Inhibit screensaver when slideshow is running

1 files changed, 256 insertions, 0 deletions

diff --git a/src/inhibit_screensaver.c b/src/inhibit_screensaver.c
new file mode 100644
index 0000000..007c550
--- /dev/null
+++ b/src/inhibit_screensaver.c
@@ -0,0 +1,256 @@
+/*
+ * inhibit_screensaver.h
+ *
+ * Copyright © 2013 Thomas White <taw@bitwiz.org.uk>
+ * Copyright © 2009-2012 Rémi Denis-Courmont
+ * Copyright © 2007-2012 Rafaël Carré
+ *
+ * This file is part of Colloquium.
+ *
+ * Colloquium 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ * >>> This file is based on dbus.c from VLC. The original licence is below. <<<
+ *
+ */
+
+/*****************************************************************************
+ * dbus.c: power management inhibition using D-Bus
+ *****************************************************************************
+ * Copyright © 2009-2012 Rémi Denis-Courmont
+ * Copyright © 2007-2012 Rafaël Carré
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/*
+ * Based on freedesktop Power Management Specification version 0.2
+ * http://people.freedesktop.org/~hughsient/temp/power-management-spec-0.2.html
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <dbus/dbus.h>
+
+
+enum inhibit_api
+{
+	FDO_SS, /**< KDE >= 4 and GNOME >= 3.6 */
+	FDO_PM, /**< KDE and GNOME <= 2.26 */
+	MATE,   /**< >= 1.0 */
+	GNOME,  /**< GNOME 2.26..3.4 */
+};
+
+#define MAX_API (GNOME+1)
+
+
+/* Currently, all services have identical service and interface names. */
+static const char dbus_service[][40] =
+{
+	[FDO_SS] = "org.freedesktop.ScreenSaver",
+	[FDO_PM] = "org.freedesktop.PowerManagement.Inhibit",
+	[MATE]   = "org.mate.SessionManager",
+	[GNOME]  = "org.gnome.SessionManager",
+};
+
+
+static const char dbus_path[][33] =
+{
+	[FDO_SS] = "/ScreenSaver",
+	[FDO_PM] = "/org/freedesktop/PowerManagement",
+	[MATE]   = "/org/mate/SessionManager",
+	[GNOME]  = "/org/gnome/SessionManager",
+};
+
+
+static const char dbus_method_uninhibit[][10] =
+{
+	[FDO_SS] = "UnInhibit",
+	[FDO_PM] = "UnInhibit",
+	[MATE]   = "Uninhibit",
+	[GNOME]  = "Uninhibit",
+};
+
+
+struct inhibit_sys
+{
+	DBusConnection *conn;
+	DBusPendingCall *pending;
+	dbus_uint32_t cookie;
+	enum inhibit_api api;
+};
+
+
+void do_inhibit(struct inhibit_sys *sys, int flags)
+{
+	enum inhibit_api type = sys->api;
+
+	/* Receive reply from previous request, possibly hours later ;-) */
+	if ( sys->pending != NULL ) {
+
+		DBusMessage *reply;
+
+		/* NOTE: Unfortunately, the pending reply cannot simply be
+		 * cancelled.   Otherwise, the cookie would be lost and
+		 * inhibition would remain on (until complete disconnection from
+		 * the bus). */
+		dbus_pending_call_block(sys->pending);
+		reply = dbus_pending_call_steal_reply(sys->pending);
+		dbus_pending_call_unref(sys->pending);
+		sys->pending = NULL;
+
+		if ( reply != NULL ) {
+			if ( !dbus_message_get_args(reply, NULL,
+		                                    DBUS_TYPE_UINT32,
+			                            &sys->cookie,
+		                                    DBUS_TYPE_INVALID))
+			{
+				sys->cookie = 0;
+			}
+			dbus_message_unref(reply);
+		}
+		fprintf(stderr, "got cookie %i", (int)sys->cookie);
+
+	}
+
+	/* FIXME: This check is incorrect if flags change from one non-zero value
+	 * to another one. But the D-Bus API cannot currently inhibit suspend
+	 * independently from the screensaver. */
+	if ( !sys->cookie == !flags ) return; /* nothing to do */
+
+	/* Send request */
+	const char *method = flags ? "Inhibit" : dbus_method_uninhibit[type];
+	dbus_bool_t ret;
+
+	DBusMessage *msg = dbus_message_new_method_call(dbus_service[type],
+	                                                dbus_path[type],
+	                                                dbus_service[type],
+	                                                method);
+	if ( msg == NULL ) return;
+
+    if (flags)
+    {
+        const char *app = PACKAGE;
+        const char *reason = "Presentation in progress";
+
+        assert(sys->cookie == 0);
+
+        switch (type)
+        {
+            case MATE:
+            case GNOME:
+            {
+                dbus_uint32_t xid = 0; // FIXME ?
+                dbus_uint32_t gflags = 0xC;
+
+                ret = dbus_message_append_args(msg, DBUS_TYPE_STRING, &app,
+                                                    DBUS_TYPE_UINT32, &xid,
+                                                    DBUS_TYPE_STRING, &reason,
+                                                    DBUS_TYPE_UINT32, &gflags,
+                                                    DBUS_TYPE_INVALID);
+                break;
+            }
+            default:
+                ret = dbus_message_append_args(msg, DBUS_TYPE_STRING, &app,
+                                                    DBUS_TYPE_STRING, &reason,
+                                                    DBUS_TYPE_INVALID);
+                break;
+        }
+
+        if (!ret
+        || !dbus_connection_send_with_reply(sys->conn, msg, &sys->pending, -1))
+            sys->pending = NULL;
+    }
+    else
+    {
+        assert(sys->cookie != 0);
+        if (!dbus_message_append_args(msg, DBUS_TYPE_UINT32, &sys->cookie,
+                                           DBUS_TYPE_INVALID)
+         || !dbus_connection_send (sys->conn, msg, NULL))
+            sys->cookie = 0;
+    }
+    dbus_connection_flush(sys->conn);
+    dbus_message_unref(msg);
+}
+
+
+void inhibit_cleanup(struct inhibit_sys *sys)
+{
+	if ( sys->pending != NULL ) {
+		dbus_pending_call_cancel(sys->pending);
+		dbus_pending_call_unref(sys->pending);
+	}
+
+	dbus_connection_close(sys->conn);
+	dbus_connection_unref(sys->conn);
+	free(sys);
+}
+
+
+struct inhibit_sys *inhibit_prepare()
+{
+	struct inhibit_sys *sys;
+	DBusError err;
+	int i;
+
+	sys = malloc(sizeof(struct inhibit_sys));
+	if ( sys == NULL ) {
+		fprintf(stderr, "Failed to allocate inhibit.\n");
+		return NULL;
+	}
+
+	dbus_error_init(&err);
+
+	sys->conn = dbus_bus_get_private(DBUS_BUS_SESSION, &err);
+	if ( sys->conn == NULL ) {
+		fprintf(stderr, "cannot connect to session bus: %s",
+		        err.message);
+		dbus_error_free(&err);
+		free(sys);
+		return NULL;
+	}
+
+	sys->pending = NULL;
+	sys->cookie = 0;
+
+	for ( i=0; i<MAX_API; i++ ) {
+		if ( dbus_bus_name_has_owner(sys->conn, dbus_service[i], NULL) )
+		{
+			fprintf(stderr, "found service %s", dbus_service[i]);
+			sys->api = i;
+			return sys;
+		}
+
+		fprintf(stderr, "cannot find service %s", dbus_service[i]);
+	}
+
+	inhibit_cleanup(sys);
+	return NULL;
+}