[gnome-music/wip/mschraal/core: 92/118] coredisc: Make model on-demand

[Marinus Schraal <mschraal src gnome org>]

commit 3764b5dedd0a3bc014ec752d9bfea860196bb37b
Author: Marinus Schraal <mschraal gnome org>
Date:   Sat Jun 22 00:38:39 2019 +0200

    coredisc: Make model on-demand

 gnomemusic/coredisc.py  | 36 ++++++++++++++++++++++--------------
 gnomemusic/coremodel.py |  2 +-
 2 files changed, 23 insertions(+), 15 deletions(-)
---
diff --git a/gnomemusic/coredisc.py b/gnomemusic/coredisc.py
index a8e9319d..4c6bfbf1 100644
--- a/gnomemusic/coredisc.py
+++ b/gnomemusic/coredisc.py
@@ -11,32 +11,40 @@ class CoreDisc(GObject.GObject):
     disc_nr = GObject.Property(type=int, default=0)
     duration = GObject.Property(type=int, default=None)
     media = GObject.Property(type=Grl.Media, default=None)
-    model = GObject.Property(type=Gio.ListModel, default=None)
 
     def __init__(self, media, nr, coremodel):
         super().__init__()
 
         self._coremodel = coremodel
+        self._filter_model = None
+        self._model = None
         self._old_album_ids = []
+        self._sort_model = None
+
+        self.update(media)
         self.props.disc_nr = nr
 
-        self._filter_model = Dazzle.ListModelFilter.new(
-            self._coremodel.get_model())
-        self._filter_model.set_filter_func(lambda a: False)
-        self._sort_model = Gfm.SortListModel.new(self._filter_model)
-        self._sort_model.set_sort_func(self._wrap_sort_func(self._disc_sort))
+    def update(self, media):
+        self.props.media = media
 
-        self.props.model = self._sort_model
-        self.update(media)
+    @GObject.Property(type=Gio.ListModel, default=None)
+    def model(self):
+        if self._model is None:
+            self._filter_model = Dazzle.ListModelFilter.new(
+                self._coremodel.get_model())
+            self._filter_model.set_filter_func(lambda a: False)
+            self._sort_model = Gfm.SortListModel.new(self._filter_model)
+            self._sort_model.set_sort_func(self._wrap_sort_func(self._disc_sort))
 
-        self._coremodel.get_model().connect(
-            "items-changed", self._on_core_changed)
+            self._model = self._sort_model
 
-        self._get_album_disc(
-            self.props.media, self.props.disc_nr, self._filter_model)
+            self._coremodel.get_model().connect(
+                "items-changed", self._on_core_changed)
 
-    def update(self, media):
-        self.props.media = media
+            self._get_album_disc(
+                self.props.media, self.props.disc_nr, self._filter_model)
+
+        return self._model
 
     def _on_core_changed(self, model, position, removed, added):
         self._get_album_disc(
diff --git a/gnomemusic/coremodel.py b/gnomemusic/coremodel.py
index 0cbebe81..24ad6866 100644
--- a/gnomemusic/coremodel.py
+++ b/gnomemusic/coremodel.py
@@ -147,7 +147,7 @@ class CoreModel(GObject.GObject):
                 self._playlist_model.remove_all()
 
                 for disc in model:
-                    for model_song in disc.model:
+                    for model_song in disc.props.model:
                         song = CoreSong(model_song.props.media)
 
                         self._playlist_model.append(song)