[gnome-music] Use models as playlists

[Vadim Rutkovsky <vrutkovsky src gnome org>]

commit 14345b4af1568511e532708cb29eddc0da762905
Author: Guillaume Quintard <guillaume quintard gmail com>
Date:   Tue Apr 23 00:55:18 2013 +0200

    Use models as playlists
    
    this is a proof-of-concept, using the listStore of the Album view as a
    playlist if one item is clicked.
    Various enhacements can be made (embedding model/iter in one object,
    warning that the song as been paused...) and the theory remains open to
    discussion

 src/player.js  |   64 +++++++++++++++-----------
 src/view.js    |    2 -
 src/widgets.js |  135 ++++++++++++++++++++++++++++----------------------------
 3 files changed, 104 insertions(+), 97 deletions(-)
---
diff --git a/src/player.js b/src/player.js
index 28c1d6c..42abd61 100644
--- a/src/player.js
+++ b/src/player.js
@@ -79,19 +79,18 @@ const Player = new Lang.Class({
 
     _init: function() {
         Signals.addSignalMethods(Player.prototype);
-        this.playlist = [];
-        this.currentTrack = 0;
+        this.playlist = null;
+       this.playlist_type = null;
+       this.playlist_id = null;
+       this.playlist_field = null;
+        this.currentTrack = null;
         this.cache = AlbumArtCache.AlbumArtCache.getDefault();
 
         Gst.init(null, 0);
         this.player = Gst.ElementFactory.make("playbin", "player");
         this.player.connect("about-to-finish", Lang.bind(this,
             function() {
-                let newCurrentTrack = parseInt(this.currentTrack) + 1;
-                if (newCurrentTrack < this.playlist.length) {
-                    this.currentTrack = newCurrentTrack;
-                    this.load(this.playlist[this.currentTrack]);
-                }
+               this.playNext();
                 return true;
             }));
         this.bus = this.player.get_bus();
@@ -153,9 +152,9 @@ const Player = new Lang.Class({
         if(this.player.get_state(1)[1] != Gst.State.PAUSED) {
             this.stop();
         }
-        this.load(this.playlist[this.currentTrack]);
+        this.load( this.playlist.get_value( this.currentTrack, this.playlist_field));
         this.player.set_state(Gst.State.PLAYING);
-        this.timeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 10, Lang.bind(this, 
this._updatePositionCallback));
+        this.timeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 100, Lang.bind(this, 
this._updatePositionCallback));
     },
 
     pause: function () {
@@ -171,30 +170,41 @@ const Player = new Lang.Class({
         }
     },
 
-    appendToPlaylist: function (track) {
-        this.playlist.push(track);
-    },
-
     playNext: function () {
-        let newCurrentTrack = parseInt(this.currentTrack) + 1;
-        if (newCurrentTrack < this.playlist.length) {
-            this.currentTrack = newCurrentTrack;
-            this.stop();
-            this.play();
-        }
+       if (!this.playlist || !this.currentTrack || !this.playlist.iter_next(this.currentTrack)){
+               this.stop();
+               this.currentTrack=null; 
+               return;
+       }
+        this.emit("playlist-item-changed", this.playlist, this.currentTrack);
+       this.stop();
+       this.play();
     },
 
     playPrevious: function () {
-        let newCurrentTrack = parseInt(this.currentTrack) - 1;
-        if (newCurrentTrack >= 0) {
-            this.currentTrack = newCurrentTrack;
-            this.stop();
-            this.play();
-        }
+       if (!this.playlist || !this.currentTrack || !this.playlist.iter_previous(this.currentTrack)){
+               this.stop();
+               this.currentTrack=null; 
+               return;}
+        this.emit("playlist-item-changed", this.playlist, this.currentTrack);
+       this.stop();
+       this.play();
+    },
+
+    setPlaylist: function (type, id, model, iter, field) {
+        this.playlist = model;
+       this.playlist_type = type;
+       this.playlist_id = id;
+        this.currentTrack = iter;
+        this.playlist_field = field;
+        this.emit("playlist-item-changed", this.playlist, this.currentTrack);
     },
 
-    setPlaylist: function (playlist) {
-        this.playlist = playlist;
+    runningPlaylist: function (type, id, force){
+           if (type == this.playlist_type && id == this.playlist_id)
+                   return this.playlist;
+           else
+                   return null;
     },
 
     setCurrentTrack: function (track) {
diff --git a/src/view.js b/src/view.js
index 23ac10d..368c420 100644
--- a/src/view.js
+++ b/src/view.js
@@ -337,7 +337,6 @@ const Songs = new Lang.Class({
 
     _addItem: function(source, param, item) {
         this.parent(source, param, item);
-        this.player.appendToPlaylist(item);
     },
 
     _addListRenderers: function() {
@@ -377,7 +376,6 @@ const Songs = new Lang.Class({
     },
 
     populate: function() {
-        this.player.playlist = [];
         if (grilo.tracker != null)
             grilo.populateSongs (this._offset, Lang.bind(this, this._addItem, null));
     },
diff --git a/src/widgets.js b/src/widgets.js
index aa20565..62a76da 100644
--- a/src/widgets.js
+++ b/src/widgets.js
@@ -40,17 +40,9 @@ const AlbumWidget = new Lang.Class({
     _init: function (player) {
         this.player = player;
         this.hbox = new Gtk.HBox ();
+       this.iterToClean = null;
         this.scrolledWindow = new Gtk.ScrolledWindow();
 
-        this.model = Gtk.ListStore.new([
-            GObject.TYPE_STRING, /*title*/
-            GObject.TYPE_STRING,
-            GObject.TYPE_STRING,
-            GObject.TYPE_BOOLEAN,/*icon shown*/
-            GdkPixbuf.Pixbuf,    /*icon*/
-            GObject.TYPE_OBJECT, /*song object*/
-            GObject.TYPE_BOOLEAN
-        ]);
         this.ui = new Gtk.Builder();
         this.ui.add_from_resource('/org/gnome/music/AlbumWidget.ui');
         this.model = this.ui.get_object("AlbumWidget_model");
@@ -59,12 +51,16 @@ const AlbumWidget = new Lang.Class({
             shadow_type:    Gtk.ShadowType.NONE
         });
         this.view.set_view_type(Gd.MainViewType.LIST);
-        this.view.set_model(this.model);
+       this.album=null;
         this.view.connect('item-activated', Lang.bind(this,
             function(widget, id, path) {
-                let iter = this.model.get_iter (path)[1];
-                let item = this.model.get_value(iter, 5);
-                this.player.setCurrentTrack(item);
+               if (this.iterToClean){
+                       let item = this.model.get_value(this.iterToClean, 5);
+                       this.model.set_value(this.iterToClean, 0, item.get_title());
+                       // Hide now playing icon
+                       this.model.set_value(this.iterToClean, 3, false);
+               }
+                this.player.setPlaylist("Album", this.album, this.model, this.model.get_iter(path)[1], 5);
                 this.player.play();
             })
         );
@@ -127,36 +123,48 @@ const AlbumWidget = new Lang.Class({
                 durationRenderer.text = this.player.seconds_to_string(duration);
             }));
     },
-
     update: function (artist, album, item) {
-        var pixbuf = albumArtCache.lookup (256, artist, item.get_string(Grl.METADATA_KEY_ALBUM));
         let released_date = item.get_publication_date();
         if (released_date != null) {
             this.ui.get_object("released_label_info").set_text(
                 released_date.get_year().toString());
         }
         let duration = 0;
-        this.model.clear()
-        var tracks = [];
-        grilo.getAlbumSongs(item.get_id(), Lang.bind(this, function (source, prefs, track) {
-            if (track != null) {
-                tracks.push(track);
-                duration = duration + track.get_duration();
-                let iter = this.model.append();
-                let path = "/usr/share/icons/gnome/scalable/actions/media-playback-start-symbolic.svg";
-                let pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(path, -1, 16, true);
-                this.model.set(iter,
-                    [0, 1, 2, 3, 4, 5],
-                    [ track.get_title(), "", "", false, pixbuf, track ]);
-                this.ui.get_object("running_length_label_info").set_text(
-                    (parseInt(duration/60) + 1) + " min");
-            }
-        }));
-
-        this.player.setPlaylist(tracks);
-        this.player.setCurrentTrack(tracks[0]);
-
-        pixbuf = albumArtCache.lookup (256, artist, item.get_string(Grl.METADATA_KEY_ALBUM));
+       this.album = album;
+       // if the active queue has been set by this album,
+       // use it as model, otherwise build the liststore
+       let cachedPlaylist = this.player.runningPlaylist("Album", album);
+       if (cachedPlaylist){
+               this.model = cachedPlaylist;
+       } else {
+               this.model = Gtk.ListStore.new([
+                               GObject.TYPE_STRING, /*title*/
+                               GObject.TYPE_STRING,
+                               GObject.TYPE_STRING,
+                               GObject.TYPE_BOOLEAN,/*icon shown*/
+                               GdkPixbuf.Pixbuf,    /*icon*/
+                               GObject.TYPE_OBJECT, /*song object*/
+                               GObject.TYPE_BOOLEAN
+                               ]);
+               this.iterToClean = null;
+               var tracks = [];
+               grilo.getAlbumSongs(item.get_id(), Lang.bind(this, function (source, prefs, track) {
+                       if (track != null) {
+                               tracks.push(track);
+                               duration = duration + track.get_duration();
+                               let iter = this.model.append();
+                               let path = 
"/usr/share/icons/gnome/scalable/actions/media-playback-start-symbolic.svg";
+                               let pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(path, -1, 16, true);
+                               this.model.set(iter,
+                                       [0, 1, 2, 3, 4, 5],
+                                       [ track.get_title(), "", "", false, pixbuf, track ]);
+                               this.ui.get_object("running_length_label_info").set_text(
+                                       (parseInt(duration/60) + 1) + " min");
+                       }
+               }));
+       }
+       this.view.set_model(this.model);
+        var pixbuf = albumArtCache.lookup (256, artist, item.get_string(Grl.METADATA_KEY_ALBUM));
         if (pixbuf == null) {
             let path = "/usr/share/icons/gnome/scalable/places/folder-music-symbolic.svg";
             pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(path, -1, 256, true);
@@ -167,36 +175,29 @@ const AlbumWidget = new Lang.Class({
         this.ui.get_object("title_label").set_markup(album);
         this.ui.get_object("released_label_info").set_text(item.get_creation_date().get_year().toString());
 
-        this.player.connect('song-changed', Lang.bind(this,
-            function(widget, id) {
-                // Highlight currently played song as bold
-                let iter = this.model.get_iter_from_string(id.toString())[1];
-                let item = this.model.get_value(iter, 5);
-                let title = "<b>" + item.get_title() + "</b>";
-                this.model.set_value(iter, 0, title);
-                // Display now playing icon
-                this.model.set_value(iter, 3, true);
-
-                // Make all previous songs shadowed
-                for (let i = 0; i < id; i++){
-                    let iter = this.model.get_iter_from_string(i.toString())[1];
-                    let item = this.model.get_value(iter, 5);
-                    let title = "<span color='grey'>" + item.get_title() + "</span>";
-                    this.model.set_value(iter, 0, title);
-                    this.model.set_value(iter, 3, false);
-                }
-
-                //Remove markup from the following songs
-                let i = parseInt(id) + 1;
-                while(this.model.get_iter_from_string(i.toString())[0]) {
-                    let iter = this.model.get_iter_from_string(i.toString())[1];
-                    let item = this.model.get_value(iter, 5);
-                    this.model.set_value(iter, 0, item.get_title());
-                    this.model.set_value(iter, 3, false);
-                    i++;
-                }
-                return true;
-            }
+        this.player.connect('playlist-item-changed', Lang.bind(this,
+            function(player, playlist, iter) {
+               //this is not our playlist, disregard the signal
+               if (playlist != this.model){
+                       print ("Album and"+type + "  "+this.album + " and "+id);
+                       return true;}
+               if (this.iterToClean){
+                       let item = this.model.get_value(this.iterToClean, 5);
+                       this.model.set_value(this.iterToClean, 0, item.get_title());
+                       // Hide now playing icon
+                       this.model.set_value(this.iterToClean, 3, false);
+               }
+               this.iterToClean = iter.copy(); 
+
+               // Highlight currently played song as bold
+               let item = this.model.get_value(iter, 5);
+               this.model.set_value(iter, 0, "<b>" + item.get_title() + "</b>");
+               // Display now playing icon
+               this.model.set_value(iter, 3, true);
+
+               // reset the previous item, if it exists
+               return true;
+           }
         ));
     },
 });
@@ -224,8 +225,6 @@ const ArtistAlbums = new Lang.Class({
             widgets.push(widget);
         }
         this.show_all();
-        this.player.setPlaylist(tracks);
-        this.player.setCurrentTrack(tracks[0]);
 
         this.player.connect('song-changed', Lang.bind(this,
             function(widget, id) {