Add basic user monitoring. Hook up to user-list.

2007-10-03  William Jon McCann  <mccann@jhu.edu>

	* configure.ac:
	* gui/simple-greeter/Makefile.am:
	* gui/simple-greeter/gdm-user-chooser-widget.c: (populate_model),
	(on_user_added), (on_user_removed), (gdm_user_chooser_widget_init):
	* gui/simple-greeter/gdm-user-manager.c:
	(gdm_user_manager_error_quark), (gdm_user_manager_get_user),
	(listify_hash_values_hfunc), (gdm_user_manager_list_users),
	(reload_passwd), (reload_shells), (shells_monitor_cb),
	(passwd_monitor_cb), (gdm_user_manager_class_init),
	(reload_passwd_timeout), (queue_reload_passwd),
	(gdm_user_manager_init), (gdm_user_manager_finalize),
	(gdm_user_manager_ref_default):
	* gui/simple-greeter/gdm-user-manager.h:
	* gui/simple-greeter/gdm-user.c: (gdm_user_class_init),
	(gdm_user_init), (gdm_user_set_property), (gdm_user_get_property),
	(gdm_user_finalize), (_gdm_user_update), (_gdm_user_add_session),
	(_gdm_user_remove_session), (_gdm_user_icon_changed),
	(gdm_user_get_uid), (gdm_user_get_real_name),
	(gdm_user_get_user_name), (gdm_user_get_home_directory),
	(gdm_user_get_shell), (gdm_user_get_sessions),
	(gdm_user_get_n_sessions), (gdm_user_collate):
	* gui/simple-greeter/gdm-user.h:
	* gui/simple-greeter/test-user-chooser.c: (main):
	* gui/simple-greeter/test-user-manager.c: (on_user_added),
	(on_user_removed), (main):
	Add basic user monitoring.  Hook up to user-list.


svn path=/branches/mccann-gobject/; revision=5331

10 files changed, 1399 insertions, 63 deletions

diff --git a/ChangeLog b/ChangeLog
index 7e6aa159..0d1128e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,32 @@
+2007-10-03  William Jon McCann  <mccann@jhu.edu>
+
+	* configure.ac:
+	* gui/simple-greeter/Makefile.am:
+	* gui/simple-greeter/gdm-user-chooser-widget.c: (populate_model),
+	(on_user_added), (on_user_removed), (gdm_user_chooser_widget_init):
+	* gui/simple-greeter/gdm-user-manager.c:
+	(gdm_user_manager_error_quark), (gdm_user_manager_get_user),
+	(listify_hash_values_hfunc), (gdm_user_manager_list_users),
+	(reload_passwd), (reload_shells), (shells_monitor_cb),
+	(passwd_monitor_cb), (gdm_user_manager_class_init),
+	(reload_passwd_timeout), (queue_reload_passwd),
+	(gdm_user_manager_init), (gdm_user_manager_finalize),
+	(gdm_user_manager_ref_default):
+	* gui/simple-greeter/gdm-user-manager.h:
+	* gui/simple-greeter/gdm-user.c: (gdm_user_class_init),
+	(gdm_user_init), (gdm_user_set_property), (gdm_user_get_property),
+	(gdm_user_finalize), (_gdm_user_update), (_gdm_user_add_session),
+	(_gdm_user_remove_session), (_gdm_user_icon_changed),
+	(gdm_user_get_uid), (gdm_user_get_real_name),
+	(gdm_user_get_user_name), (gdm_user_get_home_directory),
+	(gdm_user_get_shell), (gdm_user_get_sessions),
+	(gdm_user_get_n_sessions), (gdm_user_collate):
+	* gui/simple-greeter/gdm-user.h:
+	* gui/simple-greeter/test-user-chooser.c: (main):
+	* gui/simple-greeter/test-user-manager.c: (on_user_added),
+	(on_user_removed), (main):
+	Add basic user monitoring.  Hook up to user-list.
+
 2007-10-02  William Jon McCann  <mccann@jhu.edu>
 
 	* daemon/gdm-factory-slave.c: (on_session_relay_info),
diff --git a/configure.ac b/configure.ac
index 7c3305e3..8c884053 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,7 +26,8 @@ GNOME_DOC_INIT
 
 DBUS_GLIB_REQUIRED=0.74
 GLIB_REQUIRED=2.13.0
-GTK_REQUIRED=2.6.0
+GTK_REQUIRED=2.10.0
+GNOME_VFS_REQUIRED=2.18.0
 PANGO_REQUIRED=1.3.0
 LIBGLADE_REQUIRED=1.99.2
 SCROLLKEEPER_REQUIRED=0.1.4
@@ -169,7 +170,7 @@ PKG_CHECK_MODULES(DAEMON, gtk+-2.0 >= $GTK_REQUIRED)
 AC_SUBST(DAEMON_CFLAGS)
 AC_SUBST(DAEMON_LIBS)
 
-PKG_CHECK_MODULES(GUI, gtk+-2.0 >= $GTK_REQUIRED libglade-2.0 >= $LIBGLADE_REQUIRED)
+PKG_CHECK_MODULES(GUI, gtk+-2.0 >= $GTK_REQUIRED libglade-2.0 >= $LIBGLADE_REQUIRED gnome-vfs-2.0 >= $GNOME_VFS_REQUIRED)
 AC_SUBST(GUI_CFLAGS)
 AC_SUBST(GUI_LIBS)
 
diff --git a/gui/simple-greeter/Makefile.am b/gui/simple-greeter/Makefile.am
index a6afa7cf..9d1828a6 100644
--- a/gui/simple-greeter/Makefile.am
+++ b/gui/simple-greeter/Makefile.am
@@ -28,6 +28,7 @@ noinst_PROGRAMS = 		\
 	test-language-chooser	\
 	test-session-chooser	\
 	test-user-chooser	\
+	test-user-manager	\
 	$(NULL)
 
 test_greeter_background_SOURCES = 	\
@@ -83,12 +84,28 @@ test_user_chooser_SOURCES = 	\
 	gdm-user-chooser-widget.c	\
 	gdm-user-chooser-dialog.h	\
 	gdm-user-chooser-dialog.c	\
+	gdm-user-manager.h		\
+	gdm-user-manager.c		\
+	gdm-user.h			\
+	gdm-user.c			\
 	$(NULL)
 
 test_user_chooser_LDADD =	\
 	$(GUI_LIBS)		\
 	$(NULL)
 
+test_user_manager_SOURCES = 	\
+	test-user-manager.c	\
+	gdm-user-manager.h	\
+	gdm-user-manager.c	\
+	gdm-user.h		\
+	gdm-user.c		\
+	$(NULL)
+
+test_user_manager_LDADD =	\
+	$(GUI_LIBS)		\
+	$(NULL)
+
 libexec_PROGRAMS =					\
 	gdm-simple-greeter
 
@@ -102,6 +119,10 @@ gdm_simple_greeter_SOURCES =  		\
 	gdm-greeter-background.c	\
 	gdm-user-chooser-widget.h	\
 	gdm-user-chooser-widget.c	\
+	gdm-user-manager.h		\
+	gdm-user-manager.c		\
+	gdm-user.h			\
+	gdm-user.c			\
 	$(NULL)
 
 gdm_simple_greeter_LDADD = 		\
diff --git a/gui/simple-greeter/gdm-user-chooser-widget.c b/gui/simple-greeter/gdm-user-chooser-widget.c
index 782763ef..525edc18 100644
--- a/gui/simple-greeter/gdm-user-chooser-widget.c
+++ b/gui/simple-greeter/gdm-user-chooser-widget.c
@@ -33,6 +33,7 @@
 #include <glib/gstdio.h>
 #include <gtk/gtk.h>
 
+#include "gdm-user-manager.h"
 #include "gdm-user-chooser-widget.h"
 
 enum {
@@ -53,6 +54,7 @@ struct GdmUserChooserWidgetPrivate
 {
         GtkWidget          *iconview;
 
+        GdmUserManager     *manager;
         GHashTable         *available_users;
         char               *current_user;
 };
@@ -372,66 +374,6 @@ static void
 populate_model (GdmUserChooserWidget *widget,
                 GtkTreeModel         *model)
 {
-        GtkTreeIter   iter;
-        GdkPixbuf    *pixbuf;
-        char         *caption;
-        char         *tooltip;
-
-        /* Add some fake entries */
-
-        caption = g_strdup_printf ("<span size=\"x-large\">%s</span>\n<i>%s</i>",
-                                   _("Guest User"),
-                                   _("Already logged in"));
-        tooltip = g_strdup_printf ("%s: %s",
-                                   _("Short Name"),
-                                   "guest");
-        pixbuf = get_pixbuf_for_user (widget, "guest");
-        gtk_list_store_append (GTK_LIST_STORE (model), &iter);
-        gtk_list_store_set (GTK_LIST_STORE (model), &iter,
-                            CHOOSER_LIST_PIXBUF_COLUMN, pixbuf,
-                            CHOOSER_LIST_CAPTION_COLUMN, caption,
-                            CHOOSER_LIST_TOOLTIP_COLUMN, tooltip,
-                            CHOOSER_LIST_ID_COLUMN, "guest",
-                            -1);
-        g_free (caption);
-        g_free (tooltip);
-
-        caption = g_strdup_printf ("<span size=\"x-large\">%s</span>\n<i>%s</i>",
-                                   _("GNOME Test"),
-                                   _("Already logged in"));
-        tooltip = g_strdup_printf ("%s: %s",
-                                   _("Short Name"),
-                                   "gtest");
-        pixbuf = get_pixbuf_for_user (widget, "gtest");
-        gtk_list_store_append (GTK_LIST_STORE (model), &iter);
-        gtk_list_store_set (GTK_LIST_STORE (model), &iter,
-                            CHOOSER_LIST_PIXBUF_COLUMN, pixbuf,
-                            CHOOSER_LIST_CAPTION_COLUMN, caption,
-                            CHOOSER_LIST_TOOLTIP_COLUMN, tooltip,
-                            CHOOSER_LIST_ID_COLUMN, "gtest",
-                            -1);
-        g_free (caption);
-        g_free (tooltip);
-
-        caption = g_strdup_printf ("<span size=\"x-large\">%s</span>",
-                                   _("Administrator"));
-        tooltip = g_strdup_printf ("%s: %s",
-                                   _("Short Name"),
-                                   "administrator");
-
-        gtk_list_store_append (GTK_LIST_STORE (model), &iter);
-        gtk_list_store_set (GTK_LIST_STORE (model), &iter,
-                            CHOOSER_LIST_PIXBUF_COLUMN, pixbuf,
-                            CHOOSER_LIST_CAPTION_COLUMN, caption,
-                            CHOOSER_LIST_TOOLTIP_COLUMN, tooltip,
-                            CHOOSER_LIST_ID_COLUMN, "administrator",
-                            -1);
-        g_free (caption);
-        g_free (tooltip);
-
-        if (pixbuf != NULL) {
-                g_object_unref (pixbuf);
-        }
 
         g_hash_table_foreach (widget->priv->available_users,
                               (GHFunc)add_user_to_model,
@@ -521,6 +463,53 @@ compare_user  (GtkTreeModel *model,
 }
 
 static void
+on_user_added (GdmUserManager       *manager,
+               GdmUser              *user,
+               GdmUserChooserWidget *widget)
+{
+        GtkTreeModel *model;
+        GtkTreeIter   iter;
+        GdkPixbuf    *pixbuf;
+        char         *caption;
+        char         *tooltip;
+
+        g_debug ("User added: %s", gdm_user_get_user_name (user));
+
+        pixbuf = get_pixbuf_for_user (widget, gdm_user_get_user_name (user));
+
+        caption = g_strdup_printf ("<span size=\"x-large\">%s</span>",
+                                   gdm_user_get_real_name (user));
+        tooltip = g_strdup_printf ("%s: %s",
+                                   _("Short Name"),
+                                   gdm_user_get_user_name (user));
+
+        model = gtk_icon_view_get_model (GTK_ICON_VIEW (widget->priv->iconview));
+        gtk_list_store_append (GTK_LIST_STORE (model), &iter);
+        gtk_list_store_set (GTK_LIST_STORE (model), &iter,
+                            CHOOSER_LIST_PIXBUF_COLUMN, pixbuf,
+                            CHOOSER_LIST_CAPTION_COLUMN, caption,
+                            CHOOSER_LIST_TOOLTIP_COLUMN, tooltip,
+                            CHOOSER_LIST_ID_COLUMN, gdm_user_get_user_name (user),
+                            -1);
+        g_free (caption);
+        g_free (tooltip);
+
+        if (pixbuf != NULL) {
+                g_object_unref (pixbuf);
+        }
+}
+
+static void
+on_user_removed (GdmUserManager       *manager,
+                 GdmUser              *user,
+                 GdmUserChooserWidget *widget)
+{
+        g_debug ("User removed: %s", gdm_user_get_user_name (user));
+
+        /* FIXME: */
+}
+
+static void
 gdm_user_chooser_widget_init (GdmUserChooserWidget *widget)
 {
         GtkTreeModel      *model;
@@ -528,13 +517,24 @@ gdm_user_chooser_widget_init (GdmUserChooserWidget *widget)
 
         widget->priv = GDM_USER_CHOOSER_WIDGET_GET_PRIVATE (widget);
 
+        widget->priv->manager = gdm_user_manager_ref_default ();
+        g_signal_connect (widget->priv->manager,
+                          "user-added",
+                          G_CALLBACK (on_user_added),
+                          widget);
+        g_signal_connect (widget->priv->manager,
+                          "user-removed",
+                          G_CALLBACK (on_user_removed),
+                          widget);
+
         widget->priv->available_users = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify)chooser_user_free);
 
         scrolled = gtk_scrolled_window_new (NULL, NULL);
         gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrolled),
                                              GTK_SHADOW_IN);
         gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled),
-                                        GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
+                                        GTK_POLICY_NEVER,
+                                        GTK_POLICY_AUTOMATIC);
         gtk_box_pack_start (GTK_BOX (widget), scrolled, TRUE, TRUE, 0);
 
         widget->priv->iconview = gtk_icon_view_new ();
diff --git a/gui/simple-greeter/gdm-user-manager.c b/gui/simple-greeter/gdm-user-manager.c
new file mode 100644
index 00000000..1755d7d2
--- /dev/null
+++ b/gui/simple-greeter/gdm-user-manager.c
@@ -0,0 +1,482 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <glib.h>
+#include <glib/gi18n.h>
+#include <glib/gstdio.h>
+#include <glib-object.h>
+
+#include <libgnomevfs/gnome-vfs-ops.h>
+
+#include "gdm-user-manager.h"
+#include "gdm-user-private.h"
+
+#define GDM_USER_MANAGER_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GDM_TYPE_USER_MANAGER, GdmUserManagerPrivate))
+
+/* Prefs Defaults */
+#define DEFAULT_ALLOW_ROOT      TRUE
+#define DEFAULT_MAX_ICON_SIZE   128
+#define DEFAULT_USER_MAX_FILE   65536
+#define DEFAULT_MINIMAL_UID     500
+#define DEFAULT_GLOBAL_FACE_DIR DATADIR "/faces"
+#define DEFAULT_USER_ICON       "stock_person"
+#define DEFAULT_EXCLUDE         { "bin",        \
+                                  "daemon",     \
+                                  "adm",        \
+                                  "lp",         \
+                                  "sync",       \
+                                  "shutdown",   \
+                                  "halt",       \
+                                  "mail",       \
+                                  "news",       \
+                                  "uucp",       \
+                                  "operator",   \
+                                  "nobody",     \
+                                  "gdm",        \
+                                  "postgres",   \
+                                  "pvm",        \
+                                  "rpm",        \
+                                  "nfsnobody",  \
+                                  "pcap",       \
+                                  NULL }
+
+struct GdmUserManagerPrivate
+{
+        GHashTable            *users;
+        GHashTable            *shells;
+        GHashTable            *exclusions;
+        GnomeVFSMonitorHandle *passwd_monitor;
+        GnomeVFSMonitorHandle *shells_monitor;
+
+        guint                  reload_id;
+        uid_t                  minimal_uid;
+
+        guint8                 users_dirty : 1;
+};
+
+enum {
+        USER_ADDED,
+        USER_REMOVED,
+        LAST_SIGNAL
+};
+
+static guint signals [LAST_SIGNAL] = { 0, };
+
+static void     gdm_user_manager_class_init (GdmUserManagerClass *klass);
+static void     gdm_user_manager_init       (GdmUserManager      *user_manager);
+static void     gdm_user_manager_finalize   (GObject             *object);
+
+static gpointer user_manager_object = NULL;
+
+G_DEFINE_TYPE (GdmUserManager, gdm_user_manager, G_TYPE_OBJECT)
+
+GQuark
+gdm_user_manager_error_quark (void)
+{
+        static GQuark ret = 0;
+        if (ret == 0) {
+                ret = g_quark_from_static_string ("gdm_user_manager_error");
+        }
+
+        return ret;
+}
+
+/**
+ * gdm_manager_get_user:
+ * @manager: the manager to query.
+ * @username: the login name of the user to get.
+ *
+ * Retrieves a pointer to the #GdmUser object for the login named @username
+ * from @manager. This pointer is not a reference, and should not be released.
+ *
+ * Returns: a pointer to a #GdmUser object.
+ **/
+GdmUser *
+gdm_user_manager_get_user (GdmUserManager *manager,
+                           const char     *username)
+{
+        GdmUser *user;
+
+        g_return_val_if_fail (GDM_IS_USER_MANAGER (manager), NULL);
+        g_return_val_if_fail (username != NULL && username[0] != '\0', NULL);
+
+        user = g_hash_table_lookup (manager->priv->users, username);
+
+        if (user == NULL) {
+                struct passwd *pwent;
+
+                pwent = getpwnam (username);
+
+                if (pwent != NULL) {
+                        user = g_object_new (GDM_TYPE_USER, "manager", manager, NULL);
+                        _gdm_user_update (user, pwent);
+                        g_hash_table_insert (manager->priv->users,
+                                             g_strdup (pwent->pw_name),
+                                             user);
+                        g_signal_emit (manager, signals[USER_ADDED], 0, user);
+                }
+        }
+
+        return user;
+}
+
+static void
+listify_hash_values_hfunc (gpointer key,
+                           gpointer value,
+                           gpointer user_data)
+{
+        GSList **list = user_data;
+
+        *list = g_slist_prepend (*list, value);
+}
+
+GSList *
+gdm_user_manager_list_users (GdmUserManager *manager)
+{
+        GSList *retval;
+
+        g_return_val_if_fail (GDM_IS_USER_MANAGER (manager), NULL);
+
+        retval = NULL;
+        g_hash_table_foreach (manager->priv->users, listify_hash_values_hfunc, &retval);
+
+        return g_slist_sort (retval, (GCompareFunc) gdm_user_collate);
+}
+
+static void
+reload_passwd (GdmUserManager *manager)
+{
+        struct passwd *pwent;
+        GSList        *old_users;
+        GSList        *new_users;
+        GSList        *list;
+
+        old_users = NULL;
+        new_users = NULL;
+
+        g_hash_table_foreach (manager->priv->users, listify_hash_values_hfunc, &old_users);
+        g_slist_foreach (old_users, (GFunc) g_object_ref, NULL);
+
+        /* Make sure we keep users who are logged in no matter what. */
+        for (list = old_users; list; list = list->next) {
+                if (gdm_user_get_n_sessions (list->data)) {
+                        g_object_freeze_notify (G_OBJECT (list->data));
+                        new_users = g_slist_prepend (new_users, g_object_ref (list->data));
+                }
+        }
+
+        setpwent ();
+
+        for (pwent = getpwent (); pwent; pwent = getpwent ()) {
+                GdmUser *user;
+
+                user = NULL;
+
+                /* Skip users below MinimalUID... */
+                if (pwent->pw_uid < manager->priv->minimal_uid) {
+                        continue;
+                }
+
+                /* ...And users w/ invalid shells... */
+                if (!pwent->pw_shell ||
+                    !g_hash_table_lookup (manager->priv->shells, pwent->pw_shell)) {
+                        continue;
+                }
+
+                /* ...And explicitly excluded users */
+                if (g_hash_table_lookup (manager->priv->exclusions, pwent->pw_name)) {
+                        continue;
+                }
+
+                user = g_hash_table_lookup (manager->priv->users, pwent->pw_name);
+
+                /* Update users already in the *new* list */
+                if (g_slist_find (new_users, user)) {
+                        _gdm_user_update (user, pwent);
+                        continue;
+                }
+
+                if (user == NULL) {
+                        user = g_object_new (GDM_TYPE_USER,
+                                             "manager", manager,
+                                             NULL);
+                } else {
+                        g_object_ref (user);
+                }
+
+                /* Freeze & update users not already in the new list */
+                g_object_freeze_notify (G_OBJECT (user));
+                _gdm_user_update (user, pwent);
+
+                new_users = g_slist_prepend (new_users, user);
+        }
+
+        endpwent ();
+
+        /* Go through and handle added users */
+        for (list = new_users; list; list = list->next) {
+                if (! g_slist_find (old_users, list->data)) {
+                        g_hash_table_insert (manager->priv->users,
+                                             g_strdup (gdm_user_get_user_name (list->data)),
+                                             g_object_ref (list->data));
+                        g_signal_emit (manager, signals[USER_ADDED], 0, list->data);
+                }
+        }
+
+        /* Go through and handle removed users */
+        for (list = old_users; list; list = list->next) {
+                if (! g_slist_find (new_users, list->data)) {
+                        g_signal_emit (manager, signals[USER_REMOVED], 0, list->data);
+                        g_hash_table_remove (manager->priv->users,
+                                             gdm_user_get_user_name (list->data));
+                }
+        }
+
+        /* Cleanup */
+        g_slist_foreach (new_users, (GFunc) g_object_thaw_notify, NULL);
+        g_slist_foreach (new_users, (GFunc) g_object_unref, NULL);
+        g_slist_free (new_users);
+
+        g_slist_foreach (old_users, (GFunc) g_object_unref, NULL);
+        g_slist_free (old_users);
+}
+
+static void
+reload_shells (GdmUserManager *manager)
+{
+        char *shell;
+
+        setusershell ();
+
+        g_hash_table_remove_all (manager->priv->shells);
+        for (shell = getusershell (); shell; shell = getusershell ()) {
+                g_hash_table_insert (manager->priv->shells,
+                                     g_strdup (shell),
+                                     GUINT_TO_POINTER (TRUE));
+        }
+
+        endusershell ();
+}
+
+static void
+shells_monitor_cb (GnomeVFSMonitorHandle    *handle,
+                   const gchar              *text_uri,
+                   const gchar              *info_uri,
+                   GnomeVFSMonitorEventType  event_type,
+                   GdmUserManager           *manager)
+{
+        if (event_type != GNOME_VFS_MONITOR_EVENT_CHANGED &&
+            event_type != GNOME_VFS_MONITOR_EVENT_CREATED)
+                return;
+
+        reload_shells (manager);
+        reload_passwd (manager);
+}
+
+static void
+passwd_monitor_cb (GnomeVFSMonitorHandle    *handle,
+                   const gchar              *text_uri,
+                   const gchar              *info_uri,
+                   GnomeVFSMonitorEventType  event_type,
+                   GdmUserManager           *manager)
+{
+        if (event_type != GNOME_VFS_MONITOR_EVENT_CHANGED &&
+            event_type != GNOME_VFS_MONITOR_EVENT_CREATED)
+                return;
+
+        reload_passwd (manager);
+}
+
+static void
+gdm_user_manager_class_init (GdmUserManagerClass *klass)
+{
+        GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+
+        object_class->finalize = gdm_user_manager_finalize;
+
+        signals [USER_ADDED] =
+                g_signal_new ("user-added",
+                              G_TYPE_FROM_CLASS (klass),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdmUserManagerClass, user_added),
+                              NULL, NULL,
+                              g_cclosure_marshal_VOID__OBJECT,
+                              G_TYPE_NONE, 1, GDM_TYPE_USER);
+        signals [USER_REMOVED] =
+                g_signal_new ("user-removed",
+                              G_TYPE_FROM_CLASS (klass),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdmUserManagerClass, user_removed),
+                              NULL, NULL,
+                              g_cclosure_marshal_VOID__OBJECT,
+                              G_TYPE_NONE, 1, GDM_TYPE_USER);
+
+        g_type_class_add_private (klass, sizeof (GdmUserManagerPrivate));
+}
+
+static gboolean
+reload_passwd_timeout (GdmUserManager *manager)
+{
+        reload_passwd (manager);
+        manager->priv->reload_id = 0;
+        return FALSE;
+}
+
+static void
+queue_reload_passwd (GdmUserManager *manager)
+{
+        if (manager->priv->reload_id > 0) {
+                return;
+        }
+
+        manager->priv->reload_id = g_idle_add ((GSourceFunc)reload_passwd_timeout, manager);
+}
+
+static void
+gdm_user_manager_init (GdmUserManager *manager)
+{
+        GError        *error;
+        char          *uri;
+        GnomeVFSResult result;
+        int            i;
+        const char    *exclude_default[] = DEFAULT_EXCLUDE;
+
+        manager->priv = GDM_USER_MANAGER_GET_PRIVATE (manager);
+
+        manager->priv->minimal_uid = DEFAULT_MINIMAL_UID;
+
+        /* exclusions */
+        manager->priv->exclusions = g_hash_table_new_full (g_str_hash,
+                                                           g_str_equal,
+                                                           g_free,
+                                                           NULL);
+        for (i = 0; exclude_default[i] != NULL; i++) {
+                g_hash_table_insert (manager->priv->exclusions,
+                                     g_strdup (exclude_default [i]),
+                                     GUINT_TO_POINTER (TRUE));
+        }
+
+        /* /etc/shells */
+        manager->priv->shells = g_hash_table_new_full (g_str_hash,
+                                                       g_str_equal,
+                                                       g_free,
+                                                       NULL);
+        reload_shells (manager);
+        error = NULL;
+        uri = g_filename_to_uri ("/etc/shells", NULL, &error);
+        if (uri == NULL) {
+                g_critical ("Could not create URI for shells file `/etc/shells': %s",
+                            error->message);
+                g_error_free (error);
+        } else {
+                result = gnome_vfs_monitor_add (&(manager->priv->shells_monitor),
+                                                uri,
+                                                GNOME_VFS_MONITOR_FILE,
+                                                (GnomeVFSMonitorCallback)shells_monitor_cb,
+                                                manager);
+                g_free (uri);
+
+                if (result != GNOME_VFS_OK)
+                        g_critical ("Could not install monitor for shells file `/etc/shells': %s",
+                                    gnome_vfs_result_to_string (result));
+        }
+
+        /* /etc/passwd */
+        manager->priv->users = g_hash_table_new_full (g_str_hash,
+                                                      g_str_equal,
+                                                      g_free,
+                                                      (GDestroyNotify) g_object_run_dispose);
+        error = NULL;
+        uri = g_filename_to_uri ("/etc/passwd", NULL, &error);
+        if (uri == NULL) {
+                g_critical ("Could not create URI for password file `/etc/passwd': %s",
+                            error->message);
+                g_error_free (error);
+        } else {
+                result = gnome_vfs_monitor_add (&(manager->priv->passwd_monitor),
+                                                uri,
+                                                GNOME_VFS_MONITOR_FILE,
+                                                (GnomeVFSMonitorCallback)passwd_monitor_cb,
+                                                manager);
+                g_free (uri);
+
+                if (result != GNOME_VFS_OK)
+                        g_critical ("Could not install monitor for password file `/etc/passwd: %s",
+                                    gnome_vfs_result_to_string (result));
+        }
+
+        /* FIXME: add ConsoleKit seat monitoring */
+
+        queue_reload_passwd (manager);
+
+        manager->priv->users_dirty = FALSE;
+
+}
+
+static void
+gdm_user_manager_finalize (GObject *object)
+{
+        GdmUserManager *manager;
+
+        g_return_if_fail (object != NULL);
+        g_return_if_fail (GDM_IS_USER_MANAGER (object));
+
+        manager = GDM_USER_MANAGER (object);
+
+        g_return_if_fail (manager->priv != NULL);
+
+        if (manager->priv->reload_id > 0) {
+                g_source_remove (manager->priv->reload_id);
+                manager->priv->reload_id = 0;
+        }
+
+        gnome_vfs_monitor_cancel (manager->priv->shells_monitor);
+        g_hash_table_destroy (manager->priv->shells);
+
+        gnome_vfs_monitor_cancel (manager->priv->passwd_monitor);
+        g_hash_table_destroy (manager->priv->users);
+
+        G_OBJECT_CLASS (gdm_user_manager_parent_class)->finalize (object);
+}
+
+GdmUserManager *
+gdm_user_manager_ref_default (void)
+{
+        if (user_manager_object != NULL) {
+                g_object_ref (user_manager_object);
+        } else {
+                user_manager_object = g_object_new (GDM_TYPE_USER_MANAGER, NULL);
+                g_object_add_weak_pointer (user_manager_object,
+                                           (gpointer *) &user_manager_object);
+        }
+
+        return GDM_USER_MANAGER (user_manager_object);
+}
diff --git a/gui/simple-greeter/gdm-user-manager.h b/gui/simple-greeter/gdm-user-manager.h
new file mode 100644
index 00000000..590ab1da
--- /dev/null
+++ b/gui/simple-greeter/gdm-user-manager.h
@@ -0,0 +1,73 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef __GDM_USER_MANAGER_H
+#define __GDM_USER_MANAGER_H
+
+#include <glib-object.h>
+
+#include "gdm-user.h"
+
+G_BEGIN_DECLS
+
+#define GDM_TYPE_USER_MANAGER         (gdm_user_manager_get_type ())
+#define GDM_USER_MANAGER(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), GDM_TYPE_USER_MANAGER, GdmUserManager))
+#define GDM_USER_MANAGER_CLASS(k)     (G_TYPE_CHECK_CLASS_CAST((k), GDM_TYPE_USER_MANAGER, GdmUserManagerClass))
+#define GDM_IS_USER_MANAGER(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), GDM_TYPE_USER_MANAGER))
+#define GDM_IS_USER_MANAGER_CLASS(k)  (G_TYPE_CHECK_CLASS_TYPE ((k), GDM_TYPE_USER_MANAGER))
+#define GDM_USER_MANAGER_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), GDM_TYPE_USER_MANAGER, GdmUserManagerClass))
+
+typedef struct GdmUserManagerPrivate GdmUserManagerPrivate;
+
+typedef struct
+{
+        GObject                parent;
+        GdmUserManagerPrivate *priv;
+} GdmUserManager;
+
+typedef struct
+{
+        GObjectClass   parent_class;
+
+        void          (* user_added)    (GdmUserManager *user_manager,
+                                         GdmUser        *user);
+        void          (* user_removed)  (GdmUserManager *user_manager,
+                                         GdmUser        *user);
+} GdmUserManagerClass;
+
+typedef enum
+{
+        GDM_USER_MANAGER_ERROR_GENERAL,
+        GDM_USER_MANAGER_ERROR_KEY_NOT_FOUND
+} GdmUserManagerError;
+
+#define GDM_USER_MANAGER_ERROR gdm_user_manager_error_quark ()
+
+GQuark              gdm_user_manager_error_quark           (void);
+GType               gdm_user_manager_get_type              (void);
+
+GdmUserManager *    gdm_user_manager_ref_default           (void);
+
+GSList *            gdm_user_manager_list_users            (GdmUserManager *manager);
+GdmUser *           gdm_user_manager_get_user              (GdmUserManager *manager,
+                                                            const char     *user_name);
+G_END_DECLS
+
+#endif /* __GDM_USER_MANAGER_H */
diff --git a/gui/simple-greeter/gdm-user.c b/gui/simple-greeter/gdm-user.c
new file mode 100644
index 00000000..a7d1e9ed
--- /dev/null
+++ b/gui/simple-greeter/gdm-user.c
@@ -0,0 +1,587 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2004-2005 James M. Cape <jcape@ignore-your.tv>.
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <config.h>
+
+#include <string.h>
+#include <glib/gi18n.h>
+#include <gtk/gtkicontheme.h>
+
+#include "gdm-user-manager.h"
+#include "gdm-user-private.h"
+
+#define GDM_USER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GDM_TYPE_USER, GdmUserClass))
+#define GDM_IS_USER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GDM_TYPE_USER))
+#define GDM_USER_GET_CLASS(object) (G_TYPE_INSTANCE_GET_CLASS ((object), GDM_TYPE_USER, GdmUserClass))
+
+enum {
+        PROP_0,
+        PROP_MANAGER,
+        PROP_REAL_NAME,
+        PROP_USER_NAME,
+        PROP_UID,
+        PROP_HOME_DIR,
+        PROP_SHELL,
+        PROP_SESSIONS
+};
+
+enum {
+        ICON_CHANGED,
+        SESSIONS_CHANGED,
+        LAST_SIGNAL
+};
+
+struct _GdmUser {
+        GObject         parent;
+
+        GdmUserManager *manager;
+
+        uid_t           uid;
+        gchar          *user_name;
+        gchar          *real_name;
+        gchar          *home_dir;
+        gchar          *shell;
+        GSList         *sessions;
+};
+
+typedef struct _GdmUserClass
+{
+        GObjectClass parent_class;
+
+        void (* icon_changed)     (GdmUser *user);
+        void (* sessions_changed) (GdmUser *user);
+} GdmUserClass;
+
+/* GObject Functions */
+static void gdm_user_set_property (GObject      *object,
+                                   guint         param_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec);
+static void gdm_user_get_property (GObject      *object,
+                                   guint         param_id,
+                                   GValue       *value,
+                                   GParamSpec   *pspec);
+static void gdm_user_finalize     (GObject      *object);
+
+
+static guint signals[LAST_SIGNAL] = { 0 };
+
+G_DEFINE_TYPE (GdmUser, gdm_user, G_TYPE_OBJECT);
+
+static void
+gdm_user_class_init (GdmUserClass *class)
+{
+        GObjectClass *gobject_class;
+
+        gobject_class = G_OBJECT_CLASS (class);
+
+        gobject_class->set_property = gdm_user_set_property;
+        gobject_class->get_property = gdm_user_get_property;
+        gobject_class->finalize = gdm_user_finalize;
+
+        g_object_class_install_property (gobject_class,
+                                         PROP_MANAGER,
+                                         g_param_spec_object ("manager",
+                                                              _("Manager"),
+                                                              _("The user manager object this user is controlled by."),
+                                                              GDM_TYPE_USER_MANAGER,
+                                                              (G_PARAM_READWRITE |
+                                                               G_PARAM_CONSTRUCT_ONLY)));
+
+        g_object_class_install_property (gobject_class,
+                                         PROP_REAL_NAME,
+                                         g_param_spec_string ("real-name",
+                                                              "Real Name",
+                                                              "The real name to display for this user.",
+                                                              NULL,
+                                                              G_PARAM_READABLE));
+
+        g_object_class_install_property (gobject_class,
+                                         PROP_UID,
+                                         g_param_spec_ulong ("uid",
+                                                             "User ID",
+                                                             "The UID for this user.",
+                                                             0, G_MAXULONG, 0,
+                                                             G_PARAM_READABLE));
+        g_object_class_install_property (gobject_class,
+                                         PROP_USER_NAME,
+                                         g_param_spec_string ("user-name",
+                                                              "User Name",
+                                                              "The login name for this user.",
+                                                              NULL,
+                                                              G_PARAM_READABLE));
+        g_object_class_install_property (gobject_class,
+                                         PROP_HOME_DIR,
+                                         g_param_spec_string ("home-directory",
+                                                              "Home Directory",
+                                                              "The home directory for this user.",
+                                                              NULL,
+                                                              G_PARAM_READABLE));
+        g_object_class_install_property (gobject_class,
+                                         PROP_SHELL,
+                                         g_param_spec_string ("shell",
+                                                              "Shell",
+                                                              "The shell for this user.",
+                                                              NULL,
+                                                              G_PARAM_READABLE));
+
+        signals [ICON_CHANGED] =
+                g_signal_new ("icon-changed",
+                              G_TYPE_FROM_CLASS (class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdmUserClass, icon_changed),
+                              NULL, NULL,
+                              g_cclosure_marshal_VOID__VOID,
+                              G_TYPE_NONE, 0);
+        signals [SESSIONS_CHANGED] =
+                g_signal_new ("sessions-changed",
+                              G_TYPE_FROM_CLASS (class),
+                              G_SIGNAL_RUN_LAST,
+                              G_STRUCT_OFFSET (GdmUserClass, sessions_changed),
+                              NULL, NULL,
+                              g_cclosure_marshal_VOID__VOID,
+                              G_TYPE_NONE, 0);
+}
+
+static void
+gdm_user_init (GdmUser *user)
+{
+        user->manager = NULL;
+        user->user_name = NULL;
+        user->real_name = NULL;
+        user->sessions = NULL;
+}
+
+static void
+gdm_user_set_property (GObject      *object,
+                       guint         param_id,
+                       const GValue *value,
+                       GParamSpec   *pspec)
+{
+        GdmUser *user;
+
+        user = GDM_USER (object);
+
+        switch (param_id) {
+        case PROP_MANAGER:
+                user->manager = g_value_get_object (value);
+                g_assert (user->manager);
+                break;
+
+        default:
+                G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
+                break;
+        }
+}
+
+static void
+gdm_user_get_property (GObject    *object,
+                       guint       param_id,
+                       GValue     *value,
+                       GParamSpec *pspec)
+{
+        GdmUser *user;
+
+        user = GDM_USER (object);
+
+        switch (param_id) {
+        case PROP_MANAGER:
+                g_value_set_object (value, user->manager);
+                break;
+        case PROP_USER_NAME:
+                g_value_set_string (value, user->user_name);
+                break;
+        case PROP_REAL_NAME:
+                g_value_set_string (value, user->real_name);
+                break;
+        case PROP_HOME_DIR:
+                g_value_set_string (value, user->home_dir);
+                break;
+        case PROP_UID:
+                g_value_set_ulong (value, user->uid);
+                break;
+        case PROP_SHELL:
+                g_value_set_string (value, user->shell);
+                break;
+        case PROP_SESSIONS:
+                if (user->sessions) {
+                        GValueArray *ar;
+                        GSList      *list;
+                        GValue       tmp = { 0 };
+
+                        ar = g_value_array_new (g_slist_length (user->sessions));
+                        g_value_init (&tmp, GDM_TYPE_USER);
+                        for (list = user->sessions; list; list = list->next) {
+                                g_value_set_object (&tmp, list->data);
+                                g_value_array_append (ar, &tmp);
+                                g_value_reset (&tmp);
+                        }
+
+                        g_value_take_boxed (value, ar);
+                } else {
+                        g_value_set_boxed (value, NULL);
+                }
+
+                break;
+        default:
+                G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
+                break;
+        }
+}
+
+static void
+gdm_user_finalize (GObject *object)
+{
+        GdmUser *user;
+
+        user = GDM_USER (object);
+
+        g_free (user->user_name);
+        g_free (user->real_name);
+
+        if (G_OBJECT_CLASS (gdm_user_parent_class)->finalize)
+                (*G_OBJECT_CLASS (gdm_user_parent_class)->finalize) (object);
+}
+
+/**
+ * _gdm_user_update:
+ * @user: the user object to update.
+ * @pwent: the user data to use.
+ *
+ * Updates the properties of @user using the data in @pwent.
+ *
+ * Since: 1.0
+ **/
+void
+_gdm_user_update (GdmUser             *user,
+                  const struct passwd *pwent)
+{
+        gchar *real_name;
+
+        g_return_if_fail (GDM_IS_USER (user));
+        g_return_if_fail (pwent != NULL);
+
+        g_object_freeze_notify (G_OBJECT (user));
+
+        /* Display Name */
+        if (pwent->pw_gecos && pwent->pw_gecos[0] != '\0') {
+                gchar *first_comma;
+
+                first_comma = strchr (pwent->pw_gecos, ',');
+                if (first_comma) {
+                        real_name = g_strndup (pwent->pw_gecos,
+                                                  (first_comma - pwent->pw_gecos));
+                } else {
+                        real_name = g_strdup (pwent->pw_gecos);
+                }
+
+                if (real_name[0] == '\0') {
+                        g_free (real_name);
+                        real_name = NULL;
+                }
+        } else {
+                real_name = NULL;
+        }
+
+        if ((real_name && !user->real_name) ||
+            (!real_name && user->real_name) ||
+            (real_name &&
+             user->real_name &&
+             strcmp (real_name, user->real_name) != 0)) {
+                g_free (user->real_name);
+                user->real_name = real_name;
+                g_object_notify (G_OBJECT (user), "real-name");
+        } else {
+                g_free (real_name);
+        }
+
+        /* UID */
+        if (pwent->pw_uid != user->uid) {
+                user->uid = pwent->pw_uid;
+                g_object_notify (G_OBJECT (user), "uid");
+        }
+
+        /* Username */
+        if ((pwent->pw_name && !user->user_name) ||
+            (!pwent->pw_name && user->user_name) ||
+            (pwent->pw_name &&
+             user->user_name &&
+             strcmp (user->user_name, pwent->pw_name) != 0)) {
+                g_free (user->user_name);
+                user->user_name = g_strdup (pwent->pw_name);
+                g_object_notify (G_OBJECT (user), "user-name");
+        }
+
+        /* Home Directory */
+        if ((pwent->pw_dir && !user->home_dir) ||
+            (!pwent->pw_dir && user->home_dir) ||
+            strcmp (user->home_dir, pwent->pw_dir) != 0) {
+                g_free (user->home_dir);
+                user->home_dir = g_strdup (pwent->pw_dir);
+                g_object_notify (G_OBJECT (user), "home-directory");
+                g_signal_emit (user, signals[ICON_CHANGED], 0);
+        }
+
+        /* Shell */
+        if ((pwent->pw_shell && !user->shell) ||
+            (!pwent->pw_shell && user->shell) ||
+            (pwent->pw_shell &&
+             user->shell &&
+             strcmp (user->shell, pwent->pw_shell) != 0)) {
+                g_free (user->shell);
+                user->shell = g_strdup (pwent->pw_shell);
+                g_object_notify (G_OBJECT (user), "shell");
+        }
+
+        g_object_thaw_notify (G_OBJECT (user));
+}
+
+void
+_gdm_user_add_session (GdmUser    *user,
+                       const char *ssid)
+{
+        g_return_if_fail (GDM_IS_USER (user));
+        g_return_if_fail (ssid != NULL);
+
+        if (! g_slist_find (user->sessions, ssid)) {
+                user->sessions = g_slist_append (user->sessions, g_strdup (ssid));
+                g_signal_emit (user, signals[SESSIONS_CHANGED], 0);
+        }
+}
+
+/**
+ * _gdm_user_remove_session:
+ * @user: the user to modify.
+ * @ssid: the session id to remove
+ *
+ * Removes @ssid from the list of sessions @user is using, and emits the
+ * "sessions-changed" signal, if necessary.
+ *
+ * Since: 1.0
+ **/
+void
+_gdm_user_remove_session (GdmUser    *user,
+                          const char *ssid)
+{
+        GSList *li;
+
+        g_return_if_fail (GDM_IS_USER (user));
+        g_return_if_fail (ssid != NULL);
+
+        li = g_slist_find (user->sessions, ssid);
+        if (li != NULL) {
+                g_free (li->data);
+                user->sessions = g_slist_delete_link (user->sessions, li);
+                g_signal_emit (user, signals[SESSIONS_CHANGED], 0);
+        }
+}
+
+/**
+ * _gdm_user_icon_changed:
+ * @user: the user to emit the signal for.
+ *
+ * Emits the "icon-changed" signal for @user.
+ *
+ * Since: 1.0
+ **/
+void
+_gdm_user_icon_changed (GdmUser *user)
+{
+        g_return_if_fail (GDM_IS_USER (user));
+
+        g_signal_emit (user, signals[ICON_CHANGED], 0);
+}
+
+/**
+ * gdm_user_get_uid:
+ * @user: the user object to examine.
+ *
+ * Retrieves the ID of @user.
+ *
+ * Returns: a pointer to an array of characters which must not be modified or
+ *  freed, or %NULL.
+ *
+ * Since: 1.0
+ **/
+
+uid_t
+gdm_user_get_uid (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), -1);
+
+        return user->uid;
+}
+
+/**
+ * gdm_user_get_real_name:
+ * @user: the user object to examine.
+ * 
+ * Retrieves the display name of @user.
+ * 
+ * Returns: a pointer to an array of characters which must not be modified or
+ *  freed, or %NULL.
+ * 
+ * Since: 1.0
+ **/
+G_CONST_RETURN gchar *
+gdm_user_get_real_name (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), NULL);
+
+        return (user->real_name ? user->real_name : user->user_name);
+}
+
+/**
+ * gdm_user_get_user_name:
+ * @user: the user object to examine.
+ * 
+ * Retrieves the login name of @user.
+ * 
+ * Returns: a pointer to an array of characters which must not be modified or
+ *  freed, or %NULL.
+ * 
+ * Since: 1.0
+ **/
+
+G_CONST_RETURN gchar *
+gdm_user_get_user_name (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), NULL);
+
+        return user->user_name;
+}
+
+/**
+ * gdm_user_get_home_directory:
+ * @user: the user object to examine.
+ * 
+ * Retrieves the home directory of @user.
+ * 
+ * Returns: a pointer to an array of characters which must not be modified or
+ *  freed, or %NULL.
+ * 
+ * Since: 1.0
+ **/
+
+G_CONST_RETURN gchar *
+gdm_user_get_home_directory (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), NULL);
+
+        return user->home_dir;
+}
+
+/**
+ * gdm_user_get_shell:
+ * @user: the user object to examine.
+ * 
+ * Retrieves the login shell of @user.
+ * 
+ * Returns: a pointer to an array of characters which must not be modified or
+ *  freed, or %NULL.
+ * 
+ * Since: 1.0
+ **/
+
+G_CONST_RETURN gchar *
+gdm_user_get_shell (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), NULL);
+
+        return user->shell;
+}
+
+/**
+ * gdm_user_get_displays:
+ * @user: the user object to examine.
+ * 
+ * Retrieves a new list of the displays that @user is logged in on. The list
+ * itself must be freed with g_slist_free() when no longer needed.
+ * 
+ * Returns: a list of #GdmDisplay objects which must be freed with
+ *  g_slist_free().
+ * 
+ * Since: 1.0
+ **/
+GSList *
+gdm_user_get_sessions (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), NULL);
+
+        return g_slist_copy (user->sessions);
+}
+
+/**
+ * gdm_user_get_n_sessions:
+ * @user: the user object to examine.
+ * 
+ * Retrieves the number of sessions that @user is logged into.
+ * 
+ * Returns: an unsigned integer.
+ * 
+ * Since: 1.0
+ **/
+guint
+gdm_user_get_n_sessions (GdmUser *user)
+{
+        g_return_val_if_fail (GDM_IS_USER (user), FALSE);
+
+        return g_slist_length (user->sessions);
+}
+
+gint
+gdm_user_collate (GdmUser *user1,
+                  GdmUser *user2)
+{
+        const gchar *str1, *str2;
+
+        g_return_val_if_fail (user1 == NULL || GDM_IS_USER (user1), 0);
+        g_return_val_if_fail (user2 == NULL || GDM_IS_USER (user2), 0);
+
+        if (!user1 && user2)
+                return -1;
+
+        if (user1 && !user2)
+                return 1;
+
+        if (!user1 && !user2)
+                return 0;
+
+        if (user1->real_name)
+                str1 = user1->real_name;
+        else
+                str1 = user1->user_name;
+
+        if (user2->real_name)
+                str2 = user2->real_name;
+        else
+                str2 = user2->user_name;
+
+        if (!str1 && str2)
+                return -1;
+
+        if (str1 && !str2)
+                return 1;
+
+        if (!str1 && !str2)
+                return 0;
+
+        return g_utf8_collate (str1, str2);
+}
diff --git a/gui/simple-greeter/gdm-user.h b/gui/simple-greeter/gdm-user.h
new file mode 100644
index 00000000..fb091534
--- /dev/null
+++ b/gui/simple-greeter/gdm-user.h
@@ -0,0 +1,59 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2004-2005 James M. Cape <jcape@ignore-your.tv>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Facade object for user data, owned by GdmUserManager
+ */
+
+#ifndef __GDM_USER__
+#define __GDM_USER__ 1
+
+#include <sys/types.h>
+#include <gtk/gtkwidget.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+G_BEGIN_DECLS
+
+#define GDM_TYPE_USER (gdm_user_get_type ())
+#define GDM_USER(object) (G_TYPE_CHECK_INSTANCE_CAST ((object), GDM_TYPE_USER, GdmUser))
+#define GDM_IS_USER(object) (G_TYPE_CHECK_INSTANCE_TYPE ((object), GDM_TYPE_USER))
+
+typedef struct _GdmUser GdmUser;
+
+GType                 gdm_user_get_type           (void) G_GNUC_CONST;
+
+uid_t                 gdm_user_get_uid            (GdmUser   *user);
+G_CONST_RETURN gchar *gdm_user_get_user_name      (GdmUser   *user);
+G_CONST_RETURN gchar *gdm_user_get_real_name      (GdmUser   *user);
+G_CONST_RETURN gchar *gdm_user_get_home_directory (GdmUser   *user);
+G_CONST_RETURN gchar *gdm_user_get_shell          (GdmUser   *user);
+
+GSList               *gdm_user_get_sessions       (GdmUser   *user);
+guint                 gdm_user_get_n_sessions     (GdmUser   *user);
+
+GdkPixbuf            *gdm_user_render_icon        (GdmUser   *user,
+                                                   GtkWidget *widget,
+                                                   gint       icon_size);
+
+gint                  gdm_user_collate            (GdmUser   *user1,
+                                                   GdmUser   *user2);
+
+G_END_DECLS
+
+#endif
diff --git a/gui/simple-greeter/test-user-chooser.c b/gui/simple-greeter/test-user-chooser.c
index d3c9fec2..7efd8c33 100644
--- a/gui/simple-greeter/test-user-chooser.c
+++ b/gui/simple-greeter/test-user-chooser.c
@@ -29,6 +29,7 @@
 
 #include <glib/gi18n.h>
 #include <gtk/gtk.h>
+#include <libgnomevfs/gnome-vfs-init.h>
 
 #include "gdm-user-chooser-dialog.h"
 
@@ -44,6 +45,7 @@ main (int argc, char *argv[])
         setlocale (LC_ALL, "");
 
         gtk_init (&argc, &argv);
+        gnome_vfs_init ();
 
         dialog = gdm_user_chooser_dialog_new ();
         /*gtk_widget_set_size_request (dialog, 480, 128);*/
diff --git a/gui/simple-greeter/test-user-manager.c b/gui/simple-greeter/test-user-manager.c
new file mode 100644
index 00000000..436dce18
--- /dev/null
+++ b/gui/simple-greeter/test-user-manager.c
@@ -0,0 +1,82 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <libintl.h>
+#include <locale.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include <libgnomevfs/gnome-vfs-init.h>
+
+#include "gdm-user-manager.h"
+
+static GdmUserManager *manager = NULL;
+
+static void
+on_user_added (GdmUserManager *manager,
+               GdmUser        *user,
+               gpointer        data)
+{
+        g_debug ("User added: %s", gdm_user_get_user_name (user));
+}
+
+static void
+on_user_removed (GdmUserManager *manager,
+                 GdmUser        *user,
+                 gpointer        data)
+{
+        g_debug ("User removed: %s", gdm_user_get_user_name (user));
+}
+
+int
+main (int argc, char *argv[])
+{
+        GtkWidget *dialog;
+
+        bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR);
+        bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
+        textdomain (GETTEXT_PACKAGE);
+
+        setlocale (LC_ALL, "");
+
+        gtk_init (&argc, &argv);
+        gnome_vfs_init ();
+
+        manager = gdm_user_manager_ref_default ();
+        g_signal_connect (manager,
+                          "user-added",
+                          G_CALLBACK (on_user_added),
+                          NULL);
+        g_signal_connect (manager,
+                          "user-removed",
+                          G_CALLBACK (on_user_removed),
+                          NULL);
+
+        gtk_main ();
+
+        return 0;
+}