Qt 5.9 | Qt D-Bus | D-Bus Chat Example | chat.cpp Example File

Qt 5.9.9 Reference Documentation

# chat.cpp Example File

chat/chat.cpp

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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();
      }