From 9b0b5ba76e7311091f473e5591cb74c05f6912d6 Mon Sep 17 00:00:00 2001
From: Robert Roebling <robert@roebling.de>
Date: Mon, 7 Mar 2005 17:38:31 +0000
Subject: [PATCH]   Applied GetSystemMetric patch to suppurt GTK and multihead 
    display.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@32634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/changes.txt             |   3 +
 docs/latex/wx/settings.tex   |  15 ++-
 include/wx/settings.h        |   4 +-
 src/cocoa/settings.mm        |   2 +-
 src/gtk/settings.cpp         | 251 ++++++++++++++++++++++++++++++++---
 src/gtk1/settings.cpp        | 251 ++++++++++++++++++++++++++++++++---
 src/mac/carbon/settings.cpp  |   2 +-
 src/mac/classic/settings.cpp |   2 +-
 src/mgl/settings.cpp         |   2 +-
 src/motif/settings.cpp       |   2 +-
 src/msw/settings.cpp         |   2 +-
 src/os2/settings.cpp         |   1 +
 src/palmos/settings.cpp      |   2 +-
 src/x11/settings.cpp         |   2 +-
 14 files changed, 486 insertions(+), 55 deletions(-)

diff --git a/docs/changes.txt b/docs/changes.txt
index 11951c0b99..e9fb5ff120 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -19,6 +19,9 @@ All (GUI):
 - Added style parameter to wxBufferedDC to allow buffering just the client, or
   the whole virtual area.
 
+wxGTK:
+
+- Improved wxSystemSettings::GetMetric() to work better with X11. (Mart Raudsepp)
 
 wxPalmOS:
 
diff --git a/docs/latex/wx/settings.tex b/docs/latex/wx/settings.tex
index 674adbc131..cf7dc16b94 100644
--- a/docs/latex/wx/settings.tex
+++ b/docs/latex/wx/settings.tex
@@ -97,10 +97,13 @@ standalone function named {\tt wxSystemSettings\_GetFont}}
 
 \membersection{wxSystemSettings::GetMetric}\label{wxsystemsettingsgetmetric}
 
-\func{static int}{GetMetric}{\param{wxSystemMetric}{ index}}
+\func{static int}{GetMetric}{\param{wxSystemMetric}{ index}, \param{wxWindow*}{ win = NULL}}
 
-Returns the value of a system metric, or -1 if the metric is not
-supported on the current platform.
+Returns the value of a system metric, or -1 if the metric is not supported on the current system.
+The value of {\it win} determines if the metric returned is a global value or
+a \helpref{wxWindow}{wxwindow} based value, in which case it might determine the widget, the
+display the window is on, or something similar. The window given should be as close to the
+metric as possible (e.g a wxTopLevelWindow in case of the wxSYS_CAPTION_Y metric).
 
 {\it index} can be one of:
 
@@ -152,6 +155,12 @@ where it would otherwise present the information only in audible form; zero othe
 \twocolitem{{\bf wxSYS\_SWAP\_BUTTONS}}{Non-zero if the meanings of the left and right mouse buttons are swapped; zero otherwise.}
 \end{twocollist}
 
+{\it win} is a pointer to the window for which the metric is requested.
+Specifying the {\it win} parameter is encouraged, because some metrics on some ports are not supported without one,
+or they might be capable of reporting better values if given one. If a window does not make sense for a metric,
+one should still be given, as for example it might determine which displays cursor width is requested with
+wxSYS_CURSOR_X.
+
 \pythonnote{This static method is implemented in Python as a
 standalone function named {\tt wxSystemSettings\_GetMetric}}
 
diff --git a/include/wx/settings.h b/include/wx/settings.h
index a4dc9145c1..4bd5573696 100644
--- a/include/wx/settings.h
+++ b/include/wx/settings.h
@@ -81,7 +81,7 @@ enum wxSystemColour
     wxSYS_COLOUR_MAX
 };
 
-// possible values for wxSystemSettings::GetMetric() parameter
+// possible values for wxSystemSettings::GetMetric() index parameter
 //
 // NB: update the conversion table in msw/settings.cpp if you change the values
 //     of the elements of this enum
@@ -165,7 +165,7 @@ public:
     static wxFont GetFont(wxSystemFont index);
 
     // get a system-dependent metric
-    static int GetMetric(wxSystemMetric index);
+    static int GetMetric(wxSystemMetric index, wxWindow * win = NULL);
 
     // return true if the port has certain feature
     static bool HasFeature(wxSystemFeature index);
diff --git a/src/cocoa/settings.mm b/src/cocoa/settings.mm
index ff6ab458cb..168ab4884c 100644
--- a/src/cocoa/settings.mm
+++ b/src/cocoa/settings.mm
@@ -135,7 +135,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow *WXUNUSED(win))
 {
     switch ( index)
     {
diff --git a/src/gtk/settings.cpp b/src/gtk/settings.cpp
index dede98aa35..b8ace18988 100644
--- a/src/gtk/settings.cpp
+++ b/src/gtk/settings.cpp
@@ -2,6 +2,7 @@
 // Name:        gtk/settings.cpp
 // Purpose:
 // Author:      Robert Roebling
+// Modified by: Mart Raudsepp (GetMetric)
 // Id:          $Id$
 // Copyright:   (c) 1998 Robert Roebling
 // Licence:     wxWindows licence
@@ -19,11 +20,15 @@
 #include "wx/debug.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>
 
+#include <X11/Xatom.h>
+
 #define SHIFT (8*(sizeof(short int)-sizeof(char)))
 
 // ----------------------------------------------------------------------------
@@ -363,45 +368,249 @@ wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
     }
 }
 
-int wxSystemSettingsNative::GetMetric( wxSystemMetric index )
+int wxSystemSettingsNative::GetMetric( wxSystemMetric index, wxWindow* win )
 {
+#ifdef __WXGTK20__
+    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();
-        case wxSYS_HSCROLL_Y:  return 15;
-        case wxSYS_VSCROLL_X:  return 15;
+        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;
+                    gulong bytes_after;
+    
+                    if (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)
+                    {
+                        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
+
+        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;
 
-#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2, 4, 0)
+#ifdef __WXGTK20__
         case wxSYS_DCLICK_X:
         case wxSYS_DCLICK_Y:
             gint dclick_distance;
-            g_object_get(gtk_settings_get_default(), "gtk-double-click-distance", &dclick_distance, NULL);
-            return dclick_distance * 2;
+#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
 
-#if defined(__WXGTK20__)
+#ifdef __WXGTK20__
         case wxSYS_DRAG_X:
         case wxSYS_DRAG_Y:
             gint drag_threshold;
-            g_object_get(gtk_settings_get_default(), "gtk-dnd-drag-threshold", &drag_threshold, NULL);
-            return drag_threshold * 2;
+#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);
+            }
 
-        // VZ: is there any way to get the cursor size with GDK?
-        // Mart Raudsepp: Yes, there is a way to get the default cursor size for a display ever since GDK 2.4
-#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2, 4, 0)
-        case wxSYS_CURSOR_X:
-        case wxSYS_CURSOR_Y:
-            return gdk_display_get_default_cursor_size(gdk_display_get_default());
-#else
-        case wxSYS_CURSOR_X:   return 16;
-        case wxSYS_CURSOR_Y:   return 16;
+            return drag_threshold * 2;
 #endif
+
         // MBN: ditto for icons
         case wxSYS_ICON_X:     return 32;
         case wxSYS_ICON_Y:     return 32;
-        default:               
+
+        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;
+
+// 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;
+            gulong bytes_after;
+
+            if (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)
+            {
+                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
     }
 }
diff --git a/src/gtk1/settings.cpp b/src/gtk1/settings.cpp
index dede98aa35..b8ace18988 100644
--- a/src/gtk1/settings.cpp
+++ b/src/gtk1/settings.cpp
@@ -2,6 +2,7 @@
 // Name:        gtk/settings.cpp
 // Purpose:
 // Author:      Robert Roebling
+// Modified by: Mart Raudsepp (GetMetric)
 // Id:          $Id$
 // Copyright:   (c) 1998 Robert Roebling
 // Licence:     wxWindows licence
@@ -19,11 +20,15 @@
 #include "wx/debug.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>
 
+#include <X11/Xatom.h>
+
 #define SHIFT (8*(sizeof(short int)-sizeof(char)))
 
 // ----------------------------------------------------------------------------
@@ -363,45 +368,249 @@ wxFont wxSystemSettingsNative::GetFont( wxSystemFont index )
     }
 }
 
-int wxSystemSettingsNative::GetMetric( wxSystemMetric index )
+int wxSystemSettingsNative::GetMetric( wxSystemMetric index, wxWindow* win )
 {
+#ifdef __WXGTK20__
+    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();
-        case wxSYS_HSCROLL_Y:  return 15;
-        case wxSYS_VSCROLL_X:  return 15;
+        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;
+                    gulong bytes_after;
+    
+                    if (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)
+                    {
+                        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
+
+        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;
 
-#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2, 4, 0)
+#ifdef __WXGTK20__
         case wxSYS_DCLICK_X:
         case wxSYS_DCLICK_Y:
             gint dclick_distance;
-            g_object_get(gtk_settings_get_default(), "gtk-double-click-distance", &dclick_distance, NULL);
-            return dclick_distance * 2;
+#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
 
-#if defined(__WXGTK20__)
+#ifdef __WXGTK20__
         case wxSYS_DRAG_X:
         case wxSYS_DRAG_Y:
             gint drag_threshold;
-            g_object_get(gtk_settings_get_default(), "gtk-dnd-drag-threshold", &drag_threshold, NULL);
-            return drag_threshold * 2;
+#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);
+            }
 
-        // VZ: is there any way to get the cursor size with GDK?
-        // Mart Raudsepp: Yes, there is a way to get the default cursor size for a display ever since GDK 2.4
-#if defined(__WXGTK20__) && GTK_CHECK_VERSION(2, 4, 0)
-        case wxSYS_CURSOR_X:
-        case wxSYS_CURSOR_Y:
-            return gdk_display_get_default_cursor_size(gdk_display_get_default());
-#else
-        case wxSYS_CURSOR_X:   return 16;
-        case wxSYS_CURSOR_Y:   return 16;
+            return drag_threshold * 2;
 #endif
+
         // MBN: ditto for icons
         case wxSYS_ICON_X:     return 32;
         case wxSYS_ICON_Y:     return 32;
-        default:               
+
+        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;
+
+// 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;
+            gulong bytes_after;
+
+            if (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)
+            {
+                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
     }
 }
diff --git a/src/mac/carbon/settings.cpp b/src/mac/carbon/settings.cpp
index e61c589c69..9cdf66aa66 100644
--- a/src/mac/carbon/settings.cpp
+++ b/src/mac/carbon/settings.cpp
@@ -154,7 +154,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
     int value;
 
diff --git a/src/mac/classic/settings.cpp b/src/mac/classic/settings.cpp
index 5c53611024..cdf38e8755 100644
--- a/src/mac/classic/settings.cpp
+++ b/src/mac/classic/settings.cpp
@@ -152,7 +152,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
     int value;
 
diff --git a/src/mgl/settings.cpp b/src/mgl/settings.cpp
index 9a6ff7b612..24132c3727 100644
--- a/src/mgl/settings.cpp
+++ b/src/mgl/settings.cpp
@@ -78,7 +78,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
     }
 }
 
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
     int val;
     
diff --git a/src/motif/settings.cpp b/src/motif/settings.cpp
index 39aaf9ba2c..03ab6e5a6e 100644
--- a/src/motif/settings.cpp
+++ b/src/motif/settings.cpp
@@ -182,7 +182,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 }
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
     int return_value = 0;
 
diff --git a/src/msw/settings.cpp b/src/msw/settings.cpp
index b4436ce624..e6d4fccbfe 100644
--- a/src/msw/settings.cpp
+++ b/src/msw/settings.cpp
@@ -377,7 +377,7 @@ static const int gs_metricsMap[] =
 };
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
 #ifdef __WXMICROWIN__
     // TODO: probably use wxUniv themes functionality
diff --git a/src/os2/settings.cpp b/src/os2/settings.cpp
index 5918387a3f..264e05b4e3 100644
--- a/src/os2/settings.cpp
+++ b/src/os2/settings.cpp
@@ -251,6 +251,7 @@ wxFont wxSystemSettingsNative::GetFont(
 // Get a system metric, e.g. scrollbar size
 int wxSystemSettingsNative::GetMetric(
   wxSystemMetric                    index
+, wxWindow*                         WXUNUSED(win)
 )
 {
     switch ( index)
diff --git a/src/palmos/settings.cpp b/src/palmos/settings.cpp
index 25239aba83..bb050eb107 100644
--- a/src/palmos/settings.cpp
+++ b/src/palmos/settings.cpp
@@ -123,7 +123,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 // ----------------------------------------------------------------------------
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
     int metric = -1;
     uint32_t attrP;
diff --git a/src/x11/settings.cpp b/src/x11/settings.cpp
index 3531a9ad88..89485acb90 100644
--- a/src/x11/settings.cpp
+++ b/src/x11/settings.cpp
@@ -59,7 +59,7 @@ wxFont wxSystemSettingsNative::GetFont(wxSystemFont index)
 }
 
 // Get a system metric, e.g. scrollbar size
-int wxSystemSettingsNative::GetMetric(wxSystemMetric index)
+int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(win))
 {
 	switch ( index)
 	{
-- 
2.50.0

