#!/usr/bin/env python
# -*- coding: UTF-8
'''
xgps -- test client for gpsd

usage: xgps [-D level] [-hV?] [-l degmfmt] [-u units] [-r rotation] [server[:port[:device]]]
'''

# This code runs compatibly under Python 2 and 3.x for x >= 2.
# Preserve this property!
from __future__ import absolute_import, print_function, division

gui_about = '''\
This is xgps, a test client for the gpsd daemon.

By Eric S. Raymond for the GPSD project, December 2009
'''
#
# This file is Copyright (c) 2010 by the GPSD project
# BSD terms apply: see the file COPYING in the distribution root for details.

import math
import socket
import sys
import time

from gi.repository import GObject
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from gi.repository import Gdk
import cairo

import gps
import gps.clienthelpers

# Use our own MAXCHANNELS value, due to the tradeoff between max sats and
# the window size.  Ideally, this should be dynamic.
MAXCHANNELS = 28

# how to sort the Satellite List
# some of ("PRN","el","az","ss","used") with optional '-' to reverse sort
# by default, used at the top, then sort PRN
SKY_VIEW_SORT_FIELDS = ('-used', 'PRN')


class unit_adjustments(object):
    "Encapsulate adjustments for unit systems."

    def __init__(self, units=None):
        self.altfactor = gps.METERS_TO_FEET
        self.altunits = "ft"
        self.speedfactor = gps.MPS_TO_MPH
        self.speedunits = "mph"
        if units is None:
            units = gps.clienthelpers.gpsd_units()
        if units in (gps.clienthelpers.unspecified, gps.clienthelpers.imperial, "imperial", "i"):
            pass
        elif units in (gps.clienthelpers.nautical, "nautical", "n"):
            self.altfactor = gps.METERS_TO_FEET
            self.altunits = "ft"
            self.speedfactor = gps.MPS_TO_KNOTS
            self.speedunits = "knots"
        elif units in (gps.clienthelpers.metric, "metric", "m"):
            self.altfactor = 1
            self.altunits = "m"
            self.speedfactor = gps.MPS_TO_KPH
            self.speedunits = "kph"
        else:
            raise ValueError  # Should never happen


def fit_to_grid(x, y, line_width):
    "Adjust coordinates to produce sharp lines."
    if line_width % 1.0 != 0:
        # Can't have sharp lines for non-integral line widths.
        return float(x), float(y)  # Be consistent about returning floats
    if line_width % 2 == 0:
        # Round to a pixel corner.
        return round(x), round(y)
    else:
        # Round to a pixel center.
        return int(x) + 0.5, int(y) + 0.5


def fit_circle_to_grid(x, y, radius, line_width):
    "Adjust circle coordinates and radius to produce sharp horizontal and vertical tangents."
    r = radius
    x1, y1 = fit_to_grid(x - r, y - r, line_width)
    x2, y2 = fit_to_grid(x + r, y + r, line_width)
    x, y = (x1 + x2) / 2, (y1 + y2) / 2
    r = (x2 - x1 + y2 - y1) / 4
    return x, y, r


class SkyView(Gtk.DrawingArea):
    "Satellite skyview, encapsulates pygtk's draw-on-expose behavior."
    # See <http://faq.pygtk.org/index.py?req=show&file=faq18.008.htp>
    HORIZON_PAD = 40    # How much whitespace to leave around horizon
    SAT_RADIUS = 5      # Diameter of satellite circle

    def __init__(self, rotate=0.0):
        GObject.GObject.__init__(self)
        self.set_size_request(400, 400)
        self.cr = None   # New cairo context for each expose event
        self.step_of_grid = 45  # default step of polar grid
        self.connect('size-allocate', self.on_size_allocate)
        self.connect('draw', self.on_draw)
        self.satellites = []
        self.center_x = self.center_y = self.radius = None
        self.rotate = rotate

    def on_size_allocate(self, _unused, allocation):
        width = allocation.width
        height = allocation.height
        x = width // 2
        y = height // 2
        r = (min(width, height) - SkyView.HORIZON_PAD) // 2
        x, y, r = fit_circle_to_grid(x, y, r, 1)
        self.center_x = x
        self.center_y = y
        self.radius = r

    def set_color(self, spec):
        "Set foreground color for drawing."
        gdkcolor = Gdk.color_parse(spec)
        r = gdkcolor.red / 65535.0
        g = gdkcolor.green / 65535.0
        b = gdkcolor.blue / 65535.0
        self.cr.set_source_rgb(r, g, b)

    def draw_circle(self, x, y, radius, filled=False):
        "Draw a circle centered on the specified midpoint."
        lw = self.cr.get_line_width()
        r = int(2 * radius + 0.5) // 2

        x, y, r = fit_circle_to_grid(x, y, radius, lw)

        self.cr.arc(x, y, r, 0, math.pi * 2.0)
        self.cr.close_path()

        if filled:
            self.cr.fill()
        else:
            self.cr.stroke()

    def draw_line(self, x1, y1, x2, y2):
        "Draw a line between specified points."
        lw = self.cr.get_line_width()
        x1, y1 = fit_to_grid(x1, y1, lw)
        x2, y2 = fit_to_grid(x2, y2, lw)

        self.cr.move_to(x1, y1)
        self.cr.line_to(x2, y2)

        self.cr.stroke()

    def draw_square(self, x, y, radius, filled=False):
        "Draw a square centered on the specified midpoint."
        lw = self.cr.get_line_width()
        x1, y1 = fit_to_grid(x - radius, y - radius, lw)
        x2, y2 = fit_to_grid(x + radius, y + radius, lw)

        self.cr.rectangle(x1, y1, x2 - x1, y2 - y1)

        if filled:
            self.cr.fill()
        else:
            self.cr.stroke()

    def draw_string(self, x, y, text, centered=True):
        "Draw a text on the skyview."
        self.cr.select_font_face("Sans", cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
        self.cr.set_font_size(10)

        if centered:
            extents = self.cr.text_extents(text)
            # width / 2 + x_bearing
            x -= extents[2] / 2 + extents[0]
            # height / 2 + y_bearing
            y -= extents[3] / 2 + extents[1]

        self.cr.move_to(x, y)
        self.cr.show_text(text)
        self.cr.new_path()

    def pol2cart(self, az, el):
        "Polar to Cartesian coordinates within the horizon circle."
        az = (az - self.rotate) % 360.0
        az *= (math.pi / 180)  # Degrees to radians
        # Exact spherical projection would be like this:
        # el = sin((90.0 - el) * DEG_2_RAD);
        el = ((90.0 - el) / 90.0)
        xout = self.center_x + math.sin(az) * el * self.radius
        yout = self.center_y - math.cos(az) * el * self.radius
        return (xout, yout)

    def on_draw(self, widget, _unused):
        self.cr = widget.get_window().cairo_create()

        self.cr.set_line_width(1)

        self.cr.set_source_rgb(0, 0, 0)
        self.cr.paint()

        self.cr.set_source_rgb(1, 1, 1)
        # The zenith marker
        self.draw_circle(self.center_x, self.center_y, 6, filled=False)

        # The horizon circle
        if self.step_of_grid == 45:
            # The circle corresponding to 45 degrees elevation.
            # There are two ways we could plot this.  Projecting the sphere
            # on the display plane, the circle would have a diameter of
            # sin(45) ~ 0.7.  But the naive linear mapping, just splitting
            # the horizon diameter in half, seems to work better visually.
            self.draw_circle(self.center_x, self.center_y, self.radius / 2, filled=False)
        elif self.step_of_grid == 30:
            self.draw_circle(self.center_x, self.center_y, self.radius * 2 / 3, filled=False)
            self.draw_circle(self.center_x, self.center_y, self.radius / 3, filled=False)
        self.draw_circle(self.center_x, self.center_y, self.radius, filled=False)

        (x1, y1) = self.pol2cart(0, 0)
        (x2, y2) = self.pol2cart(180, 0)
        self.draw_line(x1, y1, x2, y2)

        (x1, y1) = self.pol2cart(90, 0)
        (x2, y2) = self.pol2cart(270, 0)
        self.draw_line(x1, y1, x2, y2)

        # The compass-point letters
        (x, y) = self.pol2cart(0, -5)
        self.draw_string(x, y, "N")
        (x, y) = self.pol2cart(90, -5)
        self.draw_string(x, y, "E")
        (x, y) = self.pol2cart(180, -5)
        self.draw_string(x, y, "S")
        (x, y) = self.pol2cart(270, -5)
        self.draw_string(x, y, "W")

        # The satellites
        self.cr.set_line_width(2)
        for sat in self.satellites:
            if sat.az == 0 and sat.el == 0:
                continue  # Skip satellites with unknown position
            (x, y) = self.pol2cart(sat.az, sat.el)
            if sat.ss < 10:
                self.set_color("Gray")
            elif sat.ss < 30:
                self.set_color("Red")
            elif sat.ss < 35:
                self.set_color("Yellow")
            elif sat.ss < 40:
                self.set_color("Green3")
            else:
                self.set_color("Green1")
            if gps.is_sbas(sat.PRN):
                self.draw_square(x, y, SkyView.SAT_RADIUS, sat.used)
            else:
                self.draw_circle(x, y, SkyView.SAT_RADIUS, sat.used)

            self.cr.set_source_rgb(1, 1, 1)
            self.draw_string(x + SkyView.SAT_RADIUS, y + (SkyView.SAT_RADIUS * 2), str(sat.PRN), centered=False)

        self.cr = None

    def redraw(self, satellites):
        "Redraw the skyview."
        self.satellites = satellites
        self.queue_draw()


class NoiseView(object):
    "Encapsulate view object for watching noise statistics."
    COLUMNS = 2
    ROWS = 4
    noisefields = (
        # First column
        ("Time", "time"),
        ("Latitude", "lat"),
        ("Longitude", "lon"),
        ("Altitude", "alt"),
        # Second column
        ("RMS", "rms"),
        ("Major", "major"),
        ("Minor", "minor"),
        ("Orient", "orient"),
    )

    def __init__(self):
        self.widget = Gtk.Table(NoiseView.COLUMNS, NoiseView.ROWS, False)
        self.noisewidgets = []
        for i in range(len(NoiseView.noisefields)):
            colbase = (i // NoiseView.ROWS) * 2
            label = Gtk.Label(label=NoiseView.noisefields[i][0] + ": ")
            # Wacky way to force right alignment
            label.set_alignment(xalign=1, yalign=0.5)
            self.widget.attach(
                label, colbase, colbase + 1,
                i % NoiseView.ROWS, i % NoiseView.ROWS + 1)
            entry = Gtk.Entry()
            # The right size for the ISO8601 timestamp
            entry.set_width_chars(20)
            entry.set_text("n/a")
            self.widget.attach(
                entry, colbase + 1, colbase + 2,
                i % NoiseView.ROWS, i % NoiseView.ROWS + 1)
            self.noisewidgets.append((NoiseView.noisefields[i][1], entry))

    def update(self, noise):
        "Update the GPGST data fields."
        for (attrname, widget) in self.noisewidgets:
            if hasattr(noise, attrname):
                widget.set_text(str(getattr(noise, attrname)))
            else:
                widget.set_text("n/a")


class MaidenheadView(object):
    "Encapsulate view object for watching Maidenhead grid location."

    def __init__(self):
        self.widget = Gtk.Entry()
        self.widget.set_editable(False)

    def update(self, tpv):
        if tpv.mode >= gps.MODE_2D and hasattr(tpv, "lat") and hasattr(tpv, "lon"):
            self.widget.set_text(gps.clienthelpers.maidenhead(tpv.lat, tpv.lon))
        else:
            return self.widget.set_text("n/a")


class AISView(object):
    "Encapsulate store and view objects for watching AIS data."
    AIS_ENTRIES = 10
    DWELLTIME = 360

    def __init__(self, deg_type):
        "Initialize the store and view."
        self.deg_type = deg_type
        self.name_to_mmsi = {}
        self.named = {}
        self.store = Gtk.ListStore(str, str, str, str, str, str)
        self.widget = Gtk.ScrolledWindow()
        self.widget.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
        self.view = Gtk.TreeView(model=self.store)
        self.widget.set_size_request(-1, 300)
        self.widget.add_with_viewport(self.view)

        for (i, label) in enumerate(('#', 'Name:', 'Callsign:', 'Destination:', "Lat/Lon:", "Information")):
            column = Gtk.TreeViewColumn(label)
            renderer = Gtk.CellRendererText()
            column.pack_start(renderer, expand=True)
            column.add_attribute(renderer, 'text', i)
            self.view.append_column(column)

    def enter(self, ais, name):
        "Add a named object (ship or station) to the store."
        if ais.mmsi in self.named:
            return False
        else:
            ais.entry_time = time.time()
            self.named[ais.mmsi] = ais
            self.name_to_mmsi[name] = ais.mmsi
            # Garbage-collect old entries
            try:
                for i in range(len(self.store)):
                    here = self.store.get_iter(i)
                    name = self.store.get_value(here, 1)
                    mmsi = self.name_to_mmsi[name]
                    if self.named[mmsi].entry_time < time.time() - AISView.DWELLTIME:
                        del self.named[mmsi]
                        if name in self.name_to_mmsi:
                            del self.name_to_mmsi[name]
                        self.store.remove(here)
            except (ValueError, KeyError):  # Invalid TreeIters throw these
                pass
            return True

    def latlon(self, lat, lon):
        "Latitude/longitude display in nice format."
        if lat < 0:
            latsuff = "S"
        elif lat > 0:
            latsuff = "N"
        else:
            latsuff = ""
        lat = abs(lat)
        lat = gps.clienthelpers.deg_to_str(self.deg_type, lat)
        if lon < 0:
            lonsuff = "W"
        elif lon > 0:
            lonsuff = "E"
        else:
            lonsuff = ""
        lon = abs(lon)
        lon = gps.clienthelpers.deg_to_str(gps.clienthelpers.deg_ddmmss, lon)
        return lat + latsuff + "/" + lon + lonsuff

    def update(self, ais):
        "Update the AIS data fields."
        if ais.type in (1, 2, 3, 18):
            if ais.mmsi in self.named:
                for i in range(len(self.store)):
                    here = self.store.get_iter(i)
                    name = self.store.get_value(here, 1)
                    if name in self.name_to_mmsi:
                        mmsi = self.name_to_mmsi[name]
                        if mmsi == ais.mmsi:
                            latlon = self.latlon(ais.lat, ais.lon)
                            self.store.set_value(here, 4, latlon)
        elif ais.type == 4:
            if self.enter(ais, ais.mmsi):
                where = self.latlon(ais.lat, ais.lon)
                self.store.prepend(
                    (ais.type, ais.mmsi, "(shore)", ais.timestamp, where, ais.epfd_text))
        elif ais.type == 5:
            if self.enter(ais, ais.shipname):
                self.store.prepend(
                    (ais.type, ais.shipname, ais.callsign, ais.destination, "", ais.shiptype))
        elif ais.type == 12:
            sender = ais.mmsi
            if sender in self.named:
                sender = self.named[sender].shipname
            recipient = ais.dest_mmsi
            if recipient in self.named and hasattr(self.named[recipient], "shipname"):
                recipient = self.named[recipient].shipname
            self.store.prepend(
                (ais.type, sender, "", recipient, "", ais.text))
        elif ais.type == 14:
            sender = ais.mmsi
            if sender in self.named:
                sender = self.named[sender].shipname
            self.store.prepend(
                (ais.type, sender, "", "(broadcast)", "", ais.text))
        elif ais.type in (19, 24):
            if self.enter(ais, ais.shipname):
                self.store.prepend(
                    (ais.type, ais.shipname, "(class B)", "", "", ais.shiptype_text))
        elif ais.type == 21:
            if self.enter(ais, ais.name):
                where = self.latlon(ais.lat, ais.lon)
                self.store.prepend(
                    (ais.type, ais.name, "(%s navaid)" % ais.epfd_text, "", where, ais.aid_type_text))


class Base(object):
    COLUMNS = 3
    ROWS = 7
    gpsfields = (
        # First column
        ("Time", lambda s, r: s.update_time(r)),
        ("Latitude", lambda s, r: s.update_latitude(r)),
        ("Longitude", lambda s, r: s.update_longitude(r)),
        ("Altitude", lambda s, r: s.update_altitude(r)),
        ("Speed", lambda s, r: s.update_speed(r)),
        ("Climb", lambda s, r: s.update_climb(r)),
        ("Track", lambda s, r: s.update_track(r)),
        # Second column
        ("Status", lambda s, r: s.update_status(r)),
        ("EPX", lambda s, r: s.update_err(r, "epx")),
        ("EPY", lambda s, r: s.update_err(r, "epy")),
        ("EPV", lambda s, r: s.update_err(r, "epv")),
        ("EPS", lambda s, r: s.update_err_speed(r, "eps")),
        ("EPC", lambda s, r: s.update_err_speed(r, "epc")),
        ("EPD", lambda s, r: s.update_err_degrees(r, "epd")),
    )

    def __init__(self, deg_type, rotate=0.0, target=[]):
        self.deg_type = deg_type
        self.rotate = rotate
        self.conversions = unit_adjustments()
        self.saved_mode = -1
        self.ais_latch = False
        self.noise_latch = False

        self.window = Gtk.Window(Gtk.WindowType.TOPLEVEL)
        if not self.window.get_display():
            raise Exception("Can't open display")
        self.window.set_title(" ".join(["xgps"] + target))
        self.window.connect("delete_event", self.delete_event)
        self.window.set_resizable(False)

        vbox = Gtk.VBox(False, 0)
        self.window.add(vbox)

        self.window.connect("destroy", lambda _unused: Gtk.main_quit())

        self.uimanager = Gtk.UIManager()
        self.accelgroup = self.uimanager.get_accel_group()
        self.window.add_accel_group(self.accelgroup)
        self.actiongroup = Gtk.ActionGroup('xgps')
        self.actiongroup.add_actions(
            [('Quit', Gtk.STOCK_QUIT, '_Quit', None,
              'Quit the Program', lambda _unused: Gtk.main_quit()),
             ('File', None, '_File'),
             ('View', None, '_View'),
             ('Units', None, '_Units'),
             ('Step of grid', None, '_Step of grid')])
        self.actiongroup.add_toggle_actions(
            [('Skyview', None, '_Skyview', '<Control>s',
              'Enable Skyview', self.view_toggle),
             ('Responses', None, '_Responses', '<Control>r',
              'Enable Response Reports', self.view_toggle),
             ('GPS', None, '_GPS Data', '<Control>g',
              'Enable GPS Data', self.view_toggle),
             ('Noise', None, '_Noise Statistics', '<Control>n',
              'Enable Noise Statistics', self.view_toggle),
             ('Maidenhead', None, '_Maidenhead', '<Control>m',
              'Enable Maidenhead locator', self.view_toggle),
             ('AIS', None, '_AIS Data', '<Control>a',
              'Enable AIS Data', self.view_toggle),
             ])
        self.actiongroup.add_radio_actions(
            [('Imperial', None, '_Imperial', '<Control>i',
              'Imperial units', 0),
             ('Nautical', None, '_Nautical', '<Control>n',
              'Nautical units', 1),
             ('Metric', None, '_Metric', '<Control>m',
              'Metric Units', 2),
             ], 0, lambda a, _unused: self.set_units(['i', 'n', 'm'][a.get_current_value()]))
        self.actiongroup.add_radio_actions(
            [('30deg', None, '30°', None, '30°', 30),
             ('45deg', None, '45°', None, '45°', 45),
             ('Off', None, 'Off', None, 'Off', 0),
             ], 45, lambda a, _unused: self.set_step_of_grid(a.get_current_value()))
        self.uimanager.insert_action_group(self.actiongroup, 0)
        self.uimanager.add_ui_from_string('''
<ui>
    <menubar name="MenuBar">
      <menu action="File">
        <menuitem action="Quit"/>
      </menu>
      <menu action="View">
        <menuitem action="Skyview"/>
        <menuitem action="Responses"/>
        <menuitem action="GPS"/>
        <menuitem action="Noise"/>
        <menuitem action="Maidenhead"/>
        <menuitem action="AIS"/>
      </menu>
      <menu action="Units">
        <menuitem action="Imperial"/>
        <menuitem action="Nautical"/>
        <menuitem action="Metric"/>
      </menu>
      <menu action="Step of grid">
        <menuitem action="30deg"/>
        <menuitem action="45deg"/>
        <menuitem action="Off"/>
      </menu>
    </menubar>
</ui>
''')
        self.uimanager.get_widget('/MenuBar/View/Skyview').set_active(True)
        self.uimanager.get_widget('/MenuBar/View/Responses').set_active(True)
        self.uimanager.get_widget('/MenuBar/View/GPS').set_active(True)
        self.uimanager.get_widget('/MenuBar/View/Noise').set_active(True)
        self.uimanager.get_widget('/MenuBar/View/Maidenhead').set_active(True)
        self.uimanager.get_widget('/MenuBar/View/AIS').set_active(True)
        menubar = self.uimanager.get_widget('/MenuBar')
        vbox.pack_start(menubar, expand=False, fill=True, padding=0)

        self.satbox = Gtk.HBox(False, 0)
        vbox.add(self.satbox)

        skyframe = Gtk.Frame(label="Satellite List")
        self.satbox.add(skyframe)

        self.satlist = Gtk.ListStore(str, str, str, str, str)
        view = Gtk.TreeView(model=self.satlist)

        for (i, label) in enumerate(('PRN:', 'Elev:', 'Azim:', 'SNR:', 'Used:')):
            column = Gtk.TreeViewColumn(label)
            renderer = Gtk.CellRendererText()
            column.pack_start(renderer, expand=True)
            column.add_attribute(renderer, 'text', i)
            view.append_column(column)

        self.row_iters = []
        for i in range(MAXCHANNELS):
            self.satlist.append(["", "", "", "", ""])
            self.row_iters.append(self.satlist.get_iter(i))

        skyframe.add(view)

        viewframe = Gtk.Frame(label="Skyview")
        self.satbox.add(viewframe)
        self.skyview = SkyView(self.rotate)
        viewframe.add(self.skyview)

        self.rawdisplay = Gtk.Entry()
        self.rawdisplay.set_editable(False)
        vbox.add(self.rawdisplay)

        self.dataframe = Gtk.Frame(label="GPS data")
        datatable = Gtk.Table(Base.COLUMNS, Base.ROWS, False)
        self.dataframe.add(datatable)
        gpswidgets = []
        for i in range(len(Base.gpsfields)):
            colbase = (i // Base.ROWS) * 2
            label = Gtk.Label(label=Base.gpsfields[i][0] + ": ")
            # Wacky way to force right alignment
            label.set_alignment(xalign=1, yalign=0.5)
            datatable.attach(label, colbase, colbase + 1,
                             i % Base.ROWS, i % Base.ROWS + 1)
            entry = Gtk.Entry()
            # The right size for the ISO8601 timestamp
            entry.set_width_chars(20)
            entry.set_text("n/a")
            datatable.attach(entry, colbase + 1, colbase + 2,
                             i % Base.ROWS, i % Base.ROWS + 1)
            gpswidgets.append(entry)
        vbox.add(self.dataframe)

        self.noisebox = Gtk.HBox(False, 0)
        vbox.add(self.noisebox)
        noiseframe = Gtk.Frame(label="Noise Statistics")
        self.noisebox.add(noiseframe)
        self.noiseview = NoiseView()
        noiseframe.add(self.noiseview.widget)

        self.gsbox = Gtk.HBox(False, 0)
        vbox.add(self.gsbox)
        gsframe = Gtk.Frame(label="Maidenhead Grid Square")
        self.gsbox.add(gsframe)
        self.gsview = MaidenheadView()
        gsframe.add(self.gsview.widget)

        self.aisbox = Gtk.HBox(False, 0)
        vbox.add(self.aisbox)
        aisframe = Gtk.Frame(label="AIS Data")
        self.aisbox.add(aisframe)
        self.aisview = AISView(self.deg_type)
        aisframe.add(self.aisview.widget)

        self.window.show_all()
        # Hide the Noise Statistics window until user selects it.
        self.uimanager.get_widget('/MenuBar/View/Noise').set_active(False)
        self.noisebox.hide()
        # Hide the Maidenhead window until user selects it.
        self.uimanager.get_widget('/MenuBar/View/Maidenhead').set_active(False)
        self.gsbox.hide()
        # Hide the AIS window until user selects it.
        self.uimanager.get_widget('/MenuBar/View/AIS').set_active(False)
        self.aisbox.hide()

        self.view_name_to_widget = {
            "Skyview": self.satbox,
            "Responses": self.rawdisplay,
            "GPS": self.dataframe,
            "Noise": self.noisebox,
            "Maidenhead": self.gsbox,
            "AIS": self.aisbox}

        # Discard field labels and associate data hooks with their widgets
        Base.gpsfields = [(label_hook_widget[0][1], label_hook_widget[1]) for label_hook_widget in zip(Base.gpsfields, gpswidgets)]

    def view_toggle(self, action):
        # print("View toggle:", action.get_active(), action.get_name())
        if hasattr(self, 'view_name_to_widget'):
            if action.get_active():
                self.view_name_to_widget[action.get_name()].show()
            else:
                self.view_name_to_widget[action.get_name()].hide()
        # The effect we're after is to make the top-level window
        # resize itself to fit when we show or hide widgets.
        # This is undocumented magic to do that.
        self.window.resize(1, 1)

    def set_satlist_field(self, row, column, value):
        "Set a specified field in the satellite list."
        try:
            self.satlist.set_value(self.row_iters[row], column, str(value))
        except IndexError:
            sys.stderr.write("xgps: channel = %d, MAXCHANNELS = %d\n" % (row, MAXCHANNELS))

    def delete_event(self, _widget, _event, _data=None):
        Gtk.main_quit()
        return False

    # State updates

    def update_time(self, data):
        if hasattr(data, "time"):
            # str() just in case we get an old-style float.
            return str(data.time)
        else:
            return "n/a"

    def update_latitude(self, data):
        if data.mode >= gps.MODE_2D and hasattr(data, "lat"):
            lat = gps.clienthelpers.deg_to_str(self.deg_type, abs(data.lat))
            if data.lat < 0:
                ns = 'S'
            else:
                ns = 'N'
            return "%s %s" % (lat, ns)
        else:
            return "n/a"

    def update_longitude(self, data):
        if data.mode >= gps.MODE_2D and hasattr(data, "lon"):
            lon = gps.clienthelpers.deg_to_str(self.deg_type, abs(data.lon))
            if data.lon < 0:
                ew = 'W'
            else:
                ew = 'E'
            return "%s %s" % (lon, ew)
        else:
            return "n/a"

    def update_altitude(self, data):
        if data.mode >= gps.MODE_3D and hasattr(data, "alt"):
            return "%.3f %s" % (
                data.alt * self.conversions.altfactor,
                self.conversions.altunits)
        else:
            return "n/a"

    def update_speed(self, data):
        if hasattr(data, "speed"):
            return "%.3f %s" % (
                data.speed * self.conversions.speedfactor,
                self.conversions.speedunits)
        else:
            return "n/a"

    def update_climb(self, data):
        if hasattr(data, "climb"):
            return "%.3f %s" % (
                data.climb * self.conversions.speedfactor,
                self.conversions.speedunits)
        else:
            return "n/a"

    def update_track(self, data):
        if hasattr(data, "track"):
            return gps.clienthelpers.deg_to_str(self.deg_type, abs(data.track))
        else:
            return "n/a"

    def update_err(self, data, errtype):
        if hasattr(data, errtype):
            return "%.3f %s" % (
                getattr(data, errtype) * self.conversions.altfactor,
                self.conversions.altunits)
        else:
            return "n/a"

    def update_err_speed(self, data, errtype):
        if hasattr(data, errtype):
            return "%.3f %s" % (
                getattr(data, errtype) * self.conversions.speedfactor,
                self.conversions.speedunits)
        else:
            return "n/a"

    def update_err_degrees(self, data, errtype):
        if hasattr(data, errtype):
            return "%.3f °" % (getattr(data, errtype))
        else:
            return "n/a"

    def update_status(self, data):
        if data.mode == gps.MODE_2D:
            status = "2D FIX"
        elif data.mode == gps.MODE_3D:
            status = "3D FIX"
        else:
            status = "NO FIX"

        if hasattr(data, 'status') and data.status == gps.STATUS_DGPS_FIX:
            status += " DIFF"
        if data.mode != self.saved_mode:
            self.last_transition = time.time()
            self.saved_mode = data.mode
        return status + " (%d secs)" % (time.time() - self.last_transition)

    def update_gpsdata(self, tpv):
        "Update the GPS data fields."
        # the first 14 fields are updated using TPV data
        for (hook, widget) in Base.gpsfields[:14]:
            if hook:  # Remove this guard when we have all hooks
                widget.set_text(hook(self, tpv))
        self.gsview.update(tpv)

    def update_skyview(self, data):
        "Update the satellite list and skyview."
        if hasattr(data, 'satellites'):
            satellites = data.satellites
            for fld in reversed(SKY_VIEW_SORT_FIELDS):
                rev = (fld[0] == '-')
                if rev:
                    fld = fld[1:]
                satellites = sorted(
                    satellites[:],
                    key=lambda x: x[fld], reverse=rev)

            for (i, satellite) in enumerate(satellites):
                self.set_satlist_field(i, 0, satellite.PRN)
                self.set_satlist_field(i, 1, satellite.el)
                self.set_satlist_field(i, 2, satellite.az)
                self.set_satlist_field(i, 3, satellite.ss)
                yesno = 'N'
                if satellite.used:
                    yesno = 'Y'
                self.set_satlist_field(i, 4, yesno)
            for i in range(len(satellites), MAXCHANNELS):
                for j in range(0, 5):
                    self.set_satlist_field(i, j, "")
            self.skyview.redraw(satellites)

    # Preferences

    def set_units(self, system):
        "Change the display units."
        self.conversions = unit_adjustments(system)

    def set_step_of_grid(self, system):
        "Change the step of grid."
        self.skyview.step_of_grid = system

    # I/O monitoring and gtk housekeeping

    def watch(self, daemon, device):
        "Set up monitoring of a daemon instance."
        self.daemon = daemon
        self.device = device
        GObject.io_add_watch(daemon.sock, GObject.IO_IN, self.handle_response)
        GObject.io_add_watch(daemon.sock, GObject.IO_ERR, self.handle_hangup)
        GObject.io_add_watch(daemon.sock, GObject.IO_HUP, self.handle_hangup)

    def handle_response(self, source, condition):
        "Handle ordinary I/O ready condition from the daemon."
        if self.daemon.read() == -1:
            self.handle_hangup(source, condition)
        if self.daemon.valid & gps.PACKET_SET:
            if self.device and "device" in self.daemon.data and self.device != self.daemon.data["device"]:
                return True
            self.rawdisplay.set_text(self.daemon.response.strip())
            if self.daemon.data["class"] == "SKY":
                self.update_skyview(self.daemon.data)
            elif self.daemon.data["class"] == "TPV":
                self.update_gpsdata(self.daemon.data)
            elif self.daemon.data["class"] == "GST":
                self.noiseview.update(self.daemon.data)
                if not self.noise_latch:
                    self.noise_latch = True
                    self.uimanager.get_widget('/MenuBar/View/Noise').set_active(True)
                    self.noisebox.show()
            elif self.daemon.data["class"] == "AIS":
                self.aisview.update(self.daemon.data)
                if not self.ais_latch:
                    self.ais_latch = True
                    self.uimanager.get_widget('/MenuBar/View/AIS').set_active(True)
                    self.aisbox.show()

        return True

    def handle_hangup(self, _source, _condition):
        "Handle hangup condition from the daemon."
        w = Gtk.MessageDialog(parent=self.window,
                              type=Gtk.MessageType.ERROR,
                              flags=Gtk.DialogFlags.DESTROY_WITH_PARENT,
                              buttons=Gtk.ButtonsType.CANCEL)
        w.connect("destroy", lambda _unused: Gtk.main_quit())
        w.set_markup("gpsd has stopped sending data.")
        w.run()
        Gtk.main_quit()
        return True

    def main(self):
        Gtk.main()

if __name__ == "__main__":
    try:
        import getopt
        (options, arguments) = getopt.getopt(sys.argv[1:], "D:hl:u:r:V?",
                                             ['verbose'])
        debug = 0
        degreefmt = 'd'
        unit_system = None
        rotate = 0.0
        for (opt, val) in options:
            if opt in '-D':
                debug = int(val)
            elif opt == '-l':
                degreeformat = val
            elif opt == '-u':
                unit_system = val
            elif opt == '-r':
                try:
                    rotate = float(val)
                except ValueError:
                    rotate = 0.0
            elif opt in ('-?', '-h', '--help'):
                print(__doc__)
                sys.exit(0)
            elif opt == 'V':
                sys.stderr.write("xgps 1.0\n")
                sys.exit(0)

        degreefmt = {'d': gps.clienthelpers.deg_dd,
                     'm': gps.clienthelpers.deg_ddmm,
                     's': gps.clienthelpers.deg_ddmmss}[degreefmt]

        (host, port, device) = ("localhost", gps.GPSD_PORT, None)
        if len(arguments):
            args = arguments[0].split(":")
            if len(args) >= 1 and args[0]:
                host = args[0]
            if len(args) >= 2 and args[1]:
                port = args[1]
            if len(args) >= 3:
                device = args[2]
            target = arguments[0:]
        else:
            target = []

        base = Base(deg_type=degreefmt, rotate=rotate, target=target)
        base.set_units(unit_system)
        try:
            daemon = gps.gps(host=host,
                             port=port,
                             mode=gps.WATCH_ENABLE | gps.WATCH_JSON | gps.WATCH_SCALED,
                             verbose=debug)
            base.watch(daemon, device)
            base.main()
        except socket.error:
            w = Gtk.MessageDialog(parent=base.window,
                                  type=Gtk.MessageType.ERROR,
                                  flags=Gtk.DialogFlags.DESTROY_WITH_PARENT,
                                  buttons=Gtk.ButtonsType.CANCEL)
            w.set_markup("gpsd is not running.")
            w.run()
            w.destroy()
    except KeyboardInterrupt:
        pass