Handling the locking of the screensaver so that we ensure

the screensaver is active before suspending.  Also, we
throttle it to ensure it doesn't start until after suspend.
(LP: #444391)

1 files changed, 326 insertions, 0 deletions

diff --git a/src/lock-helper.c b/src/lock-helper.c
new file mode 100644
index 0000000..0bdec6c
--- /dev/null
+++ b/src/lock-helper.c
@@ -0,0 +1,326 @@
+/*
+A small helper for locking the screen.
+
+Copyright 2009 Canonical Ltd.
+
+Authors:
+    Ted Gould <ted@canonical.com>
+
+This program is free software: you can redistribute it and/or modify it 
+under the terms of the GNU General Public License version 3, as published 
+by the Free Software Foundation.
+
+This program is distributed in the hope that it will be useful, but 
+WITHOUT ANY WARRANTY; without even the implied warranties of 
+MERCHANTABILITY, SATISFACTORY QUALITY, 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <dbus/dbus-glib.h>
+#include "lock-helper.h"
+
+static DBusGProxy * gss_proxy = NULL;
+static GMainLoop * gss_mainloop = NULL;
+static guint cookie = 0;
+static DBusGProxyCall * cookie_call = NULL;
+
+static DBusGProxy * gdm_settings_proxy = NULL;
+static gboolean gdm_auto_login = FALSE;
+static const gchar * gdm_auto_login_string = "daemon/AutomaticLoginEnable";
+
+static gboolean is_guest = FALSE;
+
+static gdm_autologin_cb_t gdm_autologin_cb = NULL;
+
+/* Checks to see if there is an error and reports
+   it.  Not much else we can do. */
+static void
+unthrottle_return (DBusGProxy * proxy, DBusGProxyCall * call, gpointer data)
+{
+	GError * error = NULL;
+	dbus_g_proxy_end_call(proxy, call, &error,
+	                      G_TYPE_INVALID);
+
+	if (error != NULL) {
+		g_warning("Unable to unthrottle: %s", error->message);
+	}
+	return;
+}
+
+/* Sends an unthrottle if we're throttled. */
+void
+screensaver_unthrottle (void)
+{
+	g_return_if_fail(cookie != 0);
+
+	dbus_g_proxy_begin_call(gss_proxy, "UnThrottle",
+	                        unthrottle_return, NULL,
+	                        NULL,
+	                        G_TYPE_UINT, cookie,
+	                        G_TYPE_INVALID);
+
+	cookie = 0;
+	return;
+}
+
+/* Gets there return cookie from the throttle command
+   and sets things valid */
+static void
+throttle_return (DBusGProxy * proxy, DBusGProxyCall * call, gpointer data)
+{
+	GError * error = NULL;
+	cookie_call = NULL;
+
+	dbus_g_proxy_end_call(proxy, call, &error,
+	                      G_TYPE_UINT, &cookie,
+	                      G_TYPE_INVALID);
+
+	if (error != NULL) {
+		g_warning("Unable to throttle the screensaver: %s", error->message);
+		return;
+	}
+
+
+	if (cookie == 0) {
+		g_warning("We didn't get a throttle cookie!");
+	}
+
+	return;
+}
+
+/* Throttling the screensaver by using the screen saver
+   command. */
+void
+screensaver_throttle (gchar * reason)
+{
+	g_return_if_fail(cookie_call == NULL);
+	g_return_if_fail(will_lock_screen());
+
+	if (cookie != 0) {
+		screensaver_unthrottle();
+	}
+
+	cookie_call = dbus_g_proxy_begin_call(gss_proxy, "Throttle",
+	                                      throttle_return, NULL,
+	                                      NULL,
+	                                      G_TYPE_STRING, "Session Menu",
+	                                      G_TYPE_STRING, reason,
+	                                      G_TYPE_INVALID);
+
+	return;
+}
+
+/* Setting up a call back */
+void
+lock_screen_gdm_cb_set (gdm_autologin_cb_t cb)
+{
+	if (gdm_autologin_cb) {
+		g_warning("Already had a callback, setting up a new one...");
+	}
+
+	gdm_autologin_cb = cb;
+	return;
+}
+
+/* This is our logic on whether the screen should be locked
+   or not.  It effects everything else. */
+gboolean
+will_lock_screen (void)
+{
+	if (gdm_auto_login) {
+		return FALSE;
+	}
+	if (is_guest) {
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/* Respond to the signal of autologin changing to see if the
+   setting for timed login changes. */
+static void
+gdm_settings_change (DBusGProxy * proxy, const gchar * value, const gchar * old, const gchar * new, gpointer data)
+{
+	if (g_strcmp0(value, gdm_auto_login_string)) {
+		/* This is not a setting that we care about,
+		   there is only one. */
+		return;
+	}
+	g_debug("GDM Settings change: %s", new);
+
+	if (g_strcmp0(new, "true") == 0) {
+		gdm_auto_login = TRUE;
+	} else {
+		gdm_auto_login = FALSE;
+	}
+
+	if (gdm_autologin_cb != NULL) {
+		gdm_autologin_cb();
+	}
+
+	return;
+}
+
+/* Get back the data from querying to see if there is auto
+   login enabled in GDM */
+static void
+gdm_get_autologin (DBusGProxy * proxy, DBusGProxyCall * call, gpointer data)
+{
+	GError * error = NULL;
+	gchar * value = NULL;
+
+	if (!dbus_g_proxy_end_call(proxy, call, &error, G_TYPE_STRING, &value, G_TYPE_INVALID)) {
+		g_warning("Unable to get autologin setting: %s", error != NULL ? error->message : "null");
+		g_error_free(error);
+		return;
+	}
+
+	g_return_if_fail(value != NULL);
+	gdm_settings_change(proxy, gdm_auto_login_string, NULL, value, NULL);
+
+	return;
+}
+
+/* Sets up the proxy and queries for the setting to know
+   whether we're doing an autologin. */
+static void
+build_gdm_proxy (void)
+{
+	g_return_if_fail(gdm_settings_proxy == NULL);
+
+	/* Grab the system bus */
+	DBusGConnection * bus = dbus_g_bus_get(DBUS_BUS_SYSTEM, NULL);
+	g_return_if_fail(bus != NULL);
+
+	/* Get the settings proxy */
+	gdm_settings_proxy = dbus_g_proxy_new_for_name_owner(bus,
+	                                                     "org.gnome.DisplayManager",
+	                                                     "/org/gnome/DisplayManager/Settings",
+	                                                     "org.gnome.DisplayManager.Settings", NULL);
+	g_return_if_fail(gdm_settings_proxy != NULL);
+
+	/* Signal for value changed */
+	dbus_g_proxy_add_signal(gdm_settings_proxy,
+	                        "ValueChanged",
+	                        G_TYPE_STRING,
+	                        G_TYPE_STRING,
+	                        G_TYPE_STRING,
+	                        G_TYPE_INVALID);
+	dbus_g_proxy_connect_signal(gdm_settings_proxy,
+	                            "ValueChanged",
+	                            G_CALLBACK(gdm_settings_change),
+	                            NULL,
+	                            NULL);
+
+	/* Start to get the initial value */
+	dbus_g_proxy_begin_call(gdm_settings_proxy,
+	                        "GetValue",
+	                        gdm_get_autologin,
+	                        NULL,
+	                        NULL,
+	                        G_TYPE_STRING,
+	                        gdm_auto_login_string,
+	                        G_TYPE_INVALID);
+
+	return;
+}
+
+/* When the screensave go active, if we've got a mainloop
+   running we should quit it. */
+static void
+gss_active_changed (DBusGProxy * proxy, gboolean active, gpointer data)
+{
+	if (active && gss_mainloop != NULL) {
+		g_main_loop_quit(gss_mainloop);
+	}
+
+	return;
+}
+
+/* Build the gss proxy and set up it's signals */
+void
+build_gss_proxy (void)
+{
+	DBusGConnection * session_bus = dbus_g_bus_get(DBUS_BUS_SESSION, NULL);
+	g_return_if_fail(session_bus != NULL);
+
+	gss_proxy = dbus_g_proxy_new_for_name_owner(session_bus,
+	                                            "org.gnome.ScreenSaver",
+	                                            "/",
+	                                            "org.gnome.ScreenSaver",
+	                                            NULL);
+	g_return_if_fail(gss_proxy != NULL);
+
+	dbus_g_proxy_add_signal(gss_proxy, "ActiveChanged", G_TYPE_BOOLEAN, G_TYPE_INVALID);
+	dbus_g_proxy_connect_signal(gss_proxy, "ActiveChanged", G_CALLBACK(gss_active_changed), NULL, NULL);
+
+	return;
+}
+
+/* This is a timeout, we only want to wait for the screen to
+   lock for a little bit, but not forever. */
+static gboolean
+activate_timeout (gpointer data)
+{
+	guint * address = (guint *)data;
+	*address = 0;
+
+	if (gss_mainloop != NULL) {
+		g_main_loop_quit(gss_mainloop);
+	}
+	
+	return FALSE;
+}
+
+/* A fun little function to actually lock the screen.  If,
+   that's what you want, let's do it! */
+void
+lock_screen (DbusmenuMenuitem * mi, gpointer data)
+{
+	g_debug("Lock Screen");
+	if (!will_lock_screen()) {
+		g_debug("\tGDM set to autologin, blocking lock");
+		return;
+	}
+
+	g_return_if_fail(gss_proxy != NULL);
+
+	dbus_g_proxy_call_no_reply(gss_proxy,
+	                           "Lock",
+	                           G_TYPE_INVALID,
+	                           G_TYPE_INVALID);
+
+	if (gss_mainloop == NULL) {
+		gss_mainloop = g_main_loop_new(NULL, FALSE);
+	}
+
+	guint timer = g_timeout_add_seconds(1, activate_timeout, &timer);
+
+	g_main_loop_run(gss_mainloop);
+
+	if (timer != 0) {
+		g_source_remove(timer);
+	}
+
+	return;
+}
+
+/* Do what it takes to make the lock screen function work
+   and be happy. */
+gboolean
+lock_screen_setup (gpointer data)
+{
+	if (!g_strcmp0(g_get_user_name(), "guest")) {
+		is_guest = TRUE;
+	}
+
+	build_gdm_proxy();
+	build_gss_proxy();
+
+	return FALSE;
+}
+