Refresh the GUI windows

Question

I have a Client(C++) to Server (Python) Project.

The client sent a Message to the server, and each Message contains three attributes.

The Gui should show all the attributes over the screen. When the client sent the first message, everything works. But when he sent the next message I need to close the window, and when I do that it opens a new window and shows the following message, if I don't do that he doesn't show the new messages that received.

I suspect that app.exec_() stop the program from getting a new message like in this case, but I'm not sure. my question is :

1. Is this really the case? And if so, where should I put the Thread?

2. I never used QThread before, and I saw that we are doing Override for Run() and in the Run() method we put in all the logic, what logic I should put into my particular problem. you can find the full project here

Relevant code:

def recive(self):

        global income
        global table2

        msg = Payload(0, 0, 0)

        while (True):

            print('waiting for a connection..')
            conn, addr = self.My_socket.accept()
            print("connection has been established | " + repr(addr))
            logger.info("connection has been established | " + repr(addr))

            while conn:
                myThread = MyThread()

                buff = conn.recv(sizeof(msg))

                print("recv %d bytes" % sizeof(msg))
                payload_in = Payload.from_buffer_copy(buff)

                print(f"Received id={payload_in.id}, counter={payload_in.counter}, opcode={payload_in.opcode}")

                payload_out = payload_in

                self.opcode = payload_in.opcode

                if self.opcode == 1:
                    self.export()
                elif self.opcode == 2:
                    payload_out.counter += 1
                else:
                    logger.info("Unexpected opcode %d" % self.opcode)

                nsent = conn.send(payload_out)
                print("send %d bytes" % nsent)
                print("send id=%d, counter=%d, opcode=%d" % (payload_out.id,
                                                             payload_out.counter,
                                                             payload_out.opcode))
                self.setNewTable(payload_in, payload_out)

        print("Closing connection to client")
        print("----------------------------")

        sys.exit()

    def setNewTable(self,payload_in, payload_out):
            self.insertValues(table1, payload_in)
            self.insertValues(table2, payload_out)
            ex.show()
            app.exec_()

    def insertValues(self,table, payload):
            table.setItem(0, 1, QTableWidgetItem(str(payload.id)))
            table.setItem(1, 1, QTableWidgetItem(str(payload.counter)))
            table.setItem(2, 1, QTableWidgetItem(str(payload.opcode)))

Answer 1

I know couple of things about QThread ui think you need to use python signal and slot to update ui. refer following code

from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import datetime
import sys
import struct
import threading
import os
import datetime
import time
try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)
class MySignal(QObject):
        signelforWritemsg=Signal(str)
class EchoThread(QThread):
    #def __init__(self,Inf_found1,inf_cleaned1,Auto_clean,timer,movie,Scan_btn,cancel_btn,status_text):
    def __init__(self,parent = None):
        QThread.__init__(self,parent)
        self.exiting = False
        self.signal = MySignal()

    def run(self):
        while True:
            scantimenow= datetime.datetime.now()
            scantime=scantimenow.strftime('%Y-%m-%d %H:%M:%S')
            print(scantime)
            self.signal.signelforWritemsg.emit(scantime)
            time.sleep(5)
class Ui_Clientserver(object):
    def setupUi(self, Clientserver):
        Clientserver.setObjectName(_fromUtf8("Clientserver"))
        Clientserver.resize(400, 300)
        self.label = QtGui.QLabel(Clientserver)
        self.label.setGeometry(QtCore.QRect(150, 70, 200, 200))
        self.label.setObjectName(_fromUtf8("label"))
        self.retranslateUi(Clientserver)

        self.thread = EchoThread()
        self.thread.start()
        self.thread.signal.signelforWritemsg.connect(self.signelforWritemsg)

    def signelforWritemsg(self,data):
        self.label.setText(_translate("Clientserver",str(data), None))
    def retranslateUi(self, Clientserver):
        Clientserver.setWindowTitle(_translate("Clientserver", "Clientserver", None))

        self.label.setText(_translate("Clientserver", "inProgess", None))
if __name__ == "__main__":
    import sys
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_X11InitThreads)
    app = QtGui.QApplication(sys.argv)
    Clientserver = QtGui.QWidget()
    ui = Ui_Clientserver()
    ui.setupUi(Clientserver)
    Clientserver.show()
    sys.exit(app.exec_())