audio: Give the AutoPauseScale a keep_playing property

And a function to find out if we are about to pause or not.

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

audio/scale.py

@@ -65,8 +65,12 @@ class SeekScale(ScalePlus):
 class AutoPauseScale(ScalePlus):
     def __init__(self):
         ScalePlus.__init__(self, -1, 99, 1, 5)
+        self.keep_playing = True
         self.set_digits(0)
 
+    def about_to_pause(self):
+        return self.get_value() == 0
+
     def format_value(self, scale, value):
         value = int(value)
         if   value == -1: return "Keep Playing"
@@ -74,6 +78,10 @@ class AutoPauseScale(ScalePlus):
         elif value ==  1: return "Next Track"
         return f"{value} Tracks"
 
+    def decrement(self):
+        self.keep_playing = not self.about_to_pause()
+        super().decrement()
+
 
 class VolumeScale(ScalePlus):
     def __init__(self, player):

audio/test_scale.py

@@ -145,6 +145,7 @@ class TestAutoPauseScale(unittest.TestCase):
         self.assertEqual(adj.get_upper(), 99)
         self.assertEqual(adj.get_step_increment(), 1)
         self.assertEqual(adj.get_page_increment(), 5)
+        self.assertTrue(pause.keep_playing)
 
     def test_autopause_scale_values(self):
         pause = scale.AutoPauseScale()
@@ -153,6 +154,30 @@ class TestAutoPauseScale(unittest.TestCase):
         self.assertEqual(pause.format_value(pause,  1), "Next Track")
         self.assertEqual(pause.format_value(pause,  2), "2 Tracks")
 
+    def test_keep_playing(self):
+        pause = scale.AutoPauseScale()
+        pause.set_value(2)
+
+        pause.decrement()
+        self.assertEqual(pause.get_value(), 1)
+        self.assertFalse(pause.about_to_pause())
+        self.assertTrue(pause.keep_playing)
+
+        pause.decrement()
+        self.assertEqual(pause.get_value(), 0)
+        self.assertTrue(pause.about_to_pause())
+        self.assertTrue(pause.keep_playing)
+
+        pause.decrement()
+        self.assertEqual(pause.get_value(), -1)
+        self.assertFalse(pause.about_to_pause())
+        self.assertFalse(pause.keep_playing)
+
+        pause.decrement()
+        self.assertEqual(pause.get_value(), -1)
+        self.assertFalse(pause.about_to_pause())
+        self.assertTrue(pause.keep_playing)
+
 
 class TestVolumeScale(unittest.TestCase):
     def test_volume_scale_init(self):