[gnome-music/wip/mschraal/async-queue: 20/25] artcache: Use AsyncQueue for cache retrieval

[Marinus Schraal <mschraal src gnome org>]

commit 6addf2a15d48b436fef172ce446394f86183137a
Author: Marinus Schraal <mschraal gnome org>
Date:   Tue Aug 10 15:15:55 2021 +0200

    artcache: Use AsyncQueue for cache retrieval

 gnomemusic/artcache.py         | 16 ++++++++--------
 gnomemusic/asyncqueue.py       |  4 ++--
 gnomemusic/widgets/artstack.py |  9 +++++++--
 3 files changed, 17 insertions(+), 12 deletions(-)
---
diff --git a/gnomemusic/artcache.py b/gnomemusic/artcache.py
index 96d266ef9..0e1959ca9 100644
--- a/gnomemusic/artcache.py
+++ b/gnomemusic/artcache.py
@@ -24,7 +24,7 @@
 
 from enum import Enum
 from math import pi
-from typing import Dict, Tuple
+from typing import Dict, Tuple, Union
 
 import cairo
 from gi.repository import Gdk, GdkPixbuf, Gio, Gtk, GLib, GObject
@@ -154,7 +154,7 @@ class ArtCache(GObject.GObject):
     __gtype_name__ = "ArtCache"
 
     __gsignals__ = {
-        "result": (GObject.SignalFlags.RUN_FIRST, None, (object, ))
+        "finished": (GObject.SignalFlags.RUN_FIRST, None, (object, ))
     }
 
     _log = MusicLogger()
@@ -168,7 +168,7 @@ class ArtCache(GObject.GObject):
         self._coreobject = None
         self._default_icon = None
 
-    def query(self, coreobject, size, scale):
+    def start(self, coreobject, size, scale):
         """Start the cache query
 
         :param coreobject: The object to search art for
@@ -189,7 +189,7 @@ class ArtCache(GObject.GObject):
 
         thumbnail_uri = coreobject.props.thumbnail
         if thumbnail_uri == "generic":
-            self.emit("result", self._default_icon)
+            self.emit("finished", self._default_icon)
             return
 
         thumb_file = Gio.File.new_for_uri(thumbnail_uri)
@@ -198,7 +198,7 @@ class ArtCache(GObject.GObject):
                 GLib.PRIORITY_LOW, None, self._open_stream, None)
             return
 
-        self.emit("result", self._default_icon)
+        self.emit("finished", self._default_icon)
 
     def _open_stream(self, thumb_file, result, arguments):
         try:
@@ -206,7 +206,7 @@ class ArtCache(GObject.GObject):
         except GLib.Error as error:
             self._log.warning(
                 "Error: {}, {}".format(error.domain, error.message))
-            self.emit("result", self._default_icon)
+            self.emit("finished", self._default_icon)
             return
 
         GdkPixbuf.Pixbuf.new_from_stream_async(
@@ -218,7 +218,7 @@ class ArtCache(GObject.GObject):
         except GLib.Error as error:
             self._log.warning(
                 "Error: {}, {}".format(error.domain, error.message))
-            self.emit("result", self._default_icon)
+            self.emit("finished", self._default_icon)
             return
 
         stream.close_async(GLib.PRIORITY_LOW, None, self._close_stream, None)
@@ -232,7 +232,7 @@ class ArtCache(GObject.GObject):
                 or isinstance(self._coreobject, CoreSong)):
             surface = _make_icon_frame(surface, self._size, self._scale)
 
-        self.emit("result", surface)
+        self.emit("finished", surface)
 
     def _close_stream(self, stream, result, data):
         try:
diff --git a/gnomemusic/asyncqueue.py b/gnomemusic/asyncqueue.py
index 5a3459307..53357274a 100644
--- a/gnomemusic/asyncqueue.py
+++ b/gnomemusic/asyncqueue.py
@@ -22,7 +22,7 @@
 # code, but you are not obligated to do so.  If you do not wish to do so,
 # delete this exception statement from your version.
 
-from typing import Dict, Tuple
+from typing import Any, Dict, Tuple
 
 from gi.repository import GObject
 
@@ -52,7 +52,7 @@ class AsyncQueue(GObject.GObject):
         self._async_active_pool: Dict[int, Tuple] = {}
         self._max_async = 4
 
-    def queue(self, *args) -> None:
+    def queue(self, *args: Any) -> None:
         """Queue an async call
 
         :param *args: The first item should be an async class, the
diff --git a/gnomemusic/widgets/artstack.py b/gnomemusic/widgets/artstack.py
index 5e7014d3f..a75cad9b3 100644
--- a/gnomemusic/widgets/artstack.py
+++ b/gnomemusic/widgets/artstack.py
@@ -24,6 +24,7 @@
 
 from gi.repository import GObject, Gtk
 
+from gnomemusic.asyncqueue import AsyncQueue
 from gnomemusic.artcache import ArtCache
 from gnomemusic.utils import ArtSize
 
@@ -38,6 +39,8 @@ class ArtStack(Gtk.Stack):
 
     __gtype_name__ = "ArtStack"
 
+    _async_queue = AsyncQueue()
+
     def __init__(self, size=ArtSize.MEDIUM):
         """Initialize the ArtStack
 
@@ -103,9 +106,11 @@ class ArtStack(Gtk.Stack):
     def _on_thumbnail_changed(self, coreobject, uri):
         self._disconnect_cache()
 
-        self._handler_id = self._cache.connect("result", self._on_cache_result)
+        self._handler_id = self._cache.connect(
+            "finished", self._on_cache_result)
 
-        self._cache.query(coreobject, self._size, self.props.scale_factor)
+        self._async_queue.queue(
+            self._cache, coreobject, self._size, self.props.scale_factor)
 
     def _on_cache_result(self, cache, surface):
         if self.props.visible_child_name == "B":