emmental/audio/controls.py

# Copyright 2021 (c) Anna Schumaker.
from gi.repository import Gtk, Gst
from . import menu
from . import scale

class ControlButton(Gtk.Button):
    def __init__(self, player, icon):
        Gtk.Button.__init__(self)
        self.add_css_class("large-icons")
        self.set_icon_name(icon)
        self.player = player


class PreviousButton(ControlButton):
    def __init__(self, player):
        ControlButton.__init__(self, player, "media-skip-backward")

    def do_clicked(self):
        self.player.previous()


class NextButton(ControlButton):
    def __init__(self, player):
        ControlButton.__init__(self, player, "media-skip-forward")

    def do_clicked(self):
        self.player.next()


class PlayPauseButton(ControlButton):
    def __init__(self, player):
        ControlButton.__init__(self, player, "media-playback-start")
        self.player.connect("state-changed", self.on_state_changed)

    def do_clicked(self):
        self.player.playpause()

    def on_state_changed(self, player, old, new, pending):
        icon = "pause" if new == Gst.State.PLAYING else "start"
        self.set_icon_name(f"media-playback-{icon}")


class ControlScaleBox(scale.ScaleButtonBox):
    def __init__(self, scalectrl):
        icon = Gtk.Image()
        icon.add_css_class("large-icons")
        scalectrl.connect("value-changed", self.on_value_changed, icon)
        scale.ScaleButtonBox.__init__(self, scalectrl)
        self.on_value_changed(scalectrl, icon)
        self.prepend(icon)

    def on_value_changed(self, scale, icon):
        pass


class AutoPauseControlBox(ControlScaleBox):
    def __init__(self, apscale):
        ControlScaleBox.__init__(self, apscale)

    def on_value_changed(self, scale, icon):
        name = "start" if scale.get_value() == -1 else "pause"
        icon.set_from_icon_name(f"media-playback-{name}")


class VolumeControlBox(ControlScaleBox):
    def __init__(self, player):
        ControlScaleBox.__init__(self, scale.VolumeScale(player))

    def on_value_changed(self, scale, icon):
        value = scale.get_value()
        if   value == 0:   name = "muted"
        elif value <= 1/3: name = "low"
        elif value <= 2/3: name = "medium"
        else: name  = "high"
        icon.set_from_icon_name(f"audio-volume-{name}-symbolic")


class Controls(Gtk.Box):
    def __init__(self):
        Gtk.Box.__init__(self)
        self.add_css_class("large-icons")
        self.add_css_class("linked")

        self.previous = Gtk.Button.new_from_icon_name("media-skip-backward")
        self.append(self.previous)

        self.play = Gtk.Button.new_from_icon_name("media-playback-start")
        self.append(self.play)

        self.pause = Gtk.Button.new_from_icon_name("media-playback-pause")
        self.pause.hide()
        self.append(self.pause)

        self.next = Gtk.Button.new_from_icon_name("media-skip-forward")
        self.append(self.next)

        self.menu = menu.Button()
        self.append(self.menu)

        self.sizegroup = Gtk.SizeGroup()
        self.sizegroup.add_widget(self)

    def connect(self, name, func):
        if name == "volume-changed":
            self.menu.volume.connect("value-changed", func)
        else:
            button = self.__dict__.get(name)
            button.connect("clicked", func)

    def set_state(self, state):
        self.play.set_visible(state != Gst.State.PLAYING)
        self.pause.set_visible(state == Gst.State.PLAYING)