[gnome-music/wip/mschraal/searchview-rework: 11/15] Make retrieval work

[Marinus Schraal <mschraal src gnome org>]

commit 96cc1085dfa44619f43d855834751b6298e73fcb
Author: Marinus Schraal <mschraal gnome org>
Date:   Fri Aug 2 17:57:30 2019 +0200

    Make retrieval work

 data/ui/ArtistSearchTile.ui            |   2 +-
 gnomemusic/albumartcache.py            | 102 ++++++++++++++++++-
 gnomemusic/widgets/artistartstack.py   | 178 +++++++++++++++++++++++++++++++++
 gnomemusic/widgets/artistsearchtile.py |   8 +-
 4 files changed, 285 insertions(+), 5 deletions(-)
---
diff --git a/data/ui/ArtistSearchTile.ui b/data/ui/ArtistSearchTile.ui
index 8eb4acb1..7deaae63 100644
--- a/data/ui/ArtistSearchTile.ui
+++ b/data/ui/ArtistSearchTile.ui
@@ -20,7 +20,7 @@
                 <property name="can_focus">False</property>
                 <signal name="button-release-event" handler="_on_artist_event" swapped="no"/>
                 <child>
-                  <object class="CoverStack" id="_cover_stack">
+                  <object class="ArtistArtStack" id="_artistart_stack">
                     <property name="visible">True</property>
                     <property name="can_focus">False</property>
                     <property name="vexpand">True</property>
diff --git a/gnomemusic/albumartcache.py b/gnomemusic/albumartcache.py
index 18e65532..b1c6a069 100644
--- a/gnomemusic/albumartcache.py
+++ b/gnomemusic/albumartcache.py
@@ -191,9 +191,11 @@ class ArtistArt(GObject.GObject):
             self._artist, None, "artist")
         if (not success
                 or not thumb_file.query_exists()):
-            self._coreartist.props.cached_thumbnail_uri = thumb_file.get_path()
             return False
 
+        print("setting cached uri")
+        self._coreartist.props.cached_thumbnail_uri = thumb_file.get_path()
+
         return True
 
     def _on_thumbnail_changed(self, coreartist, thumbnail):
@@ -270,6 +272,104 @@ class ArtistArt(GObject.GObject):
         except GLib.Error as error:
             logger.warning("Error: {}, {}".format(error.domain, error.message))
 
+
+class ArtistCache(GObject.GObject):
+    """Handles retrieval of MediaArt cache art
+
+    Uses signals to indicate success or failure.
+    """
+
+    __gtype_name__ = "ArtistCache"
+
+    __gsignals__ = {
+        'miss': (GObject.SignalFlags.RUN_FIRST, None, ()),
+        'hit': (GObject.SignalFlags.RUN_FIRST, None, (object, ))
+    }
+
+    def __repr__(self):
+        return "<ArtistCache>"
+
+    @log
+    def __init__(self):
+        super().__init__()
+
+        # FIXME
+        self._size = Art.Size.MEDIUM
+        self._scale = 1
+
+        # FIXME: async
+        self.cache_dir = os.path.join(GLib.get_user_cache_dir(), 'media-art')
+        if not os.path.exists(self.cache_dir):
+            try:
+                Gio.file_new_for_path(self.cache_dir).make_directory(None)
+            except GLib.Error as error:
+                logger.warning(
+                    "Error: {}, {}".format(error.domain, error.message))
+                return
+
+    @log
+    def query(self, coreartist):
+        """Start the cache query
+
+        :param CoreSong coresong: The CoreSong object to search art for
+        """
+        print("query")
+        thumb_file = Gio.File.new_for_path(
+            coreartist.props.cached_thumbnail_uri)
+        if thumb_file:
+            thumb_file.read_async(
+                GLib.PRIORITY_LOW, None, self._open_stream, None)
+            return
+
+        self.emit('miss')
+
+    @log
+    def _open_stream(self, thumb_file, result, arguments):
+        try:
+            stream = thumb_file.read_finish(result)
+        except GLib.Error as error:
+            print("hier")
+            logger.warning("Error: {}, {}".format(error.domain, error.message))
+            self.emit('miss')
+            return
+
+        GdkPixbuf.Pixbuf.new_from_stream_async(
+            stream, None, self._pixbuf_loaded, None)
+
+    @log
+    def _pixbuf_loaded(self, stream, result, data):
+        try:
+            pixbuf = GdkPixbuf.Pixbuf.new_from_stream_finish(result)
+        except GLib.Error as error:
+            print("hm")
+            logger.warning("Error: {}, {}".format(error.domain, error.message))
+            self.emit('miss')
+            return
+
+        stream.close_async(GLib.PRIORITY_LOW, None, self._close_stream, None)
+
+        surface = Gdk.cairo_surface_create_from_pixbuf(
+            pixbuf, self._scale, None)
+        surface = _make_icon_frame(surface, self._size, self._scale)
+
+        self.emit("hit", surface)
+
+    @log
+    def _close_stream(self, stream, result, data):
+        try:
+            stream.close_finish(result)
+        except GLib.Error as error:
+            logger.warning("Error: {}, {}".format(error.domain, error.message))
+
+    def _cache_hit(self, klass, pixbuf):
+        surface = Gdk.cairo_surface_create_from_pixbuf(
+            pixbuf, self._scale, None)
+        surface = _make_icon_frame(surface, self._size, self._scale)
+        self._surface = surface
+
+        self.emit('finished')
+
+
 class Art(GObject.GObject):
     """Retrieves art for an album or song
 
diff --git a/gnomemusic/widgets/artistartstack.py b/gnomemusic/widgets/artistartstack.py
new file mode 100644
index 00000000..35599c13
--- /dev/null
+++ b/gnomemusic/widgets/artistartstack.py
@@ -0,0 +1,178 @@
+# Copyright 2019 The GNOME Music developers
+#
+# GNOME Music is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# GNOME Music is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with GNOME Music; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# The GNOME Music authors hereby grant permission for non-GPL compatible
+# GStreamer plugins to be used and distributed together with GStreamer
+# and GNOME Music.  This permission is above and beyond the permissions
+# granted by the GPL license by which GNOME Music is covered.  If you
+# modify this code, you may extend this exception to your version of the
+# 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 gi.repository import GLib, GObject, Gtk
+
+from gnomemusic import log
+from gnomemusic.albumartcache import Art, ArtistCache, DefaultIcon
+from gnomemusic.coreartist import CoreArtist
+
+
+class ArtistArtStack(Gtk.Stack):
+    """Provides a smooth transition between image states
+
+    Uses a Gtk.Stack to provide an in-situ transition between an image
+    state. Either between the 'loading' state versus the 'loaded' state
+    or in between songs.
+    """
+
+    __gtype_name__ = "ArtistArtStack"
+
+    __gsignals__ = {
+        'updated': (GObject.SignalFlags.RUN_FIRST, None, ())
+    }
+
+    _default_icon = DefaultIcon()
+
+    def __repr__(self):
+        return "ArtistArtStack"
+
+    @log
+    def __init__(self, size=Art.Size.MEDIUM):
+        """Initialize the CoverStack
+
+        :param Art.Size size: The size of the art used for the cover
+        """
+        super().__init__()
+
+        self._art = None
+        self._handler_id = None
+        self._size = None
+        self._timeout = None
+
+        self._loading_cover = Gtk.Image()
+        self._cover_a = Gtk.Image()
+        self._cover_b = Gtk.Image()
+
+        self.add_named(self._loading_cover, "loading")
+        self.add_named(self._cover_a, "A")
+        self.add_named(self._cover_b, "B")
+
+        self._active_child = "loading"
+
+        self.props.size = size
+        self.props.transition_type = Gtk.StackTransitionType.CROSSFADE
+        self.props.visible_child_name = "loading"
+
+        self.show_all()
+
+    @GObject.Property(type=object, flags=GObject.ParamFlags.READWRITE)
+    def size(self):
+        """Size of the cover
+
+        :returns: The size used
+        :rtype: Art.Size
+        """
+        return self._size
+
+    @size.setter
+    def size(self, value):
+        """Set the cover size
+
+        :param Art.Size value: The size to use for the cover
+        """
+        self._size = value
+
+        icon = self._default_icon.get(
+            DefaultIcon.Type.LOADING, self.props.size, self.props.scale_factor)
+        self._loading_cover.props.surface = icon
+
+    @GObject.Property(type=CoreArtist, default=None)
+    def coreartist(self):
+        return self._coreartist
+
+    @coreartist.setter
+    def coreartist(self, coreartist):
+        self._coreartist = coreartist
+
+        print("connecting")
+        self._coreartist.connect(
+            "notify::cached-thumbnail-uri", self._on_thumbnail_changed)
+
+        if self._coreartist.props.cached_thumbnail_uri is not None:
+            self._on_thumbnail_changed(self._coreartist, None)
+
+    def _on_thumbnail_changed(self, coreartist, uri):
+        print("thumbnail changed")
+        cache = ArtistCache()
+        cache.connect("hit", self._on_cache_hit)
+
+        cache.query(coreartist)
+
+    def _on_cache_hit(self, cache, surface):
+        print("surface", surface)
+        if self._active_child == "B":
+            self._cover_a.props.surface = surface
+            self.props.visible_child_name = "A"
+        else:
+            self._cover_b.props.surface = surface
+            self.props.visible_child_name = "B"
+
+    @log
+    def update(self, coresong):
+        """Update the stack with the given CoreSong
+
+        Update the stack with the art retrieved from the given Coresong.
+        :param CoreSong coresong: The CoreSong object
+        """
+        if self._handler_id and self._art:
+            # Remove a possible dangling 'finished' callback if update
+            # is called again, but it is still looking for the previous
+            # art.
+            self._art.disconnect(self._handler_id)
+            # Set the loading state only after a delay to make between
+            # song transitions smooth if loading time is negligible.
+            self._timeout = GLib.timeout_add(100, self._set_loading_child)
+
+        self._active_child = self.props.visible_child_name
+
+        self._art = Art(self.props.size, coresong, self.props.scale_factor)
+        self._handler_id = self._art.connect('finished', self._art_retrieved)
+        self._art.lookup()
+
+    @log
+    def _set_loading_child(self):
+        self.props.visible_child_name = "loading"
+        self._active_child = self.props.visible_child_name
+        self._timeout = None
+
+        return GLib.SOURCE_REMOVE
+
+    @log
+    def _art_retrieved(self, klass):
+        if self._timeout:
+            GLib.source_remove(self._timeout)
+            self._timeout = None
+
+        if self._active_child == "B":
+            self._cover_a.props.surface = klass.surface
+            self.props.visible_child_name = "A"
+        else:
+            self._cover_b.props.surface = klass.surface
+            self.props.visible_child_name = "B"
+
+        self._active_child = self.props.visible_child_name
+        self._art = None
+
+        self.emit('updated')
diff --git a/gnomemusic/widgets/artistsearchtile.py b/gnomemusic/widgets/artistsearchtile.py
index a3a9d341..c2ca153d 100644
--- a/gnomemusic/widgets/artistsearchtile.py
+++ b/gnomemusic/widgets/artistsearchtile.py
@@ -25,6 +25,7 @@
 from gi.repository import Gdk, GObject, Gtk
 
 from gnomemusic.albumartcache import Art
+from gnomemusic.widgets.artistartstack import ArtistArtStack
 from gnomemusic.widgets.twolinetip import TwoLineTip
 
 
@@ -38,7 +39,7 @@ class ArtistSearchTile(Gtk.FlowBoxChild):
     __gtype_name__ = "ArtistSearchTile"
 
     _check = Gtk.Template.Child()
-    _cover_stack = Gtk.Template.Child()
+    _artistart_stack = Gtk.Template.Child()
     _artist_label = Gtk.Template.Child()
     _events = Gtk.Template.Child()
 
@@ -59,6 +60,9 @@ class ArtistSearchTile(Gtk.FlowBoxChild):
 
         self._coreartist = coreartist
 
+        self._artistart_stack.props.size = Art.Size.MEDIUM
+        self._artistart_stack.props.coreartist = self._coreartist
+
         self._tooltip = TwoLineTip()
 
         artist = self._coreartist.props.artist
@@ -87,8 +91,6 @@ class ArtistSearchTile(Gtk.FlowBoxChild):
 
         self._events.add_events(Gdk.EventMask.TOUCH_MASK)
 
-        self._cover_stack.props.size = Art.Size.MEDIUM
-
         self.show()
 
     def _on_thumbnail_changed(self, klass, data):