iwd/test/wfd-source

#! /usr/bin/python3
#
# Copyright (C) 2020  Intel Corporation
#
# A simplified WFD source that streams the X11 screen using gstreamer
# A more complete solution would create a virtual screen visible through the normal system calls, xrandr, etc.,
# with its pixel aspect ratio, EDID data and what not.  This would allow the user to configure it like a real
# display in mirror mode or side-by-side mode.

import sys
import dbus
import dbus.mainloop.glib
import socket
import collections
import collections.abc
import random
import dataclasses
import traceback
import codecs
try:
    import netifaces
except:
    pass

import gi
gi.require_version('GLib', '2.0')
gi.require_version('Gst', '1.0')
gi.require_version('Gtk', '3.0')
from gi.repository import GLib, Gst, Gtk, Gdk, Pango, GObject

class WFDRTSPServer:
    class RTSPException(Exception):
        pass

    Prop = collections.namedtuple('Prop', ['name', 'desc', 'getter', 'setter', 'type', 'vals'])

    def __init__(self, port, state_handler, error_handler, init_values, prop_handler):
        # Should start the TCP server only on the P2P connection's local IP but we won't
        # know the IP or interface name until after the connection is established.  At that
        # time the sink may try to make the TCP connection at any time so our listen
        # socket should be up before this.
        server_address = ('0.0.0.0', port)
        self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
        self.server.bind(server_address)
        self.server.listen(1)
        GLib.io_add_watch(self.server, GLib.IO_IN, self.handle_connection)
        self.conn = None
        self.tx_queue = []
        self.rx_queue = b''

        self.state_handler = state_handler
        self.error_handler = error_handler
        self.prop_handler = prop_handler
        self.sm_init(init_values)

    def handle_data_out(self, conn, *args):
        try:
            cmd = self.tx_queue.pop(0)
            sent = self.conn.send(cmd)

            if sent < len(cmd):
                self.tx_queue.insert(0, cmd[sent:])

            return len(self.tx_queue) > 0
        except Exception as e:
            self.error_handler(e)
            return False

    def tx_queue_append(self, cmd):
        if not self.tx_queue:
            GLib.io_add_watch(self.conn.fileno(), GLib.IO_OUT, self.handle_data_out)

        self.tx_queue.append(cmd.encode('utf-8'))
        self.debug('queued cmd: ' + cmd)

    def handle_data_hup(self, conn, *args):
        try:
            self.debug('HUP')
            self.error('Disconnected')
        except Exception as e:
            self.error_handler(e)
            return False

    def handle_data_in(self, conn, *args):
        try:
            newdata = self.conn.recv(4096)
            if len(newdata) == 0:
                self.debug('recv returned 0 bytes')
                # Disconnect from P2P
                self.error('Disconnected')
                return False

            self.debug('received data: ' + str(newdata))
            self.rx_queue += newdata

            while b'\r\n\r\n' in self.rx_queue:
                msg, content = self.rx_queue.split(b'\r\n\r\n', 1)
                lines = msg.split(b'\r\n')

                headers = {}
                for line in lines[1:]:
                    if b':' not in line:
                        # Bad syntax
                        rxbuf = b''
                        return True

                    name, value = line.decode('utf8').split(':', 1)
                    name = name.lower()
                    while len(value) and value[0] == ' ':
                        value = value[1:]

                    if name in headers:
                        # Duplicate
                        rxbuf = b''
                        return True

                    headers[name] = value

                cl = 0
                if 'content-length' in headers:
                    try:
                        cl = int(headers['content-length'])
                        if cl < 1 or cl > 1000:
                            raise Exception('')
                    except:
                        # Bad syntax
                        rxbuf = b''
                        return True

                    if len(content) < cl:
                        # Wait for more data
                        return True

                top_line = lines[0].decode('utf8').split(None, 2)
                self.rx_queue = self.rx_queue[len(msg) + 4 + cl:]
                content = content[:cl]

                if top_line[2] == 'RTSP/1.0':
                    self.source_handle_message(method=top_line[0], target=top_line[1], headers=headers, content=content)
                elif top_line[0] == 'RTSP/1.0':
                    try:
                        status = int(top_line[1])
                        if status < 1 or status > 999:
                            raise Exception('Status out of range')
                    except:
                        self.error('Couldn\'t parse response status')

                    self.source_handle_message(status=status, reason=top_line[2], headers=headers, content=content)
                else:
                    # Bad protocol
                    self.error('Unknown protocol in ' + str(top_line))

            return True
        except Exception as e:
            self.error_handler(e)
            return False

    def handle_connection(self, sock, *args):
        try:
            if self.conn:
                return False
            self.conn, addr = sock.accept()
            self.debug('RTSP connection from: ' + str(addr))
            self.remote_ip = addr[0]

            if self.expected_remote_ip and self.remote_ip != self.expected_remote_ip:
                self.conn.close()
                self.conn = None
                self.debug('Connection refused, bad source address')
                return True

            sock.close()
            self.server = None
            GLib.io_add_watch(self.conn.fileno(), GLib.IO_IN, self.handle_data_in)
            GLib.io_add_watch(self.conn.fileno(), GLib.IO_HUP, self.handle_data_hup)

            self._state = 'init'
            self.source_handle_message()
            return False
        except Exception as e:
            self.error_handler(e)
            return False

    def error(self, msg):
        self.enter_state('failed')
        e = WFDRTSPServer.RTSPException('State ' + self._state + ': ' + msg)
        self.debug('error: ' + msg)
        raise e

    def warning(self, msg):
        self.debug('warning: ' + msg)
        print('Warning: ' + msg + '\n')

    def debug(self, msg):
        pass

    @property
    def state(self):
        return self._state

    def enter_state(self, new_state):
        self.debug('state change: ' + self._state + ' -> ' + new_state)
        self._state = new_state
        self.state_handler()

    @property
    def ready(self):
        return self._state in ['streaming', 'paused']

    @property
    def props(self):
        return self._props

    def sm_init(self, init_values):
        self._state = 'waiting-rtsp'
        self.local_params = {
            'wfd_video_formats': '00 00 01 08 00000000 00000000 00000040 00 0000 0000 00 none none'
        }
        self.remote_params = {}
        self.local_methods = [ 'org.wfa.wfd1.0', 'SET_PARAMETER', 'GET_PARAMETER', 'PLAY', 'SETUP', 'TEARDOWN' ]
        self.presentation_url = [ 'rtsp://127.0.0.1/wfd1.0/streamid=0', 'none' ] # Table 88
        self.alternative_urls = [ 'rtsp://localhost/wfd1.0/streamid=0' ]
        self.session_stream_url = None
        self.session_id = None
        self.session_timeout = 60
        self.local_cseq = 0
        self.remote_cseq = None
        self.last_method = None
        self.last_require = []
        self.last_params = []
        self.remote_rtp_port = None
        self.remote_rtcp_port = None
        self.local_rtp_port = None
        self.local_rtcp_port = None
        self.use_tcp = None
        self.rtp_pipeline = None
        self.rtsp_keepalive = None
        self.rtsp_keepalive_timeout = None
        self.expected_remote_ip = None
        self.remote_ip = None
        self.init_width = init_values['width']
        self.init_height = init_values['height']
        self.rtcp_enabled = init_values['rtcp_enabled']

        self._props = []

    @staticmethod
    def get_init_props():
        props = []
        values = {
            'width': 800,
            'height': 600,
            'rtcp_enabled': True
        }

        def set_val(key, val):
            values[key] = val
        props.append(WFDRTSPServer.Prop('Output width', 'Scale the video stream to this X resolution for sending',
            lambda: values['width'], lambda x: set_val('width', x), int, (640, 1920)))
        props.append(WFDRTSPServer.Prop('Output height', 'Scale the video stream to this Y resolution for sending',
            lambda: values['height'], lambda x: set_val('height', x), int, (480, 1080)))
        props.append(WFDRTSPServer.Prop('Enable RTCP', 'Use RTCP if the Sink requests it during setup',
            lambda: values['rtcp_enabled'], lambda x: set_val('rtcp_enabled', x), bool, None))
        # TODO: Enable Audio
        # TODO: Audio source

        return props, values

    def close(self):
        # Avoid passing self to io watches so that the refcount can ever reach 0 and
        # all this can be done in __del__
        if self.rtsp_keepalive:
            GLib.source_remove(self.rtsp_keepalive)
            self.rtsp_keepalive = None
        if self.rtsp_keepalive_timeout:
            GLib.source_remove(self.rtsp_keepalive_timeout)
            self.rtsp_keepalive_timeout = None
        if self.rtp_pipeline:
            self.rtp_pipeline.set_state(Gst.State.NULL)
            self.rtp_pipeline = None
        if self.server:
            self.server.close()
            self.server = None
        if self.conn:
            self.conn.close()
            self.conn = None

    def set_local_interface(self, new_value):
        try:
            local_ip = netifaces.ifaddresses(new_value)[netifaces.AF_INET][0]['addr']
            self.alternative_urls.append('rtsp://' + local_ip + '/wfd1.0/streamid=0')
        except:
            pass

    def set_remote_ip(self, new_value):
        self.expected_remote_ip = new_value

        if self.conn and self.remote_ip != self.expected_remote_ip:
            self.error_handler(WFDRTSPServer.RTSPException('Connection was from a wrong IP')) # TODO: do this in an idle cb

    def validate_msg(self, method, expected_method, status, reason, headers, target, content):
        if expected_method is None:
            # Expected a response, not a request
            if method is not None:
                self.error('Received a "' + method + '" request where a response was expected')
            if status < 200 or status > 299:
                self.error('Response status ' + str(status) + ' and reason: ' + reason)
            if status != 200:
                self.warning('Response status was ' + str(status) + ' ("' + reason + '") in state ' + self._state)

            try:
                if int(headers['cseq']) != self.local_cseq:
                    self.error('Response CSeq doesn\'t match')
            except:
                self.error('Missing or unparsable CSeq in a response')

            if self.last_method == 'OPTIONS':
                if 'public' not in headers:
                    self.error('Missing "Public" header in OPTIONS response')
                public = [ m.strip() for m in headers['public'].split(',') ]
                missing = [ m for m in self.last_require if m not in public ]
                if missing:
                    self.error('Missing required method(s) "' + '", "'.join(missing) + '" in OPTIONS response')

            if self.last_method == 'GET_PARAMETER':
                params = {}
                for line in content.split(b'\r\n'):
                    if b':' not in line:
                        continue
                    k, v = line.decode('utf8').split(':', 1)
                    if k.strip() in params:
                        self.error('Duplicate key "' + k + '" in GET_PARAMETER response')
                    params[k.strip()] = v.strip()
                missing = [ p for p in self.last_params if p not in params ]
                if missing: # Not an error
                    self.warning('Missing key(s) "' + '", "'.join(missing) + '" in GET_PARAMETER response')
                self.remote_params.update(params)

            return

        if method is None:
            self.error('Received an RTSP response where a ' + expected_method + ' was expected')

        if method != expected_method:
            self.error('Received a "' + method + '" request where a ' + expected_method + ' was expected')
        try:
            if self.remote_cseq is not None and int(headers['cseq']) <= self.remote_cseq:
                self.error('Unchanged CSeq in a new request')
            self.remote_cseq = int(headers['cseq'])
        except:
            self.error('Missing or unparsable CSeq in a new request')
        if method == 'OPTIONS' and 'require' not in headers:
            self.error('Missing "Require" header in OPTIONS request')
        elif method == 'SETUP' and 'transport' not in headers:
            self.error('Missing "Transport" header in SETUP request')
        elif method == 'SETUP' and (target not in self.presentation_url + self.alternative_urls or target == 'none'):
            self.error('Unknown target "' + target + '" in SETUP request')
        elif method == 'PLAY' and ('session' not in headers  or headers['session'] != self.session_id):
            self.error('Missing or invalid "Session" header in PLAY request')
        elif method == 'PLAY' and target != self.session_stream_url:
            self.error('Unknown target "' + target + '" in PLAY request')
        elif method == 'PAUSE' and 'session' not in headers:
            self.error('Missing "Session" header in PAUSE request')
        elif method == 'PAUSE' and target != self.session_stream_url:
            self.error('Unknown target "' + target + '" in PAUSE request')
        elif method == 'TEARDOWN' and 'session' not in headers:
            self.error('Missing "Session" header in TEARDOWN request')
        elif method == 'TEARDOWN' and target != self.session_stream_url:
            self.error('Unknown target "' + target + '" in TEARDOWN request')
        elif method == 'SET_PARAMETER':
            params = []
            names = []
            for line in content.split(b'\r\n'):
                param = (line.decode('utf8').strip(), None)
                if not param[0]:
                    continue
                if ':' in param[0]:
                    k, v = param[0].split(':', 1)
                    param = (k.strip(), v.strip())
                if param[0] in names:
                    self.error('Duplicate key "' + param[0] + '" in SET_PARAMETER response')

                names.append(param[0])
                params.append(param)
            self.last_params = params

    def request(self, method, target, require=[], params=[]):
        content = ''
        cmd = method + ' ' + target + ' RTSP/1.0\r\n'

        self.local_cseq += 1
        cmd += 'CSeq: ' + str(self.local_cseq) + '\r\n'

        if require:
            cmd += 'Require: ' + ', '.join(require) + '\r\n'

        if params:
            if isinstance(params, collections.abc.Mapping):
                content = ''.join([ k + ': ' + params[k] + '\r\n' for k in params ])
            else:
                content = ''.join([ k + '\r\n' for k in params ])
            content_type = 'text/parameters'

        if content:
            cmd += 'Content-Type: ' + content_type + '\r\n'
            cmd += 'Content-Length: ' + str(len(content)) + '\r\n'

        cmd += '\r\n'
        self.tx_queue_append(cmd + content)
        self.last_method = method
        self.last_require = require
        self.last_params = params

    def response(self, public=[], session=None, transport=None):
        cmd = 'RTSP/1.0 200 OK\r\n'

        cmd += 'CSeq: ' + str(self.remote_cseq) + '\r\n'

        if public:
            cmd += 'Public: ' + ', '.join(public) + '\r\n'
        if session is not None:
            cmd += 'Session: ' + session + '\r\n'
        if transport is not None:
            cmd += 'Transport: ' + transport + '\r\n'

        cmd += '\r\n'
        self.tx_queue_append(cmd)

    def parse_video_formats(self, value):
        # TODO
        pass

    def parse_client_rtp_ports(self, value):
        profile, rtp_p0_str, rtp_p1_str, mode = value.split()
        try:
            rtp_p0 = int(rtp_p0_str)
            rtp_p1 = int(rtp_p1_str)
        except:
            self.error('Can\'t parse rtp-port in wfd-client-rtp-ports: ' + value)
        if rtp_p0 < 1 or rtp_p0 > 65535:
            self.error('rtp-port0 not valid for Primary Sink: ' + rtp_p0_str)
        if rtp_p1 != 0: # Table 90
            self.error('rtp-port1 not valid for Primary Sink: ' + rtp_p1_str)
        if profile not in ['RTP/AVP/UDP;unicast', 'RTP/AVP/TCP;unicast']:
            self.error('Unknown RTP transport in wfd-client-rtp-ports: ' + profile)
        if mode != 'mode=play':
            self.error('Unknown mode in wfd-client-rtp-ports: ' + mode)
        self.remote_rtp_port = rtp_p0
        self.use_tcp = (profile == 'RTP/AVP/TCP;unicast')

    def parse_transport(self, value):
        params = value.split(';')
        if len(params) < 3:
            self.error('Can\'t split SETUP Transport header into profile and port numbers: ' + value)
        profile = ';'.join(params[0:2])
        if profile not in ['RTP/AVP/UDP;unicast', 'RTP/AVP/TCP;unicast']:
            self.error('Unknown RTP transport in SETUP Transport header: ' + profile)
        if self.use_tcp != (profile == 'RTP/AVP/TCP;unicast'):
            self.error('RTP transport in SETUP Transport header different from what we sent in M4: ' + profile)
        client_port_strs = [p for p in params[2:] if p.startswith('client_port=')]
        if len(client_port_strs) != 1:
            self.error('Can\'t find client-port in SETUP Transport header: ' + value)
        client_ports = client_port_strs[0].split('=', 1)[1].split('-')
        try:
            rtp_port = int(client_ports[0])
            if len(client_ports) > 1:
                rtcp_port = int(client_ports[1])
        except:
            self.error('Can\'t parse client-port in SETUP Transport header: ' + client_port_strs[0])
        if rtp_port != self.remote_rtp_port:
            self.error('client-port in SETUP Transport header doesn\'t match what we sent in M4: ' + str(rtp_port))
        if len(client_ports) > 1:
            if rtcp_port < 1 or rtcp_port > 65535 or rtcp_port == rtp_port: # Actually must be rtp_port + 1...
                self.error('Optional RTCP port not valid in SETUP Transport header: ' + str(rtcp_port))
            self.remote_rtcp_port = rtcp_port

        self._props.append(WFDRTSPServer.Prop('RTP transport', '', lambda: 'TCP' if self.use_tcp else 'UDP', None, str, None))
        self._props.append(WFDRTSPServer.Prop('Remote RTP port', '', lambda: self.remote_rtp_port, None, int, None))
        self._props.append(WFDRTSPServer.Prop('Remote RTCP port', '', lambda: self.remote_rtcp_port, None, int, None))

    def parse_display_edid(self):
        try:
            len_str, hex_str = self.remote_params['wfd_display_edid'].split(' ', 1)
            if len(len_str.strip()) != 4:
                raise Exception('edid-block-count length is not 4 hex digits')
            blocks = int(len_str, 16)
            edid = codecs.decode(hex_str.strip(), 'hex')
            if blocks < 1 or blocks > 256 or blocks * 128 != len(edid):
                raise Exception('edid-block-count value wrong')
        except:
            edid = None

        self._props.append(WFDRTSPServer.Prop('EDID info', 'Remote display\'s EDID data', lambda: edid, None, bytes, None))

    def create_running_props(self):
        src = self.rtp_pipeline.get_by_name('src')
        fps = self.rtp_pipeline.get_by_name('fps')
        enc = self.rtp_pipeline.get_by_name('videnc')
        res = self.rtp_pipeline.get_by_name('res')
        sink = self.rtp_pipeline.get_by_name('sink')
        self.pipeline_props = []

        srcpadcaps = src.srcpads[0].get_allowed_caps()
        width = srcpadcaps[0]['width']
        height = srcpadcaps[0]['height']
        props = []
        props.append(WFDRTSPServer.Prop('Local width', 'Local screen X resolution', lambda: width, None, int, None))
        props.append(WFDRTSPServer.Prop('Local height', 'Local screen Y resolution', lambda: height, None, int, None))

        def set_use_damage(val):
            src.props.use_damage = val
        props.append(WFDRTSPServer.Prop('Use XDamage', 'Try to use XDamage to reduce bandwidth usage',
            lambda: src.props.use_damage, set_use_damage, bool, None))

        src.props.endx = width
        src.props.endy = height
        def set_startx(val):
            src.set_property('startx', min(val, src.props.endx - 1))
        def set_starty(val):
            src.set_property('starty', min(val, src.props.endy - 1))
        def set_endx(val):
            src.set_property('endx', max(val, src.props.startx + 1))
        def set_endy(val):
            src.set_property('endy', max(val, src.props.starty + 1))
        props.append(WFDRTSPServer.Prop('Window min X', 'Skip this many pixels on the left side of the local screen',
            lambda: src.props.startx, set_startx, int, (0, width - 1)))
        props.append(WFDRTSPServer.Prop('Window min Y', 'Skip this many pixels on the top of the local screen',
            lambda: src.props.starty, set_starty, int, (0, height - 1)))
        props.append(WFDRTSPServer.Prop('Window max X', 'Send screen contents only up to this X coordinate',
            lambda: src.props.endx, set_endx, int, (1, width)))
        props.append(WFDRTSPServer.Prop('Window max Y', 'Send screen contents only up to this Y coordinate',
            lambda: src.props.endy, set_endy, int, (1, height)))

        def set_framerate(val):
            fps.props.caps[0]['framerate'] = Gst.Fraction(val)
        def set_width(val):
            res.props.caps[0]['width'] = val
        def set_height(val):
            res.props.caps[0]['height'] = val
        props.append(WFDRTSPServer.Prop('Framerate', 'Try to output this many frames per second',
            lambda: int(fps.props.caps[0]['framerate'].num), set_framerate, int, (1, 30)))
        props.append(WFDRTSPServer.Prop('Output width', 'Scale the video stream to this X resolution for sending',
            lambda: res.props.caps[0]['width'], set_width, int, (640, 1920)))
        props.append(WFDRTSPServer.Prop('Output height', 'Scale the video stream to this Y resolution for sending',
            lambda: res.props.caps[0]['height'], set_height, int, (480, 1080)))

        preset_values = ['veryslow', 'slower', 'slow', 'medium', 'fast', 'faster', 'veryfast', 'superfast', 'ultrafast', 'placebo']
        preset_map = {'veryslow': 9, 'slower': 8, 'slow': 7, 'medium': 6, 'fast': 5, 'faster': 4, 'veryfast': 3, 'superfast': 2, 'ultrafast': 1, 'placebo': 10}

        def set_speed_preset(val):
            enc.props.speed_preset = preset_map[val]
        props.append(WFDRTSPServer.Prop('H.264 speed preset', 'Speed/quality setting of the H.264 encoder to optimise bandwidth/latency',
            lambda: enc.props.speed_preset.value_nick, set_speed_preset, str, preset_values))

        def set_max_lateness(val):
            if val <= 0:
                sink.props.max_lateness = -1
            else:
                sink.props.max_lateness = val * 1000000 # milliseconds to nanoseconds
        props.append(WFDRTSPServer.Prop('Max lateness', 'Maximum number of milliseconds that a buffer can be late before it is dropped, or 0 for unlimited',
            lambda: 0 if sink.props.max_lateness == -1 else sink.props.max_lateness / 1000000, set_max_lateness, int, (-1, 3000)))

        return props

    def on_gst_message(self, bus, message):
        t = message.type
        if t == Gst.MessageType.EOS:
            self.error('Gstreamer end-of-stream')
        elif t == Gst.MessageType.STATE_CHANGED:
            old, new, pending = message.parse_state_changed()
            self.debug('Gstreamer state change for ' + message.src.name + ' from ' + str(old) + ' to ' + str(new) + ', pending=' + str(pending))
            if message.src == self.rtp_pipeline:
                self.prop_handler()
        elif t == Gst.MessageType.INFO:
            err, debug = message.parse_info()
            self.debug('Gstreamer info for ' + message.src.name + ': ' + str(err) + '\nDebug: ' + str(debug))
        elif t == Gst.MessageType.WARNING:
            err, debug = message.parse_warning()
            self.debug('Gstreamer warning for ' + message.src.name + ': ' + str(err) + '\nDebug: ' + str(debug))
        elif t == Gst.MessageType.ERROR:
            err, debug = message.parse_error()
            self.error('Gstreamer error for ' + message.src.name + ': ' + str(err) + '\nDebug: ' + str(debug))
        else:
            self.debug('Gstreamer message of type ' + str(t) + ' for ' + message.src.name + ': ' + str(message))
        return True

    def force_keyframe(self):
        enc = self.rtp_pipeline.get_by_name('videnc')
        sink = enc.get_static_pad('sink')
        timestamp = Gst.CLOCK_TIME_NONE # can/should we use sink.query_position?

        s = Gst.Structure('GstForceKeyUnit')
        s.set_value('timestamp', GObject.Value(GObject.TYPE_UINT64, timestamp))
        s.set_value('stream-time', GObject.Value(GObject.TYPE_UINT64, timestamp))
        s.set_value('all-headers', GObject.Value(GObject.TYPE_BOOLEAN, True))
        # TODO: can we also send this event directly to the element instead of the pad?
        sink.send_event(Gst.Event.new_custom(Gst.EventType.CUSTOM_DOWNSTREAM, s))

    def reset_stream(self):
        if self.rtp_pipeline.get_state(timeout=0)[1] == Gst.State.PLAYING:
            self.rtp_pipeline.set_state(Gst.State.PAUSED)
            self.rtp_pipeline.set_state(Gst.State.PLAYING)

    def rtsp_keepalive_timeout_cb(self):
        try:
            self.rtsp_keepalive_timeout = None
            self.error('Keep-alive response timed out')
        except Exception as e:
            self.error_handler(e)
            return False

    def rtsp_keepalive_cb(self):
        try:
            # Send M16
            # May need to start being careful with other requests that may be running...
            self.request('GET_PARAMETER', 'rtsp://localhost/wfd1.0')
            self.rtsp_keepalive_timeout = GLib.timeout_add_seconds(5, self.rtsp_keepalive_timeout_cb)
            return True
        except Exception as e:
            self.error_handler(e)
            return False

    def source_handle_message(self, method=None, target=None, status=None, reason=None, headers={}, content=None):
        # TODO: check the 6s timeouts as per Section 6.5
        # Source side M1-M8 simplified state machine
        if self._state == 'init':
            # Send M1
            self.request('OPTIONS', '*', require=['org.wfa.wfd1.0'])
            self.enter_state('M1')
        elif self._state == 'M1':
            # Validate M1 response
            self.validate_msg(method, None, status, reason, headers, None, content)
            methods = [ m.strip() for m in headers['public'].split(',') ]
            required = [ 'org.wfa.wfd1.0', 'SET_PARAMETER', 'GET_PARAMETER' ]
            missing = [ m for m in required if m not in methods ]
            if missing:
                self.error('Missing required method(s) "' + '", "'.join(missing) + '" in OPTIONS response')
            self.enter_state('M2')
        elif self._state == 'M2':
            # Validate M2
            self.validate_msg(method, 'OPTIONS', status, reason, headers, target, content)
            if target not in [ '*' ] + self.presentation_url:
                self.error('Unknown OPTIONS target "' + target + '"')
            required = [ m.strip() for m in headers['require'].split(',') ]
            missing = [ m for m in required if m not in self.local_methods ]
            if missing:
                self.error('Required methods in OPTIONS request that we don\'t support: ' + ','.join(missing))

            # Send M2 response
            self.response(public=self.local_methods)
            # Send M3
            params = ['wfd_audio_codecs', 'wfd_video_formats', 'wfd_client_rtp_ports', 'wfd_display_edid', 'wfd_uibc_capability']
            self.request('GET_PARAMETER', 'rtsp://localhost/wfd1.0', params=params)
            self.enter_state('M3')
        elif self._state == 'M3':
            # Validate M3 response
            self.validate_msg(method, None, status, reason, headers, None, content)
            if 'wfd_video_formats' not in self.remote_params or 'wfd_client_rtp_ports' not in self.remote_params:
                self.error('Required parameters missing from GET_PARAMETER response')
            self.parse_video_formats(self.remote_params['wfd_video_formats'])
            self.parse_client_rtp_ports(self.remote_params['wfd_client_rtp_ports'])
            self.parse_display_edid()
            self.prop_handler()
            # Send M4
            params = {
                'wfd_video_formats': self.local_params['wfd_video_formats'],
                'wfd_client_rtp_ports': self.remote_params['wfd_client_rtp_ports'],
                'wfd_presentation_URL': self.presentation_url[0] + ' ' + self.presentation_url[1],
                # TODO: include wfd_audio_codecs if audio present, make video optional, too
                # TODO: support wfd2_video_formats and wfd2_audio_codecs
            }
            self.request('SET_PARAMETER', 'rtsp://localhost/wfd1.0', params=params)
            self.enter_state('M4')
        elif self._state == 'M4':
            # Validate M4 response
            self.validate_msg(method, None, status, reason, headers, None, content)
            # Send M5
            self.request('SET_PARAMETER', 'rtsp://localhost/wfd1.0', params={'wfd_trigger_method': 'SETUP'})
            self.enter_state('M5')
        elif self._state == 'M5':
            # Validate M5 response
            self.validate_msg(method, None, status, reason, headers, None, content)
            self.enter_state('M6')
        elif self._state == 'M6':
            # Validate M6
            self.validate_msg(method, 'SETUP', status, reason, headers, target, content)
            self.parse_transport(headers['transport'])
            self.session_stream_url = target
            self.session_id = str(random.randint(a=1, b=999999))
            self.local_rtp_port = random.randint(a=20000, b=30000)
            if self.remote_rtcp_port is not None and self.rtcp_enabled:
                self.local_rtcp_port = self.local_rtp_port + 1
            profile ='RTP/AVP/TCP;unicast' if self.use_tcp else 'RTP/AVP/UDP;unicast'
            client_port = str(self.remote_rtp_port) + (('-' + str(self.remote_rtcp_port)) if self.remote_rtcp_port is not None else '')
            server_port = str(self.local_rtp_port) + (('-' + str(self.local_rtcp_port)) if self.local_rtcp_port is not None else '')
            transport = profile + ';client_port' + client_port + ';server_port=' + server_port
            # Section B.1
            pipeline = ('ximagesrc name=src use-damage=false do-timestamp=true ! capsfilter name=fps caps=video/x-raw,framerate=10/1' +
                ' ! videoscale method=0 ! capsfilter name=res caps=video/x-raw,width=' + str(self.init_width) + ',height=' + str(self.init_height) +
                ' ! videoconvert ! video/x-raw,format=I420 ! x264enc tune=zerolatency speed-preset=ultrafast name=videnc' +
                ' ! queue' + # TODO: add leaky=downstream
                ' ! mpegtsmux name=mux' +
                ' ! rtpmp2tpay pt=33 mtu=1472 ! .send_rtp_sink rtpsession name=session .send_rtp_src' +
                ' ! udpsink name=sink host=' + self.remote_ip + ' port=' + str(self.remote_rtp_port) + ' bind-port=' + str(self.local_rtp_port)) # TODO: bind-address
            if self.local_rtcp_port is not None:
                pipeline += ' session.send_rtcp_src ! udpsink name=rtcp_sink host=' + self.remote_ip + \
                    ' port=' + str(self.remote_rtcp_port) + ' bind-port=' + str(self.local_rtcp_port) # TODO: bind-address
            self._props.append(WFDRTSPServer.Prop('RTCP enabled', 'Whether we\'re currently sending RTCP data',
                lambda: self.local_rtcp_port is not None, None, bool, None))

            self.rtp_pipeline = Gst.parse_launch(pipeline)
            bus = self.rtp_pipeline.get_bus()
            bus.enable_sync_message_emission()
            bus.add_signal_watch()
            bus.connect('message', self.on_gst_message)

            self._props += self.create_running_props()
            self.prop_handler()

            # Send M6 response
            self.response(session=self.session_id + ';timeout=' + str(self.session_timeout), transport=transport)
            self.enter_state('M7')
        elif self._state in ['M7', 'paused']:
            # Validate M7
            self.validate_msg(method, 'PLAY', status, reason, headers, target, content)
            # Send M7 response
            self.response()
            self.rtp_pipeline.set_state(Gst.State.PLAYING)
            # Set up the keep-alive timer, interval must be less than timeout minus 5 seconds
            self.rtsp_keepalive = GLib.timeout_add_seconds(self.session_timeout - 10, self.rtsp_keepalive_cb)
            self.enter_state('streaming')
        elif self._state == 'streaming':
            if method is None:
                if self.rtsp_keepalive_timeout:
                    # The M16 response is not to be validated (Section 6.4.16)
                    GLib.source_remove(self.rtsp_keepalive_timeout)
                    self.rtsp_keepalive_timeout = None
                    return
                self.error('Received an RTSP response where a request was expected')
            if method == 'PAUSE':
                self.validate_msg(method, 'PAUSE', status, reason, headers, target, content)
                self.rtp_pipeline.set_state(Gst.State.PAUSED)
                self.enter_state('paused')
                self.response()
                return
            if method == 'SET_PARAMETER':
                self.validate_msg(method, 'SET_PARAMETER', status, reason, headers, target, content)
                for k, v in self.last_params:
                    if k == 'wfd_idr_request' and v is None:
                        self.force_keyframe()
                        self.response()
                    else:
                        self.error('Unknown request "' + k + '" with value ' + repr(v))
                return
            if method == 'TEARDOWN':
                # The spec suggests a more graceful teardown but we just close the connection
                self.error('Teardown requested')
            self.error('Unsupported method "' + method + '"')

WIPHY_IF = 'net.connman.iwd.Adapter'
DEVICE_IF = 'net.connman.iwd.p2p.Device'
PEER_IF = 'net.connman.iwd.p2p.Peer'
WSC_IF = 'net.connman.iwd.SimpleConfiguration'
WFD_IF = 'net.connman.iwd.p2p.Display'
SVC_MGR_IF = 'net.connman.iwd.p2p.ServiceManager'

class WFDSource(Gtk.Window):
    @dataclasses.dataclass
    class Device:
        props: dict
        dev_proxy: dbus.Interface
        props_proxy: dbus.Interface
        peers: dict
        sorted_peers: list
        widget: Gtk.Widget
        expanded: bool
        scan_request: bool
        selected_peer: object
        connecting_peer: object
        disconnecting_peer: object
        connected: list
        dbus_call: dbus.lowlevel.PendingCall

    @dataclasses.dataclass
    class Peer:
        peer_proxy: dbus.Interface
        wfd_proxy: dbus.Interface
        wsc_proxy: dbus.Interface
        widget: Gtk.Widget
        rtsp: WFDRTSPServer

    indent = '\xbb '

    def __init__(self):
        Gtk.Window.__init__(self, type=Gtk.WindowType.TOPLEVEL, title='WFD Source')
        self.set_decorated(True)
        self.set_resizable(False)
        self.connect('destroy', self.on_destroy, "WM destroy")
        self.set_size_request(900, 300)
        self.device_box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
        leftscroll = Gtk.ScrolledWindow(hscrollbar_policy=Gtk.PolicyType.NEVER)
        leftscroll.add(self.device_box)
        self.infopane = Gtk.FlowBox(orientation=Gtk.Orientation.VERTICAL)
        self.infopane.set_selection_mode(Gtk.SelectionMode.NONE)
        self.infopane.set_max_children_per_line(20)
        self.infopane.set_min_children_per_line(3)
        self.infopane.set_column_spacing(20)
        self.infopane.set_row_spacing(5)
        self.infopane.set_valign(Gtk.Align.START)
        self.infopane.set_halign(Gtk.Align.START)
        rightscroll = Gtk.ScrolledWindow(vscrollbar_policy=Gtk.PolicyType.NEVER)
        rightscroll.add(self.infopane)
        paned = Gtk.Paned(orientation=Gtk.Orientation.HORIZONTAL)
        paned.pack1(leftscroll, True, True)
        paned.pack2(rightscroll, False, False)
        paned.set_wide_handle(True)
        paned.props.position = 400
        paned.props.position_set = True
        self.add(paned)
        self.show_all()
        self.connect('notify::is-active', self.on_notify_is_active)

        self.rtsp_props = None
        self.rtsp_init_values = {}
        self.rtsp_port = 7236
        self.devices = None
        self.objects = {}
        self.populate_devices()
        self.dbus = dbus.SystemBus()
        self.dbus.watch_name_owner('net.connman.iwd', self.on_name_owner_change)
        self.on_name_owner_change('dummy' if self.dbus.name_has_owner('net.connman.iwd') else '')

    def on_name_owner_change(self, new_name):
        if not new_name:
            if self.devices is None:
                return True

            for dev_path in self.devices:
                device = self.devices[dev_path]
                if device.connecting_peer or device.disconnecting_peer:
                    device.dbus_call.cancel()

                for peer_path in device.peers:
                    peer = device.peers[peer_path]
                    if peer.rtsp:
                        peer.rtsp.close()

            self.devices = None
            self.objects = {}
            self.populate_devices()
            self.dbus.remove_signal_receiver(self.on_properties_changed)
            self.dbus.remove_signal_receiver(self.on_interfaces_added)
            self.dbus.remove_signal_receiver(self.on_interfaces_removed)
            return True

        if self.devices is not None:
            return True

        manager = dbus.Interface(self.dbus.get_object('net.connman.iwd', '/'), 'org.freedesktop.DBus.ObjectManager')

        self.dbus.add_signal_receiver(self.on_properties_changed,
            bus_name="net.connman.iwd",
            dbus_interface="org.freedesktop.DBus.Properties",
            signal_name="PropertiesChanged",
            path_keyword="path")
        self.dbus.add_signal_receiver(self.on_interfaces_added,
            bus_name="net.connman.iwd",
            dbus_interface="org.freedesktop.DBus.ObjectManager",
            signal_name="InterfacesAdded")
        self.dbus.add_signal_receiver(self.on_interfaces_removed,
            bus_name="net.connman.iwd",
            dbus_interface="org.freedesktop.DBus.ObjectManager",
            signal_name="InterfacesRemoved")

        self.objects = manager.GetManagedObjects()
        self.devices = {}

        for path in self.objects:
            if DEVICE_IF in self.objects[path]:
                self.add_dev(path)
        for path in self.objects:
            if PEER_IF in self.objects[path]:
                self.add_peer(path)

        self.populate_devices()

        svc_mgr = dbus.Interface(self.dbus.get_object('net.connman.iwd', '/net/connman/iwd'), SVC_MGR_IF)
        svc_mgr.RegisterDisplayService({
            'Source': True,
            'Port': dbus.UInt16(self.rtsp_port)
        })

        return True

    def add_dev(self, path):
        obj_proxy = self.dbus.get_object('net.connman.iwd', path)
        # Default to expanded for first device found
        expanded = len(self.devices) == 0
        self.devices[path] = WFDSource.Device(
            props=self.objects[path][DEVICE_IF],
            dev_proxy=dbus.Interface(obj_proxy, DEVICE_IF),
            props_proxy=dbus.Interface(obj_proxy, 'org.freedesktop.DBus.Properties'),
            peers={},
            sorted_peers=[],
            widget=None,
            expanded=expanded,
            scan_request=False,
            selected_peer=None,
            connecting_peer=None,
            disconnecting_peer=None,
            connected=[],
            dbus_call=None)

    def add_peer(self, path):
        dev_path = self.objects[path][PEER_IF]['Device']
        if dev_path not in self.devices or path in self.devices[dev_path].peers:
            return False

        self.devices[dev_path].peers[path] = WFDSource.Peer(
            peer_proxy=None,
            wfd_proxy=None,
            wsc_proxy=None,
            widget=None,
            rtsp=None)
        return True

    def on_properties_changed(self, interface, changed, invalidated, path):
        if path not in self.objects:
            self.objects[path] = {}
        if interface not in self.objects[path]:
            self.objects[path][interface] = {}

        self.objects[path][interface].update(changed)
        for prop in invalidated:
            if prop in self.objects[path][interface]:
                del self.objects[path][interface][prop]

        if path in self.devices:
            self.update_dev_props(path)
            if interface == DEVICE_IF and 'AvailableConnections' in changed:
                self.update_selected_peer(path)

        if PEER_IF in self.objects[path]:
            dev_path = self.objects[path][PEER_IF]['Device']
            if dev_path in self.devices:
                device = self.devices[dev_path]
                if path in device.peers:
                    peer = device.peers[path]
                    if interface == PEER_IF and 'Connected' in changed:
                        if changed['Connected'] and peer not in device.connected:
                            device.connected.append(peer)
                        elif not changed['Connected'] and peer in device.connected:
                            device.connected.remove(peer)
                        self.update_dev_props(dev_path)
                        self.update_peer_props(dev_path, path)
                        if peer != device.selected_peer:
                            self.update_selected_peer(dev_path)
                    if interface == PEER_IF and peer.rtsp:
                        if 'ConnectedInterface' in changed:
                            peer.rtsp.set_local_interface(changed['ConnectedInterface'])
                        if 'ConnectedIp' in changed:
                            peer.rtsp.set_remote_ip(changed['ConnectedIp'])

                self.update_peer_props(dev_path, path)

        return True

    def on_interfaces_added(self, path, interfaces):
        if path not in self.objects:
            self.objects[path] = {}
        self.objects[path].update(interfaces)

        if DEVICE_IF in interfaces:
            self.add_dev(path)
            # This should happen rarely enough that we can repopulate the whole list
            self.populate_devices()

        update_dev_props = False
        if PEER_IF in interfaces:
            update_dev_props = self.add_peer(path)

        if PEER_IF in self.objects[path]:
            dev_path = self.objects[path][PEER_IF]['Device']
            if dev_path in self.devices:
                if update_dev_props:
                    # Update device's peer count
                    self.update_dev_props(dev_path)
                self.update_peer_props(dev_path, path)

    def on_interfaces_removed(self, path, interfaces):
        if path not in self.objects:
            return

        dev_path = None
        if PEER_IF in interfaces or WFD_IF in interfaces or WSC_IF in interfaces:
            if PEER_IF in self.objects[path]:
                dev_path = self.objects[path][PEER_IF]['Device']

        for i in interfaces:
            if i in self.objects[path]:
                del self.objects[path][i]
        if len(self.objects[path]) == 0:
            del self.objects[path]

        if DEVICE_IF in interfaces and path in self.devices:
            device = self.devices[path]
            if device.connecting_peer or device.disconnecting_peer:
                device.dbus_call.cancel()
            # TODO: check if connected
            del self.devices[path]
            # This should happen rarely enough that we can repopulate the whole list
            self.populate_devices()

        if dev_path is not None and dev_path in self.devices:
            device = self.devices[dev_path]
            if path in device.peers:
                # Make sure the widget is removed
                self.update_peer_props(dev_path, path)
                if PEER_IF in interfaces:
                    del device.peers[path]
                    # Update device's peer count
                    self.update_dev_props(dev_path)

    def populate_devices(self):
        self.device_box.foreach(lambda x, y: self.device_box.remove(x), None)

        if self.devices is None:
            label = Gtk.Label(label="Not connected to IWD")
            self.device_box.pack_start(label, expand=True, fill=True, padding=0)
            self.device_box.show_all()
            return

        if len(self.devices) == 0:
            label = Gtk.Label(label="No P2P-capable adapters :-(")
            self.device_box.pack_start(label, expand=True, fill=True, padding=0)
            self.device_box.show_all()
            return

        for path in self.devices:
            label = Gtk.Label()
            label.set_halign(Gtk.Align.START)
            label.set_line_wrap(False)
            label.set_single_line_mode(False)
            label.set_ellipsize(Pango.EllipsizeMode.END)
            switch = Gtk.Switch()
            switch.connect('state-set', self.on_dev_enabled, path)
            switch.set_halign(Gtk.Align.END)
            switch.set_valign(Gtk.Align.START)
            box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)
            box.pack_start(label, expand=True, fill=True, padding=0)
            box.pack_end(switch, expand=False, fill=False, padding=0)
            peer_list = Gtk.ListBox() # can also use an IconView.. or make it switchable
            peer_list.set_size_request(150, 120)
            peer_list.set_selection_mode(Gtk.SelectionMode.SINGLE)
            peer_list.set_placeholder(Gtk.Label(label='No Wi-Fi Displays discovered yet...'))
            peer_list.connect('row-selected', self.on_peer_selected, path)
            frame = Gtk.Frame()
            frame.props.margin = 10
            frame.add(peer_list)
            expander = Gtk.Expander()
            expander.set_label_fill(True)
            expander.set_expanded(self.devices[path].expanded)
            expander.set_label_widget(box)
            expander.add(frame)
            expander.connect('notify::expanded', self.on_dev_expanded, path)
            expander.show_all()
            self.device_box.add(expander)
            self.devices[path].widget = expander
            self.update_dev_props(path)
            GLib.idle_add(self.expander_workaround, expander)

            for peer_path in self.devices[path].peers:
                self.update_peer_props(path, peer_path)

            # Basically implement Gtk.Expander's set_label_fill which for some reason
            # doesn't do anything.  Use size-allocate because configure-event doesn't work either...
            self.margin_left = None
            def on_exp_resize(widget, event):
                if self.margin_left is None:
                    self.margin_left = box.get_allocation().x
                posx, posy = expander.translate_coordinates(self, 0, 0)
                # Add posx to force the label widget (box) to be aligned to the left side of the
                # window even if GTK already decided to push the expander off the left side with a
                # negative allocation.x.  This way it won't push it any further left as the available
                # space shrinks.
                box.set_size_request(max(posx + expander.get_allocated_width() - self.margin_left - 1, 0), -1)
                return False
            expander.connect('size-allocate', on_exp_resize)

    def expander_workaround(self, widget):
        box = widget.get_label_widget()
        widget.set_label_widget(None)
        widget.set_label_widget(box)
        return False

    def update_dev_props(self, path):
        device = self.devices[path]
        if not device.props['Enabled']:
            state = 'disabled'
        elif device.disconnecting_peer is not None:
            state = 'disconnecting...'
        elif device.connecting_peer is not None:
            state = 'connecting...'
        elif len(device.connected) > 0:
            if all([not peer.rtsp or peer.rtsp.ready for peer in device.connected]):
                state = 'connected'
            else:
                state = 'negotiating...'
        elif device.scan_request:
            state = 'discovering... (' + str(len(device.peers)) + ')'
        else:
            state = 'idle'

        label, switch = device.widget.get_label_widget().get_children()
        dev_str = self.get_dev_string(path)
        name = str(device.props['Name'])
        label.set_markup(dev_str + '\n<small>' + ('Local name: ' + name + '\n' if dev_str != name else '') + 'State: ' + state + '</small>')
        switch.set_state(device.props['Enabled'])

    def update_peer_props(self, dev_path, path):
        device = self.devices[dev_path]
        peer = device.peers[path]
        props = self.objects[path] if path in self.objects else {}
        peer_list = device.widget.get_child().get_child()
        if peer.widget is None:
            if PEER_IF not in props or WFD_IF not in props or WSC_IF not in props:
                return
            if not props[WFD_IF]['Sink']:
                return

            name = str(props[PEER_IF]['Name'])
            device.sorted_peers.append(name)
            device.sorted_peers.sort()
            index = device.sorted_peers.index(name)

            obj_proxy = self.dbus.get_object('net.connman.iwd', path)
            peer.peer_proxy=dbus.Interface(obj_proxy, PEER_IF)
            peer.wfd_proxy=dbus.Interface(obj_proxy, WFD_IF)
            peer.wsc_proxy=dbus.Interface(obj_proxy, WSC_IF)
            label = Gtk.Label()
            label.set_halign(Gtk.Align.START)
            label.set_single_line_mode(True)
            label.set_ellipsize(Pango.EllipsizeMode.END)
            event_box = Gtk.EventBox()
            event_box.add(label)
            event_box.connect('button-press-event', self.on_peer_click, (dev_path, path))
            button = Gtk.Button()
            button.set_use_stock(True)
            button.connect('clicked', self.on_peer_button, (dev_path, path))
            box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)
            box.props.margin = 5;
            box.pack_start(event_box, expand=True, fill=True, padding=0)
            box.pack_end(button, expand=False, fill=False, padding=0)
            peer.widget = Gtk.ListBoxRow()
            peer.widget.add(box)
            peer_list.insert(peer.widget, index)
            peer.widget.show_all()
        elif (PEER_IF not in props or WFD_IF not in props or WSC_IF not in props or not props[WFD_IF]['Sink']) and peer.widget:
            tmp = peer.widget
            peer.widget = None
            del device.sorted_peers[tmp.get_index()]
            peer_list.remove(tmp)
            if peer == device.selected_peer:
                device.selected_peer = None
                self.update_info_pane(dev_path, None)
            if peer == device.connecting_peer:
                device.dbus_call.cancel()
                device.connecting_peer = None
                self.update_selected_peer(dev_path)
            if peer == device.disconnecting_peer:
                device.dbus_call.cancel()
                device.disconnecting_peer = None
                self.update_selected_peer(dev_path)
            if peer in device.connected:
                device.connected.remove(peer)
                self.update_selected_peer(dev_path)
            peer.peer_proxy = None
            peer.wfd_proxy = None
            peer.wsc_proxy = None
            if peer.rtsp:
                peer.rtsp.close()
                peer.rtsp = None
            return

        subcat = 'unknown type'
        if 'DeviceSubcategory' in props[PEER_IF]:
            subcat = props[PEER_IF]['DeviceSubcategory']

        weight = 'heavy' if peer in device.connected else 'normal'
        box = peer.widget.get_child()
        event_box, button = box.get_children()
        label, = event_box.get_children()
        label.set_markup('<span weight="' + weight + '">' + props[PEER_IF]['Name'] + '</span> <span foreground="grey" size="small">' + subcat + '</span>')

        if device.disconnecting_peer or (device.connecting_peer and peer != device.connecting_peer):
            # This peer's row should not have any buttons
            button.hide()
        elif peer == device.connecting_peer:
            button.set_label('Cancel')
            button.show()
        elif peer in device.connected:
            if not peer.rtsp or peer.rtsp.ready:
                button.set_label('Disconnect')
            else:
                button.set_label('Cancel')
            button.show()
        elif peer == device.selected_peer and device.props['AvailableConnections'] > 0:
            button.set_label('Connect')
            button.show()
        else:
            button.hide()

        if peer == device.selected_peer:
            self.update_info_pane(dev_path, path)

    def update_selected_peer(self, dev_path):
        device = self.devices[dev_path]
        if device.selected_peer:
            sel_path = self.get_peer_path(device, device.selected_peer)
            self.update_peer_props(dev_path, sel_path)

    def add_info(self, name, desc, valuewidget):
        namelabel = Gtk.Label(label=name + ':', xalign=0)
        box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)
        box.pack_start(namelabel, expand=False, fill=False, padding=3)
        if valuewidget:
            box.pack_end(valuewidget, expand=False, fill=False, padding=3)
        if desc:
            box.set_tooltip_text(desc)
        self.infopane.add(box)

    def add_info_str(self, name, value):
        vlabel = Gtk.Label(xalign=0)
        vlabel.set_markup('<span weight="bold">' + value + '</span>')
        self.add_info(name, None, vlabel)

    def add_info_prop(self, prop):
        val = prop.getter()
        if prop.setter is None:
            if val is None:
                return
            if prop.type == bool:
                vals = prop.vals if prop.vals is not None else ['no', 'yes']
                text = vals[val]
            elif prop.name == 'EDID info':
                text = WFDSource.edid_to_text(val)
                if isinstance(text, collections.abc.Sequence):
                    self.add_info(prop.name, prop.desc, None)
                    for name, val in text:
                        if val:
                            v = Gtk.Label(xalign=0)
                            v.set_markup('<span weight="bold">' + str(val) + '</span>')
                        else:
                            v = None
                        self.add_info(self.indent + name, prop.desc, v)
                    return
            else:
                text = str(val)
            v = Gtk.Label(xalign=0)
            v.set_markup('<span weight="bold">' + text + '</span>')
        elif val is None:
            return
        elif prop.type == bool:
            v = Gtk.Switch()
            v.set_active(val)
            v.connect('state-set', lambda switch, state: prop.setter(state))
        elif prop.type == int:
            v = Gtk.SpinButton.new_with_range(min=prop.vals[0], max=prop.vals[1], step=prop.vals[2] if len(prop.vals) > 2 else 1)
            v.set_value(val)
            v.connect('value-changed', lambda sb: prop.setter(int(sb.get_value())))
        elif prop.type == str:
            if prop.vals:
                v = Gtk.ComboBoxText()
                for option in prop.vals:
                    v.append(option, option)
                v.set_active_id(val)
                v.connect('changed', lambda entry: prop.setter(entry.get_active_text()))
            else:
                v = Gtk.Entry(text=val)
                v.connect('changed', lambda entry: prop.setter(entry.get_text()))
        self.add_info(prop.name, prop.desc, v)

    def update_info_pane(self, dev_path, path):
        self.infopane.foreach(lambda x, y: self.infopane.remove(x), None)

        if path is None:
            return

        device = self.devices[dev_path]
        peer = device.peers[path]

        if peer == device.connecting_peer:
            state = 'IWD connecting'
        elif peer == device.disconnecting_peer:
            state = 'disconnecting'
        elif peer in device.connected:
            if peer.rtsp is not None:
                if peer.rtsp.ready:
                    state = peer.rtsp.state
                else:
                    state = 'RTSP negotiation: ' + peer.rtsp.state
            else:
                state = 'connected'
        else:
            state = 'not connected'
        self.add_info_str('Connection state', state)

        subcat = 'unknown'
        if 'DeviceSubcategory' in self.objects[path][PEER_IF]:
            subcat = self.objects[path][PEER_IF]['DeviceSubcategory']
        self.add_info_str('Peer category', self.objects[path][PEER_IF]['DeviceCategory'])
        self.add_info_str('Peer subcategory', subcat)

        if WFD_IF in self.objects[path]:
            if self.objects[path][WFD_IF]['Source']:
                if self.objects[path][WFD_IF]['Sink']:
                    t = 'dual-role'
                else:
                    t = 'source'
            else:
                t = 'sink'
            self.add_info_str('Peer WFD type', t)

            if self.objects[path][WFD_IF]['Sink']:
                self.add_info_str('Peer audio support', 'yes' if self.objects[path][WFD_IF]['HasAudio'] else 'no')

            self.add_info_str('Peer UIBC support', 'yes' if self.objects[path][WFD_IF]['HasUIBC'] else 'no')

            self.add_info_str('Peer content protection', 'yes' if self.objects[path][WFD_IF]['HasContentProtection'] else 'no')

        if peer.rtsp is not None and peer.rtsp.ready:
            def force_keyframe(widget):
                peer.rtsp.force_keyframe()
                return True
            def reset_stream(widget):
                peer.rtsp.reset_stream()
                return True
            # The idea for these buttons is to make sure any parameter changes get fully applied
            button1 = Gtk.Button()
            button1.set_label('Force keyframe')
            button1.connect('clicked', force_keyframe)
            button2 = Gtk.Button()
            button2.set_label('Reset stream')
            button2.connect('clicked', reset_stream)
            box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)
            box.pack_start(button1, expand=False, fill=False, padding=3)
            box.pack_start(button2, expand=False, fill=False, padding=3)
            self.infopane.add(box)

        if self.rtsp_props is None:
            self.rtsp_props, self.rtsp_init_values = WFDRTSPServer.get_init_props()

        if peer.rtsp is not None:
            props = peer.rtsp.props
        else:
            props = self.rtsp_props

        for prop in props:
            self.add_info_prop(prop)

        self.infopane.show_all()

    # Direct method calls on dbus.Interface's don't return dbus.lowlevel.PendingCall objects so
    # we have to use bus.call_async to make cancellable async calls
    def async_call(self, proxy, method, signature='', *args, **kwargs):
        return self.dbus.call_async(proxy.bus_name, proxy.object_path, proxy.dbus_interface, method, signature, args, **kwargs)

    def connect_peer(self, dev_path, path):
        device = self.devices[dev_path]
        peer = device.peers[path]

        def on_reply():
            device.connected.append(peer)
            device.connecting_peer = None
            # Local interface and remote IP get set in the PropertiesChanged handler
            self.update_dev_props(dev_path)
            self.update_peer_props(dev_path, path)
            if peer != device.selected_peer:
                self.update_selected_peer(dev_path)

        def on_error(excp):
            device.connecting_peer = None
            if peer.rtsp:
                peer.rtsp.close()
                peer.rtsp = None
            self.update_dev_props(dev_path)
            self.update_peer_props(dev_path, path)
            if peer != device.selected_peer:
                self.update_selected_peer(dev_path)
            dialog = Gtk.MessageDialog(parent=self, message_type=Gtk.MessageType.ERROR, buttons=Gtk.ButtonsType.OK, text='Connection failed')
            dialog.format_secondary_text('Connection to ' + self.objects[path][PEER_IF]['Name'] + ' failed: ' + repr(excp))
            dialog.show()

            def on_ok(response, *args):
                dialog.destroy()

            dialog.connect('response', on_ok)

        def on_rtsp_state():
            self.update_dev_props(dev_path)
            self.update_peer_props(dev_path, path)
            if peer != device.selected_peer:
                self.update_selected_peer(dev_path)

        def on_rtsp_error(excp):
            self.disconnect_peer(dev_path, path)
            tb = ''
            try:
                tb = '\n\nDebug info: ' + traceback.format_exc()
            except:
                pass
            dialog = Gtk.MessageDialog(parent=self, message_type=Gtk.MessageType.ERROR, buttons=Gtk.ButtonsType.OK, text='Negotiation failed')
            dialog.format_secondary_text('RTSP error when talking to ' + self.objects[path][PEER_IF]['Name'] + ': ' + repr(excp) + tb)
            dialog.show()

            def on_ok(response, *args):
                dialog.destroy()

            dialog.connect('response', on_ok)

        def on_rtsp_props_changed():
            # Should also check if the infopane is currently showing a selected peer on another device...
            if peer == device.selected_peer:
                self.update_info_pane(dev_path, path)

        # Cannot use peer.wsc_proxy.PushButton()
        device.dbus_call = self.async_call(peer.wsc_proxy, 'PushButton', reply_handler=on_reply, error_handler=on_error, timeout=120)
        device.connecting_peer = peer
        # Create the RTSP server now so it's ready as soon as the P2P connection succeeds even if
        # we haven't received the DBus reply yet
        peer.rtsp = WFDRTSPServer(self.rtsp_port, on_rtsp_state, on_rtsp_error, self.rtsp_init_values, on_rtsp_props_changed)
        self.update_dev_props(dev_path)
        self.update_peer_props(dev_path, path)
        if peer != device.selected_peer:
            self.update_selected_peer(dev_path)

    def disconnect_peer(self, dev_path, path):
        device = self.devices[dev_path]
        peer = device.peers[path]

        def on_reply():
            device.disconnecting_peer = None
            self.update_dev_props(dev_path)
            self.update_peer_props(dev_path, path)
            if peer != device.selected_peer:
                self.update_selected_peer(dev_path)

        def on_error(excp):
            device.disconnecting_peer = None
            self.update_dev_props(dev_path)
            self.update_peer_props(dev_path, path)
            if peer != device.selected_peer:
                self.update_selected_peer(dev_path)

            if isinstance(excp, dbus.exceptions.DBusException) and excp.get_dbus_name() == 'net.connman.iwd.NotConnected':
                return

            dialog = Gtk.MessageDialog(parent=self, message_type=Gtk.MessageType.ERROR, buttons=Gtk.ButtonsType.OK, text='Disconnecting failed')
            dialog.format_secondary_text('Disconnecting from ' + self.objects[path][PEER_IF]['Name'] + ' failed: ' + repr(excp))
            dialog.show()

            def on_ok(response, *args):
                dialog.destroy()

            dialog.connect('response', on_ok)

        if peer == device.connecting_peer:
            device.dbus_call.cancel()
            device.connecting_peer = None

        if peer in device.connected:
            device.connected.remove(peer)

        if peer.rtsp:
            peer.rtsp.close()
            peer.rtsp = None

        device.dbus_call = self.async_call(peer.peer_proxy, 'Disconnect', reply_handler=on_reply, error_handler=on_error)
        device.disconnecting_peer = peer
        self.update_dev_props(dev_path)
        self.update_peer_props(dev_path, path)
        if peer != device.selected_peer:
            self.update_selected_peer(dev_path)

    def on_peer_click(self, widget, event, data):
        if event.button != 1 or event.type != Gdk.EventType._2BUTTON_PRESS:
            return False
        dev_path, path = data
        device = self.devices[dev_path]
        if device.disconnecting_peer:
            return True
        if device.connecting_peer or not device.props['AvailableConnections']:
            # Should we auto-disconnect from the connected peer? Show an "Are you sure?" dialog?
            return True
        self.connect_peer(dev_path, path)
        return True

    def on_peer_button(self, widget, data):
        dev_path, path = data
        action = widget.get_label()
        device = self.devices[dev_path]
        if device.disconnecting_peer:
            return True
        if action == 'Connect':
            self.connect_peer(dev_path, path)
        elif action in ['Disconnect', 'Cancel']:
            self.disconnect_peer(dev_path, path)
        return True

    def get_peer_path(self, device, peer):
        for path in device.peers:
            if device.peers[path] == device.selected_peer:
                return path
        return None

    def on_peer_selected(self, widget, row, dev_path):
        device = self.devices[dev_path]

        if device.selected_peer is not None:
            if device.selected_peer.widget == row:
                return True

            path = self.get_peer_path(device, device.selected_peer)
            device.selected_peer = None
            self.update_peer_props(dev_path, path)
            self.update_info_pane(dev_path, None)

        if row is None:
            return True

        for path in device.peers:
            if device.peers[path].widget == row:
                device.selected_peer = device.peers[path]
                self.update_peer_props(dev_path, path)
                return True

    def update_dev_scan_request(self, path):
        device = self.devices[path]
        should_request = device.expanded and self.is_active()
        if device.scan_request == should_request:
            return

        device.scan_request = should_request
        if device.scan_request:
            device.dev_proxy.RequestDiscovery()
        else:
            device.dev_proxy.ReleaseDiscovery()
        self.update_dev_props(path)

    def on_notify_is_active(self, window, value):
        if self.devices is None:
            return True

        for path in self.devices:
            self.update_dev_scan_request(path)
        return True

    def on_dev_enabled(self, switch, state, path):
        device = self.devices[path]
        if device.props['Enabled'] == state:
            return
        device.props_proxy.Set(DEVICE_IF, 'Enabled', state)
        return True

    def on_dev_expanded(self, expander, value, path):
        device = self.devices[path]
        device.expanded = expander.get_expanded()
        self.update_dev_scan_request(path)
        return True

    def get_dev_string(self, path):
        wiphy = self.objects[path][WIPHY_IF]
        if 'Model' in wiphy:
            return wiphy['Model']
        if 'Vendor' in wiphy:
            return wiphy['Vendor']
        return wiphy['Name']

    def on_destroy(self, widget, data):
        global mainloop
        if self.devices is not None:
            svc_mgr = dbus.Interface(self.dbus.get_object('net.connman.iwd', '/net/connman/iwd'), SVC_MGR_IF)
            svc_mgr.UnregisterDisplayService()
            self.on_name_owner_change('')
        mainloop.quit()
        return False

    @staticmethod
    def edid_to_text(edid):
        if edid is None:
            return 'unavailable'
        if len(edid) < 128:
            return 'invalid (too short)'
        if edid[0:8] != b'\0\xff\xff\xff\xff\xff\xff\0':
            return 'invalid (bad magic)'
        if sum(edid[0:128]) & 255 != 0:
            return 'invalid (bad checksum)'

        header = edid[0:20]
        manf_id = (header[8] << 8) + header[9]
        text = [('Header', '')]
        text.append((WFDSource.indent + 'Version', str(header[18]) + '.' + str(header[19])))
        text.append((WFDSource.indent + 'Manufacturer ID', chr(64 + ((manf_id >> 10) & 31)) + chr(64 + ((manf_id >> 5) & 31)) + chr(64 + ((manf_id >> 0) & 31))))
        text.append((WFDSource.indent + 'Product code', hex((header[11] << 8) + header[10])))
        text.append((WFDSource.indent + 'Serial', hex((header[15] << 24) +(header[14] << 16) +  (header[13] << 8) + header[12])))
        text.append((WFDSource.indent + 'Manufactured', str(1990 + header[17]) + ' week ' + str(header[16])))

        basic_params = edid[20:25]
        text.append(('Basic parameters', ''))
        if basic_params[0] & 0x80:
            intf_table = {
                2: 'HDMIa',
                3: 'HDMIb',
                4: 'MDDI',
                5: 'DisplayPort'
            }
            dt_table = {
                0: 'RGB 4:4:4',
                1: 'RGB 4:4:4 + YCrCb 4:4:4',
                2: 'RGB 4:4:4 + YCrCb 4:2:2',
                3: 'RGB 4:4:4 + YCrCb 4:4:4 + YCrCb 4:2:2'
            }
            bpp = (basic_params[0] >> 4) & 7
            intf = (basic_params[0] >> 0) & 7

            text.append((WFDSource.indent + 'Video input type', 'digital'))
            text.append((WFDSource.indent + 'Bit depth', 'undefined' if bpp in [0, 7] else str(4 + bpp * 2)))
            text.append((WFDSource.indent + 'Interface', 'undefined' if intf not in intf_table else intf_table[intf]))
        else:
            level_table = {
                0: '+0.7 / -0.3 V',
                1: '+0.714 / -0.286 V',
                2: '+1.0 / -0.4 V',
                3: '+0.7 / 0 V'
            }
            dt_table = {
                0: 'monochrome/grayscale',
                1: 'RGB color',
                2: 'non-RGB color',
                3: 'undefined'
            }
            text.append((WFDSource.indent + 'Video input type', 'analog'))
            text.append((WFDSource.indent + 'Video white/sync level', level_table[(basic_parmas[0] >> 5) & 3]))

        if basic_params[1] and basic_params[2]:
            text.append((WFDSource.indent + 'Screen width', str(basic_params[1]) + ' cm'))
            text.append((WFDSource.indent + 'Screen height', str(basic_params[2]) + ' cm'))
        elif basic_params[2] == 0:
            text.append((WFDSource.indent + 'Landscape aspect ratio', str((basic_params[1] + 99) * 0.01)))
        else:
            text.append((WFDSource.indent + 'Portrait aspect ratio', str(100.0 / (basic_params[2] + 99))))

        text.append((WFDSource.indent + 'Gamma', str((basic_params[3] + 100) * 0.01)))
        text.append((WFDSource.indent + 'DPMS Standby', 'supported' if (basic_params[4] >> 7) & 1 else 'unsupported'))
        text.append((WFDSource.indent + 'DPMS Suspend', 'supported' if (basic_params[4] >> 6) & 1 else 'unsupported'))
        text.append((WFDSource.indent + 'DPMS Active-off', 'supported' if (basic_params[4] >> 5) & 1 else 'unsupported'))
        text.append((WFDSource.indent + 'Color type', dt_table[(basic_params[4] >> 3) & 3]))
        text.append((WFDSource.indent + 'sRGB color space', 'yes' if (basic_params[4] >> 2) & 1 else 'no'))
        text.append((WFDSource.indent + 'Continuous timings', 'yes' if (basic_params[4] >> 0) & 1 else 'no'))

        # TODO: timing information and extensions
        return text

dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
Gst.init(None)
WFDSource()
mainloop = GLib.MainLoop()
mainloop.run()