listing28-1.py

《Beginning Python--From Novice to Professional》 的源码

from xmlrpclib import ServerProxy, Fault
from server import Node, UNHANDLED
from client import randomString
from threading import Thread
from time import sleep
from os import listdir
import sys
import wx

HEAD_START = 0.1 # Seconds
SECRET_LENGTH = 100

class Client(wx.App):
    """
    The main client class, which takes care of setting up the GUI and
    starts a Node for serving files.
    """
    def __init__(self, url, dirname, urlfile):
        """
        Creates a random secret, instantiates a Node with that secret,
        starts a Thread with the Node's _start method (making sure the
        Thread is a daemon so it will quit when the application quits),
        reads all the URLs from the URL file and introduces the Node to
        them.
        """
        super(Client, self).__init__()
        self.secret = randomString(SECRET_LENGTH)
        n = Node(url, dirname, self.secret)
        t = Thread(target=n._start)
        t.setDaemon(1)
        t.start()
        # Give the server a head start:
        sleep(HEAD_START)
        self.server = ServerProxy(url)
        for line in open(urlfile):
            line = line.strip()
            self.server.hello(line)


    def OnInit(self):
        """
        Sets up the GUI. Creates a window, a text field, and a button, and
        lays them out. Binds the submit button to self.fetchHandler.
        """

        win = wx.Frame(None, title="File Sharing Client", size=(400, 45))

        bkg = wx.Panel(win)

        self.input = input = wx.TextCtrl(bkg);

        submit = wx.Button(bkg, label="Fetch", size=(80, 25))
        submit.Bind(wx.EVT_BUTTON, self.fetchHandler)

        hbox = wx.BoxSizer()

        hbox.Add(input, proportion=1, flag=wx.ALL | wx.EXPAND, border=10)
        hbox.Add(submit, flag=wx.TOP | wx.BOTTOM | wx.RIGHT, border=10)

        vbox = wx.BoxSizer(wx.VERTICAL)
        vbox.Add(hbox, proportion=0, flag=wx.EXPAND)

        bkg.SetSizer(vbox)

        win.Show()

        return True

    def fetchHandler(self, event):
        """
        Called when the user clicks the 'Fetch' button. Reads the
        query from the text field, and calls the fetch method of the
        server Node. If the query is not handled, an error message is
        printed.
        """

        query = self.input.GetValue()
        try:
            self.server.fetch(query, self.secret)
        except Fault, f:
            if f.faultCode != UNHANDLED: raise
            print "Couldn't find the file", query


def main():
    urlfile, directory, url = sys.argv[1:]
    client = Client(url, directory, urlfile)
    client.MainLoop()

if __name__ == "__main__": main()