Network/IRC/IrcWidget.py

# -*- coding: utf-8 -*-

# Copyright (c) 2012 - 2013 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the IRC window.
"""

import re
import logging

from PyQt4.QtCore import pyqtSlot, pyqtSignal, Qt, QByteArray, QTimer
from PyQt4.QtGui import QWidget, QToolButton, QLabel, QTabWidget
from PyQt4.QtNetwork import QTcpSocket, QAbstractSocket
try:
    from PyQt4.QtNetwork import QSslSocket, QSslConfiguration
    from E5Network.E5SslErrorHandler import E5SslErrorHandler
    SSL_AVAILABLE = True
except ImportError:
    SSL_AVAILABLE = False

from E5Gui import E5MessageBox

from .Ui_IrcWidget import Ui_IrcWidget

import Preferences
import UI.PixmapCache

from Globals import isMacPlatform

from UI.Info import Version, Copyright


class IrcWidget(QWidget, Ui_IrcWidget):
    """
    Class implementing the IRC window.
    
    @signal autoConnected() emitted after an automatic connection was initiated
    """
    autoConnected = pyqtSignal()
    
    ServerDisconnected = 1
    ServerConnected = 2
    ServerConnecting = 3
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent widget (QWidget)
        """
        super().__init__(parent)
        self.setupUi(self)
        
        from .IrcNetworkManager import IrcNetworkManager
        self.__ircNetworkManager = IrcNetworkManager(self)
        
        self.__leaveButton = QToolButton(self)
        self.__leaveButton.setIcon(UI.PixmapCache.getIcon("ircCloseChannel.png"))
        self.__leaveButton.setToolTip(self.trUtf8("Press to leave the current channel"))
        self.__leaveButton.clicked[()].connect(self.__leaveChannel)
        self.__leaveButton.setEnabled(False)
        self.channelsWidget.setCornerWidget(self.__leaveButton, Qt.BottomRightCorner)
        self.channelsWidget.setTabsClosable(False)
        if not isMacPlatform():
            self.channelsWidget.setTabPosition(QTabWidget.South)
        
        height = self.height()
        self.splitter.setSizes([height * 0.6, height * 0.4])
        
        self.__channelList = []
        self.__channelTypePrefixes = ""
        self.__userName = ""
        self.__identityName = ""
        self.__quitMessage = ""
        self.__nickIndex = -1
        self.__nickName = ""
        self.__server = None
        self.__registering = False
        
        self.__connectionState = IrcWidget.ServerDisconnected
        self.__sslErrorLock = False
        
        self.__buffer = ""
        self.__userPrefix = {}
        
        self.__socket = None
        if SSL_AVAILABLE:
            self.__sslErrorHandler = E5SslErrorHandler(self)
        else:
            self.__sslErrorHandler = None
        
        self.__patterns = [
            # :foo_!n=foo@foohost.bar.net PRIVMSG bar_ :some long message
            (re.compile(r":([^!]+)!([^ ]+)\sPRIVMSG\s([^ ]+)\s:(.*)"), self.__query),
            # :foo.bar.net COMMAND some message
            (re.compile(r""":([^ ]+)\s+([A-Z]+)\s+(.+)"""), self.__handleNamedMessage),
            # :foo.bar.net 123 * :info
            (re.compile(r""":([^ ]+)\s+(\d{3})\s+(.+)"""), self.__handleNumericMessage),
            # PING :ping message
            (re.compile(r"""PING\s+:(.*)"""), self.__ping),
        ]
        self.__prefixRe = re.compile(r""".*\sPREFIX=\((.*)\)([^ ]+).*""")
        self.__chanTypesRe = re.compile(r""".*\sCHANTYPES=([^ ]+).*""")
        
        ircPic = UI.PixmapCache.getPixmap("irc128.png")
        self.__emptyLabel = QLabel()
        self.__emptyLabel.setPixmap(ircPic)
        self.__emptyLabel.setAlignment(Qt.AlignVCenter | Qt.AlignHCenter)
        self.channelsWidget.addTab(self.__emptyLabel, "")
        
        # all initialized, do connections now
        self.__ircNetworkManager.dataChanged.connect(self.__networkDataChanged)
        self.networkWidget.initialize(self.__ircNetworkManager)
        self.networkWidget.connectNetwork.connect(self.__connectNetwork)
        self.networkWidget.editNetwork.connect(self.__editNetwork)
        self.networkWidget.joinChannel.connect(self.__joinChannel)
        self.networkWidget.nickChanged.connect(self.__changeNick)
        self.networkWidget.sendData.connect(self.__send)
        self.networkWidget.away.connect(self.__away)
        self.networkWidget.autoConnected.connect(self.autoConnected)
    
    def shutdown(self):
        """
        Public method to shut down the widget.
        
        @return flag indicating successful shutdown (boolean)
        """
        if self.__server:
            if Preferences.getIrc("AskOnShutdown"):
                ok = E5MessageBox.yesNo(self,
                    self.trUtf8("Disconnect from Server"),
                    self.trUtf8("""<p>Do you really want to disconnect from"""
                                """ <b>{0}</b>?</p><p>All channels will be closed."""
                                """</p>""").format(self.__server.getName()))
            else:
                ok = True
            if ok:
                self.__socket.blockSignals(True)
                
                self.__send("QUIT :" + self.__quitMessage)
                self.__socket.flush()
                self.__socket.close()
                self.__socket.deleteLater()
                self.__socket = None
        else:
            ok = True
        
        if ok:
            self.__ircNetworkManager.close()
        return ok
    
    def autoConnect(self):
        """
        Public method to initiate the IRC auto connection.
        """
        self.networkWidget.autoConnect()

    def __connectNetwork(self, name, connect, silent=False):
        """
        Private slot to connect to or disconnect from the given network.
        
        @param name name of the network to connect to (string)
        @param connect flag indicating to connect (boolean)
        @keyparam silent flag indicating a silent connect/disconnect (boolean)
        """
        if connect:
            network = self.__ircNetworkManager.getNetwork(name)
            if network:
                self.__server = network.getServer()
                self.__identityName = network.getIdentityName()
                identity = self.__ircNetworkManager.getIdentity(self.__identityName)
                self.__userName = identity.getIdent()
                self.__quitMessage = identity.getQuitMessage()
                if self.__server:
                    useSSL = self.__server.useSSL()
                    if useSSL and not SSL_AVAILABLE:
                        E5MessageBox.critical(self,
                            self.trUtf8("SSL Connection"),
                            self.trUtf8("""An encrypted connection to the IRC network"""
                                        """ was requested but SSL is not available."""
                                        """ Please change the server configuration."""))
                        return
                    
                    if useSSL:
                        # create SSL socket
                        self.__socket = QSslSocket(self)
                        self.__socket.encrypted.connect(self.__hostConnected)
                        self.__socket.sslErrors.connect(self.__sslErrors)
                    else:
                        # create TCP socket
                        self.__socket = QTcpSocket(self)
                        self.__socket.connected.connect(self.__hostConnected)
                    self.__socket.hostFound.connect(self.__hostFound)
                    self.__socket.disconnected.connect(self.__hostDisconnected)
                    self.__socket.readyRead.connect(self.__readyRead)
                    self.__socket.error.connect(self.__tcpError)
                    
                    self.__connectionState = IrcWidget.ServerConnecting
                    if useSSL:
                        self.networkWidget.addServerMessage(self.trUtf8("Info"),
                            self.trUtf8("Looking for server {0} (port {1}) using"
                                        " an SSL encrypted connection...").format(
                                self.__server.getName(), self.__server.getPort()))
                        self.__socket.connectToHostEncrypted(self.__server.getName(),
                                                             self.__server.getPort())
                    else:
                        self.networkWidget.addServerMessage(self.trUtf8("Info"),
                            self.trUtf8("Looking for server {0} (port {1})...").format(
                                self.__server.getName(), self.__server.getPort()))
                        self.__socket.connectToHost(self.__server.getName(),
                                                    self.__server.getPort())
        else:
            if silent:
                ok = True
            else:
                ok = E5MessageBox.yesNo(self,
                    self.trUtf8("Disconnect from Server"),
                    self.trUtf8("""<p>Do you really want to disconnect from"""
                                """ <b>{0}</b>?</p><p>All channels will be"""
                                """ closed.</p>""")\
                        .format(self.__server.getName()))
            if ok:
                self.networkWidget.addServerMessage(self.trUtf8("Info"),
                    self.trUtf8("Disconnecting from server {0}...").format(
                        self.__server.getName()))
                self.__closeAllChannels()
                self.__send("QUIT :" + self.__quitMessage)
                self.__socket and self.__socket.flush()
                self.__socket and self.__socket.close()
                self.__userName = ""
                self.__identityName = ""
                self.__quitMessage = ""
    
    def __editNetwork(self, name):
        """
        Private slot to edit the network configuration.
        
        @param name name of the network to edit (string)
        """
        from .IrcNetworkListDialog import IrcNetworkListDialog
        dlg = IrcNetworkListDialog(self.__ircNetworkManager, self)
        dlg.exec_()
    
    def __networkDataChanged(self):
        """
        Private slot handling changes of the network and identity definitions.
        """
        identity = self.__ircNetworkManager.getIdentity(self.__identityName)
        if identity:
            partMsg = identity.getPartMessage()
            for channel in self.__channelList:
                channel.setPartMessage(partMsg)
    
    def __joinChannel(self, name, key=""):
        """
        Private slot to join a channel.
        
        @param name name of the channel (string)
        @param key key of the channel (string)
        """
        # step 1: check, if this channel is already joined
        for channel in self.__channelList:
            if channel.name() == name:
                return
        
        from .IrcChannelWidget import IrcChannelWidget
        channel = IrcChannelWidget(self)
        channel.setName(name)
        channel.setUserName(self.__nickName)
        identity = self.__ircNetworkManager.getIdentity(self.__identityName)
        channel.setPartMessage(identity.getPartMessage())
        channel.setUserPrivilegePrefix(self.__userPrefix)
        channel.initAutoWho()
        
        channel.sendData.connect(self.__send)
        channel.sendCtcpReply.connect(self.__sendCtcpReply)
        channel.channelClosed.connect(self.__closeChannel)
        channel.openPrivateChat.connect(self.__openPrivate)
        
        self.channelsWidget.addTab(channel, name)
        self.__channelList.append(channel)
        self.channelsWidget.setCurrentWidget(channel)
        
        joinCommand = ["JOIN", name]
        if key:
            joinCommand.append(key)
        self.__send(" ".join(joinCommand))
        self.__send("MODE " + name)
        
        emptyIndex = self.channelsWidget.indexOf(self.__emptyLabel)
        if emptyIndex > -1:
            self.channelsWidget.removeTab(emptyIndex)
            self.__leaveButton.setEnabled(True)
        self.channelsWidget.setTabsClosable(True)
    
    def __query(self, match):
        """
        Private method to handle a new private connection.
        
        @param reference to the match object
        @return flag indicating, if the message was handled (boolean)
        """
        # group(1)   sender user name
        # group(2)   sender user@host
        # group(3)   target nick
        # group(4)   message
        if match.group(4).startswith("\x01"):
            return self.__handleCtcp(match)
        
        self.__openPrivate(match.group(1))
        # the above call sets the new channel as the current widget
        channel = self.channelsWidget.currentWidget()
        channel.addMessage(match.group(1), match.group(4))
        channel.setPrivateInfo("{0} - {1}".format(match.group(1), match.group(2)))
        
        return True
    
    @pyqtSlot(str)
    def __openPrivate(self, name):
        """
        Private slot to open a private chat with the given user.
        
        @param name name of the user (string)
        """
        from .IrcChannelWidget import IrcChannelWidget
        channel = IrcChannelWidget(self)
        channel.setName(self.__nickName)
        channel.setUserName(self.__nickName)
        identity = self.__ircNetworkManager.getIdentity(self.__identityName)
        channel.setPartMessage(identity.getPartMessage())
        channel.setUserPrivilegePrefix(self.__userPrefix)
        channel.setPrivate(True, name)
        channel.addUsers([name, self.__nickName])
        
        channel.sendData.connect(self.__send)
        channel.sendCtcpReply.connect(self.__sendCtcpReply)
        channel.channelClosed.connect(self.__closeChannel)
        
        self.channelsWidget.addTab(channel, name)
        self.__channelList.append(channel)
        self.channelsWidget.setCurrentWidget(channel)
    
    @pyqtSlot()
    def __leaveChannel(self):
        """
        Private slot to leave a channel and close the associated tab.
        """
        channel = self.channelsWidget.currentWidget()
        channel.requestLeave()
    
    def __closeAllChannels(self):
        """
        Private method to close all channels.
        """
        while self.__channelList:
            channel = self.__channelList.pop()
            self.channelsWidget.removeTab(self.channelsWidget.indexOf(channel))
            channel.deleteLater()
            channel = None
        
        self.channelsWidget.addTab(self.__emptyLabel, "")
        self.__emptyLabel.show()
        self.__leaveButton.setEnabled(False)
        self.channelsWidget.setTabsClosable(False)
    
    def __closeChannel(self, name):
        """
        Private slot handling the closing of a channel.
        
        @param name name of the closed channel (string)
        """
        for channel in self.__channelList:
            if channel.name() == name:
                self.channelsWidget.removeTab(self.channelsWidget.indexOf(channel))
                self.__channelList.remove(channel)
                channel.deleteLater()
        
        if self.channelsWidget.count() == 0:
            self.channelsWidget.addTab(self.__emptyLabel, "")
            self.__emptyLabel.show()
            self.__leaveButton.setEnabled(False)
            self.channelsWidget.setTabsClosable(False)
    
    @pyqtSlot(int)
    def on_channelsWidget_tabCloseRequested(self, index):
        """
        Private slot to close a channel by pressing the close button of
        the channels widget.
        
        @param index index of the tab to be closed (integer)
        """
        channel = self.channelsWidget.widget(index)
        channel.requestLeave()
    
    def __send(self, data):
        """
        Private slot to send data to the IRC server.
        
        @param data data to be sent (string)
        """
        if self.__socket:
            self.__socket.write(QByteArray("{0}\r\n".format(data).encode("utf-8")))
    
    def __sendCtcpReply(self, receiver, text):
        """
        Private slot to send a CTCP reply.
        
        @param receiver nick name of the receiver (string)
        @param text text to be sent (string)
        """
        self.__send("NOTICE {0} :\x01{1}\x01".format(receiver, text))
    
    def __hostFound(self):
        """
        Private slot to indicate the host was found.
        """
        self.networkWidget.addServerMessage(self.trUtf8("Info"),
            self.trUtf8("Server found,connecting..."))
    
    def __hostConnected(self):
        """
        Private slot to log in to the server after the connection was established.
        """
        self.networkWidget.addServerMessage(self.trUtf8("Info"),
            self.trUtf8("Connected,logging in..."))
        self.networkWidget.setConnected(True)
        
        self.__registering = True
        serverPassword = self.__server.getPassword()
        if serverPassword:
            self.__send("PASS " + serverPassword)
        nick = self.networkWidget.getNickname()
        if not nick:
            self.__nickIndex = 0
            try:
                nick = self.__ircNetworkManager.getIdentity(self.__identityName)\
                    .getNickNames()[self.__nickIndex]
            except IndexError:
                nick = ""
        if not nick:
            nick = self.__userName
        self.__nickName = nick
        self.networkWidget.setNickName(nick)
        realName = self.__ircNetworkManager.getIdentity(self.__identityName).getRealName()
        if not realName:
            realName = "eric IDE chat"
        self.__send("NICK " + nick)
        self.__send("USER " + self.__userName + " 0 * :" + realName)
    
    def __hostDisconnected(self):
        """
        Private slot to indicate the host was disconnected.
        """
        self.__closeAllChannels()
        self.networkWidget.addServerMessage(self.trUtf8("Info"),
            self.trUtf8("Server disconnected."))
        self.networkWidget.setRegistered(False)
        self.networkWidget.setConnected(False)
        self.__server = None
        self.__nickName = ""
        self.__nickIndex = -1
        self.__channelTypePrefixes = ""
        
        self.__socket.deleteLater()
        self.__socket = None
        
        self.__connectionState = IrcWidget.ServerDisconnected
        self.__sslErrorLock = False
    
    def __readyRead(self):
        """
        Private slot to read data from the socket.
        """
        self.__buffer += str(self.__socket.readAll(),
                Preferences.getSystem("IOEncoding"),
                'replace')
        if self.__buffer.endswith("\r\n"):
            for line in self.__buffer.splitlines():
                line = line.strip()
                if line:
                    logging.debug("<IRC> " + line)
                    handled = False
                    # step 1: give channels a chance to handle the message
                    for channel in self.__channelList:
                        handled = channel.handleMessage(line)
                        if handled:
                            break
                    else:
                        # step 2: try to process the message ourselves
                        for patternRe, patternFunc in self.__patterns:
                            match = patternRe.match(line)
                            if match is not None:
                                if patternFunc(match):
                                    break
                        else:
                            # Oops, the message wasn't handled
                            self.networkWidget.addErrorMessage(
                                self.trUtf8("Message Error"),
                                self.trUtf8("Unknown message received from server:"
                                            "<br/>{0}").format(line))
            
            self.__updateUsersCount()
            self.__buffer = ""
    
    def __handleNamedMessage(self, match):
        """
        Private method to handle a server message containing a message name.
        
        @param reference to the match object
        @return flag indicating, if the message was handled (boolean)
        """
        name = match.group(2)
        if name == "NOTICE":
            try:
                msg = match.group(3).split(":", 1)[1]
            except IndexError:
                msg = match.group(3)
            if "!" in match.group(1):
                name = match.group(1).split("!", 1)[0]
                msg = "-{0}- {1}".format(name, msg)
            self.networkWidget.addServerMessage(self.trUtf8("Notice"), msg)
            return True
        elif name == "MODE":
            self.__registering = False
            if ":" in match.group(3):
                # :detlev_ MODE detlev_ :+i
                name, modes = match.group(3).split(" :")
                sourceNick = match.group(1)
                if not self.isChannelName(name):
                    if name == self.__nickName:
                        if sourceNick == self.__nickName:
                            msg = self.trUtf8(
                                "You have set your personal modes to <b>[{0}]</b>.")\
                                .format(modes)
                        else:
                            msg = self.trUtf8(
                                "{0} has changed your personal modes to <b>[{1}]</b>.")\
                                .format(sourceNick, modes)
                        self.networkWidget.addServerMessage(
                            self.trUtf8("Mode"), msg, filterMsg=False)
                        return True
        elif name == "PART":
            nick = match.group(1).split("!", 1)[0]
            if nick == self.__nickName:
                channel = match.group(3).split(None, 1)[0]
                self.networkWidget.addMessage(
                    self.trUtf8("You have left channel {0}.").format(channel))
                return True
        elif name == "QUIT":
            # don't do anything with it here
            return True
        elif name == "NICK":
            # :foo_!n=foo@foohost.bar.net NICK :newnick
            oldNick = match.group(1).split("!", 1)[0]
            newNick = match.group(3).split(":", 1)[1]
            if oldNick == self.__nickName:
                self.networkWidget.addMessage(
                    self.trUtf8("You are now known as {0}.").format(newNick))
                self.__nickName = newNick
                self.networkWidget.setNickName(newNick)
            else:
                self.networkWidget.addMessage(
                    self.trUtf8("User {0} is now known as {1}.").format(
                    oldNick, newNick))
            return True
        elif name == "ERROR":
            self.networkWidget.addErrorMessage(
                self.trUtf8("Server Error"), match.group(3).split(":", 1)[1])
            return True
        
        return False
    
    def __handleNumericMessage(self, match):
        """
        Private method to handle a server message containing a numeric code.
        
        @param reference to the match object
        @return flag indicating, if the message was handled (boolean)
        """
        code = int(match.group(2))
        if code < 400:
            return self.__handleServerReply(code, match.group(1), match.group(3))
        else:
            return self.__handleServerError(code, match.group(1), match.group(3))
    
    def __handleServerError(self, code, server, message):
        """
        Private slot to handle a server error reply.
        
        @param code numerical code sent by the server (integer)
        @param server name of the server (string)
        @param message message sent by the server (string)
        @return flag indicating, if the message was handled (boolean)
        """
        if code == 433:
            if self.__registering:
                self.__handleNickInUseLogin()
            else:
                self.__handleNickInUse()
        else:
            self.networkWidget.addServerMessage(self.trUtf8("Error"), message)
        
        return True
    
    def __handleServerReply(self, code, server, message):
        """
        Private slot to handle a server reply.
        
        @param code numerical code sent by the server (integer)
        @param server name of the server (string)
        @param message message sent by the server (string)
        @return flag indicating, if the message was handled (boolean)
        """
        # determine message type
        if code in [1, 2, 3, 4]:
            msgType = self.trUtf8("Welcome")
        elif code == 5:
            msgType = self.trUtf8("Support")
        elif code in [250, 251, 252, 253, 254, 255, 265, 266]:
            msgType = self.trUtf8("User")
        elif code in [372, 375, 376]:
            msgType = self.trUtf8("MOTD")
        elif code in [305, 306]:
            msgType = self.trUtf8("Away")
        else:
            msgType = self.trUtf8("Info ({0})").format(code)
        
        # special treatment for some messages
        if code == 375:
            message = self.trUtf8("Message of the day")
        elif code == 376:
            message = self.trUtf8("End of message of the day")
        elif code == 4:
            parts = message.strip().split()
            message = self.trUtf8("Server {0} (Version {1}), User-Modes: {2},"
                " Channel-Modes: {3}").format(parts[1], parts[2], parts[3], parts[4])
        elif code == 265:
            parts = message.strip().split()
            message = self.trUtf8("Current users on {0}: {1}, max. {2}").format(
                server, parts[1], parts[2])
        elif code == 266:
            parts = message.strip().split()
            message = self.trUtf8("Current users on the network: {0}, max. {1}").format(
                parts[1], parts[2])
        elif code == 305:
            message = self.trUtf8("You are no longer marked as being away.")
        elif code == 306:
            message = self.trUtf8("You have been marked as being away.")
        else:
            first, message = message.split(None, 1)
            if message.startswith(":"):
                message = message[1:]
            else:
                message = message.replace(":", "", 1)
        
        self.networkWidget.addServerMessage(msgType, message)
        
        if code == 1:
            # register with services after the welcome message
            self.__connectionState = IrcWidget.ServerConnected
            self.__registerWithServices()
            self.networkWidget.setRegistered(True)
            QTimer.singleShot(1000, self.__autoJoinChannels)
        elif code == 5:
            # extract the user privilege prefixes
            # ... PREFIX=(ov)@+ ...
            m = self.__prefixRe.match(message)
            if m:
                self.__setUserPrivilegePrefix(m.group(1), m.group(2))
            # extract the channel type prefixes
            # ... CHANTYPES=# ...
            m = self.__chanTypesRe.match(message)
            if m:
                self.__setChannelTypePrefixes(m.group(1))
        
        return True
    
    def __registerWithServices(self):
        """
        Private method to register to services.
        """
        identity = self.__ircNetworkManager.getIdentity(self.__identityName)
        service = identity.getServiceName()
        password = identity.getPassword()
        if service and password:
            self.__send("PRIVMSG " + service + " :identify " + password)
    
    def __autoJoinChannels(self):
        """
        Private slot to join channels automatically once a server got connected.
        """
        for channel in self.networkWidget.getNetworkChannels():
            if channel.autoJoin():
                name = channel.getName()
                key = channel.getKey()
                self.__joinChannel(name, key)
    
    def __tcpError(self, error):
        """
        Private slot to handle errors reported by the TCP socket.
        
        @param error error code reported by the socket
            (QAbstractSocket.SocketError)
        """
        if error == QAbstractSocket.RemoteHostClosedError:
            # ignore this one, it's a disconnect
            if self.__sslErrorLock:
                self.networkWidget.addErrorMessage(self.trUtf8("SSL Error"),
                    self.trUtf8("""Connection to server {0} (port {1}) lost while"""
                                """ waiting for user response to an SSL error.""").format(
                    self.__server.getName(), self.__server.getPort()))
                self.__connectionState = IrcWidget.ServerDisconnected
        elif error == QAbstractSocket.HostNotFoundError:
            self.networkWidget.addErrorMessage(self.trUtf8("Socket Error"),
                self.trUtf8("The host was not found. Please check the host name"
                            " and port settings."))
        elif error == QAbstractSocket.ConnectionRefusedError:
            self.networkWidget.addErrorMessage(self.trUtf8("Socket Error"),
                self.trUtf8("The connection was refused by the peer. Please check the"
                            " host name and port settings."))
        elif error == QAbstractSocket.SslHandshakeFailedError:
            self.networkWidget.addErrorMessage(self.trUtf8("Socket Error"),
                self.trUtf8("The SSL handshake failed."))
        else:
            if self.__socket:
                self.networkWidget.addErrorMessage(self.trUtf8("Socket Error"),
                    self.trUtf8("The following network error occurred:<br/>{0}").format(
                    self.__socket.errorString()))
            else:
                self.networkWidget.addErrorMessage(self.trUtf8("Socket Error"),
                    self.trUtf8("A network error occurred."))
    
    def __sslErrors(self, errors):
        """
        Private slot to handle SSL errors.
        
        @param errors list of SSL errors (list of QSslError)
        """
        ignored, defaultChanged = self.__sslErrorHandler.sslErrors(
            errors, self.__server.getName(), self.__server.getPort())
        if ignored == E5SslErrorHandler.NotIgnored:
            self.networkWidget.addErrorMessage(self.trUtf8("SSL Error"),
                self.trUtf8("""Could not connect to {0} (port {1}) using an SSL"""
                            """ encrypted connection. Either the server does not"""
                            """ support SSL (did you use the correct port?) or"""
                            """ you rejected the certificate.""").format(
                self.__server.getName(), self.__server.getPort()))
            self.__socket.close()
        else:
            if defaultChanged:
                self.__socket.setSslConfiguration(
                    QSslConfiguration.defaultConfiguration())
            if ignored == E5SslErrorHandler.UserIgnored:
                self.networkWidget.addErrorMessage(self.trUtf8("SSL Error"),
                    self.trUtf8("""The SSL certificate for the server {0} (port {1})"""
                                """ failed the authenticity check. SSL errors"""
                                """ were accepted by you.""").format(
                    self.__server.getName(), self.__server.getPort()))
            if self.__connectionState == IrcWidget.ServerConnecting:
                self.__socket.ignoreSslErrors()
    
    def __setUserPrivilegePrefix(self, prefix1, prefix2):
        """
        Private method to set the user privilege prefix.
        
        @param prefix1 first part of the prefix (string)
        @param prefix2 indictors the first part gets mapped to (string)
        """
        # PREFIX=(ov)@+
        # o = @ -> @ircbot , channel operator
        # v = + -> +userName , voice operator
        for i in range(len(prefix1)):
            self.__userPrefix["+" + prefix1[i]] = prefix2[i]
            self.__userPrefix["-" + prefix1[i]] = ""
    
    def __ping(self, match):
        """
        Private method to handle a PING message.
        
        @param reference to the match object
        @return flag indicating, if the message was handled (boolean)
        """
        self.__send("PONG " + match.group(1))
        return True
    
    def __handleCtcp(self, match):
        """
        Private method to handle a CTCP command.
        
        @param reference to the match object
        @return flag indicating, if the message was handled (boolean)
        """
        # group(1)   sender user name
        # group(2)   sender user@host
        # group(3)   target nick
        # group(4)   message
        if match.group(4).startswith("\x01"):
            ctcpCommand = match.group(4)[1:].split("\x01", 1)[0]
            if " " in ctcpCommand:
                ctcpRequest, ctcpArg = ctcpCommand.split(" ", 1)
            else:
                ctcpRequest, ctcpArg = ctcpCommand, ""
            ctcpRequest = ctcpRequest.lower()
            if ctcpRequest == "version":
                if Version.startswith("@@"):
                    vers = ""
                else:
                    vers = " " + Version
                msg = "Eric IRC client{0}, {1}".format(vers, Copyright)
                self.networkWidget.addServerMessage(self.trUtf8("CTCP"),
                    self.trUtf8("Received Version request from {0}.").format(
                    match.group(1)))
                self.__sendCtcpReply(match.group(1), "VERSION " + msg)
            elif ctcpRequest == "ping":
                self.networkWidget.addServerMessage(self.trUtf8("CTCP"),
                    self.trUtf8("Received CTCP-PING request from {0},"
                    " sending answer.").format(match.group(1)))
                self.__sendCtcpReply(match.group(1), "PING {0}".format(ctcpArg))
            elif ctcpRequest == "clientinfo":
                self.networkWidget.addServerMessage(self.trUtf8("CTCP"),
                    self.trUtf8("Received CTCP-CLIENTINFO request from {0},"
                        " sending answer.").format(match.group(1)))
                self.__sendCtcpReply(match.group(1),
                    "CLIENTINFO CLIENTINFO PING VERSION")
            else:
                self.networkWidget.addServerMessage(self.trUtf8("CTCP"),
                    self.trUtf8("Received unknown CTCP-{0} request from {1}.").format(
                    ctcpRequest, match.group(1)))
            return True
        
        return False
    
    def __updateUsersCount(self):
        """
        Private method to update the users count on the channel tabs.
        """
        for channel in self.__channelList:
            index = self.channelsWidget.indexOf(channel)
            self.channelsWidget.setTabText(index,
                self.trUtf8("{0} ({1})", "channel name, users count").format(
                channel.name(), channel.getUsersCount()))
    
    def __handleNickInUseLogin(self):
        """
        Private method to handle a 443 server error at login.
        """
        self.__nickIndex += 1
        try:
            nick = self.__ircNetworkManager.getIdentity(self.__identityName)\
                .getNickNames()[self.__nickIndex]
            self.__nickName = nick
        except IndexError:
            self.networkWidget.addServerMessage(self.trUtf8("Critical"),
                self.trUtf8("No nickname acceptable to the server configured"
                            " for <b>{0}</b>. Disconnecting...").format(self.__userName),
                            filterMsg=False)
            self.__connectNetwork("", False, silent=True)
            self.__nickName = ""
            self.__nickIndex = -1
            return
        
        self.networkWidget.setNickName(nick)
        self.__send("NICK " + nick)
    
    def __handleNickInUse(self):
        """
        Private method to handle a 443 server error.
        """
        self.networkWidget.addServerMessage(self.trUtf8("Critical"),
            self.trUtf8("The given nickname is already in use."))
    
    def __changeNick(self, nick):
        """
        Private slot to use a new nick name.
        
        @param nick nick name to use (str)
        """
        if nick and nick != self.__nickName:
            self.__send("NICK " + nick)
    
    def __setChannelTypePrefixes(self, prefixes):
        """
        Private method to set the channel type prefixes.
        
        @param prefixes channel prefix characters (string)
        """
        self.__channelTypePrefixes = prefixes
    
    def isChannelName(self, name):
        """
        PublicisChannelName method to check, if the given name is a channel name.
        
        @return flag indicating a channel name (boolean)
        """
        if not name:
            return False
        
        if self.__channelTypePrefixes:
            return name[0] in self.__channelTypePrefixes
        else:
            return name[0] in "#&"
    
    def __away(self, isAway):
        """
        Private slot handling the change of the away state.
        
        @param isAway flag indicating the current away state (boolean)
        """
        if isAway and self.__identityName:
            identity = self.__ircNetworkManager.getIdentity(self.__identityName)
            if identity.rememberAwayPosition():
                for channel in self.__channelList:
                    channel.setMarkerLine()