[gdm] Don't add all users to the model at once

[William Jon McCann <mccann src gnome org>]

commit 9424e3e8c49879db9d83ba4d8b6333af227b8014
Author: William Jon McCann <jmccann redhat com>
Date:   Wed Jun 9 18:44:37 2010 -0400

    Don't add all users to the model at once
    
    Chunk the updates into groups of 50.  This is well more than can be displayed
    in the visible part of the list anyway.  This prevents blocking the UI
    while the model is loaded.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=621131

 gui/simple-greeter/gdm-user-chooser-widget.c |   50 +++++++++++++++++++++++--
 1 files changed, 46 insertions(+), 4 deletions(-)
---
diff --git a/gui/simple-greeter/gdm-user-chooser-widget.c b/gui/simple-greeter/gdm-user-chooser-widget.c
index ac966dc..e4c5e72 100644
--- a/gui/simple-greeter/gdm-user-chooser-widget.c
+++ b/gui/simple-greeter/gdm-user-chooser-widget.c
@@ -52,12 +52,15 @@ enum {
 #define GDM_USER_CHOOSER_WIDGET_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GDM_TYPE_USER_CHOOSER_WIDGET, GdmUserChooserWidgetPrivate))
 
 #define MAX_ICON_SIZE 128
+#define NUM_USERS_TO_ADD_PER_ITERATION 50
 
 struct GdmUserChooserWidgetPrivate
 {
         GdmUserManager *manager;
         GtkIconTheme   *icon_theme;
 
+        GSList         *users_to_add;
+
         GdkPixbuf      *logged_in_pixbuf;
         GdkPixbuf      *stock_person_pixbuf;
 
@@ -71,6 +74,7 @@ struct GdmUserChooserWidgetPrivate
 
         guint           update_other_visibility_idle_id;
         guint           load_idle_id;
+        guint           add_users_idle_id;
 };
 
 enum {
@@ -547,6 +551,31 @@ on_user_changed (GdmUserManager       *manager,
         update_item_for_user (widget, user);
 }
 
+static gboolean
+add_users (GdmUserChooserWidget *widget)
+{
+        guint cnt;
+
+        cnt = 0;
+        while (widget->priv->users_to_add != NULL && cnt < NUM_USERS_TO_ADD_PER_ITERATION) {
+                add_user (widget, widget->priv->users_to_add->data);
+                g_object_unref (widget->priv->users_to_add->data);
+                widget->priv->users_to_add = g_slist_delete_link (widget->priv->users_to_add, widget->priv->users_to_add);
+                cnt++;
+        }
+        g_debug ("GdmUserChooserWidget: added %u items", cnt);
+
+        return (widget->priv->users_to_add != NULL);
+}
+
+static void
+queue_add_users (GdmUserChooserWidget *widget)
+{
+        if (widget->priv->add_users_idle_id == 0) {
+                widget->priv->add_users_idle_id = g_idle_add ((GSourceFunc) add_users, widget);
+        }
+}
+
 static void
 on_is_loaded_changed (GdmUserManager       *manager,
                       GParamSpec           *pspec,
@@ -555,13 +584,15 @@ on_is_loaded_changed (GdmUserManager       *manager,
         GSList *users;
         gboolean list_visible;
 
+        /* FIXME: handle is-loaded=FALSE */
+
         g_debug ("GdmUserChooserWidget: Users loaded");
 
         users = gdm_user_manager_list_users (manager);
-        while (users != NULL) {
-                add_user (widget, users->data);
-                users = g_slist_delete_link (users, users);
-        }
+        g_slist_foreach (users, (GFunc) g_object_ref, NULL);
+        widget->priv->users_to_add = g_slist_concat (widget->priv->users_to_add, g_slist_copy (users));
+
+        queue_add_users (widget);
 
         g_object_get (G_OBJECT (widget), "list-visible", &list_visible, NULL);
 
@@ -641,11 +672,22 @@ gdm_user_chooser_widget_dispose (GObject *object)
                 widget->priv->load_idle_id = 0;
         }
 
+        if (widget->priv->add_users_idle_id > 0) {
+                g_source_remove (widget->priv->add_users_idle_id);
+                widget->priv->add_users_idle_id = 0;
+        }
+
         if (widget->priv->update_other_visibility_idle_id > 0) {
                 g_source_remove (widget->priv->update_other_visibility_idle_id);
                 widget->priv->update_other_visibility_idle_id = 0;
         }
 
+        if (widget->priv->users_to_add != NULL) {
+                g_slist_foreach (widget->priv->users_to_add, (GFunc) g_object_ref, NULL);
+                g_slist_free (widget->priv->users_to_add);
+                widget->priv->users_to_add = NULL;
+        }
+
         if (widget->priv->logged_in_pixbuf != NULL) {
                 g_object_unref (widget->priv->logged_in_pixbuf);
                 widget->priv->logged_in_pixbuf = NULL;