audio: Implement our own about-to-finish handling

The playbin's about-to-finish signal triggers in a different thread,
which Gtk is very much not happy about, and often results in both the
about-to-finish and eos handlers getting called (and therefore multiple
tracks getting picked from the queue).

Fix this by checking how much time is left during the regular position
changed timeout function and triggering about-to-finish manually

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

audio/bass.py

@@ -11,6 +11,8 @@ Gst.init(sys.argv)
 
 from . import replaygain
 
+TIMEOUT = 100
+
 
 class BassPlayer(GObject.GObject):
     def __init__(self):
@@ -22,7 +24,6 @@ class BassPlayer(GObject.GObject):
         self.video  = Gst.ElementFactory.make("fakesink")
 
         self.playbin = Gst.ElementFactory.make("playbin")
-        self.playbin.connect("about-to-finish", self.__about_to_finish__)
         self.playbin.set_property("audio-sink", self.audio)
         self.playbin.set_property("video-sink", self.video)
         self.playbin.set_property("volume", lib.settings.get_float("audio.volume"))
@@ -38,9 +39,6 @@ class BassPlayer(GObject.GObject):
 
         self.timeout = None
 
-    def __about_to_finish__(self, playbin):
-        self.emit("about-to-finish")
-
     def __eos__(self, bus, message):
         self.emit("eos")
 
@@ -110,9 +108,6 @@ class BassPlayer(GObject.GObject):
         self.playbin.set_property("volume", vol)
         lib.settings.set("audio.volume", vol)
 
-    def about_to_finish(self, playbin):
-        pass
-
     def state_changed(self, bus, message):
         if message.src == self.playbin:
             (old, new, pending) = message.parse_state_changed()
@@ -152,7 +147,7 @@ class BassPlayer(GObject.GObject):
     @GObject.Signal
     def playback_start(self):
         if not self.timeout:
-            self.timeout = GLib.timeout_add(200, self.timeout_function)
+            self.timeout = GLib.timeout_add(TIMEOUT, self.timeout_function)
 
     @GObject.Signal
     def playback_paused(self):
@@ -162,4 +157,7 @@ class BassPlayer(GObject.GObject):
 
     @GObject.Signal
     def position_changed(self):
-        pass
+        remaining = self.duration - self.position
+        if remaining < 2 * Gst.SECOND:
+            if remaining + (TIMEOUT * Gst.MSECOND) >= 2 * Gst.SECOND:
+                self.emit("about-to-finish")

audio/test_bass.py

@@ -32,7 +32,7 @@ class TestBassPlayer(unittest.TestCase):
         self.assertEqual(base.playbin.get_property("video-sink"), base.video)
         self.assertEqual(base.playbin.get_state(Gst.CLOCK_TIME_NONE)[1],
                          Gst.State.READY)
-        self.assertIsNone(base.timeout, 0)
+        self.assertIsNone(base.timeout)
 
     def test_bass_player_bus(self):
         base = bass.BassPlayer()