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/*
Copyright 2010 Canonical Ltd.
Authors:
Conor Curran <conor.curran@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/>.
*/
using Xml;
[DBus (name = "org.freedesktop.DBus")]
public interface FreeDesktopObject: Object {
public abstract async string[] list_names() throws IOError;
public abstract signal void name_owner_changed ( string name,
string old_owner,
string new_owner );
}
[DBus (name = "org.freedesktop.DBus.Introspectable")]
public interface FreeDesktopIntrospectable: Object {
public abstract string Introspect() throws IOError;
}
public errordomain XmlError {
FILE_NOT_FOUND,
XML_DOCUMENT_EMPTY
}
public class Mpris2Watcher : GLib.Object
{
private const string FREEDESKTOP_SERVICE = "org.freedesktop.DBus";
private const string FREEDESKTOP_OBJECT = "/org/freedesktop/DBus";
public const string MPRIS_PREFIX = "org.mpris.MediaPlayer2.";
private const string MPRIS_MEDIA_PLAYER_PATH = "/org/mpris/MediaPlayer2";
FreeDesktopObject fdesktop_obj;
FreeDesktopIntrospectable introspectable;
public signal void client_appeared ( string desktop_file_name,
string dbus_name,
bool use_playlists );
public signal void client_disappeared ( string dbus_name );
public Mpris2Watcher ()
{
}
construct
{
try {
this.fdesktop_obj = Bus.get_proxy_sync ( BusType.SESSION,
FREEDESKTOP_SERVICE,
FREEDESKTOP_OBJECT,
DBusProxyFlags.DO_NOT_LOAD_PROPERTIES );
this.fdesktop_obj.name_owner_changed.connect (this.name_changes_detected);
this.check_for_active_clients.begin();
}
catch ( IOError e ){
warning( "Mpris2watcher could not set up a watch for mpris clients appearing on the bus: %s",
e.message );
}
}
// At startup check to see if there are clients up that we are interested in
// More relevant for development and daemon's like mpd.
private async void check_for_active_clients()
{
string[] interfaces;
try{
interfaces = yield this.fdesktop_obj.list_names();
}
catch ( IOError e) {
warning( "Mpris2watcher could fetch active interfaces at startup: %s",
e.message );
return;
}
foreach (var address in interfaces) {
if (address.has_prefix (MPRIS_PREFIX)){
MprisRoot? mpris2_root = this.create_mpris_root(address);
if (mpris2_root == null) return;
bool use_playlists = this.supports_playlists ( address );
client_appeared (mpris2_root.DesktopEntry, address, use_playlists);
}
}
}
private void name_changes_detected ( FreeDesktopObject dbus_obj,
string name,
string previous_owner,
string current_owner )
{
MprisRoot? mpris2_root = this.create_mpris_root(name);
if (mpris2_root == null) return;
if (previous_owner != "" && current_owner == "") {
debug ("Client '%s' gone down", name);
client_disappeared (name);
}
else if (previous_owner == "" && current_owner != "") {
debug ("Client '%s' has appeared", name);
bool use_playlists = this.supports_playlists ( name );
client_appeared (mpris2_root.DesktopEntry, name, use_playlists);
}
}
private MprisRoot? create_mpris_root ( string name ){
MprisRoot mpris2_root = null;
if ( name.has_prefix (MPRIS_PREFIX) ){
try {
mpris2_root = Bus.get_proxy_sync ( BusType.SESSION,
name,
MPRIS_MEDIA_PLAYER_PATH );
}
catch (IOError e){
warning( "Mpris2watcher could not create a root interface: %s",
e.message );
}
}
return mpris2_root;
}
private bool supports_playlists ( string name )
{
try {
/* The dbusproxy flag parameter is needed to ensure Banshee does not
blow up. I suspect the issue is that if you
try to instantiate a dbus object which does not have any properties
associated with it, gdbus will attempt to fetch the properties (this is
in the documentation) but the banshee mpris dbus object more than likely
causes a crash because it doesn't check for the presence of properties
before attempting to access them.
*/
this.introspectable = Bus.get_proxy_sync ( BusType.SESSION,
name,
MPRIS_MEDIA_PLAYER_PATH,
GLib.DBusProxyFlags.DO_NOT_LOAD_PROPERTIES);
var results = introspectable.Introspect();
return this.parse_interfaces (results);
}
catch (IOError e){
warning( "Could not create an introspectable object: %s",
e.message );
}
return false;
}
private bool parse_interfaces( string interface_info )
{
//parse the document from path
bool result = false;
Xml.Doc* xml_doc = Parser.parse_doc (interface_info);
if (xml_doc == null) {
warning ("Mpris2Watcher - parse-interfaces - failed to instantiate xml doc");
return false;
}
//get the root node. notice the dereferencing operator -> instead of .
Xml.Node* root_node = xml_doc->get_root_element ();
if (root_node == null) {
//free the document manually before throwing because the garbage collector can't work on pointers
delete xml_doc;
warning ("Mpris2Watcher - the interface info xml is empty");
return false;
}
//let's parse those nodes
for (Xml.Node* iter = root_node->children; iter != null; iter = iter->next) {
//spaces btw. tags are also nodes, discard them
if (iter->type != ElementType.ELEMENT_NODE){
continue;
}
Xml.Attr* attributes = iter->properties; //get the node's name
string interface_name = attributes->children->content;
debug ( "this dbus object has interface %s ", interface_name );
if ( interface_name == MPRIS_PREFIX.concat("Playlists")){
result = true;
}
}
delete xml_doc;
return result;
}
}
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