xsettings: Expose monitored settings through D-Bus

A number of things that gnome-settings-daemon monitors for all the GTK+
applications aren't currently available for GTK+ Wayland clients, only
through XSettings.

As we already monitor fontconfig configurations, enabled GTK+ modules
and whether applications should use animations, export those through a
D-Bus interface.

See https://bugzilla.gnome.org/show_bug.cgi?id=786693

Based on patch by Martin Blanchard <tchaik@gmx.com>

https://bugzilla.gnome.org/show_bug.cgi?id=786694

1 files changed, 134 insertions, 2 deletions

diff --git a/plugins/xsettings/gsd-xsettings-manager.c b/plugins/xsettings/gsd-xsettings-manager.c
index ca5fa502..eb55b8b7 100644
--- a/plugins/xsettings/gsd-xsettings-manager.c
+++ b/plugins/xsettings/gsd-xsettings-manager.c
@@ -71,6 +71,18 @@
 #define FONT_HINTING_KEY      "hinting"
 #define FONT_RGBA_ORDER_KEY   "rgba-order"
 
+#define GTK_SETTINGS_DBUS_PATH "/org/gtk/Settings"
+#define GTK_SETTINGS_DBUS_NAME "org.gtk.Settings"
+
+static const gchar introspection_xml[] =
+"<node name='/org/gtk/Settings'>"
+"  <interface name='org.gtk.Settings'>"
+"    <property name='FontconfigTimestamp' type='x' access='read'/>"
+"    <property name='Modules' type='s' access='read'/>"
+"    <property name='EnableAnimations' type='b' access='read'/>"
+"  </interface>"
+"</node>";
+
 typedef enum _DisplayLayoutMode {
         DISPLAY_LAYOUT_MODE_LOGICAL = 1,
         DISPLAY_LAYOUT_MODE_PHYSICAL = 2
@@ -265,10 +277,12 @@ struct GnomeXSettingsManagerPrivate
 
         GSettings         *plugin_settings;
         FcMonitor         *fontconfig_monitor;
+        gint64             fontconfig_timestamp;
 
         GsdXSettingsGtk   *gtk;
 
         GsdRemoteDisplayManager *remote_display;
+        gboolean           enable_animations;
 
         guint              display_config_watch_id;
         guint              monitors_changed_id;
@@ -278,7 +292,9 @@ struct GnomeXSettingsManagerPrivate
 
         guint              notify_idle_id;
 
+        GDBusNodeInfo     *introspection_data;
         GDBusConnection   *dbus_connection;
+        guint              gtk_settings_name_id;
 };
 
 #define GSD_XSETTINGS_ERROR gsd_xsettings_error_quark ()
@@ -291,6 +307,8 @@ static void     gnome_xsettings_manager_class_init  (GnomeXSettingsManagerClass
 static void     gnome_xsettings_manager_init        (GnomeXSettingsManager      *xsettings_manager);
 static void     gnome_xsettings_manager_finalize    (GObject                  *object);
 
+static void     register_manager_dbus               (GnomeXSettingsManager *manager);
+
 G_DEFINE_TYPE (GnomeXSettingsManager, gnome_xsettings_manager, G_TYPE_OBJECT)
 
 static gpointer manager_object = NULL;
@@ -483,7 +501,9 @@ static gboolean
 notify_idle (gpointer data)
 {
         GnomeXSettingsManager *manager = data;
+
         xsettings_manager_notify (manager->priv->manager);
+
         manager->priv->notify_idle_id = 0;
         return G_SOURCE_REMOVE;
 }
@@ -498,6 +518,49 @@ queue_notify (GnomeXSettingsManager *manager)
         g_source_set_name_by_id (manager->priv->notify_idle_id, "[gnome-settings-daemon] notify_idle");
 }
 
+typedef enum {
+        GTK_SETTINGS_FONTCONFIG_TIMESTAMP = 1 << 0,
+        GTK_SETTINGS_MODULES              = 1 << 1,
+        GTK_SETTINGS_ENABLE_ANIMATIONS    = 1 << 2
+} GtkSettingsMask;
+
+static void
+send_dbus_event (GnomeXSettingsManager *manager,
+                 GtkSettingsMask        mask)
+{
+        GVariantBuilder props_builder;
+        GVariant *props_changed = NULL;
+
+        g_variant_builder_init (&props_builder, G_VARIANT_TYPE ("a{sv}"));
+
+        if (mask & GTK_SETTINGS_FONTCONFIG_TIMESTAMP) {
+                g_variant_builder_add (&props_builder, "{sv}", "FontconfigTimestamp",
+                                       g_variant_new_int64 (manager->priv->fontconfig_timestamp));
+        }
+
+        if (mask & GTK_SETTINGS_MODULES) {
+                const char *modules = gsd_xsettings_gtk_get_modules (manager->priv->gtk);
+                g_variant_builder_add (&props_builder, "{sv}", "Modules",
+                                       g_variant_new_string (modules ? modules : ""));
+        }
+
+        if (mask & GTK_SETTINGS_ENABLE_ANIMATIONS) {
+                g_variant_builder_add (&props_builder, "{sv}", "EnableAnimations",
+                                       g_variant_new_boolean (manager->priv->enable_animations));
+        }
+
+        props_changed = g_variant_new ("(s@a{sv}@as)", GTK_SETTINGS_DBUS_NAME,
+                                       g_variant_builder_end (&props_builder),
+                                       g_variant_new_strv (NULL, 0));
+
+        g_dbus_connection_emit_signal (manager->priv->dbus_connection,
+                                       NULL,
+                                       GTK_SETTINGS_DBUS_PATH,
+                                       "org.freedesktop.DBus.Properties",
+                                       "PropertiesChanged",
+                                       props_changed, NULL);
+}
+
 static double
 get_dpi_from_gsettings (GnomeXSettingsManager *manager)
 {
@@ -889,18 +952,24 @@ gtk_modules_callback (GsdXSettingsGtk       *gtk,
         }
 
         queue_notify (manager);
+        send_dbus_event (manager, GTK_SETTINGS_MODULES);
 }
 
 static void
 fontconfig_callback (FcMonitor              *monitor,
                      GnomeXSettingsManager  *manager)
 {
-        int timestamp = time (NULL);
+        gint64 timestamp = g_get_real_time ();
+        gint timestamp_sec = (int)(timestamp / G_TIME_SPAN_SECOND);
 
         gnome_settings_profile_start (NULL);
 
-        xsettings_manager_set_int (manager->priv->manager, "Fontconfig/Timestamp", timestamp);
+        xsettings_manager_set_int (manager->priv->manager, "Fontconfig/Timestamp", timestamp_sec);
+
+        manager->priv->fontconfig_timestamp = timestamp;
+
         queue_notify (manager);
+        send_dbus_event (manager, GTK_SETTINGS_FONTCONFIG_TIMESTAMP);
         gnome_settings_profile_end (NULL);
 }
 
@@ -1100,9 +1169,11 @@ force_disable_animation_changed (GObject    *gobject,
                 value = g_settings_get_boolean (settings, "enable-animations");
         }
 
+        manager->priv->enable_animations = value;
         xsettings_manager_set_int (manager->priv->manager, "Gtk/EnableAnimations", value);
 
         queue_notify (manager);
+        send_dbus_event (manager, GTK_SETTINGS_ENABLE_ANIMATIONS);
 }
 
 static void
@@ -1264,6 +1335,8 @@ gnome_xsettings_manager_start (GnomeXSettingsManager *manager,
         /* Xft settings */
         update_xft_settings (manager);
 
+        register_manager_dbus (manager);
+
         start_fontconfig_monitor (manager);
 
         start_shell_monitor (manager);
@@ -1315,6 +1388,11 @@ gnome_xsettings_manager_stop (GnomeXSettingsManager *manager)
                 p->plugin_settings = NULL;
         }
 
+        if (p->gtk_settings_name_id > 0) {
+                g_bus_unown_name (p->gtk_settings_name_id);
+                p->gtk_settings_name_id = 0;
+        }
+
         if (p->fontconfig_monitor != NULL) {
                 g_signal_handlers_disconnect_by_data (p->fontconfig_monitor, manager);
                 fc_monitor_stop (p->fontconfig_monitor);
@@ -1378,6 +1456,60 @@ gnome_xsettings_manager_finalize (GObject *object)
         G_OBJECT_CLASS (gnome_xsettings_manager_parent_class)->finalize (object);
 }
 
+static GVariant *
+handle_get_property (GDBusConnection *connection,
+                     const gchar *sender,
+                     const gchar *object_path,
+                     const gchar *interface_name,
+                     const gchar *property_name,
+                     GError **error,
+                     gpointer user_data)
+{
+        GnomeXSettingsManager *manager = user_data;
+
+        if (g_strcmp0 (property_name, "FontconfigTimestamp") == 0) {
+                return g_variant_new_int64 (manager->priv->fontconfig_timestamp);
+        } else if (g_strcmp0 (property_name, "Modules") == 0) {
+                const char *modules = gsd_xsettings_gtk_get_modules (manager->priv->gtk);
+                return g_variant_new_string (modules ? modules : "");
+        } else if (g_strcmp0 (property_name, "EnableAnimations") == 0) {
+                return g_variant_new_boolean (manager->priv->enable_animations);
+        } else {
+                g_set_error (error, G_DBUS_ERROR, G_DBUS_ERROR_FAILED,
+                             "No such interface: %s", interface_name);
+                return NULL;
+        }
+}
+
+static const GDBusInterfaceVTable interface_vtable =
+{
+        NULL,
+        handle_get_property,
+        NULL
+};
+
+static void
+register_manager_dbus (GnomeXSettingsManager *manager)
+{
+        g_assert (manager->priv->dbus_connection != NULL);
+
+        manager->priv->introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
+        g_assert (manager->priv->introspection_data != NULL);
+
+        g_dbus_connection_register_object (manager->priv->dbus_connection,
+                                           GTK_SETTINGS_DBUS_PATH,
+                                           manager->priv->introspection_data->interfaces[0],
+                                           &interface_vtable,
+                                           manager,
+                                           NULL,
+                                           NULL);
+
+        manager->priv->gtk_settings_name_id = g_bus_own_name_on_connection (manager->priv->dbus_connection,
+                                                                            GTK_SETTINGS_DBUS_NAME,
+                                                                            G_BUS_NAME_OWNER_FLAGS_NONE,
+                                                                            NULL, NULL, NULL, NULL);
+}
+
 GnomeXSettingsManager *
 gnome_xsettings_manager_new (void)
 {