[gnome-music/wip/mschraal/playlists-fixes: 5/7] coremodel: Splice playlist model on changes

[Marinus Schraal <mschraal src gnome org>]

commit 8406a21286a0abb4f42fa89be5ed39b2e16d170c
Author: Marinus Schraal <mschraal gnome org>
Date:   Sat Feb 22 16:23:24 2020 +0100

    coremodel: Splice playlist model on changes
    
    When reacting to the items-changed signal on the current playlist model,
    all items were removed & added one at a time. This would result in
    changes possibly stopping the playing playlist, as the playlist could
    effectively could become empty.
    
    Instead make the signal handler smarter and splice the changes in
    one go.

 gnomemusic/coremodel.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/gnomemusic/coremodel.py b/gnomemusic/coremodel.py
index 17eb5167..2b5d7c12 100644
--- a/gnomemusic/coremodel.py
+++ b/gnomemusic/coremodel.py
@@ -232,10 +232,7 @@ class CoreModel(GObject.GObject):
             return
 
         def _on_items_changed(model, position, removed, added):
-            if removed > 0:
-                for i in list(range(removed)):
-                    self._playlist_model.remove(position)
-
+            songs_list = []
             if added > 0:
                 for i in list(range(added)):
                     coresong = model[position + i]
@@ -253,6 +250,10 @@ class CoreModel(GObject.GObject):
                         GObject.BindingFlags.BIDIRECTIONAL
                         | GObject.BindingFlags.SYNC_CREATE)
 
+                    songs_list.append(song)
+
+            self._playlist_model.splice(position, removed, songs_list)
+
         played_states = [SongWidget.State.PLAYING, SongWidget.State.PLAYED]
         for song in self._playlist_model:
             if song.props.state in played_states: