[gnome-settings-daemon/wip/carlosg/xsettings-gtk-im-module] xsettings: Adopt code to look up GTK IM module

[Carlos Garnacho <carlosg src gnome org>]

commit 7b21049b5b6bcee7cd9f3929fcc75dd298422f08
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Dec 3 23:38:50 2021 +0100

    xsettings: Adopt code to look up GTK IM module
    
    Right now, gsd-keyboard and gsd-xsettings have a strange relation
    where the first sets the gtk-im-module dconf setting for the latter
    to read the setting and forward it through XSettings.
    
    Since this detection is highly X11 specific, make it happen in the
    Xsettings daemon itself, from the relevant setting and device presence.
    
    This makes users still able to shoot themselves in the foot by changing
    the setting, X11 clients able to be told to switch to ibus if it turns
    out necessary, and Wayland clients unaffected otherwise.
    
    Related: https://gitlab.gnome.org/GNOME/gtk/-/issues/4443

 plugins/keyboard/gsd-keyboard-manager.c   | 147 -----------------------------
 plugins/xsettings/gsd-xsettings-manager.c | 152 ++++++++++++++++++++++++++++++
 2 files changed, 152 insertions(+), 147 deletions(-)
---
diff --git a/plugins/keyboard/gsd-keyboard-manager.c b/plugins/keyboard/gsd-keyboard-manager.c
index 6e2465bc..d41393bc 100644
--- a/plugins/keyboard/gsd-keyboard-manager.c
+++ b/plugins/keyboard/gsd-keyboard-manager.c
@@ -57,10 +57,6 @@
 
 #define GNOME_DESKTOP_INTERFACE_DIR "org.gnome.desktop.interface"
 
-#define KEY_GTK_IM_MODULE    "gtk-im-module"
-#define GTK_IM_MODULE_SIMPLE "gtk-im-context-simple"
-#define GTK_IM_MODULE_IBUS   "ibus"
-
 #define GNOME_DESKTOP_INPUT_SOURCES_DIR "org.gnome.desktop.input-sources"
 
 #define KEY_INPUT_SOURCES        "sources"
@@ -71,9 +67,6 @@
 
 #define DEFAULT_LAYOUT "us"
 
-#define GNOME_A11Y_APPLICATIONS_INTERFACE_DIR "org.gnome.desktop.a11y.applications"
-#define KEY_OSK_ENABLED "screen-keyboard-enabled"
-
 struct _GsdKeyboardManager
 {
         GObject    parent;
@@ -81,21 +74,14 @@ struct _GsdKeyboardManager
         guint      start_idle_id;
         GSettings *settings;
         GSettings *input_sources_settings;
-        GSettings *a11y_settings;
         GDBusProxy *localed;
         GCancellable *cancellable;
-
-        GdkSeat *user_seat;
-        guint device_added_id;
-        guint device_removed_id;
 };
 
 static void     gsd_keyboard_manager_class_init  (GsdKeyboardManagerClass *klass);
 static void     gsd_keyboard_manager_init        (GsdKeyboardManager      *keyboard_manager);
 static void     gsd_keyboard_manager_finalize    (GObject                 *object);
 
-static void     update_gtk_im_module (GsdKeyboardManager *manager);
-
 G_DEFINE_TYPE (GsdKeyboardManager, gsd_keyboard_manager, G_TYPE_OBJECT)
 
 static gpointer manager_object = NULL;
@@ -218,121 +204,6 @@ settings_changed (GSettings          *settings,
 
 }
 
-static void
-device_added_cb (GdkSeat            *user_seat,
-                 GdkDevice          *device,
-                 GsdKeyboardManager *manager)
-{
-        GdkInputSource source;
-
-        source = gdk_device_get_source (device);
-        if (source == GDK_SOURCE_TOUCHSCREEN) {
-                update_gtk_im_module (manager);
-        }
-}
-
-static void
-device_removed_cb (GdkSeat            *user_seat,
-                   GdkDevice          *device,
-                   GsdKeyboardManager *manager)
-{
-        GdkInputSource source;
-
-        source = gdk_device_get_source (device);
-        if (source == GDK_SOURCE_TOUCHSCREEN)
-                update_gtk_im_module (manager);
-}
-
-static void
-set_devicepresence_handler (GsdKeyboardManager *manager)
-{
-        GdkSeat *user_seat;
-
-        if (gnome_settings_is_wayland ())
-                return;
-
-        user_seat = gdk_display_get_default_seat (gdk_display_get_default ());
-
-        manager->device_added_id = g_signal_connect (G_OBJECT (user_seat), "device-added",
-                                                     G_CALLBACK (device_added_cb), manager);
-        manager->device_removed_id = g_signal_connect (G_OBJECT (user_seat), "device-removed",
-                                                       G_CALLBACK (device_removed_cb), manager);
-        manager->user_seat = user_seat;
-}
-
-static gboolean
-need_ibus (GVariant *sources)
-{
-        GVariantIter iter;
-        const gchar *type;
-
-        g_variant_iter_init (&iter, sources);
-        while (g_variant_iter_next (&iter, "(&s&s)", &type, NULL))
-                if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS))
-                        return TRUE;
-
-        return FALSE;
-}
-
-static gboolean
-need_osk (GsdKeyboardManager *manager)
-{
-        gboolean has_touchscreen = FALSE;
-        GList *devices;
-        GdkSeat *seat;
-
-        if (g_settings_get_boolean (manager->a11y_settings,
-                                    KEY_OSK_ENABLED))
-                return TRUE;
-
-        seat = gdk_display_get_default_seat (gdk_display_get_default ());
-        devices = gdk_seat_get_slaves (seat, GDK_SEAT_CAPABILITY_TOUCH);
-
-        has_touchscreen = devices != NULL;
-
-        g_list_free (devices);
-
-        return has_touchscreen;
-}
-
-static void
-set_gtk_im_module (GsdKeyboardManager *manager,
-                   GSettings          *settings,
-                   GVariant           *sources)
-{
-        const gchar *new_module;
-        gchar *current_module;
-
-        if (need_ibus (sources) || need_osk (manager))
-                new_module = GTK_IM_MODULE_IBUS;
-        else
-                new_module = GTK_IM_MODULE_SIMPLE;
-
-        current_module = g_settings_get_string (settings, KEY_GTK_IM_MODULE);
-        if (!g_str_equal (current_module, new_module))
-                g_settings_set_string (settings, KEY_GTK_IM_MODULE, new_module);
-        g_free (current_module);
-}
-
-static void
-update_gtk_im_module (GsdKeyboardManager *manager)
-{
-        GSettings *interface_settings;
-        GVariant *sources;
-
-        /* Gtk+ uses the IM module advertised in XSETTINGS so, if we
-         * have IBus input sources, we want it to load that
-         * module. Otherwise we can use the default "simple" module
-         * which is builtin gtk+
-         */
-        interface_settings = g_settings_new (GNOME_DESKTOP_INTERFACE_DIR);
-        sources = g_settings_get_value (manager->input_sources_settings,
-                                        KEY_INPUT_SOURCES);
-        set_gtk_im_module (manager, interface_settings, sources);
-        g_object_unref (interface_settings);
-        g_variant_unref (sources);
-}
-
 static void
 get_sources_from_xkb_config (GsdKeyboardManager *manager)
 {
@@ -580,18 +451,7 @@ start_keyboard_idle_cb (GsdKeyboardManager *manager)
 
         manager->settings = g_settings_new (GSD_KEYBOARD_DIR);
 
-       set_devicepresence_handler (manager);
-
         manager->input_sources_settings = g_settings_new (GNOME_DESKTOP_INPUT_SOURCES_DIR);
-        g_signal_connect_swapped (manager->input_sources_settings,
-                                  "changed::" KEY_INPUT_SOURCES,
-                                  G_CALLBACK (update_gtk_im_module), manager);
-
-        manager->a11y_settings = g_settings_new (GNOME_A11Y_APPLICATIONS_INTERFACE_DIR);
-        g_signal_connect_swapped (manager->a11y_settings,
-                                  "changed::" KEY_OSK_ENABLED,
-                                  G_CALLBACK (update_gtk_im_module), manager);
-        update_gtk_im_module (manager);
 
         manager->cancellable = g_cancellable_new ();
 
@@ -645,14 +505,7 @@ gsd_keyboard_manager_stop (GsdKeyboardManager *manager)
 
         g_clear_object (&manager->settings);
         g_clear_object (&manager->input_sources_settings);
-        g_clear_object (&manager->a11y_settings);
         g_clear_object (&manager->localed);
-
-        if (manager->user_seat != NULL) {
-                g_signal_handler_disconnect (manager->user_seat, manager->device_added_id);
-                g_signal_handler_disconnect (manager->user_seat, manager->device_removed_id);
-                manager->user_seat = NULL;
-        }
 }
 
 static void
diff --git a/plugins/xsettings/gsd-xsettings-manager.c b/plugins/xsettings/gsd-xsettings-manager.c
index 5f1b4583..0cd2b210 100644
--- a/plugins/xsettings/gsd-xsettings-manager.c
+++ b/plugins/xsettings/gsd-xsettings-manager.c
@@ -56,6 +56,8 @@
 #define PRIVACY_SETTINGS_SCHEMA     "org.gnome.desktop.privacy"
 #define WM_SETTINGS_SCHEMA        "org.gnome.desktop.wm.preferences"
 #define A11Y_SCHEMA               "org.gnome.desktop.a11y"
+#define A11Y_APPLICATIONS_SCHEMA   "org.gnome.desktop.a11y.applications"
+#define INPUT_SOURCES_SCHEMA       "org.gnome.desktop.input-sources"
 #define CLASSIC_WM_SETTINGS_SCHEMA "org.gnome.shell.extensions.classic-overrides"
 
 #define XSETTINGS_PLUGIN_SCHEMA "org.gnome.settings-daemon.plugins.xsettings"
@@ -72,9 +74,18 @@
 #define FONT_HINTING_KEY      "font-hinting"
 #define FONT_RGBA_ORDER_KEY   "font-rgba-order"
 
+#define INPUT_SOURCES_KEY      "sources"
+#define OSK_ENABLED_KEY        "screen-keyboard-enabled"
+#define GTK_IM_MODULE_KEY      "gtk-im-module"
+
 #define GTK_SETTINGS_DBUS_PATH "/org/gtk/Settings"
 #define GTK_SETTINGS_DBUS_NAME "org.gtk.Settings"
 
+#define INPUT_SOURCE_TYPE_IBUS "ibus"
+
+#define GTK_IM_MODULE_SIMPLE "gtk-im-context-simple"
+#define GTK_IM_MODULE_IBUS   "ibus"
+
 static const gchar introspection_xml[] =
 "<node name='/org/gtk/Settings'>"
 "  <interface name='org.gtk.Settings'>"
@@ -277,6 +288,11 @@ struct _GsdXSettingsManager
         FcMonitor         *fontconfig_monitor;
         gint64             fontconfig_timestamp;
 
+        GSettings         *interface_settings;
+        GSettings         *input_sources_settings;
+        GSettings         *a11y_settings;
+        GdkSeat           *user_seat;
+
         GsdXSettingsGtk   *gtk;
 
         guint              introspect_properties_changed_id;
@@ -286,6 +302,9 @@ struct _GsdXSettingsManager
         guint              display_config_watch_id;
         guint              monitors_changed_id;
 
+        guint              device_added_id;
+        guint              device_removed_id;
+
         guint              shell_name_watch_id;
         gboolean           have_shell;
 
@@ -1291,6 +1310,112 @@ migrate_settings (void)
                                     mouse_entries, G_N_ELEMENTS (mouse_entries));
 }
 
+static gboolean
+need_ibus (GsdXSettingsManager *manager)
+{
+        GVariant *sources;
+        GVariantIter iter;
+        const gchar *type;
+        gboolean needs_ibus = FALSE;
+
+        sources = g_settings_get_value (manager->input_sources_settings,
+                                        INPUT_SOURCES_KEY);
+
+        g_variant_iter_init (&iter, sources);
+        while (g_variant_iter_next (&iter, "(&s&s)", &type, NULL)) {
+                if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS)) {
+                        needs_ibus = TRUE;
+                        break;
+                }
+        }
+
+        g_variant_unref (sources);
+
+        return needs_ibus;
+}
+
+static gboolean
+need_osk (GsdXSettingsManager *manager)
+{
+        gboolean has_touchscreen = FALSE;
+        GList *devices;
+        GdkSeat *seat;
+
+        if (g_settings_get_boolean (manager->a11y_settings,
+                                    OSK_ENABLED_KEY))
+                return TRUE;
+
+        seat = gdk_display_get_default_seat (gdk_display_get_default ());
+        devices = gdk_seat_get_slaves (seat, GDK_SEAT_CAPABILITY_TOUCH);
+
+        has_touchscreen = devices != NULL;
+
+        g_list_free (devices);
+
+        return has_touchscreen;
+}
+
+static void
+update_gtk_im_module (GsdXSettingsManager *manager)
+{
+        const gchar *module;
+        gchar *setting;
+
+        setting = g_settings_get_string (manager->interface_settings,
+                                         GTK_IM_MODULE_KEY);
+        if (setting && *setting)
+                module = setting;
+        else if (need_ibus (manager) || need_osk (manager))
+                module = GTK_IM_MODULE_IBUS;
+        else
+                module = GTK_IM_MODULE_SIMPLE;
+
+        xsettings_manager_set_string (manager->manager, "Gtk/IMModule", module);
+        g_free (setting);
+}
+
+static void
+device_added_cb (GdkSeat             *user_seat,
+                 GdkDevice           *device,
+                 GsdXSettingsManager *manager)
+{
+        GdkInputSource source;
+
+        source = gdk_device_get_source (device);
+        if (source == GDK_SOURCE_TOUCHSCREEN) {
+                update_gtk_im_module (manager);
+        }
+}
+
+static void
+device_removed_cb (GdkSeat             *user_seat,
+                   GdkDevice           *device,
+                   GsdXSettingsManager *manager)
+{
+        GdkInputSource source;
+
+        source = gdk_device_get_source (device);
+        if (source == GDK_SOURCE_TOUCHSCREEN)
+                update_gtk_im_module (manager);
+}
+
+static void
+set_devicepresence_handler (GsdXSettingsManager *manager)
+{
+        GdkSeat *user_seat;
+
+        if (gnome_settings_is_wayland ())
+                return;
+
+        user_seat = gdk_display_get_default_seat (gdk_display_get_default ());
+
+        manager->device_added_id = g_signal_connect (G_OBJECT (user_seat), "device-added",
+                                                     G_CALLBACK (device_added_cb), manager);
+        manager->device_removed_id = g_signal_connect (G_OBJECT (user_seat), "device-removed",
+                                                       G_CALLBACK (device_removed_cb), manager);
+        manager->user_seat = user_seat;
+}
+
 gboolean
 gsd_xsettings_manager_start (GsdXSettingsManager *manager,
                              GError             **error)
@@ -1312,6 +1437,23 @@ gsd_xsettings_manager_start (GsdXSettingsManager *manager,
                 return FALSE;
         }
 
+       set_devicepresence_handler (manager);
+        manager->interface_settings = g_settings_new (INTERFACE_SETTINGS_SCHEMA);
+        g_signal_connect_swapped (manager->interface_settings,
+                                  "changed::" GTK_IM_MODULE_KEY,
+                                  G_CALLBACK (update_gtk_im_module), manager);
+
+        manager->input_sources_settings = g_settings_new (INPUT_SOURCES_SCHEMA);
+        g_signal_connect_swapped (manager->input_sources_settings,
+                                  "changed::" INPUT_SOURCES_KEY,
+                                  G_CALLBACK (update_gtk_im_module), manager);
+
+        manager->a11y_settings = g_settings_new (A11Y_APPLICATIONS_SCHEMA);
+        g_signal_connect_swapped (manager->a11y_settings,
+                                  "changed::" OSK_ENABLED_KEY,
+                                  G_CALLBACK (update_gtk_im_module), manager);
+        update_gtk_im_module (manager);
+
         manager->monitors_changed_id =
                 g_dbus_connection_signal_subscribe (manager->dbus_connection,
                                                     "org.gnome.Mutter.DisplayConfig",
@@ -1507,6 +1649,16 @@ gsd_xsettings_manager_stop (GsdXSettingsManager *manager)
                 g_object_unref (manager->gtk);
                 manager->gtk = NULL;
         }
+
+        if (manager->user_seat != NULL) {
+                g_signal_handler_disconnect (manager->user_seat, manager->device_added_id);
+                g_signal_handler_disconnect (manager->user_seat, manager->device_removed_id);
+                manager->user_seat = NULL;
+        }
+
+        g_clear_object (&manager->a11y_settings);
+        g_clear_object (&manager->input_sources_settings);
+        g_clear_object (&manager->interface_settings);
 }
 
 static void