root/projects/WinDictator/trunk/windictator/windows/pb.py

# WinDictator:
# Dictate in Windows, have the text typed in Linux via X faked keystroke events
#
# Copyright (C) 2005-2006 by Edwin A. Suominen, http://www.eepatents.com
#
# 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 file COPYING 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 Street, Fifth Floor, Boston, MA 02110-1301, USA


"""
Twisted Perspective Broker server that runs as a Windows service, waiting for a
Linux client to connect to it and accept text for virtual typing.
"""

from twisted.spread.pb import Root, PBServerFactory
from twisted.internet import defer, reactor

import dictate


class Server(Root):
    """
    I provide a method for remote clients to tell me their root object, if no
    other clients are connected, and a data sink method for sending text to the
    connected remote client.

    @ivar d: A C{Deferred} that fires when my GUI application shuts down.
    """
    def __init__(self):
        """
        Instantiates me with a GUI application window and a C{Deferred} that
        will fire when the GUI application shuts down.
        """
        self.window = dictate.TextWindow()
        
    def remote_greeter(self, clientRoot):
        """
        First remote method run by client. If another client is connected,
        returns an informative rejection. Otherwise, sets my clientRoot
        attribute to the remote client's root object

        """
        if getattr(self, 'clientRoot', None) is not None:
            # Status: No connection
            return False
        else:
            # The text updater
            updater = dictate.TextUpdater(clientRoot)
            # Get the application running, and chain my deferred to its
            # shutdown deferred
            self.window.run(updater)
            # Indicate that we're connected
            self.window.label("Connected")
            # Status: Connected
            return True


class ServerFactory(PBServerFactory):
    """
    Customized version of L{PBServerFactory} that provides a disconnection
    callback.
    """
    def __init__(self, serverRoot):
        self.__serverRoot = serverRoot
        PBServerFactory.__init__(self, serverRoot)
    
    def clientConnectionMade(self, protocol):
        """
        This method is intended to be defined by L{PBServerFactory} subclasses,
        and does so here to take care of my special disconnection needs.
        """
        def disconnected():
            self.__serverRoot.clientRoot = None
            self.__serverRoot.window.label("Disconnected")
            
        protocol.notifyOnDisconnect(disconnected)


def startServer(port):
    """
    Starts a PB server and sits around. Does NOT return.
    """
    serverRoot = Server()
    reactor.listenTCP(port, ServerFactory(serverRoot))
    reactor.run()
    # Here there be Tygers