sugar-toolkit-gtk3/sugar-emulator

#!/usr/bin/env python

# Copyright (C) 2006, Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

import os
import sys
import socket

import pygtk
pygtk.require('2.0')
import gtk
import gobject

from sugar import env
import _sugar

def _get_display_number():
    """Find a free display number trying to connect to 6000+ ports"""
    retries = 20
    display_number = 1
    display_is_free = False    

    while not display_is_free and retries > 0:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
            s.connect(('127.0.0.1', 6000 + display_number))
            s.close()

            display_number += 1
            retries -= 1
        except:
            display_is_free = True

    if display_is_free:
        return display_number
    else:
        logging.error('Cannot find a free display.')
        sys.exit(0)

def _start_xephyr(width, height, dpi):
    display = _get_display_number()

    cmd = [ 'Xephyr' ]
    cmd.append(':%d' % display)
    cmd.append('-ac') 

    if width > 0 and height > 0:
        cmd.append('-screen %dx%d' % (width, height))
    else:
        cmd.append('-fullscreen')

    if dpi > 0:
        cmd.append('-dpi')
        cmd.append(str(dpi))

    result = gobject.spawn_async(cmd, flags=gobject.SPAWN_SEARCH_PATH)
    pid = result[0]

    os.environ['DISPLAY'] = ":%d" % (display)
    os.environ['SUGAR_EMULATOR_PID'] = str(pid)

os.environ['SUGAR_EMULATOR'] = 'yes'

if len(sys.argv) == 1:
    program = 'sugar-shell'
else:
    program = sys.argv[1]

if gtk.gdk.screen_width() < 1200 or gtk.gdk.screen_height() < 900:
    width = -1
    height = -1
else:
    width = 1200
    height = 900

_start_xephyr(width, height, min(_sugar.get_screen_dpi(), 96))

os.execlp('dbus-launch', 'dbus-launch', '--exit-with-session', program)