window: Parse _GTK_THEME_VARIANT property

Since version 3.0, GTK+ has support for style variants. At the moment,
themes may provide a dark variant, which can be requested by
applications via GtkSettings. The requested variant is exported to
X11 via the _GTK_THEME_VARIANT property - support this property, in
order to pick up the correct style variant in the future.

https://bugzilla.gnome.org/show_bug.cgi?id=645355

NOTE: Patch is adapted for metacity.

4 files changed, 33 insertions, 0 deletions

diff --git a/src/core/atomnames.h b/src/core/atomnames.h
index 43293f0c..9e20cf58 100644
--- a/src/core/atomnames.h
+++ b/src/core/atomnames.h
@@ -57,6 +57,7 @@ item(_METACITY_RELOAD_THEME_MESSAGE)
 item(_METACITY_SET_KEYBINDINGS_MESSAGE)
 item(_METACITY_SET_MOUSEMODS_MESSAGE)
 item(_METACITY_TOGGLE_VERBOSE)
+item(_GTK_THEME_VARIANT)
 item(_GTK_FRAME_EXTENTS)
 item(_GNOME_PANEL_ACTION)
 item(_GNOME_PANEL_ACTION_MAIN_MENU)
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 5668d92f..a98cee36 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -114,6 +114,7 @@ struct _MetaWindow
   char *sm_client_id;
   char *wm_client_machine;
   char *startup_id;
+  char *gtk_theme_variant;
 
   int net_wm_pid;
 
diff --git a/src/core/window-props.c b/src/core/window-props.c
index 505bcefa..586fb996 100644
--- a/src/core/window-props.c
+++ b/src/core/window-props.c
@@ -1627,6 +1627,29 @@ reload_transient_for (MetaWindow    *window,
     meta_window_queue (window, META_QUEUE_MOVE_RESIZE);
 }
 
+static void
+reload_gtk_theme_variant (MetaWindow    *window,
+                          MetaPropValue *value,
+                          gboolean       initial)
+{
+  char *requested_variant = NULL;
+  char *current_variant = window->gtk_theme_variant;
+
+  if (value->type != META_PROP_VALUE_INVALID)
+    {
+      requested_variant = value->v.str;
+      meta_verbose ("Requested \"%s\" theme variant for window %s.\n",
+                    requested_variant, window->desc);
+    }
+
+  if (g_strcmp0 (requested_variant, current_variant) != 0)
+    {
+      g_free (current_variant);
+
+      window->gtk_theme_variant = g_strdup (requested_variant);
+    }
+}
+
 /**
  * Initialises the property hooks system.  Each row in the table named "hooks"
  * represents an action to take when a property is found on a newly-created
@@ -1748,6 +1771,12 @@ meta_display_init_window_prop_hooks (MetaDisplay *display)
       LOAD_INIT
     },
     {
+      display->atom__GTK_THEME_VARIANT,
+      META_PROP_VALUE_UTF8,
+      reload_gtk_theme_variant,
+      LOAD_INIT
+    },
+    {
       display->atom__GTK_FRAME_EXTENTS,
       META_PROP_VALUE_CARDINAL_LIST,
       reload_gtk_frame_extents,
diff --git a/src/core/window.c b/src/core/window.c
index a7c7d5a6..2c829e9b 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -536,6 +536,7 @@ meta_window_new_with_attrs (MetaDisplay       *display,
   window->sm_client_id = NULL;
   window->wm_client_machine = NULL;
   window->startup_id = NULL;
+  window->gtk_theme_variant = NULL;
 
   window->net_wm_pid = -1;
 
@@ -1175,6 +1176,7 @@ meta_window_free (MetaWindow  *window,
   g_free (window->title);
   g_free (window->icon_name);
   g_free (window->desc);
+  g_free (window->gtk_theme_variant);
   g_free (window);
 }