Resolves #85: removed flicker from Albums panel

sublime/cache_manager.py

@@ -530,7 +530,8 @@ class CacheManager(metaclass=Singleton):
 
                 # If it is the placeholder LastFM image, try and use the cover
                 # art filename given by the server.
-                if lastfm_url.endswith('2a96cbd8b46e442fc41c2b86b821562f.png'):
+                if (lastfm_url == '' or lastfm_url.endswith(
+                        '2a96cbd8b46e442fc41c2b86b821562f.png')):
                     if isinstance(artist, ArtistWithAlbumsID3):
                         return CacheManager.get_cover_art_filename(
                             artist.coverArt, size=300)

sublime/ui/artists.py

@@ -458,14 +458,26 @@ class AlbumsListWithSongs(Gtk.Overlay):
         self.albums = []
 
     def update(self, artist):
-        # TODO this introduces a flicker. Fix this. Need to do some diffing.
-        for c in self.box.get_children():
-            self.box.remove(c)
+        def remove_all():
+            for c in self.box.get_children():
+                self.box.remove(c)
 
         if artist is None:
+            remove_all()
+            self.spinner.hide()
             return
 
-        for album in artist.get('album', artist.get('child', [])):
+        new_albums = artist.get('album', artist.get('child', []))
+
+        if self.albums == new_albums:
+            # No need to do anything.
+            return
+
+        self.albums = new_albums
+
+        remove_all()
+
+        for album in self.albums:
             album_with_songs = AlbumWithSongs(album, show_artist_name=False)
             album_with_songs.connect(
                 'song-clicked',

sublime/ui/common/album_with_songs.py

@@ -141,9 +141,7 @@ class AlbumWithSongs(Gtk.Box):
             return column
 
         self.loading_indicator = Gtk.Spinner(
-            name='album-list-song-list-spinner',
-            active=True,
-        )
+            name='album-list-song-list-spinner')
         album_details.add(self.loading_indicator)
 
         self.album_songs = Gtk.TreeView(
@@ -266,10 +264,18 @@ class AlbumWithSongs(Gtk.Box):
     def update(self, force=False):
         self.update_album_songs(self.album.id)
 
+    def set_loading(self, loading):
+        if loading:
+            self.loading_indicator.start()
+            self.loading_indicator.show()
+        else:
+            self.loading_indicator.stop()
+            self.loading_indicator.hide()
+
     @util.async_callback(
         lambda *a, **k: CacheManager.get_album(*a, **k),
-        before_download=lambda self: self.loading_indicator.show(),
-        on_failure=lambda self, e: self.loading_indicator.hide(),
+        before_download=lambda self: self.set_loading(True),
+        on_failure=lambda self, e: self.set_loading(False),
     )
     def update_album_songs(
             self,