#9631: Hint GNOME 3 window manager to use dark window borders

src/gui/gtk.c

@@ -46,6 +46,8 @@
 #include <math.h>
 #include <gtk/gtk.h>
 #include <gdk/gdkkeysyms.h>
+#include <gdk/gdkx.h>
+#include <X11/Xatom.h>
 #ifdef MAC_INTEGRATION
 #   include <gtkosxapplication.h>
 #endif
@@ -658,6 +660,13 @@ window_configure (GtkWidget *da, GdkEvent *event, gpointer user_data)
   return FALSE;
 }
 
+static gboolean
+window_realize (GtkWidget *da, gpointer user_data)
+{
+  gdk_property_change(GDK_WINDOW(da), gdk_atom_intern("_GTK_THEME_VARIANT", FALSE), (GdkAtom)XA_STRING, 8, GDK_PROP_MODE_REPLACE, (guchar *)"dark", 4);
+  return FALSE;
+}
+
 static gboolean
 key_pressed_override (GtkWidget *w, GdkEventKey *event, gpointer user_data)
 {
@@ -897,6 +906,9 @@ dt_gui_gtk_init(dt_gui_gtk_t *gui, int argc, char *argv[])
   widget = dt_ui_main_window(darktable.gui->ui);
   g_signal_connect (G_OBJECT (widget), "configure-event", G_CALLBACK (window_configure), NULL);
 
+  // Hint GNOME 3 window manager to use dark window borders
+  g_signal_connect (G_OBJECT (widget), "realize", G_CALLBACK(window_realize), NULL);
+
   // register keys for view switching
   dt_accel_register_global(NC_("accel", "capture view"), GDK_KEY_t, 0);
   dt_accel_register_global(NC_("accel", "lighttable view"), GDK_KEY_l, 0);