[gnome-music/wip/mschraal/gapless-v3: 80/83] Introduce gapless playback

[Marinus Schraal <mschraal src gnome org>]

commit 7651edaab85fc4ae867364f480f32b62f56c1661
Author: Marinus Schraal <mschraal gnome org>
Date:   Wed Aug 22 01:39:11 2018 +0200

    Introduce gapless playback

 gnomemusic/gstplayer.py             | 33 ++++++++++++++++++++++++++++-----
 gnomemusic/player.py                | 19 +++++++++++++++----
 gnomemusic/widgets/playertoolbar.py |  6 ++++--
 gnomemusic/widgets/smoothscale.py   |  3 +++
 4 files changed, 50 insertions(+), 11 deletions(-)
---
diff --git a/gnomemusic/gstplayer.py b/gnomemusic/gstplayer.py
index ec67891c..b9b6c332 100644
--- a/gnomemusic/gstplayer.py
+++ b/gnomemusic/gstplayer.py
@@ -30,7 +30,7 @@ import gi
 gi.require_version('Gst', '1.0')
 gi.require_version('GstAudio', '1.0')
 gi.require_version('GstPbutils', '1.0')
-from gi.repository import Gtk, Gio, GObject, Gst, GstAudio, GstPbutils
+from gi.repository import Gtk, Gio, GLib, GObject, Gst, GstAudio, GstPbutils
 
 from gnomemusic import log
 from gnomemusic.playlists import Playlists
@@ -53,8 +53,9 @@ class GstPlayer(GObject.GObject):
     Handles GStreamer interaction for Player and SmoothScale.
     """
     __gsignals__ = {
-        'eos': (GObject.SignalFlags.RUN_FIRST, None, ()),
-        'clock-tick': (GObject.SignalFlags.RUN_FIRST, None, (int, ))
+        'clock-tick': (GObject.SignalFlags.RUN_FIRST, None, (int, )),
+        'eos': (GObject.SignalFlags.RUN_FIRST, None, (bool, )),
+        'stream-start': (GObject.SignalFlags.RUN_FIRST, None, ())
     }
 
     def __repr__(self):
@@ -88,6 +89,9 @@ class GstPlayer(GObject.GObject):
         self._bus.connect(
             'message::duration-changed', self._on_duration_changed)
         self._bus.connect('message::new-clock', self._on_new_clock)
+        self._bus.connect('message::stream-start', self._on_stream_start)
+
+        self._player.connect('about-to-finish', self._on_about_to_finish)
 
         self.state = Playback.STOPPED
 
@@ -116,6 +120,11 @@ class GstPlayer(GObject.GObject):
             logger.debug("Replay Gain is not available")
             return
 
+    @log
+    def _on_about_to_finish(self, klass, data=None):
+        print("about to finish")
+        self.emit('eos', True)
+
     @log
     def _on_replaygain_setting_changed(self, settings, value):
         if value:
@@ -183,12 +192,25 @@ class GstPlayer(GObject.GObject):
                 message.src.get_name(), error.message))
         logger.warning("Debugging info:\n{}".format(debug))
 
-        self.emit('eos')
+        self.emit('eos', False)
         return True
 
     @log
     def _on_bus_eos(self, bus, message):
-        self.emit('eos')
+        print("bus eos")
+        self.emit('eos', False)
+
+    @log
+    def _on_stream_start(self, bus, message):
+        print("stream start")
+
+        def delayed_query(bus, message):
+            self._on_duration_changed(None, None)
+            self.emit('stream-start')
+
+            return False
+
+        GLib.timeout_add(1, delayed_query, bus, message)
 
     @log
     def _get_playback_status(self):
@@ -308,6 +330,7 @@ class GstPlayer(GObject.GObject):
 
         :param float seconds: Position in seconds to seek
         """
+        print("seek", seconds)
         # FIXME: seek should be signalled to MPRIS
         self._player.seek_simple(
             Gst.Format.TIME, Gst.SeekFlags.FLUSH | Gst.SeekFlags.KEY_UNIT,
diff --git a/gnomemusic/player.py b/gnomemusic/player.py
index 1da1f16b..99fc6f17 100644
--- a/gnomemusic/player.py
+++ b/gnomemusic/player.py
@@ -530,6 +530,7 @@ class Player(GObject.GObject):
         self._player = GstPlayer()
         self._player.connect('clock-tick', self._on_clock_tick)
         self._player.connect('eos', self._on_eos)
+        self._player.connect('stream-start', self._on_stream_start)
 
         root_window = parent_window.get_toplevel()
         self._inhibit_suspend = InhibitSuspend(root_window, self)
@@ -575,18 +576,28 @@ class Player(GObject.GObject):
         if url_ != self._player.url:
             self._player.url = url_
 
-        self.emit('song-changed', self._playlist.get_current_index())
+        # self.emit('song-changed', self._playlist.get_current_index())
 
     @log
-    def _on_eos(self, klass):
+    def _on_eos(self, klass, gapless=False):
+        print("eos, gapless:", gapless)
         def on_glib_idle():
             self._playlist.next()
             self.play()
 
         if self.props.has_next:
-            GLib.idle_add(on_glib_idle)
+            if gapless:
+                self._playlist.next()
+                new_url = self._playlist.props.current_song.get_url()
+                self._player.props.url = new_url
+            else:
+                GLib.idle_add(on_glib_idle)
         else:
-            self.stop()
+            GLib.idle_add(self.stop)
+
+    @log
+    def _on_stream_start(self, klass):
+        self.emit('song-changed', self._playlist.get_current_index())
 
     @log
     def play(self, song_index=None):
diff --git a/gnomemusic/widgets/playertoolbar.py b/gnomemusic/widgets/playertoolbar.py
index 5091dd13..cc4e8ff8 100644
--- a/gnomemusic/widgets/playertoolbar.py
+++ b/gnomemusic/widgets/playertoolbar.py
@@ -161,8 +161,10 @@ class PlayerToolbar(Gtk.ActionBar):
         :param int position: current song position
         """
         current_song = player.props.current_song
-        self._duration_label.set_label(
-            utils.seconds_to_string(current_song.get_duration()))
+        duration = player._player.props.duration
+        if duration is not None:
+            self._duration_label.set_label(
+                utils.seconds_to_string(int(duration)))
 
         self._play_button.set_sensitive(True)
         self._sync_prev_next()
diff --git a/gnomemusic/widgets/smoothscale.py b/gnomemusic/widgets/smoothscale.py
index e995540b..50c7356f 100644
--- a/gnomemusic/widgets/smoothscale.py
+++ b/gnomemusic/widgets/smoothscale.py
@@ -117,10 +117,13 @@ class SmoothScale(Gtk.Scale):
     @log
     def _on_duration_changed(self, klass, arguments):
         duration = self._player.duration
+        print("duration changed", duration)
 
         if duration is not None:
             self.set_range(0.0, duration * 60)
             self.set_increments(300, 600)
+            self.set_value(0)
+            self._on_smooth_scale_event(None, None)
 
     @log
     def _on_smooth_scale_seek_finish(self, value):