[CentralOH] How-To non-blocking GUI with Tkinter

[pybokeh]

Hello,
I am new to GUI programming and threading in Tkinter and I am basically
trying to create a chat or instant messaging program for fun or as a
learning experience.  The problem I am having is my while loop doesn't loop
through due to the mainloop() function since it doesn't return to the main
thread until the root is closed or exited.  So what ends up happening is I
can receive an instant message only once from the client, but server can
send message ok and the client receives the message fine.  I've been doing
a lot of searching and it appears I need to either run a separate thread
for the part of the program that is waiting for the data from the client.
 I've also looked at tkinter.createfilehandler(), but I just don't know how
to implement this.  Any help with this in terms of documentation or
reference material would be greatly appreciated.  Thanks in advance!

- Daniel

Here's my server code (it is GUI):

from Tkinter import *

import socket


 class TCP_Server_GUI(Frame):

    def __init__(self, master):

        self.server_socket = socket.socket(socket.AF_INET,
socket.SOCK_STREAM)

        self.max_data = 512

        self.host = '127.0.0.1'

        self.port = 1060

        self.server_socket.bind((self.host,self.port))

        self.server_socket.listen(5)


         self.frame = Frame(master)

        self.frame.pack()


         self.lblServer = Label(self.frame, text="Server IP:")

        self.lblServer.grid(row=0, column=0)


         self.strServer = StringVar()

        self.Server = Entry(self.frame, textvariable=self.strServer,
width=16, borderwidth=2)

        self.Server.grid(row=0, column=1)


         self.lblPort = Label(self.frame, text="Server Port:")

        self.lblPort.grid(row=1, column=0)


         self.strPort = StringVar()

        self.Port = Entry(self.frame, textvariable=self.strPort, width=6,
borderwidth=2)

        self.Port.grid(row=1, column=1)


         self.lblHistory = Label(self.frame, text="Message History:")

        self.lblHistory.grid(row=2, column=0)


         self.History = Listbox(self.frame, height=5, width=50)

        self.History.grid(row=3, columnspan=2)


         self.sbar = Scrollbar(self.frame, orient=VERTICAL,
command=self.History.yview)

        self.sbar.grid(row=3, column=2)

        self.History['yscrollcommand']=self.sbar.set


         self.lblMessage = Label(self.frame, text="Outgoing Message:")

        self.lblMessage.grid(row=4, column=0)


         self.strMessage = StringVar()

        self.Message = Entry(self.frame, textvariable=self.strMessage,
borderwidth=2, width=50)

        self.Message.grid(row=5, columnspan=2)


        self.strServer.set(self.host)

        self.strPort.set(self.port)

         self.client_socket, self.client_address =
self.server_socket.accept()


    def SendBtn(self):

        self.History.insert(END,
self.host+':'+str(self.port)+'--->'+self.strMessage.get())

        self.History.yview_scroll(1, "units")

        self.client_socket.send(self.strMessage.get())

        self.strMessage.set('')"""


 if __name__ == "__main__":

    def SendBtn():

        app.History.insert(END,
app.host+':'+str(app.port)+'--->'+app.strMessage.get())

        app.History.yview_scroll(1, "units")

        app.client_socket.send(app.strMessage.get())

        print "Server sent data..."

        app.strMessage.set('')


     root = Tk()

    root.title("TCP Chat Server GUI")

    app = TCP_Server_GUI(root)

    app.btnSend = Button(app.frame,text="Send", command=SendBtn)

    app.btnSend.grid(row=6, column=0)


     def checkdata():

        print "Checking for incoming message from client..."

        data = app.client_socket.recv(app.max_data)

        client_ip, client_port = app.client_address

        app.History.insert(END,
client_ip+':'+str(client_port)+'--->'+str(data))

        print "Inserted message into history..."

        root.update()

        print "Done checking for incoming data..."


   while True:

    checkdata()

    print "Excecuting main loop"

    root.mainloop()



Client code (it is not GUI, just console):

import socket

client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

client_socket.connect(("127.0.0.1", 1060))

while 1:

    data = raw_input ( "SEND( TYPE q or Q to Quit):" )

    if (data <> 'Q' and data <> 'q'):

        client_socket.send(data)

    else:

        client_socket.send(data)

        client_socket.close()

        break;


 server_message = client_socket.recv(512)

print "Message from server:", server_message
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