[gnome-music/wip/jfelder/mpris-fix-activateplaylist] playlistview: Fix activate_playlist method

[Jean Felder <jfelder src gnome org>]

commit 4797559bbb6af6f458bc1270a5d052b6e371a2ef
Author: Jean Felder <jfelder src gnome org>
Date:   Sat Apr 13 16:43:59 2019 +0200

    playlistview: Fix activate_playlist method
    
    This method is used by MPRIS to start playing a playlist.
    With the multiple refactorings and rewrites of BaseView (mostly the
    populate logic change) and PlaylistView, this method does not work
    anymore.
    
    Fix the method and simplify it (remove the signal logic).

 gnomemusic/grilo.py              |  6 ++-
 gnomemusic/views/playlistview.py | 96 ++++++++++++++++++----------------------
 2 files changed, 47 insertions(+), 55 deletions(-)
---
diff --git a/gnomemusic/grilo.py b/gnomemusic/grilo.py
index 0a81f641..6a90dec7 100644
--- a/gnomemusic/grilo.py
+++ b/gnomemusic/grilo.py
@@ -289,14 +289,16 @@ class Grilo(GObject.GObject):
         self.populate_items(Query.all_songs(), offset, callback, count)
 
     @log
-    def populate_playlists(self, offset, callback, count=-1):
+    def populate_playlists(self, offset, callback, count=-1, data=None):
         """Asynchronously get playlists (user and smart ones)
 
         :param int offset: start index
         :param function callback: callback function
         :param int count: limit number of results
+        :param object data: user data
         """
-        self.populate_items(Query.all_playlists(), offset, callback, count)
+        self.populate_items(
+            Query.all_playlists(), offset, callback, count, data)
 
     @log
     def populate_user_playlists(self, offset, callback, count=-1):
diff --git a/gnomemusic/views/playlistview.py b/gnomemusic/views/playlistview.py
index f77722fc..3f8d8358 100644
--- a/gnomemusic/views/playlistview.py
+++ b/gnomemusic/views/playlistview.py
@@ -44,11 +44,6 @@ playlists = Playlists.get_default()
 class PlaylistView(BaseView):
     """Main view for playlists"""
 
-    __gsignals__ = {
-        'playlists-loaded': (GObject.SignalFlags.RUN_FIRST, None, ()),
-        'playlist-songs-loaded': (GObject.SignalFlags.RUN_FIRST, None, ()),
-    }
-
     def __repr__(self):
         return '<PlaylistView>'
 
@@ -122,6 +117,7 @@ class PlaylistView(BaseView):
         self._iter_to_clean_model = None
         self._current_playlist = None
         self._current_playlist_index = None
+        self._plays_songs_on_activation = False
         self.pls_todelete = {}
         self._songs_todelete = {}
         self._songs_count = 0
@@ -273,8 +269,9 @@ class PlaylistView(BaseView):
         return False
 
     @log
-    def _add_playlist_item(self, source, param, playlist, remaining=0,
-                           data=None):
+    def _add_playlist_item(
+            self, source, param, playlist, remaining=0,
+            select_playlist_id=None):
         """Grilo.populate_playlists callback.
 
         Add all playlists found by Grilo to sidebar
@@ -283,17 +280,22 @@ class PlaylistView(BaseView):
         :param int param: param
         :param GrlMedia playlist: playlist to add
         :param int remaining: next playlist_id or zero if None
-        :param data: associated data
+        :param str select_playlist_id: playlist id to select on load
         """
         if not playlist:
             self._window.notifications_popup.pop_loading()
-            self.emit('playlists-loaded')
+            if not self._sidebar.get_selected_row():
+                first_row = self._sidebar.get_row_at_index(0)
+                self._sidebar.select_row(first_row)
+                self._sidebar.emit('row-activated', first_row)
             return
 
-        self._add_playlist_to_sidebar(playlist, None)
+        select_playlist = (playlist.get_id() == select_playlist_id)
+        self._add_playlist_to_sidebar(playlist, None, select_playlist)
 
     @log
-    def _add_playlist_to_sidebar(self, playlist, index=None):
+    def _add_playlist_to_sidebar(
+            self, playlist, index=None, select_playlist=False):
         """Add a playlist to sidebar
 
         :param GrlMedia playlist: playlist to add
@@ -313,7 +315,7 @@ class PlaylistView(BaseView):
         self._sidebar.insert(row, index)
         self._offset += 1
 
-        if len(self._sidebar) == 1:
+        if select_playlist:
             self._sidebar.select_row(row)
             self._sidebar.emit('row-activated', row)
 
@@ -480,48 +482,29 @@ class PlaylistView(BaseView):
 
     @log
     def activate_playlist(self, playlist_id):
+        """Selects and starts playing a playlist.
 
-        def find_and_activate_playlist():
-            for row in self._sidebar:
-                if row.playlist.get_id() == playlist_id:
-                    selection = self._sidebar.get_selected_row()
-                    if selection.get_index() == row.get_index():
-                        self._on_play_activate(None)
-                    else:
-                        self._sidebar.select_row(row)
-                        handler = 0
-
-                        def songs_loaded_callback(view):
-                            self.disconnect(handler)
-                            self._on_play_activate(None)
-
-                        handler = self.connect('playlist-songs-loaded',
-                                               songs_loaded_callback)
-                        self._sidebar.emit('row-activated', row)
-
-                    return
-
-        if self._init:
-            find_and_activate_playlist()
-        else:
-            handler = 0
-
-            def playlists_loaded_callback(view):
-                self.disconnect(handler)
-                def_handler = 0
-
-                def songs_loaded_callback(view):
-                    self.disconnect(def_handler)
-                    find_and_activate_playlist()
+        If the view has not been populated yet, populate it and then
+        select the requested playlist. Otherwise, directly select the
+        requested playlist and start playing.
 
-                # Skip load of default playlist
-                def_handler = self.connect('playlist-songs-loaded',
-                                           songs_loaded_callback)
-
-            handler = self.connect('playlists-loaded',
-                                   playlists_loaded_callback)
+        :param str playlist_id: requested playlist id
+        """
+        if not self._init:
+            self._plays_songs_on_activation = True
+            self._populate(playlist_id)
+            return
 
-            self._populate()
+        for row in self._sidebar:
+            if row.playlist.get_id() == playlist_id:
+                selection = self._sidebar.get_selected_row()
+                if selection.get_index() == row.get_index():
+                    self._on_play_activate(None)
+                else:
+                    self._plays_songs_on_activation = True
+                    self._sidebar.select_row(row)
+                    self._sidebar.emit('row-activated', row)
+                return
 
     @log
     def remove_playlist(self):
@@ -579,6 +562,13 @@ class PlaylistView(BaseView):
         if remaining == 0:
             self._view.set_model(self.model)
             self._pl_ctrls.props.display_songs_count = True
+            if self._plays_songs_on_activation:
+                first_iter = self.model.get_iter_first()
+                self.player.set_playlist(
+                    PlayerPlaylist.Type.PLAYLIST,
+                    self._current_playlist.get_id(), self.model, first_iter)
+                self.player.play()
+                self._plays_songs_on_activation = False
 
     @log
     def _add_song_to_model(self, song, model, index=-1):
@@ -587,7 +577,6 @@ class PlaylistView(BaseView):
         :param Gtk.ListStore model: model
         """
         if not song:
-            self.emit('playlist-songs-loaded')
             return None
 
         title = utils.get_media_title(song)
@@ -782,5 +771,6 @@ class PlaylistView(BaseView):
         Do not reload playlists already displayed.
         """
         self._window.notifications_popup.push_loading()
-        grilo.populate_playlists(self._offset, self._add_playlist_item)
+        grilo.populate_playlists(
+            self._offset, self._add_playlist_item, -1, data)
         self._init = True