Move grilo.tracker checks to grilo

We were checking for a grilo.tracker instance all around the codebase,
while this could be just as well be done inside grilo.

gnomemusic/grilo.py

@@ -232,19 +232,27 @@ class Grilo(GObject.GObject):
 
     @log
     def populate_artists(self, offset, callback, count=-1):
-        self.populate_items(Query.all_artists(), offset, callback, count)
+        if self.tracker:
+            GLib.idle_add(self.populate_items, Query.all_artists(), offset,
+                          callback, count)
 
     @log
     def populate_albums(self, offset, callback, count=-1):
-        self.populate_items(Query.all_albums(), offset, callback, count)
+        if self.tracker:
+            GLib.idle_add(self.populate_items, Query.all_albums(), offset,
+                                                callback, count)
 
     @log
     def populate_songs(self, offset, callback, count=-1):
-        self.populate_items(Query.all_songs(), offset, callback, count)
+        if self.tracker:
+            GLib.idle_add(self.populate_items, Query.all_songs(), offset,
+                                                callback, count)
 
     @log
     def populate_playlists(self, offset, callback, count=-1):
-        self.populate_items(Query.all_playlists(), offset, callback, count)
+        if self.tracker:
+            GLib.idle_add(self.populate_items, Query.all_playlists(), offset,
+                                                callback, count)
 
     @log
     def populate_album_songs(self, album, callback, count=-1):

gnomemusic/mpris.py

@@ -384,10 +384,7 @@ class MediaPlayer2Service(Server):
             else:
                 callback(playlists)
 
-        if grilo.tracker:
-            GLib.idle_add(grilo.populate_playlists, 0, populate_callback)
-        else:
-            callback(playlists)
+        grilo.populate_playlists(0, populate_callback)
 
     @log
     def _get_active_playlist(self):

gnomemusic/views/albumsview.py

@@ -123,7 +123,6 @@ class AlbumsView(BaseView):
 
     @log
     def populate(self):
-        if grilo.tracker:
         self.window._init_loading_notification()
         GLib.idle_add(grilo.populate_albums, self._offset, self._add_item)
 

gnomemusic/views/artistsview.py

@@ -167,7 +167,6 @@ class ArtistsView(BaseView):
 
     @log
     def populate(self):
-        if grilo.tracker:
         self.window._init_loading_notification()
         GLib.idle_add(grilo.populate_artists, self._offset, self._add_item)
 

gnomemusic/views/playlistview.py

@@ -524,7 +524,6 @@ class PlaylistView(BaseView):
 
     @log
     def populate(self):
-        if grilo.tracker:
         self.playlists_model.clear()
         GLib.idle_add(grilo.populate_playlists, self._offset,
                       self._add_playlist_item)

gnomemusic/views/songsview.py

@@ -222,7 +222,6 @@ class SongsView(BaseView):
     @log
     def populate(self):
         self._init = True
-        if grilo.tracker:
         self.window._init_loading_notification()
         GLib.idle_add(grilo.populate_songs, self._offset, self._add_item)
 

gnomemusic/widgets/playlistdialog.py

@@ -100,8 +100,7 @@ class PlaylistDialog():
 
     @log
     def populate(self):
-        if grilo.tracker:
-            GLib.idle_add(grilo.populate_playlists, 0, self._add_item)
+        grilo.populate_playlists(0, self._add_item)
 
     @log
     def _add_item(self, source, param, item, remaining=0, data=None):