audio: Add a custom SeekScale widget

For handling seeks to the audio player

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

audio/scale.py

@@ -1,5 +1,7 @@
 # Copyright 2021 (c) Anna Schumaker.
+from gi.repository import GLib
 from gi.repository import Gtk
+from gi.repository import Gst
 
 class ScalePlus(Gtk.Scale):
     def __init__(self, min, max, step, page):
@@ -32,3 +34,26 @@ class ScalePlus(Gtk.Scale):
 
     def format_value(self, scale, value):
         return str(value)
+
+
+class SeekScale(ScalePlus):
+    def __init__(self, player):
+        ScalePlus.__init__(self, 0, 0, 5 * Gst.SECOND, 30 * Gst.SECOND)
+        self.set_size_request(200, -1)
+        self.player = player
+        GLib.timeout_add(200, self.update)
+
+    def do_change_value(self, scroll, value):
+        self.player.seek(value)
+
+    def format_value(self, scale, value):
+        position = int(value / Gst.SECOND)
+        duration = int(self.get_adjustment().get_upper() / Gst.SECOND)
+        (p_m, p_s) = divmod(position, 60)
+        (r_m, r_s) = divmod(duration - position, 60)
+        return f"{p_m:02}:{p_s:02} / {r_m:02}:{r_s:02}"
+
+    def update(self):
+        self.set_range(0, self.player.duration())
+        self.set_value(self.player.position())
+        return GLib.SOURCE_CONTINUE

audio/test_scale.py

@@ -1,8 +1,21 @@
 # Copyright 2021 (c) Anna Schumaker.
 import unittest
+from gi.repository import GObject
 from gi.repository import Gtk
+from gi.repository import Gst
 from . import scale
 
+class FakePlayer(GObject.GObject):
+    def __init__(self, position, duration):
+        GObject.GObject.__init__(self)
+        self.pos = position
+        self.dur = duration
+
+    def position(self): return self.pos
+    def duration(self): return self.dur
+    def seek(self, value): self.seek_val = value
+
+
 class TestScalePlus(unittest.TestCase):
     def on_change_value(self, scale, scroll, value):
         self.change_value = (scroll, value)
@@ -50,3 +63,44 @@ class TestScalePlus(unittest.TestCase):
         self.change_value = None
         self.assertIsNone(splus.increment())
         self.assertIsNone(self.change_value)
+
+
+class TestSeekScale(unittest.TestCase):
+    def test_seek_scale_init(self):
+        fake = FakePlayer(0, 5 * Gst.SECOND)
+        seek = scale.SeekScale(fake)
+        adj  = seek.get_adjustment()
+
+        self.assertIsInstance(seek, scale.ScalePlus)
+
+        self.assertEqual(seek.get_size_request(), (200, -1))
+        self.assertEqual(seek.player, fake)
+        self.assertEqual(adj.get_value(), 0)
+        self.assertEqual(adj.get_lower(), 0)
+        self.assertEqual(adj.get_upper(), 0)
+        self.assertEqual(adj.get_step_increment(), 5 * Gst.SECOND)
+        self.assertEqual(adj.get_page_increment(), 30 * Gst.SECOND)
+
+    def test_seek_scale_update(self):
+        fake = FakePlayer(3 * Gst.SECOND, 15 * Gst.SECOND)
+        seek = scale.SeekScale(fake)
+        adj  = seek.get_adjustment()
+
+        seek.update()
+        self.assertEqual(seek.player, fake)
+        self.assertEqual(adj.get_value(), 3 * Gst.SECOND)
+        self.assertEqual(adj.get_lower(), 0)
+        self.assertEqual(adj.get_upper(), 15 * Gst.SECOND)
+
+    def test_seek_scale_values(self):
+        fake = FakePlayer(0, 15 * Gst.SECOND)
+        seek = scale.SeekScale(fake)
+
+        seek.update()
+        seek.increment()
+        self.assertEqual(fake.seek_val, 5 * Gst.SECOND)
+        self.assertEqual(seek.format_value(seek, 5 * Gst.SECOND),
+                                          "00:05 / 00:10")
+
+        seek.decrement()
+        self.assertEqual(fake.seek_val, 0)