[gnome-music/wip/gbsneto/contained-playlists: 10/35] playlists: Dynamically instantiate the static playlists

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 8948708c0a02ff3ad4e32269a2c36e6940d297fe
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Mon Nov 28 18:15:14 2016 +0100

    playlists: Dynamically instantiate the static playlists
    
    This commit makes the static playlists be allocated when the
    StaticPlaylists class is instantiated. This forces the code
    to only instantiate it only once, which is achieved by reusing
    the private instance of the Playlists class for now - this will
    obviously be changed in future commits.
    
    This step was necessary for two reasons:
     * GObject properties are dynamic, and we cannot set them as class
       fields.
     * We really want to move away from singletons and python hacks
       to use the static playlists.

 gnomemusic/playlists.py                 |  127 +++++++++++++++++++------------
 gnomemusic/views/playlistview.py        |    2 +-
 gnomemusic/widgets/starhandlerwidget.py |    2 +-
 3 files changed, 80 insertions(+), 51 deletions(-)
---
diff --git a/gnomemusic/playlists.py b/gnomemusic/playlists.py
index 1051949..bf2e93a 100644
--- a/gnomemusic/playlists.py
+++ b/gnomemusic/playlists.py
@@ -50,62 +50,91 @@ class Playlist(GObject.Object):
         'title': (str, 'Title', 'title', '', GObject.ParamFlags.READWRITE),
     }
 
-class StaticPlaylists:
+    @log
+    def __init__(self, id=None, title=None, query=None, tag_text=None):
+        GObject.Object.__init__(self)
 
-    def __repr__(self):
-        return '<StaticPlaylists>'
+        self.id = id
+        self.query = query
+        self.tag_text = tag_text
+        self.title = title
 
-    class MostPlayed(Playlist):
-        TAG_TEXT = "MOST_PLAYED"
+
+class MostPlayed(Playlist):
+    """Most Played static playlist"""
+    @log
+    def __init__(self):
+        self.tag_text = "MOST_PLAYED"
         # TRANSLATORS: this is a playlist name
-        TITLE = _("Most Played")
+        self.title = _("Most Played")
+        self.query = Query.get_never_played_songs()
+
 
-    class NeverPlayed(Playlist):
-        TAG_TEXT = "NEVER_PLAYED"
+class NeverPlayed(Playlist):
+    """Never Played static playlist"""
+    @log
+    def __init__(self):
+        self.tag_text = "NEVER_PLAYED"
         # TRANSLATORS: this is a playlist name
-        TITLE = _("Never Played")
+        self.title = _("Never Played")
+        self.query = Query.get_never_played_songs()
 
-    class RecentlyPlayed(Playlist):
-        TAG_TEXT = "RECENTLY_PLAYED"
+
+class RecentlyPlayed(Playlist):
+    """Recently Played static playlist"""
+    @log
+    def __init__(self):
+        self.tag_text = "RECENTLY_PLAYED"
         # TRANSLATORS: this is a playlist name
-        TITLE = _("Recently Played")
+        self.title = _("Recently Played")
+        self.query = Query.get_recently_played_songs()
+
 
-    class RecentlyAdded(Playlist):
-        TAG_TEXT = "RECENTLY_ADDED"
+class RecentlyAdded(Playlist):
+    """Recently Added static playlist"""
+    @log
+    def __init__(self):
+        self.tag_text = "RECENTLY_ADDED"
         # TRANSLATORS: this is a playlist name
-        TITLE = _("Recently Added")
+        self.title = _("Recently Added")
+        self.query = Query.get_recently_added_songs()
 
-    class Favorites(Playlist):
-        TAG_TEXT = "FAVORITES"
+
+class Favorites(Playlist):
+    """Favories static playlist"""
+    @log
+    def __init__(self):
+        self.tag_text = "FAVORITES"
         # TRANSLATORS: this is a playlist name
-        TITLE = _("Favorite Songs")
+        self.title = _("Favorite Songs")
+        self.query = Query.get_favorite_songs()
+
+
+class StaticPlaylists:
+
+    def __repr__(self):
+        return '<StaticPlaylists>'
 
     def __init__(self):
         Query()
-        self.MostPlayed.QUERY = Query.get_most_played_songs()
-        self.NeverPlayed.QUERY = Query.get_never_played_songs()
-        self.RecentlyPlayed.QUERY = Query.get_recently_played_songs()
-        self.RecentlyAdded.QUERY = Query.get_recently_added_songs()
-        self.Favorites.QUERY = Query.get_favorite_songs()
-
-    @staticmethod
-    def get_ids():
+        self.MostPlayed = MostPlayed()
+        self.NeverPlayed = NeverPlayed()
+        self.RecentlyPlayed = RecentlyPlayed()
+        self.RecentlyAdded = RecentlyAdded()
+        self.Favorites = Favorites()
+
+        self.playlists = [self.MostPlayed, self.NeverPlayed,
+                          self.RecentlyPlayed, self.RecentlyAdded,
+                          self.Favorites]
+
+    @log
+    def get_ids(self):
         """Get all static playlist IDs
 
         :return: A list of tracker.id's
         :rtype: A list of integers
         """
-        return [str(playlist.ID) for playlist in StaticPlaylists.get_all()]
-
-    @staticmethod
-    def get_all():
-        """Get all static playlist classes
-
-        :return: All StaticPlaylists innerclasses
-        :rtype: A list of classes
-        """
-        return [cls for name, cls in inspect.getmembers(StaticPlaylists)
-                if inspect.isclass(cls) and not name == "__class__"]
+        return [str(playlist.id) for playlist in self.playlists]
 
 
 class Playlists(GObject.GObject):
@@ -154,9 +183,9 @@ class Playlists(GObject.GObject):
                 logger.warn("Error: %s, %s", err.__class__, err)
                 return
 
-            playlist.ID = cursor.get_integer(1)
+            playlist.id = cursor.get_integer(1)
 
-            if not playlist.ID:
+            if not playlist.id:
                 # Create the  static playlist
                 self._create_static_playlist(playlist)
             else:
@@ -175,9 +204,9 @@ class Playlists(GObject.GObject):
             cursor.next_async(None, playlist_id_fetched_cb, playlist)
 
         # Start fetching all the static playlists
-        for playlist in self._static_playlists.get_all():
+        for playlist in self._static_playlists.playlists:
             self.tracker.query_async(
-                Query.get_playlist_with_tag(playlist.TAG_TEXT), None,
+                Query.get_playlist_with_tag(playlist.tag_text), None,
                 callback, playlist)
 
     @log
@@ -185,8 +214,8 @@ class Playlists(GObject.GObject):
         """ Create the tag and the static playlist, and fetch the newly created
         playlist's songs.
         """
-        title = playlist.TITLE
-        tag_text = playlist.TAG_TEXT
+        title = playlist.title
+        tag_text = playlist.tag_text
 
         def playlist_next_async_cb(cursor, res, playlist):
             """ Called after we finished moving the Tracker cursor, and ready
@@ -198,7 +227,7 @@ class Playlists(GObject.GObject):
                 logger.warn("Error: %s, %s", err.__class__, err)
                 return
 
-            playlist.ID = cursor.get_integer(0)
+            playlist.id = cursor.get_integer(0)
 
             # Fetch the playlist contents
             self.update_static_playlist(playlist)
@@ -246,7 +275,7 @@ class Playlists(GObject.GObject):
     @log
     def clear_playlist(self, playlist):
         """Starts cleaning the playlist"""
-        query = Query.clear_playlist_with_id(playlist.ID)
+        query = Query.clear_playlist_with_id(playlist.id)
         self.tracker.update_async(query, GLib.PRIORITY_LOW, None,
                                   self._static_playlist_cleared_cb, playlist)
 
@@ -254,7 +283,7 @@ class Playlists(GObject.GObject):
     def _static_playlist_cleared_cb(self, connection, res, playlist):
         """After clearing the playlist, start querying the playlist's songs"""
         # Get a list of matching songs
-        self.tracker.query_async(playlist.QUERY, None,
+        self.tracker.query_async(playlist.query, None,
                                  self._static_playlist_query_cb, playlist)
 
     @log
@@ -271,7 +300,7 @@ class Playlists(GObject.GObject):
 
         def callback(cursor, res, final_query):
             uri = cursor.get_string(0)[0]
-            final_query += Query.add_song_to_playlist(playlist.ID, uri)
+            final_query += Query.add_song_to_playlist(playlist.id, uri)
 
             try:
                 has_next = cursor.next_finish(res)
@@ -288,14 +317,14 @@ class Playlists(GObject.GObject):
                                             None, None, None)
 
             # tell system we updated the playlist so playlist is reloaded
-            self.emit('playlist-updated', playlist.ID)
+            self.emit('playlist-updated', playlist.id)
 
         # Asynchronously form the playlist's final query
         cursor.next_async(None, callback, final_query)
 
     @log
     def update_all_static_playlists(self):
-        for playlist in self._static_playlists.get_all():
+        for playlist in self._static_playlists.playlists:
             self.update_static_playlist(playlist)
 
     @log
diff --git a/gnomemusic/views/playlistview.py b/gnomemusic/views/playlistview.py
index 26a536d..d6806b7 100644
--- a/gnomemusic/views/playlistview.py
+++ b/gnomemusic/views/playlistview.py
@@ -428,7 +428,7 @@ class PlaylistView(BaseView):
     @log
     def current_playlist_is_protected(self):
         current_playlist_id = self.current_playlist.get_id()
-        if current_playlist_id in StaticPlaylists().get_ids():
+        if current_playlist_id in playlists._static_playlists.get_ids():
             return True
         else:
             return False
diff --git a/gnomemusic/widgets/starhandlerwidget.py b/gnomemusic/widgets/starhandlerwidget.py
index 87d738b..5690a14 100644
--- a/gnomemusic/widgets/starhandlerwidget.py
+++ b/gnomemusic/widgets/starhandlerwidget.py
@@ -123,7 +123,7 @@ class StarHandlerWidget(object):
         self._parent.model[_iter][self._star_index] = new_value
         song_item = self._parent.model[_iter][5]
         grilo.toggle_favorite(song_item)
-        playlists.update_static_playlist(StaticPlaylists.Favorites)
+        playlists.update_static_playlist(playlists._static_playlists.Favorites)
 
         # Use this flag to ignore the upcoming _on_item_activated call
         self.star_renderer_click = True