[gnome-music/wip/mschraal/insanely-slow-startup-fix-41-backport: 1/3] Introduce CoreObjectType enum

[Marinus Schraal <mschraal src gnome org>]

commit fcf63313d4d8db921310991f2883f220f3fd2bc2
Author: Marinus Schraal <mschraal gnome org>
Date:   Tue Feb 15 09:35:02 2022 +0100

    Introduce CoreObjectType enum
    
    Instead of using isinstance to figure out the coreobject type, use an
    enum. This resolves circular imports that would otherwise arise in
    following commits.

 gnomemusic/grilowrappers/grltrackerwrapper.py | 10 +++++++---
 gnomemusic/storeart.py                        | 12 +++++-------
 gnomemusic/utils.py                           |  6 ++++++
 3 files changed, 18 insertions(+), 10 deletions(-)
---
diff --git a/gnomemusic/grilowrappers/grltrackerwrapper.py b/gnomemusic/grilowrappers/grltrackerwrapper.py
index 7567275a4..2da9bb1b7 100644
--- a/gnomemusic/grilowrappers/grltrackerwrapper.py
+++ b/gnomemusic/grilowrappers/grltrackerwrapper.py
@@ -39,6 +39,7 @@ from gnomemusic.grilowrappers.grltrackerplaylists import (
     GrlTrackerPlaylists, Playlist)
 from gnomemusic.storeart import StoreArt
 from gnomemusic.trackerwrapper import TrackerWrapper
+from gnomemusic.utils import CoreObjectType
 if typing.TYPE_CHECKING:
     from gnomemusic.application import Application
     from gnomemusic.coremodel import CoreModel
@@ -1232,7 +1233,8 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             self._async_queue.queue(
-                StoreArt(), coresong, queried_media.get_thumbnail())
+                StoreArt(), coresong, queried_media.get_thumbnail(),
+                CoreObjectType.SONG)
 
         song_id: str = media.get_id()
         query: str = self._get_album_for_media_id_query(song_id)
@@ -1260,7 +1262,8 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             self._async_queue.queue(
-                StoreArt(), corealbum, queried_media.get_thumbnail())
+                StoreArt(), corealbum, queried_media.get_thumbnail(),
+                CoreObjectType.ALBUM)
 
         album_id: str = media.get_id()
         query: str = self._get_album_for_media_id_query(album_id, False)
@@ -1290,7 +1293,8 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             self._async_queue.queue(
-                StoreArt(), coreartist, resolved_media.get_thumbnail())
+                StoreArt(), coreartist, resolved_media.get_thumbnail(),
+                CoreObjectType.ARTIST)
 
         self.props.source.resolve(
             media, [Grl.METADATA_KEY_THUMBNAIL], self._full_options_lprio,
diff --git a/gnomemusic/storeart.py b/gnomemusic/storeart.py
index 7cbec9dad..60d91809e 100644
--- a/gnomemusic/storeart.py
+++ b/gnomemusic/storeart.py
@@ -27,9 +27,7 @@ gi.require_versions({"MediaArt": "2.0", "Soup": "2.4"})
 from gi.repository import Gio, GLib, GObject, MediaArt, Soup, GdkPixbuf
 
 from gnomemusic.musiclogger import MusicLogger
-from gnomemusic.coreartist import CoreArtist
-from gnomemusic.corealbum import CoreAlbum
-from gnomemusic.coresong import CoreSong
+from gnomemusic.utils import CoreObjectType
 
 
 class StoreArt(GObject.Object):
@@ -54,7 +52,7 @@ class StoreArt(GObject.Object):
         self._log = MusicLogger()
         self._soup_session = Soup.Session.new()
 
-    def start(self, coreobject, uri):
+    def start(self, coreobject, uri, coreobjecttype):
         self._coreobject = coreobject
 
         if (uri is None
@@ -62,14 +60,14 @@ class StoreArt(GObject.Object):
             self.emit("finished")
             return
 
-        if isinstance(self._coreobject, CoreArtist):
+        if coreobjecttype == CoreObjectType.ARTIST:
             success, self._file = MediaArt.get_file(
                 self._coreobject.props.artist, None, "artist")
-        elif isinstance(self._coreobject, CoreAlbum):
+        elif coreobjecttype == CoreObjectType.ALBUM:
             success, self._file = MediaArt.get_file(
                 self._coreobject.props.artist, self._coreobject.props.title,
                 "album")
-        elif isinstance(self._coreobject, CoreSong):
+        elif coreobjecttype == CoreObjectType.SONG:
             success, self._file = MediaArt.get_file(
                 self._coreobject.props.artist, self._coreobject.props.album,
                 "album")
diff --git a/gnomemusic/utils.py b/gnomemusic/utils.py
index 5d3262a00..1b320455e 100644
--- a/gnomemusic/utils.py
+++ b/gnomemusic/utils.py
@@ -46,6 +46,12 @@ class ArtSize(Enum):
         self.height = height
 
 
+class CoreObjectType(Enum):
+    ALBUM = 0
+    ARTIST = 1
+    SONG = 2
+
+
 class SongStateIcon(Enum):
     """Enum for icons used in song playing and validation"""
     ERROR = "dialog-error-symbolic"