Problem with signals and slots...

[SPlatten]

Since the update to Qt Creator 4.14.0 and 5.15.2, I am getting:

clsMsgSender::tryToConnect is not a signal [clazy-connect-non-signal]

This is now typical on every connect I have, the above is on the line:

QObject::connect(this, &clsMsgSender::tryToConnect
                ,this, &clsMsgSender::onTryToConnect);

This connect is in the class clsMsgSender, the prototype for this class:

    class clsMsgSender : public QObject {
    Q_OBJECT

    private:        
        static const quint16 mscuint16ConnectionTO;
        static mpMsgSenders msmpMsgSenders;
        static clsMsgSender* mspService;
        static QThread* mspThread;
        static qulonglong msulnglngMsgID;

        bool mblnRun;
        QTcpSocket* mpsckClient;
        mqueJSON mqueMsgsOut;
        QMutex mMutex;
        quint16 muint16Port;

        bool blnAnythingToDo(QJsonObject& robjJSON);
        void push(QJsonObject& robjJSON);

    public:
        explicit clsMsgSender(quint16 uint16Port);
        ~clsMsgSender();

        QTcpSocket* pGetClient() { return mpsckClient; }
        static clsMsgSender* pGetMsgSndr(quint16 uint16Port);
        static clsMsgSender* pGetService() { return clsMsgSender::mspService; }
        static QString strGetLocalIP();
        void terminate() { mblnRun = false; }
        quint16 uint16Port() { return muint16Port; }
        static qulonglong ulnglngGetMsgID() { return clsMsgSender::msulnglngMsgID; }

    signals:
        void cannotConnect();
        void connected();
        void disconnected();
        void finished();
        void sendJSON(QJsonObject robjJSON);
        void startService();
        void tryToConnect(const QString& crstrHost, const quint16 cint16Port);
        void write(QJsonObject robjJSON);

    public slots:        
        void onCreateMsgSndrThrd();
        void onErrorOccurred(QAbstractSocket::SocketError sckError);
        void onSendJSON(QJsonObject robjJSON);
        void onStartMsgSndrThrd();
        void onTryToConnect(const QString& crstrHost, const quint16 cint16Port);
        void onWrite(QJsonObject robjJSON);
        void run();
    };

Using the debugger I have stepped over an emit of the tryToConnect:

emit tryToConnect(clsMsgSender::strGetLocalIP(), muint16Port);

With a breakpoint in the onTryToConnect slot:

void clsMsgSender::onTryToConnect(const QString& crstrHost, const quint16 cint16Port) {
    //Get local IP address
    qdbg() << "Connecting to: " << crstrHost << ":" << cint16Port;
    //Connect to the Application
    mpsckClient->connectToHost(crstrHost, cint16Port);

    if ( mpsckClient->waitForConnected(clsMsgSender::mscuint16ConnectionTO) != true ) {
        emit cannotConnect();
    }
}

The breakpoint is on the qdbg() line, it never gets there. I am assuming that this is related to the warning message, but why? This looks like a Qt Creator issue, how can I fix this? In desperation I uninstalled Qt Creator and the Qt folder then re-installed again, it automatically installs Qt Creator 4.14.0 and 5.15.2.

Anyone else using these versions and found the same problems?

[mrjj]

@SPlatten
hi

[SGaist]

Hi,

@SPlatten said in Problem with signals and slots...:

Using the debugger I have stepped over an emit of the tryToConnect:
emit mpobjMsgSender->sendJSON(objMsg);

With a breakpoint in the onTryToConnect slot:

How is sendJSON related to onTryToConnect ?

By the way, signals should only be emitted from within the classes they are defined in.

[SPlatten]

@SGaist , sorry, my bad, I cut and pasted the wrong code into the post, will correct now. The emit I pasted in is called from the run() which is a slot within the same class.

void clsMsgSender::run() {    
    QTcpSocket::SocketState sckCurState, sckLastState;
    QJsonObject objJSON;
    while( mblnRun == true  ) {
    //Sleep to allow a small cap between transmission
        QThread::usleep(100);

        sckCurState = mpsckClient->state();

        if ( sckLastState != sckCurState ) {
            sckLastState = sckCurState;
            qdbg() << mpsckClient->state();
        }
        if ( mpsckClient->state() != QAbstractSocket::ConnectedState ) {
            if ( mpsckClient->state() != QAbstractSocket::ConnectingState ) {
                emit tryToConnect(clsMsgSender::strGetLocalIP(), muint16Port);
            }
            if ( mpsckClient->state() != QAbstractSocket::ConnectedState ) {
                continue;
            }
        }
        if ( blnAnythingToDo(objJSON) != true ) {
    //Nothing to do...yet!
            continue;
        }
    //Look for a module name in the message
        QJsonObject::iterator itrFound = objJSON.find(clsJSON::mscszMsgType);

        if ( itrFound != objJSON.end() ) {
            const QJsonValueRef crobjMsgType = itrFound.value();
            QString strMsgType(crobjMsgType.toString());

            if ( strMsgType.compare(clsJSON::mscszAck) != 0 ) {
    //Insert a unique message ID into the message
                objJSON.insert(clsJSON::mscszMsgID, QString::number(++clsMsgSender::msulnglngMsgID));
    //Create entry to monitor status of this message
                new clsMsgTrkr(this, objJSON);
            }
        }
    //Writes message to socket
        emit write(objJSON);
    }
}

[Christian Ehrlicher]

Why do you think that clazy now magically is fixed without any other changes and asking the same question as 4 days ago?
https://forum.qt.io/topic/121934

[SPlatten]

@Christian-Ehrlicher , I was hoping since this is the latest offering, that someone could confirm that this is a Qt issue and not my own?

Is there a way to role back to an earlier version of Qt Creator?

[SPlatten]

I have now uninstalled Qt Creator 4.14 and 5.15.2 and switched to Qt Creator 4.13.1 using 5.15.1 and SDK 5.12.10.

All the faulty messages have now disappeared.

[JonB]

@SPlatten
Well done! Now be sure to switch off any "auto-update" of Creator! :)

[SPlatten]

This post is deleted!

[SPlatten]

@JonB , how?

[mrjj]

@SPlatten
hi