move a bunch of logic into playbin

also yeah yeah fixme those buttons are gone for now

src/playbin.vala

@@ -31,19 +31,24 @@ class Playbin : Object {
     public int64 position { get; private set; }
     public int64 duration { get; private set; }
 
-    private bool notify_next_transition;
+    public Subsonic api { get; set; }
+    private ListModel play_queue;
 
-    // public void begin_playback (string uri);
+    public signal void now_playing (uint index, Song song, int64 duration);
-    // public void prepare_next (string? next_uri);
+    private uint playing_index;
-    public signal void song_transition (string uri);
+
-    public signal void playback_finished ();
+    private bool next_gapless;
-    // public void stop_playback ();
 
     private void source_setup (Gst.Element playbin, dynamic Gst.Element source) {
         source.user_agent = "audrey/linux";
     }
 
-    construct {
+    public Playbin (ListModel play_queue) {
+        this.play_queue = play_queue;
+
+        this.next_uri = new AsyncQueue<string?> ();
+        this.next_uri.push ("");
+
         // gstreamer docs: GNOME-based applications, for example, will usually
         // want to create gconfaudiosink and gconfvideosink elements and make
         // playbin3 use those, so that output happens to whatever the user has
@@ -53,6 +58,53 @@ class Playbin : Object {
         this.playbin.source_setup.connect (this.source_setup);
         this.playbin.about_to_finish.connect (this.about_to_finish);
 
+        play_queue.items_changed.connect ((play_queue, position, removed, added) => {
+            if (this.state == PlaybinState.STOPPED) {
+                return;
+            }
+
+            if (this.playing_index >= position) {
+                if (this.playing_index < position+removed) {
+                    // current track was removed, start playing something else
+                    // TODO check if it was actually reordered
+
+                    this.begin_playback (position);
+                } else {
+                    // unaffected
+                    // fix up playing index though
+                    this.playing_index += added;
+                    this.playing_index -= removed;
+                }
+            } else if (this.playing_index+1 == position) {
+                // next track was changed
+                // try to fix up gapless transition
+                this.next_uri.lock ();
+                switch (this.next_uri.length_unlocked ()) {
+                case 1:
+                    // we're in luck, about-to-finish hasn't been triggered yet
+                    // we can get away with replacing it
+                    this.next_uri.try_pop_unlocked ();
+                    if (this.playing_index+1 < play_queue.get_n_items ()) {
+                        Song song = (Song) play_queue.get_item (this.playing_index+1);
+                        this.next_uri.push_unlocked (this.api.stream_uri (song.id));
+                    } else {
+                        this.next_uri.push_unlocked ("");
+                    }
+                    break;
+
+                case 0:
+                    // about-to-finish already triggered
+                    // we'll need to stop the new track when it starts playing
+                    assert (false); // TODO
+                    break;
+
+                default:
+                    error ("invalid next_uri queue length %u\n", this.next_uri.length_unlocked ());
+                }
+                this.next_uri.unlock ();
+            }
+        });
+
         // regularly update position/duration
         Timeout.add (500, () => {
             if (this.update_position) {
@@ -95,10 +147,20 @@ class Playbin : Object {
 
             this.position = 0;
 
-            if (notify_next_transition) {
+            if (this.next_gapless) {
-                this.song_transition ((string) this.playbin.current_uri);
+                // advance position in play queue
+                this.playing_index += 1;
             } else {
-                notify_next_transition = true;
+                this.next_gapless = true;
+            }
+
+            this.now_playing (this.playing_index, (Song) play_queue.get_item (this.playing_index), this.duration);
+
+            if (this.playing_index+1 < play_queue.get_n_items ()) {
+                Song song = (Song) play_queue.get_item (this.playing_index+1);
+                this.next_uri.push (this.api.stream_uri (song.id));
+            } else {
+                this.next_uri.push ("");
             }
         });
 
@@ -112,8 +174,7 @@ class Playbin : Object {
         });
         
         bus.message["eos"].connect ((message) => {
-            assert (notify_next_transition);
+            assert (false); // TODO
-            this.playback_finished ();
         });
     }
 
@@ -123,32 +184,54 @@ class Playbin : Object {
         }
     }
 
-    public void begin_playback (string uri) {
+    public void begin_playback (uint position) {
-        this.playbin.set_state (Gst.State.READY);
-        this.playbin.uri = uri;
-        this.playbin.set_state (Gst.State.PLAYING);
-
         this.state = PlaybinState.PLAYING;
-        this.notify_next_transition = false;
+
+        this.playing_index = position;
+        this.playbin.set_state (Gst.State.READY);
+        this.playbin.uri = this.api.stream_uri (((Song) this.play_queue.get_item (position)).id);
+        this.playbin.set_state (Gst.State.PLAYING);
+        this.next_gapless = false;
+
+        this.next_uri.lock ();
+        switch (this.next_uri.length_unlocked ()) {
+          case 1:
+            // we're in luck, about-to-finish hasn't been triggered yet
+            this.next_uri.try_pop_unlocked ();
+            break;
+
+          case 0:
+            // about-to-finish already triggered
+            // we'll need to stop the new track when it starts playing
+            assert (false); // TODO
+            break;
+
+          case -1:
+            // about-to-finish is blocked
+            // extremely stupid edge case
+            assert (false); // TODO
+            break;
+
+          default:
+            error ("invalid next_uri queue length %u\n", this.next_uri.length_unlocked ());
+        }
+        this.next_uri.unlock ();
     }
 
-    Mutex next_uri_lock;
+    // ASSUMPTION: about-to-finish will be signalled exactly once per track
-    string? next_uri;
+    // even if seeking backwards after
-
+    AsyncQueue<string?> next_uri;
-    public void prepare_next (string? next_uri) {
-        this.next_uri_lock.lock ();
-        this.next_uri = next_uri;
-        this.next_uri_lock.unlock ();
-    }
 
     // called when uri can be switched for gapless playback
     // need async queue because this might be called from a gstreamer thread
     private void about_to_finish (dynamic Gst.Element playbin) {
-        this.next_uri_lock.lock ();
+        print ("about to finish\n");
-        string? next_uri = this.next_uri;
-        this.next_uri_lock.unlock ();
 
-        if (next_uri != null) {
+        // will block if the next uri isn't ready yet
+        // leaves the queue empty as per the ASSUMPTION above
+        string? next_uri = this.next_uri.pop ();
+
+        if (next_uri != "") {
             playbin.uri = next_uri;
         }
     }

src/ui/play_queue.blp

@@ -9,7 +9,7 @@ template $UiPlayQueue: Adw.NavigationPage {
     Adw.HeaderBar {
       Button {
         icon-name: "edit-clear-all";
-        clicked => $clear ();
+        clicked => $on_clear ();
         sensitive: bind template.can_clear_all;
       }
     }
@@ -18,6 +18,8 @@ template $UiPlayQueue: Adw.NavigationPage {
       ColumnView view {
         styles [ "data-table" ]
 
+        model: bind template.model;
+
         //ColumnViewColumn {
         //  factory: SignalListItemFactory {
         //    setup => $on_delete_cell_setup ();

src/ui/play_queue.vala

@@ -1,64 +1,58 @@
-class Ui.PlayQueueStore : Object, ListModel, Gtk.SelectionModel {
+// this is a custom SelectionModel that lets us only signal the
-    public ListStore inner = new ListStore (typeof (Song));
+// selection has changed on user interaction
-    public uint playing_index { get; private set; default = 0; }
+class PlayQueueSelection : Object, ListModel, Gtk.SelectionModel {
+    public ListStore inner { get; private set; }
     
-    public signal void begin_playback (Song song);
+    private uint _selected_position;
-    public signal void prepare_next (Song? song);
+    public uint selected_position {
-    public signal void playback_continues (Song song);
+        get { return _selected_position; }
-    public signal void stop_playback ();
+        set {
+            var previous = _selected_position;
+            _selected_position = value;
+
+            if (previous < inner.get_n_items ()) {
+                this.selection_changed (previous, 1);
+            }
+            if (value < inner.get_n_items ()) {
+                this.selection_changed (value, 1);
+            }
+        }
+    }
+
+    public signal void user_selected (uint position);
+
+    internal PlayQueueSelection () {
+        this.inner = new ListStore (typeof (Song));
+        this._selected_position = inner.get_n_items ();
 
-    construct {
         this.inner.items_changed.connect ((position, removed, added) => {
             bool emit_signal = false;
 
-            if (this.playing_index >= position) {
+            if (this.selected_position >= position) {
-                if (this.playing_index < position+removed) {
+                if (this.selected_position < position+removed && added == 0) {
-                    this.playing_index = position;
-                    if (this.playing_index < this.inner.get_n_items ()) {
                     emit_signal = true;
-                        this.begin_playback ((Song) this.inner.get_item (this.playing_index));
+                    this._selected_position = position;
-                        this.prepare_next ((Song?) this.inner.get_item (this.playing_index+1));
                 } else {
-                        this.stop_playback ();
+                    this._selected_position += added;
+                    this._selected_position -= removed;
                 }
-                } else {
-                    this.playing_index += added;
-                    this.playing_index -= removed;
-                }
-            } else {
-                this.prepare_next ((Song?) this.inner.get_item (this.playing_index+1));
             }
 
             this.items_changed (position, removed, added);
-            if (emit_signal) {
+            if (emit_signal) this.selection_changed (position, 1);
-                this.selection_changed (this.playing_index, 1);
-            }
         });
     }
 
-    public void song_transition () {
-        this.playing_index += 1;
-        this.selection_changed (this.playing_index-1, 2);
-        this.playback_continues ((Song) this.inner.get_item (this.playing_index));
-        this.prepare_next ((Song?) this.inner.get_item (this.playing_index+1));
-    }
-
-    public void playback_finished () {
-        this.playing_index += 1;
-        assert (this.playing_index == this.inner.get_n_items ());
-        this.selection_changed (this.playing_index-1, 1);
-    }
-
     Gtk.Bitset get_selection_in_range (uint position, uint n_items) {
         var bitset = new Gtk.Bitset.empty ();
-        if (this.playing_index < this.inner.get_n_items ()) {
+        if (this.selected_position < this.inner.get_n_items ()) {
-            bitset.add (playing_index);
+            bitset.add (selected_position);
         }
         return bitset;
     }
 
     bool is_selected (uint position) {
-        return position == this.playing_index;
+        return position == this.selected_position;
     }
 
     bool select_all () {
@@ -70,21 +64,8 @@ class Ui.PlayQueueStore : Object, ListModel, Gtk.SelectionModel {
             return false;
         }
       
-        var previous = this.playing_index;
+        this.selected_position = position;
-        this.playing_index = position;
+        this.user_selected (position);
-
-        if (previous < this.inner.get_n_items ()) {
-            if (previous < position) {
-                this.selection_changed (previous, position-previous+1);
-            } else if (previous > position) {
-                this.selection_changed (position, previous-position+1);
-            }
-        } else {
-            this.selection_changed (position, 1);
-        }
-
-        this.begin_playback ((Song) this.inner.get_item (this.playing_index));
-        this.prepare_next ((Song) this.inner.get_item (this.playing_index+1));
 
         return true;
     }
@@ -125,62 +106,13 @@ class Ui.PlayQueueStore : Object, ListModel, Gtk.SelectionModel {
 [GtkTemplate (ui = "/eu/callcc/audrey/ui/play_queue.ui")]
 public class Ui.PlayQueue : Adw.NavigationPage {
     [GtkChild] private unowned Gtk.ColumnView view;
-    PlayQueueStore store = new PlayQueueStore ();
+    public Gtk.SelectionModel model { get; set; }
-
-    public signal void begin_playback (Song song);
-    public signal void prepare_next (Song? next_song);
-    public signal void playback_continues (Song song);
-    public signal void stop_playback ();
 
     public bool can_clear_all { get; private set; default = false; }
 
-    construct {
+    public signal void clear ();
-        this.view.model = this.store;
 
-        this.store.begin_playback.connect ((song) => this.begin_playback (song));
+    [GtkCallback] private void on_clear () {
-        this.store.prepare_next.connect ((next_song) => this.prepare_next (next_song));
+        this.clear ();
-        this.store.playback_continues.connect ((song) => this.playback_continues (song));
-        this.store.stop_playback.connect (() => this.stop_playback ());
     }
-
-    [GtkCallback] public void clear () {
-        this.store.inner.remove_all ();
-        this.can_clear_all = false;
-    }
-
-    public void queue (Song song) {
-        this.store.inner.append (song);
-    }
-
-    internal void song_transition () {
-        this.store.song_transition ();
-    }
-
-    internal void playback_finished () {
-        this.store.playback_finished ();
-    }
-
-    internal void restart () {
-        this.store.select_item (0, true);
-    }
-
-    public void skip_forward () {
-        this.store.select_item (this.store.playing_index+1, true);
-    }
-
-    public void skip_backward () {
-        if (this.store.playing_index >= 1) {
-            this.store.select_item (this.store.playing_index-1, true);
-        }
-    }
-/*
-    [GtkCallback] private void on_delete_cell_setup (Object object) {
-        var cell = (Gtk.ColumnViewCell) object;
-        var button = new Gtk.Button.from_icon_name ("edit-delete");
-        button.add_css_class ("flat");
-        button.clicked.connect (() => {
-            //this.store.inner.remove (cell.position);
-        });
-        cell.child = button;
-    }*/
 }

src/ui/window.blp

@@ -81,7 +81,9 @@ template $UiWindow: Adw.ApplicationWindow {
           name: "play_queue";
           title: _("Play queue");
 
-          child: $UiPlayQueue play_queue {};
+          child: $UiPlayQueue play_queue {
+            model: bind template.play_queue_model;
+          };
         }
       }
     }
@@ -146,7 +148,7 @@ template $UiWindow: Adw.ApplicationWindow {
             adjustment: Adjustment {
               lower: 0;
               value: bind template.position;
-              upper: bind template.playbin as <$Playbin>.duration;
+              upper: bind template.duration;
             };
 
             change-value => $on_play_position_seek ();
@@ -159,7 +161,7 @@ template $UiWindow: Adw.ApplicationWindow {
               "numeric",
             ]
 
-            label: bind $format_timestamp (template.playbin as <$Playbin>.duration) as <string>;
+            label: bind $format_timestamp (template.duration) as <string>;
           }
         }
 
@@ -170,7 +172,7 @@ template $UiWindow: Adw.ApplicationWindow {
           Button {
             icon-name: "media-skip-backward";
             valign: center;
-            sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
+            //sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
 
             clicked => $on_skip_backward_clicked ();
           }
@@ -178,15 +180,15 @@ template $UiWindow: Adw.ApplicationWindow {
           Button {
             icon-name: "media-seek-backward";
             valign: center;
-            sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
+            //sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
 
             clicked => $seek_backward ();
           }
 
           Button {
-            icon-name: bind $play_pause_icon_name (template.playbin as <$Playbin>.state as <$PlaybinState>) as <string>;
+            //icon-name: bind $play_pause_icon_name (template.playbin as <$Playbin>.state as <$PlaybinState>) as <string>;
             valign: center;
-            sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
+            //sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
 
             clicked => $on_play_pause_clicked ();
           }
@@ -194,7 +196,7 @@ template $UiWindow: Adw.ApplicationWindow {
           Button {
             icon-name: "media-seek-forward";
             valign: center;
-            sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
+            //sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
 
             clicked => $seek_forward ();
           }
@@ -202,7 +204,7 @@ template $UiWindow: Adw.ApplicationWindow {
           Button {
             icon-name: "media-skip-forward";
             valign: center;
-            sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
+            //sensitive: bind $playbin_active (template.playbin as <$Playbin>.state as <$PlaybinState>) as <bool>;
 
             clicked => $on_skip_forward_clicked ();
           }

src/ui/window.vala

@@ -10,6 +10,7 @@ class Ui.Window : Adw.ApplicationWindow {
     private Setup setup;
     
     public int64 position { get; private set; }
+    public int64 duration { get; private set; }
 
     public double volume {
         get { return this.playbin.volume; }
@@ -28,7 +29,8 @@ class Ui.Window : Adw.ApplicationWindow {
 
     private Gdk.Paintable next_cover_art = null;
 
-    internal Playbin playbin { get; default = new Playbin (); }
+    internal Playbin playbin;
+    public PlayQueueSelection play_queue_model { get; private set; default = new PlayQueueSelection (); }
 
     public Window (Gtk.Application app) {
         Object (application: app);
@@ -61,15 +63,30 @@ class Ui.Window : Adw.ApplicationWindow {
 
         this.setup = new Setup ();
 
+        this.playbin = new Playbin (this.play_queue_model);
+
         this.setup.connected.connect ((api) => {
+            this.playbin.api = api;
+
+            this.playbin.now_playing.connect ((position, song, duration) => {
+                this.song = song;
+                this.duration = duration;
+                api.scrobble.begin (song.id);
+                this.play_queue_model.selected_position = position;
+            });
+
+            this.play_queue_model.user_selected.connect ((position) => {
+                this.playbin.begin_playback (position);
+            });
+
             public_api = api;
 
             this.shuffle_all_tracks.sensitive = true;
             this.shuffle_all_tracks.activated.connect (() => {
                 this.shuffle_all_tracks.sensitive = false;
-                this.play_queue.clear ();
+                this.play_queue_model.inner.remove_all ();
                 api.get_random_songs.begin (null, (song) => {
-                    this.play_queue.queue (song);
+                    this.play_queue_model.inner.append (song);
                 }, (obj, res) => {
                     try {
                         api.get_random_songs.end (res);
@@ -78,41 +95,9 @@ class Ui.Window : Adw.ApplicationWindow {
                     }
                     this.shuffle_all_tracks.sensitive = true;
 
-                    this.play_queue.restart ();
+                    this.playbin.begin_playback (0);
                 });
             });
-
-            this.play_queue.begin_playback.connect ((song) => {
-                var uri = api.stream_uri (song.id);
-                this.playbin.begin_playback (uri);
-
-                this.song = song;
-                api.scrobble.begin (song.id);
-            });
-
-            this.play_queue.prepare_next.connect ((next_song) => {
-                var next_uri = next_song == null ? null : api.stream_uri (next_song.id);
-                this.playbin.prepare_next (next_uri);
-            });
-
-            this.playbin.song_transition.connect ((uri) => {
-                this.play_queue.song_transition ();
-            });
-
-            this.play_queue.playback_continues.connect ((song) => {
-                this.song = song;
-                api.scrobble.begin (song.id);
-            });
-
-            this.playbin.playback_finished.connect (() => {
-                this.play_queue.playback_finished ();
-                this.song = null;
-            });
-
-            this.play_queue.stop_playback.connect (() => {
-                this.playbin.stop_playback ();
-                this.song = null;
-            });
         });
         this.setup.load ();
 
@@ -190,6 +175,7 @@ class Ui.Window : Adw.ApplicationWindow {
         }
     }
 
+/*
     [GtkCallback] private string play_pause_icon_name (PlaybinState state) {
         if (state == PlaybinState.PLAYING) {
             return "media-playback-pause";
@@ -200,7 +186,7 @@ class Ui.Window : Adw.ApplicationWindow {
 
     [GtkCallback] private bool playbin_active (PlaybinState state) {
         return state != PlaybinState.STOPPED;
-    }
+    }*/
 
     [GtkCallback] private string mute_button_icon_name (bool mute) {
         return mute ? "audio-volume-muted" : "audio-volume-high";
@@ -211,11 +197,11 @@ class Ui.Window : Adw.ApplicationWindow {
     }
 
     [GtkCallback] private void on_skip_forward_clicked () {
-        this.play_queue.skip_forward ();
+        //this.play_queue.skip_forward ();
     }
 
     [GtkCallback] private void on_skip_backward_clicked () {
-        this.play_queue.skip_backward ();
+        //this.play_queue.skip_backward ();
     }
 
     [GtkCallback] private void show_setup_dialog () {