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Python pyqt (gui) example 'chat'
chat
Python pyqt example: chat
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
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## $QT_BEGIN_LICENSE:BSD$
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## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
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## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
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## $QT_END_LICENSE$
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#############################################################################
from PyQt5.QtCore import pyqtSignal, pyqtSlot, Q_CLASSINFO
from PyQt5.QtWidgets import QApplication, QDialog, QMainWindow, QMessageBox
from PyQt5.QtDBus import (QDBusAbstractAdaptor, QDBusAbstractInterface,
QDBusConnection, QDBusMessage)
from ui_chatmainwindow import Ui_ChatMainWindow
from ui_chatsetnickname import Ui_NicknameDialog
class ChatAdaptor(QDBusAbstractAdaptor):
Q_CLASSINFO("D-Bus Interface", 'org.example.chat')
Q_CLASSINFO("D-Bus Introspection", ''
' <interface name="org.example.chat">\n'
' <signal name="message">\n'
' <arg direction="out" type="s" name="nickname"/>\n'
' <arg direction="out" type="s" name="text"/>\n'
' </signal>\n'
' <signal name="action">\n'
' <arg direction="out" type="s" name="nickname"/>\n'
' <arg direction="out" type="s" name="text"/>\n'
' </signal>\n'
' </interface>\n'
'')
action = pyqtSignal(str, str)
message = pyqtSignal(str, str)
def __init__(self, parent):
super(ChatAdaptor, self).__init__(parent)
self.setAutoRelaySignals(True)
class ChatInterface(QDBusAbstractInterface):
action = pyqtSignal(str, str)
message = pyqtSignal(str, str)
def __init__(self, service, path, connection, parent=None):
super(ChatInterface, self).__init__(service, path, 'org.example.chat',
connection, parent)
class ChatMainWindow(QMainWindow, Ui_ChatMainWindow):
action = pyqtSignal(str, str)
message = pyqtSignal(str, str)
def __init__(self):
super(ChatMainWindow, self).__init__()
self.m_nickname = "nickname"
self.m_messages = []
self.setupUi(self)
self.sendButton.setEnabled(False)
self.messageLineEdit.textChanged.connect(self.textChangedSlot)
self.sendButton.clicked.connect(self.sendClickedSlot)
self.actionChangeNickname.triggered.connect(self.changeNickname)
self.actionAboutQt.triggered.connect(self.aboutQt)
QApplication.instance().lastWindowClosed.connect(self.exiting)
# Add our D-Bus interface and connect to D-Bus.
ChatAdaptor(self)
QDBusConnection.sessionBus().registerObject('/', self)
iface = ChatInterface('', '', QDBusConnection.sessionBus(), self)
QDBusConnection.sessionBus().connect('', '', 'org.example.chat',
'message', self.messageSlot)
iface.action.connect(self.actionSlot)
dialog = NicknameDialog()
dialog.cancelButton.setVisible(False)
dialog.exec_()
self.m_nickname = dialog.nickname.text().strip()
self.action.emit(self.m_nickname, "joins the chat")
def rebuildHistory(self):
history = '\n'.join(self.m_messages)
self.chatHistory.setPlainText(history)
@pyqtSlot(str, str)
def messageSlot(self, nickname, text):
self.m_messages.append("<%s> %s" % (nickname, text))
if len(self.m_messages) > 100:
self.m_messages.pop(0)
self.rebuildHistory()
@pyqtSlot(str, str)
def actionSlot(self, nickname, text):
self.m_messages.append("* %s %s" % (nickname, text))
if len(self.m_messages) > 100:
self.m_messages.pop(0)
self.rebuildHistory()
@pyqtSlot(str)
def textChangedSlot(self, newText):
self.sendButton.setEnabled(newText != '')
@pyqtSlot()
def sendClickedSlot(self):
msg = QDBusMessage.createSignal('/', 'org.example.chat', 'message')
msg << self.m_nickname << self.messageLineEdit.text()
QDBusConnection.sessionBus().send(msg)
self.messageLineEdit.setText('')
@pyqtSlot()
def changeNickname(self):
dialog = NicknameDialog(self)
if dialog.exec_() == QDialog.Accepted:
old = self.m_nickname
self.m_nickname = dialog.nickname.text().strip()
self.action.emit(old, "is now known as %s" % self.m_nickname)
@pyqtSlot()
def aboutQt(self):
QMessageBox.aboutQt(self)
@pyqtSlot()
def exiting(self):
self.action.emit(self.m_nickname, "leaves the chat")
class NicknameDialog(QDialog, Ui_NicknameDialog):
def __init__(self, parent=None):
super(NicknameDialog, self).__init__(parent)
self.setupUi(self)
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
if not QDBusConnection.sessionBus().isConnected():
sys.stderr.write("Cannot connect to the D-Bus session bus.\n"
"Please check your system settings and try again.\n")
sys.exit(1)
chat = ChatMainWindow()
chat.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/