#!/usr/bin/python2

# hwmixvolume - ALSA hardware mixer volume control applet
# Copyright (c) 2009-2010 Clemens Ladisch
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

import gobject, gtk
from pyalsa import alsacard, alsahcontrol

INTF_PCM = alsahcontrol.interface_id['PCM']
INTF_MIXER = alsahcontrol.interface_id['MIXER']
TYPE_INTEGER = alsahcontrol.element_type['INTEGER']
EVENT_VALUE = alsahcontrol.event_mask['VALUE']
EVENT_INFO = alsahcontrol.event_mask['INFO']
EVENT_REMOVE = alsahcontrol.event_mask_remove

class Stream:
	def __init__(self, element, parent):
		self.element = element
		self.element.set_callback(self)
		self.parent = parent
		self.label = None
		self.scales = []
		self.adjustments = []
		self.callback(self.element, EVENT_INFO)

	def destroy(self):
		self.deactivate()

	def callback(self, e, mask):
		if mask == EVENT_REMOVE:
			self.deactivate()
		elif (mask & EVENT_INFO) != 0:
			info = alsahcontrol.Info(self.element)
			if info.is_inactive:
				self.deactivate()
			else:
				self.activate()
		elif (mask & EVENT_VALUE) != 0:
			self.update_scales_from_ctl()

	def activate(self):
		if self.label:
			return
		info = alsahcontrol.Info(self.element)
		value = alsahcontrol.Value(self.element)
		value.read()
		values = value.get_tuple(TYPE_INTEGER, info.count)
		self.label = gtk.Label(self.get_label(info))
		self.label.set_single_line_mode(True)
		self.parent.scales_vbox.pack_start(self.label, expand=False)
		for i in range(info.count):
			adj = gtk.Adjustment(value=values[i],
					lower=info.min, upper=info.max,
					step_incr=1,
					page_incr=(info.max-info.min+1)/8)
			adj.connect('value-changed', self.update_ctl_from_scale, i)
			scale = gtk.HScale(adj)
			scale.set_draw_value(False)
			self.parent.scales_vbox.pack_start(scale, expand=False)
			self.scales.append(scale)
			self.adjustments.append(adj)
		self.parent.scales_vbox.show_all()
		self.parent.update_msg_label()

	def deactivate(self):
		if not self.label:
			return
		self.label.destroy()
		for s in self.scales:
			s.destroy()
		self.label = None
		self.scales = []
		self.adjustments = []
		self.parent.update_msg_label()

	def update_scales_from_ctl(self):
		if not self.label:
			return
		count = len(self.adjustments)
		value = alsahcontrol.Value(self.element)
		value.read()
		values = value.get_tuple(TYPE_INTEGER, count)
		for i in range(count):
			self.adjustments[i].set_value(values[i])

	def update_ctl_from_scale(self, adj, index):
		scale_value = adj.get_value()
		value_to_set = int(round(adj.get_value()))
		count = len(self.adjustments)
		value = alsahcontrol.Value(self.element)
		if self.parent.lock_check.get_active():
			values = [value_to_set  for i in range(count)]
		else:
			value.read()
			values = value.get_array(TYPE_INTEGER, count)
			values[index] = value_to_set
		value.set_array(TYPE_INTEGER, values)
		value.write()
		if value_to_set != scale_value:
			adj.set_value(value_to_set)

	def get_label(self, info):
		pid = self.get_pid(info)
		if pid:
			cmdline = self.get_pid_cmdline(pid)
			if cmdline:
				return cmdline
			else:
				return "PID %d" % pid
		else:
			name = info.name
			if name[-7:] == " Volume":
				name = name[:-7]
			if name[-9:] == " Playback":
				name = name[:-9]
			return name

	def get_pid(self, info):
		card = self.parent.current_card
		device = info.device
		subdevice = info.subdevice
		if subdevice == 0:
			subdevice = info.index
		filename = "/proc/asound/card%d/pcm%dp/sub%d/status" % (card, device, subdevice)
		try:
			f = open(filename, "r")
		except IOError:
			return None
		try:
			for line in f.readlines():
				if line[:9] == "owner_pid":
					return int(line.split(':')[1].strip())
		finally:
			f.close()
		return None

	def get_pid_cmdline(self, pid):
		try:
			f = open("/proc/%d/cmdline" % pid, "r")
		except IOError:
			return None
		try:
			cmdline = f.read()
		finally:
			f.close()
		return cmdline.replace('\x00', ' ').strip()

class MixerWindow(gtk.Window):
	card_numbers = alsacard.card_list()
	current_card = -1
	hcontrol = None
	scales_vbox = None
	msg_label = None
	streams = []
	hctl_sources = []

	def __init__(self):
		gtk.Window.__init__(self)
		self.connect('destroy', lambda w: gtk.main_quit())
		self.set_title("Hardware Mixer Volumes")

		vbox = gtk.VBox()
		self.add(vbox)

		hbox = gtk.HBox()
		vbox.pack_start(hbox, expand=False)

		label = gtk.Label("_Sound Card: ")
		label.set_use_underline(True)
		hbox.pack_start(label, expand=False)

		combo = gtk.combo_box_new_text()
		for i in self.card_numbers:
			str = "%d: %s" % (i, alsacard.card_get_name(i))
			combo.append_text(str)
		if len(self.card_numbers) > 0:
			combo.set_active(0)
		combo.connect('changed', lambda c: self.change_card(self.card_numbers[combo.get_active()]))
		hbox.pack_start(combo)
		label.set_mnemonic_widget(combo)

		self.lock_check = gtk.CheckButton(label="_Lock Channels")
		self.lock_check.set_active(True)
		vbox.pack_start(self.lock_check, expand=False)

		scrollwin = gtk.ScrolledWindow()
		scrollwin.set_policy(hscrollbar_policy=gtk.POLICY_NEVER, vscrollbar_policy=gtk.POLICY_AUTOMATIC)
		scrollwin.set_shadow_type(gtk.SHADOW_NONE)
		vbox.pack_start(scrollwin)

		self.scales_vbox = gtk.VBox()
		scrollwin.add_with_viewport(self.scales_vbox)

		label = gtk.Label()
		label.set_single_line_mode(True)
		line_height = label.size_request()[1]
		label.destroy()
		scale = gtk.HScale()
		scale.set_draw_value(False)
		line_height += scale.size_request()[1]
		scale.destroy()
		# always have space for at least four sliders
		scrollwin.set_size_request(width=-1, height=line_height*4+4)

		# TODO: select the default card or the first card with stream controls
		if len(self.card_numbers) > 0:
			self.change_card(self.card_numbers[0])
		self.update_msg_label()

		self.show_all()

	def change_card(self, cardnum):
		for s in self.hctl_sources:
			gobject.source_remove(s)
		self.hctl_sources = []

		self.hcontrol = self.open_hcontrol_for_card(cardnum)

		for s in self.streams:
			s.destroy()
		self.streams = []

		self.current_card = cardnum

		if not self.hcontrol:
			self.update_msg_label()
			return

		for id in self.hcontrol.list():
			if not self.is_stream_elem(id):
				continue
			elem = alsahcontrol.Element(self.hcontrol, id[0])
			info = alsahcontrol.Info(elem)
			if not self.is_stream_info(info):
				continue
			stream = Stream(elem, self)
			self.streams.append(stream)

		for fd,condition in self.hcontrol.poll_fds:
			self.hctl_sources.append(gobject.io_add_watch(fd, condition, self.hctl_io_callback))

		self.update_msg_label()

		self.scales_vbox.show_all()

	def update_msg_label(self):
		needs_msg = len(self.scales_vbox.get_children()) < 2
		has_msg = self.msg_label
		if has_msg and not needs_msg:
			self.msg_label.destroy()
			self.msg_label = None
		elif needs_msg:
			if len(self.streams) > 0:
				msg = "There are no open streams."
			else:
				msg = "This card does not have stream controls."
			if not has_msg:
				self.msg_label = gtk.Label(msg)
				self.scales_vbox.pack_start(self.msg_label)
				self.scales_vbox.show_all()
			elif self.msg_label.get_text() != msg:
				self.msg_label.set_text(msg)

	def open_hcontrol_for_card(self, cardnum):
		devname = "hw:CARD=" + str(cardnum)
		try:
			hc = alsahcontrol.HControl(name=devname,
					mode=alsahcontrol.open_mode['NONBLOCK'])
		except:
			# TODO: alsa error msg
			dlg = gtk.MessageDialog(self,
					gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,
					gtk.MESSAGE_ERROR, gtk.BUTTONS_OK,
					"Cannot open sound card control device.")
			dlg.run()
			dlg.destroy()
			return None
		return hc

	def is_stream_elem(self, id):
		return ((id[1] == INTF_PCM and
			 id[4] in ("PCM Playback Volume", "EMU10K1 PCM Volume")) or
			(id[1] == INTF_MIXER and
			 id[4] == "VIA DXS Playback Volume"))

	def is_stream_info(self, info):
		return info.is_readable and info.is_writable and info.type == TYPE_INTEGER

	def hctl_io_callback(self, source, condition):
		self.hcontrol.handle_events()
		return True

def main():
	MixerWindow()
	gtk.main()

main()