>From 7679c96fb785bc682b086f08482411311d12f84a Mon Sep 17 00:00:00 2001
From: Antono Vasiljev <self@antono.info>
Date: Wed, 30 May 2012 16:56:42 +0300
Subject: [PATCH] Implemented lisp function application-prefer-dark-theme

* src/xsettings.c: GtkSetting and function definition
* src/xsettings.h: EXFUN macro for application-prefer-dark-theme
---
 src/xsettings.c |   32 ++++++++++++++++++++++++++++++++
 src/xsettings.h |    1 +
 2 files changed, 33 insertions(+)

diff --git a/src/xsettings.c b/src/xsettings.c
index 69ef22f..d8c01c7 100644
--- a/src/xsettings.c
+++ b/src/xsettings.c
@@ -201,6 +201,7 @@ struct xsettings
 /* The single GSettings instance, or NULL if not connected to GSettings.  */
 
 static GSettings *gsettings_client;
+static GtkSettings *gtk_settings;
 
 /* Callback called when something changed in GSettings.  */
 
@@ -824,6 +825,8 @@ init_gsettings (void)
   g_signal_connect (G_OBJECT (gsettings_client), "changed",
                     G_CALLBACK (something_changed_gsettingsCB), NULL);
 
+  gtk_settings = gtk_settings_get_default ();
+
   val = g_settings_get_value (gsettings_client, GSETTINGS_TOOL_BAR_STYLE);
   if (val)
     {
@@ -1004,6 +1007,30 @@ known style.  Otherwise return image.  */)
   return Qimage;
 }
 
+DEFUN ("application-prefer-dark-theme",
+       Fapplication_prefer_dark_theme,
+       Sapplication_prefer_dark_theme,
+       0, 1, 0,
+       doc: /* Set dark theme variant for application if supported by
+GUI toolkit and ARG is not nil. */)
+  (Lisp_Object arg)
+{
+  gboolean result = FALSE;
+
+#ifdef HAVE_GSETTINGS
+  if (NILP (arg) || (NUMBERP(arg) && (XINT(arg) < 0))) {
+    result = FALSE;
+  } else {
+    result = TRUE;
+  }
+
+  g_object_set (G_OBJECT (gtk_settings),
+                "gtk-application-prefer-dark-theme", result, NULL);
+#endif
+
+  return result ? Fmake_symbol (build_string ("t")) : Qnil;
+}
+
 void
 syms_of_xsettings (void)
 {
@@ -1012,6 +1039,7 @@ syms_of_xsettings (void)
   first_dpyinfo = NULL;
 #ifdef HAVE_GSETTINGS
   gsettings_client = NULL;
+  gtk_settings = NULL;
 #endif
 #ifdef HAVE_GCONF
   gconf_client = NULL;
@@ -1041,6 +1069,10 @@ If this variable is nil, Emacs ignores system font changes.  */);
 #endif
 #endif
 
+#ifdef HAVE_GSETTINGS
+  defsubr (&Sapplication_prefer_dark_theme);
+#endif
+
   current_tool_bar_style = Qnil;
   DEFSYM (Qtool_bar_style, "tool-bar-style");
   defsubr (&Stool_bar_get_system_style);
diff --git a/src/xsettings.h b/src/xsettings.h
index d6b0c09..83b5cfc 100644
--- a/src/xsettings.h
+++ b/src/xsettings.h
@@ -21,6 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define XSETTINGS_H
 
 EXFUN (Ftool_bar_get_system_style, 0);
+EXFUN (Fapplication_prefer_dark_theme, 1);
 
 extern void xsettings_initialize (struct x_display_info *dpyinfo);
 extern void xft_settings_event (struct x_display_info *dpyinfo,
-- 
1.7.9.5