[rygel] Only load DVB plugin if service is available

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 1abd7f2307a6ef6123346d7ee76bb52b0094bae5
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Mon May 25 23:28:48 2009 +0300

    Only load DVB plugin if service is available
    
    Try to launch the DVB Daemon service by name and if we fail, don't load
    the DVB plugin.
---
 src/plugins/dvb/Makefile.am                   |    7 ++-
 src/plugins/dvb/rygel-dvb-plugin-factory.vala |   76 +++++++++++++++++++++++++
 src/plugins/dvb/rygel-dvb-plugin.vala         |   21 +++----
 3 files changed, 91 insertions(+), 13 deletions(-)

diff --git a/src/plugins/dvb/Makefile.am b/src/plugins/dvb/Makefile.am
index 87ec098..4d06510 100644
--- a/src/plugins/dvb/Makefile.am
+++ b/src/plugins/dvb/Makefile.am
@@ -15,7 +15,8 @@ BUILT_SOURCES = rygel-dvb.stamp \
 		rygel-dvb-root-container.c \
 		rygel-dvb-channel-group.c \
 		rygel-dvb-channel.c \
-		rygel-dvb-plugin.c
+		rygel-dvb-plugin.c \
+		rygel-dvb-plugin-factory.c
 
 librygel_dvb_la_SOURCES = rygel-dvb-content-dir.c \
 			  rygel-dvb-content-dir.vala \
@@ -26,7 +27,9 @@ librygel_dvb_la_SOURCES = rygel-dvb-content-dir.c \
 			  rygel-dvb-channel.c \
 			  rygel-dvb-channel.vala \
 			  rygel-dvb-plugin.c \
-			  rygel-dvb-plugin.vala
+			  rygel-dvb-plugin.vala \
+			  rygel-dvb-plugin-factory.c \
+			  rygel-dvb-plugin-factory.vala
 
 rygel-dvb.stamp: $(filter %.vala,$(librygel_dvb_la_SOURCES))
 	$(VALAC) -C --vapidir=$(top_srcdir)/src/rygel \
diff --git a/src/plugins/dvb/rygel-dvb-plugin-factory.vala b/src/plugins/dvb/rygel-dvb-plugin-factory.vala
new file mode 100644
index 0000000..18e981e
--- /dev/null
+++ b/src/plugins/dvb/rygel-dvb-plugin-factory.vala
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2009 Zeeshan Ali (Khattak) <zeeshanak gnome org>.
+ * Copyright (C) 2009 Nokia Corporation, all rights reserved.
+ *
+ * Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
+ *                               <zeeshan ali nokia com>
+ *
+ * This file is part of Rygel.
+ *
+ * Rygel 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 of the License, or
+ * (at your option) any later version.
+ *
+ * Rygel 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.
+ */
+
+using Rygel;
+using Gee;
+using CStuff;
+
+private DVBPluginFactory plugin_factory;
+
+[ModuleInit]
+public void module_init (PluginLoader loader) {
+    try {
+        plugin_factory = new DVBPluginFactory (loader);
+    } catch (DBus.Error error) {
+        critical ("Failed to fetch list of external services: %s\n",
+                error.message);
+    }
+}
+
+public class DVBPluginFactory {
+    private const string DBUS_SERVICE = "org.freedesktop.DBus";
+    private const string DBUS_OBJECT = "/org/freedesktop/DBus";
+    private const string DBUS_IFACE = "org.freedesktop.DBus";
+
+    private const string TRACKER_SERVICE = "org.gnome.DVB";
+
+    dynamic DBus.Object dbus_obj;
+    PluginLoader        loader;
+
+    public DVBPluginFactory (PluginLoader loader) throws DBus.Error {
+        var connection = DBus.Bus.get (DBus.BusType.SESSION);
+
+        this.dbus_obj = connection.get_object (DBUS_SERVICE,
+                                               DBUS_OBJECT,
+                                               DBUS_IFACE);
+        this.loader = loader;
+
+        dbus_obj.StartServiceByName (TRACKER_SERVICE,
+                                     (uint32) 0,
+                                     this.start_service_cb);
+    }
+
+    private void start_service_cb (uint32 status, GLib.Error err) {
+        if (err != null) {
+            warning ("Failed to start DVB service: %s\n",
+                     err.message);
+            warning ("DVB plugin disabled.\n");
+
+            return;
+        }
+
+        this.loader.add_plugin (new DVBPlugin ());
+    }
+}
+
diff --git a/src/plugins/dvb/rygel-dvb-plugin.vala b/src/plugins/dvb/rygel-dvb-plugin.vala
index bc24c8d..86dc696 100644
--- a/src/plugins/dvb/rygel-dvb-plugin.vala
+++ b/src/plugins/dvb/rygel-dvb-plugin.vala
@@ -28,18 +28,17 @@ using Rygel;
 using Gee;
 using CStuff;
 
-[ModuleInit]
-public void module_init (PluginLoader loader) {
-    Plugin plugin = new Plugin ("DVB", "Digital TV");
+public class DVBPlugin : Plugin {
+    public DVBPlugin () {
+        base ("DVB", "Digital TV");
 
-    // We only implement a ContentDirectory service
-    var resource_info = new ResourceInfo (ContentDirectory.UPNP_ID,
-                                          ContentDirectory.UPNP_TYPE,
-                                          ContentDirectory.DESCRIPTION_PATH,
-                                          typeof (DVBContentDir));
+        // We only implement a ContentDirectory service
+        var resource_info = new ResourceInfo (ContentDirectory.UPNP_ID,
+                                              ContentDirectory.UPNP_TYPE,
+                                              ContentDirectory.DESCRIPTION_PATH,
+                                              typeof (DVBContentDir));
 
-    plugin.add_resource (resource_info);
-
-    loader.add_plugin (plugin);
+        this.add_resource (resource_info);
+    }
 }