- Qt 5.5
- Qt D-Bus
- D-Bus Chat Example
- chat.cpp Example File
- Qt 5.5.1 Reference Documentation

# chat.cpp Example File

chat/chat.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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    #include <QApplication>
    #include <QMessageBox>

    #include "chat.h"
    #include "chat_adaptor.h"
    #include "chat_interface.h"

    ChatMainWindow::ChatMainWindow()
        : m_nickname(QLatin1String("nickname"))
    {
        setupUi(this);
        sendButton->setEnabled(false);

        connect(messageLineEdit, SIGNAL(textChanged(QString)),
                this, SLOT(textChangedSlot(QString)));
        connect(sendButton, SIGNAL(clicked(bool)), this, SLOT(sendClickedSlot()));
        connect(actionChangeNickname, SIGNAL(triggered(bool)), this, SLOT(changeNickname()));
        connect(actionAboutQt, SIGNAL(triggered(bool)), this, SLOT(aboutQt()));
        connect(qApp, SIGNAL(lastWindowClosed()), this, SLOT(exiting()));

        // add our D-Bus interface and connect to D-Bus
        new ChatAdaptor(this);
        QDBusConnection::sessionBus().registerObject("/", this);

        org::example::chat *iface;
        iface = new org::example::chat(QString(), QString(), QDBusConnection::sessionBus(), this);
        //connect(iface, SIGNAL(message(QString,QString)), this, SLOT(messageSlot(QString,QString)));
        QDBusConnection::sessionBus().connect(QString(), QString(), "org.example.chat", "message", this, SLOT(messageSlot(QString,QString)));
        connect(iface, SIGNAL(action(QString,QString)), this, SLOT(actionSlot(QString,QString)));

        NicknameDialog dialog;
        dialog.cancelButton->setVisible(false);
        dialog.exec();
        m_nickname = dialog.nickname->text().trimmed();
        emit action(m_nickname, QLatin1String("joins the chat"));
    }

    ChatMainWindow::~ChatMainWindow()
    {
    }

    void ChatMainWindow::rebuildHistory()
    {
        QString history = m_messages.join( QLatin1String("\n" ) );
        chatHistory->setPlainText(history);
    }

    void ChatMainWindow::messageSlot(const QString &nickname, const QString &text)
    {
        QString msg( QLatin1String("<%1> %2") );
        msg = msg.arg(nickname, text);
        m_messages.append(msg);

        if (m_messages.count() > 100)
            m_messages.removeFirst();
        rebuildHistory();
    }

    void ChatMainWindow::actionSlot(const QString &nickname, const QString &text)
    {
        QString msg( QLatin1String("* %1 %2") );
        msg = msg.arg(nickname, text);
        m_messages.append(msg);

        if (m_messages.count() > 100)
            m_messages.removeFirst();
        rebuildHistory();
    }

    void ChatMainWindow::textChangedSlot(const QString &newText)
    {
        sendButton->setEnabled(!newText.isEmpty());
    }

    void ChatMainWindow::sendClickedSlot()
    {
        //emit message(m_nickname, messageLineEdit->text());
        QDBusMessage msg = QDBusMessage::createSignal("/", "org.example.chat", "message");
        msg << m_nickname << messageLineEdit->text();
        QDBusConnection::sessionBus().send(msg);
        messageLineEdit->setText(QString());
    }

    void ChatMainWindow::changeNickname()
    {
        NicknameDialog dialog(this);
        if (dialog.exec() == QDialog::Accepted) {
            QString old = m_nickname;
            m_nickname = dialog.nickname->text().trimmed();
            emit action(old, QString("is now known as %1").arg(m_nickname));
        }
    }

    void ChatMainWindow::aboutQt()
    {
        QMessageBox::aboutQt(this);
    }

    void ChatMainWindow::exiting()
    {
        emit action(m_nickname, QLatin1String("leaves the chat"));
    }

    NicknameDialog::NicknameDialog(QWidget *parent)
        : QDialog(parent)
    {
        setupUi(this);
    }

    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);

        if (!QDBusConnection::sessionBus().isConnected()) {
            qWarning("Cannot connect to the D-Bus session bus.\n"
                     "Please check your system settings and try again.\n");
            return 1;
        }

        ChatMainWindow chat;
        chat.show();
        return app.exec();
    }