_COLOUR_INFOTEXT above) is used for
+            // tooltip windows - Robert, please change this code to use the
+            // real GTK tooltips when/if you can (TODO)
+        case wxSYS_COLOUR_INFOBK:
+            return wxColour(255, 255, 225);
 
         case wxSYS_COLOUR_HIGHLIGHTTEXT:
-            if (!g_systemHighlightTextColour)
+            if (!gs_objects.m_colHighlightText.Ok())
             {
                 wxColour hclr = GetColour(wxSYS_COLOUR_HIGHLIGHT);
                 if (hclr.Red() > 200 && hclr.Green() > 200 && hclr.Blue() > 200)
-                    g_systemHighlightTextColour = new wxColour(*wxBLACK);
+                    gs_objects.m_colHighlightText = wxColour(*wxBLACK);
                 else
-                    g_systemHighlightTextColour = new wxColour(*wxWHITE);
+                    gs_objects.m_colHighlightText = wxColour(*wxWHITE);
             }
-            return *g_systemHighlightTextColour;
+            return gs_objects.m_colHighlightText;
 
-        case wxSYS_COLOUR_INFOBK:
         case wxSYS_COLOUR_APPWORKSPACE:
             return *wxWHITE;    // ?
-  }
 
-  return *wxWHITE;
+        case wxSYS_COLOUR_ACTIVECAPTION:
+        case wxSYS_COLOUR_MENUHILIGHT:
+            if (!gs_objects.m_colMenuItemHighlight.Ok())
+            {
+                int red, green, blue;
+                if ( !GetColourFromGTKWidget(red, green, blue,
+                                             wxGTK_MENUITEM,
+                                             GTK_STATE_SELECTED,
+                                             wxGTK_BG) )
+                {
+                    red =
+                    green =
+                    blue = 0;
+                }
+
+                gs_objects.m_colMenuItemHighlight = wxColour( red  >> SHIFT,
+                                                              green >> SHIFT,
+                                                              blue  >> SHIFT );
+            }
+            return gs_objects.m_colMenuItemHighlight;
+
+        case wxSYS_COLOUR_HOTLIGHT:
+        case wxSYS_COLOUR_GRADIENTACTIVECAPTION:
+        case wxSYS_COLOUR_GRADIENTINACTIVECAPTION:
+            // TODO
+            return *wxBLACK;
+
+        case wxSYS_COLOUR_MAX:
+        default:
+            wxFAIL_MSG( _T("unknown system colour index") );
+    }
+
+    return *wxWHITE;
 }
 
 wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
@@ -343,12 +328,40 @@ wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
         case wxSYS_DEVICE_DEFAULT_FONT:
         case wxSYS_DEFAULT_GUI_FONT:
         {
-            if (!g_systemFont)
+            if (!gs_objects.m_fontSystem.Ok())
             {
-                g_systemFont = new wxFont( 12, wxSWISS, wxNORMAL, wxNORMAL );
-
+#ifdef __WXGTK20__
+                GtkWidget *widget = gtk_button_new();
+                GtkStyle *def = gtk_rc_get_style( widget );
+                if ( !def || !def->font_desc )
+                    def = gtk_widget_get_default_style();  
+                if ( def && def->font_desc )
+                {  
+                    wxNativeFontInfo info;  
+                    info.description = 
+                        pango_font_description_copy(def->font_desc);
+                    gs_objects.m_fontSystem = wxFont(info);  
+                }  
+                else  
+                {  
+                    GtkSettings *settings = gtk_settings_get_default();
+                    gchar *font_name = NULL;
+                    g_object_get ( settings,
+                                   "gtk-font-name", 
+                                   &font_name,
+                                   NULL);
+                    if (!font_name)
+                        gs_objects.m_fontSystem = wxFont( 12, wxSWISS, wxNORMAL, wxNORMAL );
+                    else
+                        gs_objects.m_fontSystem = wxFont(wxString::FromAscii(font_name));
+                    g_free (font_name);
+                }  
+                gtk_widget_destroy( widget );
+#else
+                gs_objects.m_fontSystem = wxFont( 12, wxSWISS, wxNORMAL, wxNORMAL );
+#endif
             }
-            return *g_systemFont;
+            return gs_objects.m_fontSystem;
         }
 
         default:
@@ -356,17 +369,266 @@ wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
     }
 }
 
-int wxSystemSettingsNative::GetMetric( wxSystemMetric index )
+int wxSystemSettingsNative::GetMetric( wxSystemMetric index, wxWindow* win )
 {
+#ifdef __WXGTK20__
+    bool success = false;
+            
+    guchar *data = NULL;
+    GdkWindow *window = NULL;
+    if(win && GTK_WIDGET_REALIZED(win->GetHandle()))
+        window = win->GetHandle()->window;
+#endif
+
     switch (index)
     {
-        case wxSYS_SCREEN_X:   return gdk_screen_width();
-        case wxSYS_SCREEN_Y:   return gdk_screen_height();
+#ifdef __WXGTK20__
+        case wxSYS_BORDER_X:
+        case wxSYS_BORDER_Y:
+        case wxSYS_EDGE_X:
+        case wxSYS_EDGE_Y:
+        case wxSYS_FRAMESIZE_X:
+        case wxSYS_FRAMESIZE_Y:
+            // If a window is specified/realized, and it is a toplevel window, we can query from wm.
+            // The returned border thickness is outside the client area in that case.
+            if (window)
+            {
+                wxTopLevelWindow *tlw = wxDynamicCast(win, wxTopLevelWindow);
+                if (!tlw)
+                    return -1; // not a tlw, not sure how to approach
+                else
+                {
+                    // Check if wm supports frame extents - we can't know
+                    // the border widths if it does not.
+#if GTK_CHECK_VERSION(2,2,0)
+                    if (!gtk_check_version(2,2,0))
+                    {
+                        if (!gdk_x11_screen_supports_net_wm_hint(
+                                gdk_drawable_get_screen(window),
+                                gdk_atom_intern("_NET_FRAME_EXTENTS", false) ) )
+                            return -1;
+                    }
+                    else
+#endif
+                    {
+                        if (!gdk_net_wm_supports(gdk_atom_intern("_NET_FRAME_EXTENTS", false)))
+                            return -1;
+                    }
+    
+                    // Get the frame extents from the windowmanager.
+                    // In most cases the top extent is the titlebar, so we use the bottom extent
+                    // for the heights.
+    
+                    Atom type;
+                    gint format;
+                    gulong nitems;
+                    
+#if GTK_CHECK_VERSION(2,2,0)
+                    if (!gtk_check_version(2,2,0))
+                    {
+                        gulong bytes_after;
+                        success = (XGetWindowProperty (GDK_DISPLAY_XDISPLAY(gdk_drawable_get_display(window)),
+                                            GDK_WINDOW_XWINDOW(window),
+                                            gdk_x11_get_xatom_by_name_for_display (
+                                                    gdk_drawable_get_display(window),
+                                                    "_NET_FRAME_EXTENTS" ),
+                                            0, // left, right, top, bottom, CARDINAL[4]/32
+                                            G_MAXLONG, // size of long
+                                            false, // do not delete property
+                                            XA_CARDINAL, // 32 bit
+                                            &type, &format, &nitems, &bytes_after, &data
+                                           ) == Success);
+                    }
+#endif
+                    if (success)
+                    {
+                        int border_return = -1;
+
+                        if ((type == XA_CARDINAL) && (format == 32) && (nitems >= 4) && (data))
+                        {
+                            long *borders;
+                            borders = (long*)data;
+                            switch(index)
+                            {
+                                case wxSYS_BORDER_X:
+                                case wxSYS_EDGE_X:
+                                case wxSYS_FRAMESIZE_X:
+                                    border_return = borders[1]; // width of right extent
+                                    break;
+                                default:
+                                    border_return = borders[3]; // height of bottom extent
+                                    break;
+                            }
+                        }
+
+                        if (data)
+                            XFree(data);
+
+                        return border_return;
+                    }
+                }
+            }
+
+            return -1; // no window specified
+#endif // gtk2
+
+        case wxSYS_CURSOR_X:
+        case wxSYS_CURSOR_Y:
+#ifdef __WXGTK24__
+            if (!gtk_check_version(2,4,0))
+            {
+                if (window)
+                    return gdk_display_get_default_cursor_size(gdk_drawable_get_display(window));
+                else
+                    return gdk_display_get_default_cursor_size(gdk_display_get_default());
+            }
+            else
+#endif
+                return 16;
+
+#ifdef __WXGTK20__
+        case wxSYS_DCLICK_X:
+        case wxSYS_DCLICK_Y:
+            gint dclick_distance;
+#if GTK_CHECK_VERSION(2,2,0)
+            if (window && !gtk_check_version(2,2,0))
+                g_object_get(gtk_settings_get_for_screen(gdk_drawable_get_screen(window)),
+                                "gtk-double-click-distance", &dclick_distance, NULL);
+            else
+#endif
+                g_object_get(gtk_settings_get_default(),
+                                "gtk-double-click-distance", &dclick_distance, NULL);
+
+            return dclick_distance * 2;
+#endif // gtk2
+
+#ifdef __WXGTK20__
+        case wxSYS_DRAG_X:
+        case wxSYS_DRAG_Y:
+            gint drag_threshold;
+#if GTK_CHECK_VERSION(2,2,0)
+            if (window && !gtk_check_version(2,2,0))
+            {
+                g_object_get(
+                        gtk_settings_get_for_screen(gdk_drawable_get_screen(window)),
+                        "gtk-dnd-drag-threshold",
+                        &drag_threshold, NULL);
+            }
+            else
+#endif
+            {
+                g_object_get(gtk_settings_get_default(),
+                             "gtk-dnd-drag-threshold", &drag_threshold, NULL);
+            }
+
+            return drag_threshold * 2;
+#endif
+
+        // MBN: ditto for icons
+        case wxSYS_ICON_X:     return 32;
+        case wxSYS_ICON_Y:     return 32;
+
+        case wxSYS_SCREEN_X:
+#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2,2,0)
+            if (window && !gtk_check_version(2,2,0))
+                return gdk_screen_get_width(gdk_drawable_get_screen(window));
+            else
+#endif
+                return gdk_screen_width();
+
+        case wxSYS_SCREEN_Y:
+#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2,2,0)
+            if (window && !gtk_check_version(2,2,0))
+                return gdk_screen_get_height(gdk_drawable_get_screen(window));
+            else
+#endif
+                return gdk_screen_height();
+
         case wxSYS_HSCROLL_Y:  return 15;
         case wxSYS_VSCROLL_X:  return 15;
-        default:               
-            wxFAIL_MSG( wxT("wxSystemSettings::GetMetric not fully implemented") );
+
+// a gtk1 implementation should be possible too if gtk2 efficiency/convenience functions aren't used
+#ifdef __WXGTK20__
+        case wxSYS_CAPTION_Y:
+            if (!window)
+                // No realized window specified, and no implementation for that case yet.
+                return -1;
+
+            // Check if wm supports frame extents - we can't know the caption height if it does not.
+#if GTK_CHECK_VERSION(2,2,0)
+            if (!gtk_check_version(2,2,0))
+            {
+                if (!gdk_x11_screen_supports_net_wm_hint(
+                        gdk_drawable_get_screen(window),
+                        gdk_atom_intern("_NET_FRAME_EXTENTS", false) ) )
+                    return -1;
+            }
+            else
+#endif
+            {
+                if (!gdk_net_wm_supports(gdk_atom_intern("_NET_FRAME_EXTENTS", false)))
+                    return -1;
+            }
+
+            wxASSERT_MSG( wxDynamicCast(win, wxTopLevelWindow),
+                          wxT("Asking for caption height of a non toplevel window") );
+
+            // Get the height of the top windowmanager border.
+            // This is the titlebar in most cases. The titlebar might be elsewhere, and
+            // we could check which is the thickest wm border to decide on which side the
+            // titlebar is, but this might lead to interesting behaviours in used code.
+            // Reconsider when we have a way to report to the user on which side it is.
+
+            Atom type;
+            gint format;
+            gulong nitems;
+
+#if GTK_CHECK_VERSION(2,2,0)
+            if (!gtk_check_version(2,2,0))
+            {
+                gulong bytes_after;
+                success = (XGetWindowProperty (GDK_DISPLAY_XDISPLAY(gdk_drawable_get_display(window)),
+                                    GDK_WINDOW_XWINDOW(window),
+                                    gdk_x11_get_xatom_by_name_for_display (
+                                            gdk_drawable_get_display(window),
+                                            "_NET_FRAME_EXTENTS" ),
+                                    0, // left, right, top, bottom, CARDINAL[4]/32
+                                    G_MAXLONG, // size of long
+                                    false, // do not delete property
+                                    XA_CARDINAL, // 32 bit
+                                    &type, &format, &nitems, &bytes_after, &data
+                                   ) == Success);
+            }
+#endif
+            if (success)
+            {
+                int caption_height = -1;
+
+                if ((type == XA_CARDINAL) && (format == 32) && (nitems >= 3) && (data))
+                {
+                    long *borders;
+                    borders = (long*)data;
+                    caption_height = borders[2]; // top frame extent
+                }
+
+                if (data)
+                    XFree(data);
+
+                return caption_height;
+            }
+
+            // Try a default approach without a window pointer, if possible
+            // ...
+
+            return -1;
+#endif // gtk2
+
+        case wxSYS_PENWINDOWS_PRESENT:
+            // No MS Windows for Pen computing extension available in X11 based gtk+.
             return 0;
+
+        default:
+            return -1;   // metric is unknown
     }
 }