emmental/audio/scale.py

# 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):
        Gtk.Scale.__init__(self)
        self.set_range(min, max)
        self.set_increments(step, page)
        self.set_value(min)
        self.set_draw_value(True)
        self.set_hexpand(True)
        self.set_format_value_func(self.format_value)

    def __change_value__(self, n, scroll):
        value = self.get_value()
        self.set_value(value + n)
        new = self.get_value()
        if value == new:
            return None
        self.emit("change-value", scroll, new)
        return new

    def decrement(self):
        adjustment = self.get_adjustment()
        return self.__change_value__(-adjustment.get_step_increment(),
                                      Gtk.ScrollType.STEP_BACKWARD)

    def increment(self):
        adjustment = self.get_adjustment()
        return self.__change_value__(adjustment.get_step_increment(),
                                     Gtk.ScrollType.STEP_FORWARD)

    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