examples/network/blockingfortuneclient¶
(You can also check this code in the repository)
# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
from __future__ import annotations
"""PySide6 port of the network/blockingfortunclient example from Qt v5.x, originating from PyQt"""
from PySide6.QtCore import (Signal, QDataStream, QMutex, QMutexLocker,
QThread, QWaitCondition)
from PySide6.QtGui import QIntValidator
from PySide6.QtWidgets import (QApplication, QDialogButtonBox, QGridLayout,
QLabel, QLineEdit, QMessageBox, QPushButton,
QWidget)
from PySide6.QtNetwork import (QAbstractSocket, QHostAddress, QNetworkInterface,
QTcpSocket)
class FortuneThread(QThread):
new_fortune = Signal(str)
error = Signal(int, str)
def __init__(self, parent=None):
super().__init__(parent)
self.quit = False
self._host_name = ''
self.cond = QWaitCondition()
self.mutex = QMutex()
self.port = 0
def __del__(self):
self.mutex.lock()
self.quit = True
self.cond.wakeOne()
self.mutex.unlock()
self.wait()
def request_new_fortune(self, hostname, port):
with QMutexLocker(self.mutex):
self._host_name = hostname
self.port = port
if not self.isRunning():
self.start()
else:
self.cond.wakeOne()
def run(self):
self.mutex.lock()
server_name = self._host_name
server_port = self.port
self.mutex.unlock()
while not self.quit:
timeout = 5 * 1000
socket = QTcpSocket()
socket.connectToHost(server_name, server_port)
if not socket.waitForConnected(timeout):
self.error.emit(socket.error(), socket.errorString())
return
while socket.bytesAvailable() < 2:
if not socket.waitForReadyRead(timeout):
self.error.emit(socket.error(), socket.errorString())
return
instr = QDataStream(socket)
instr.setVersion(QDataStream.Qt_4_0)
block_size = instr.readUInt16()
while socket.bytesAvailable() < block_size:
if not socket.waitForReadyRead(timeout):
self.error.emit(socket.error(), socket.errorString())
return
self.mutex.lock()
fortune = instr.readQString()
self.new_fortune.emit(fortune)
self.cond.wait(self.mutex)
server_name = self._host_name
server_port = self.port
self.mutex.unlock()
class BlockingClient(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.thread = FortuneThread()
self._current_fortune = ''
host_label = QLabel("&Server name:")
port_label = QLabel("S&erver port:")
for ip_address in QNetworkInterface.allAddresses():
if ip_address != QHostAddress.LocalHost and ip_address.toIPv4Address() != 0:
break
else:
ip_address = QHostAddress(QHostAddress.LocalHost)
ip_address = ip_address.toString()
self._host_line_edit = QLineEdit(ip_address)
self._port_line_edit = QLineEdit()
self._port_line_edit.setValidator(QIntValidator(1, 65535, self))
host_label.setBuddy(self._host_line_edit)
port_label.setBuddy(self._port_line_edit)
self._status_label = QLabel(
"This example requires that you run the Fortune Server example as well.")
self._status_label.setWordWrap(True)
self._get_fortune_button = QPushButton("Get Fortune")
self._get_fortune_button.setDefault(True)
self._get_fortune_button.setEnabled(False)
quit_button = QPushButton("Quit")
button_box = QDialogButtonBox()
button_box.addButton(self._get_fortune_button, QDialogButtonBox.ActionRole)
button_box.addButton(quit_button, QDialogButtonBox.RejectRole)
self._get_fortune_button.clicked.connect(self.request_new_fortune)
quit_button.clicked.connect(self.close)
self._host_line_edit.textChanged.connect(self.enable_get_fortune_button)
self._port_line_edit.textChanged.connect(self.enable_get_fortune_button)
self.thread.new_fortune.connect(self.show_fortune)
self.thread.error.connect(self.display_error)
main_layout = QGridLayout()
main_layout.addWidget(host_label, 0, 0)
main_layout.addWidget(self._host_line_edit, 0, 1)
main_layout.addWidget(port_label, 1, 0)
main_layout.addWidget(self._port_line_edit, 1, 1)
main_layout.addWidget(self._status_label, 2, 0, 1, 2)
main_layout.addWidget(button_box, 3, 0, 1, 2)
self.setLayout(main_layout)
self.setWindowTitle("Blocking Fortune Client")
self._port_line_edit.setFocus()
def request_new_fortune(self):
self._get_fortune_button.setEnabled(False)
self.thread.request_new_fortune(self._host_line_edit.text(),
int(self._port_line_edit.text()))
def show_fortune(self, nextFortune):
if nextFortune == self._current_fortune:
self.request_new_fortune()
return
self._current_fortune = nextFortune
self._status_label.setText(self._current_fortune)
self._get_fortune_button.setEnabled(True)
def display_error(self, socketError, message):
if socketError == QAbstractSocket.HostNotFoundError:
QMessageBox.information(self, "Blocking Fortune Client",
"The host was not found. Please check the host and port "
"settings.")
elif socketError == QAbstractSocket.ConnectionRefusedError:
QMessageBox.information(self, "Blocking Fortune Client",
"The connection was refused by the peer. Make sure the "
"fortune server is running, and check that the host name "
"and port settings are correct.")
else:
QMessageBox.information(self, "Blocking Fortune Client",
f"The following error occurred: {message}.")
self._get_fortune_button.setEnabled(True)
def enable_get_fortune_button(self):
self._get_fortune_button.setEnabled(self._host_line_edit.text() != ''
and self._port_line_edit.text() != '')
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
client = BlockingClient()
client.show()
sys.exit(app.exec())