Update album metadata images when Files/Tracks emit signal

Add a signal to Files/Tracks that gets emitted when the images
change (or might have changed), and update the album's metadata images
on such signals instead of each time the album is selected in the
user interface.

picard/album.py

@@ -72,6 +72,7 @@ class Album(DataObject, Item):
         self.errors = []
         self.status = None
         self._album_artists = []
+        self.update_metadata_images_enabled = True
 
     def __repr__(self):
         return '<Album %s %r>' % (self.id, self.metadata[u"album"])
@@ -255,6 +256,7 @@ class Album(DataObject, Item):
             self._tracks_loaded = True
 
         if not self._requests:
+            self.update_metadata_images_enabled = False
             # Prepare parser for user's script
             if config.setting["enable_tagger_scripts"]:
                 for s_pos, s_name, s_enabled, s_text in config.setting["list_of_scripts"]:
@@ -276,6 +278,7 @@ class Album(DataObject, Item):
                         self._new_metadata.strip_whitespace()
 
             for track in self.tracks:
+                track.metadata_images_changed.connect(self.update_metadata_images)
                 for file in list(track.linked_files):
                     file.move(self.unmatched_files)
             self.metadata = self._new_metadata
@@ -285,6 +288,7 @@ class Album(DataObject, Item):
             self.loaded = True
             self.status = None
             self.match_files(self.unmatched_files.files)
+            self.update_metadata_images_enabled = True
             self.update()
             self.tagger.window.set_statusbar_message(
                 N_('Album %(id)s loaded: %(artist)s - %(album)s'),
@@ -379,14 +383,19 @@ class Album(DataObject, Item):
     def update(self, update_tracks=True):
         if self.item:
             self.item.update(update_tracks)
+        self.update_metadata_images()
 
     def _add_file(self, track, file):
         self._files += 1
         self.update(update_tracks=False)
+        file.metadata_images_changed.connect(self.update_metadata_images)
+        self.update_metadata_images()
 
     def _remove_file(self, track, file):
         self._files -= 1
         self.update(update_tracks=False)
+        file.metadata_images_changed.disconnect(self.update_metadata_images)
+        self.update_metadata_images()
 
     def match_files(self, files, use_recordingid=True):
         """Match files to tracks on this album, based on metadata similarity or recordingid."""
@@ -554,6 +563,8 @@ class Album(DataObject, Item):
             self.load(priority=True, refresh=True)
 
     def update_metadata_images(self):
+        if not self.update_metadata_images_enabled:
+            return
         new_images = []
         orig_images = []
 

picard/file.py

@@ -54,6 +54,8 @@ from picard.const import QUERY_LIMIT
 
 class File(QtCore.QObject, Item):
 
+    metadata_images_changed = QtCore.pyqtSignal()
+
     UNDEFINED = -1
     PENDING = 0
     NORMAL = 1
@@ -156,6 +158,7 @@ class File(QtCore.QObject, Item):
 
         if acoustid:
             self.metadata["acoustid_id"] = acoustid
+        self.metadata_images_changed.emit()
 
     def has_error(self):
         return self.state == File.ERROR

picard/track.py

@@ -19,6 +19,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
 from functools import partial
+from PyQt4 import QtCore
 from picard import config, log
 from picard.metadata import Metadata, run_track_metadata_processors
 from picard.dataobj import DataObject
@@ -44,6 +45,8 @@ class TrackArtist(DataObject):
 
 class Track(DataObject, Item):
 
+    metadata_images_changed = QtCore.pyqtSignal()
+
     def __init__(self, id, album=None):
         DataObject.__init__(self, id)
         self.album = album

picard/ui/coverartbox.py

@@ -316,18 +316,23 @@ class CoverArtBox(QtGui.QGroupBox):
             album.metadata.set_front_image(coverartimage)
             for track in album.tracks:
                 track.metadata.set_front_image(coverartimage)
+                track.metadata_images_changed.emit()
             for file in album.iterfiles():
                 file.metadata.set_front_image(coverartimage)
+                file.metadata_images_changed.emit()
                 file.update()
         elif isinstance(self.item, Track):
             track = self.item
             track.metadata.set_front_image(coverartimage)
+            track.metadata_images_changed.emit()
             for file in track.iterfiles():
                 file.metadata.set_front_image(coverartimage)
+                file.metadata_images_changed.emit()
                 file.update()
         elif isinstance(self.item, File):
             file = self.item
             file.metadata.set_front_image(coverartimage)
+            file.metadata_images_changed.emit()
             file.update()
         self.cover_art.set_metadata(self.item.metadata)
         self.show()

picard/ui/mainwindow.py

@@ -956,7 +956,6 @@ class MainWindow(QtGui.QMainWindow):
                     self.set_statusbar_message(msg, mparms, echo=None,
                                                history=None)
             elif isinstance(obj, Album):
-                obj.update_metadata_images()
                 metadata = obj.metadata
                 orig_metadata = obj.orig_metadata
             elif obj.can_edit_tags():