Signal Slot not working

Avtansh Sharma

HI,

header

#ifndef DEVICEDATA_H
#define DEVICEDATA_H
#include<QString>

#include<QtSql/QSqlDatabase>
#include<QSqlQuery>
#include<QSqlError>
#include <QString>
#include <QObject>
#include <QtBluetooth/QBluetoothSocket>
QT_FORWARD_DECLARE_CLASS(QBluetoothSocket)

QT_USE_NAMESPACE



class DeviceData : public QObject
{
    Q_OBJECT




public:
    explicit DeviceData(QObject *parent=0);
    ~DeviceData();
    int SaveData(QString s_Data,QString Str_Sensor);
    QList<QString> getData(QString tbl_sensor);
    int syncDevice(bool b_terminate);
    int syncDeviceData(bool b_terminate);
    bool m_bterminate;
    void stopClient();


private:
    QSqlDatabase m_db;
    QString getMax(QString Str_Table);

    //QString ReadData();
QBluetoothSocket *m_bluetoothSocket;
signals:
    void messageReceived(const QString &sender, const QString &message);
    void connected(const QString &name);
    void disconnected();

private slots:
    void readSocket();
    void connected();
public slots:
    void sendMessage(const QString &message);



};

#endif // DEVICEDATA_H

cpp file

#include <devicedata.h>
#include <QDebug>
#include <QDateTime>
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/rfcomm.h>
#include <QDebug>
#include <devicedata.h>
#include <QtBluetooth/QBluetoothSocket>
/*
 *
 *
 *
 *
sqllite3 db_Health.db;

create table tbl_BodyTemperature
(
c_id primarykey integer,
c_Temperature text,
c_TimeStamp text
);

create table tbl_HeartSensor
(
c_id integer,
c_HeartBeatPulse integer,
c_TimeStamp text
);

create table tbl_BeatInterval
(
c_id primarykey integer,
c_BeatInterval text,
c_TimeStamp text
);
*
*
*
**/


DeviceData::DeviceData(QObject *parent)
:   QObject(parent), m_bluetoothSocket(0)
{
    m_bterminate=false;
  
}

DeviceData::~DeviceData()
{
    stopClient();
}



void DeviceData::stopClient()
{
    delete m_bluetoothSocket;
    m_bluetoothSocket = 0;
}
//! [stopClient]

//! [readSocket]
void DeviceData::readSocket()
{
    if (!m_bluetoothSocket)
        return;

    while (1||m_bluetoothSocket->canReadLine()) {
        QByteArray line = m_bluetoothSocket->readLine();
        qInfo()<< QString::fromUtf8(line.constData(), line.length());
        emit messageReceived(m_bluetoothSocket->peerName(),
                            QString::fromUtf8(line.constData(), line.length()));
    }
}
//! [readSocket]

//! [sendMessage]
void DeviceData::sendMessage(const QString &message)
{
    QByteArray text = message.toUtf8() + '\n';
    m_bluetoothSocket->write(text);
}
//! [sendMessage]

//! [connected]
void DeviceData::connected()
{
    emit connected(m_bluetoothSocket->peerName());
}
/*
 * DeviceData::DeviceData()
{

}
*/
int DeviceData::syncDeviceData(bool b_terminate)
{

        m_bluetoothSocket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol);


    connect(m_bluetoothSocket, SIGNAL(readyReadn()), this, SLOT(readSocket()));
    connect(m_bluetoothSocket, SIGNAL(connected()), this, SLOT(connected()));
    connect(m_bluetoothSocket, SIGNAL(disconnected()), this, SIGNAL(disconnected()));

    m_bluetoothSocket->connectToService((QBluetoothAddress)"B8:27:EB:54:81:BE",(quint16)1);

  //  qInfo()<<m_bluetoothSocket->canReadLine();

  //  connect(m_bluetoothSocket, SIGNAL(), this, SIGNAL(disconnected()));

return 0;

}

int DeviceData::syncDevice(bool b_terminate)
{
syncDeviceData(b_terminate);
    return 0;

}

Regards,
Avtansh Sharma

mrjj

Hi
check if connects fails
Q_ASSUME ( connect(m_bluetoothSocket, SIGNAL(readyReadn()), this, SLOT(readSocket())) );
Q_ASSUME ( connect(m_bluetoothSocket, SIGNAL(connected()), this, SLOT(connected())));
Q_ASSUME ( connect(m_bluetoothSocket, SIGNAL(disconnected()), this, SIGNAL(disconnected())));

Avtansh Sharma

@mrjj said in Signal Slot not working:

Q_ASSUME

No difference.

Connect fails if i change the names of slot. Hence correct connections are being done.

On server side I am getting a notification that a client is connected.

mrjj

@Avtansh-Sharma
Do you run it in a thread ?
If not, maybe your while loop strangulate the event loop.

Anyway, i think you will need to use the debugger to find the cause of "not working"

Avtansh Sharma

I created a custom signal slot . It is working in this class.

No I am not using a thread

mrjj

@Avtansh-Sharma

Ok so what exactly is not working ?

Avtansh Sharma

The signal slot mechanism of QBluetooth
Socket is not working
readSocket,connected are never getting called even after server says a client has made a connection

mrjj

@Avtansh-Sharma

Ok, might be a bug or something im not seeing in the code.
You can check https://bugreports.qt.io

Is other signals being sent ? like disconnected ?

make sure all connects are using Q_ASSUME so its not something trivial.

There is nothing that spring to mind. Maybe others can spot something.

Avtansh Sharma

@mrjj Thanks for help.

I remember you were saying something about thread can you please explain int detail. I will be using thread anyway in future. Maybe it will work in thread.

VRonin

@Avtansh-Sharma said in Signal Slot not working:

connect(m_bluetoothSocket, SIGNAL(readyReadn())

Typo? should be connect(m_bluetoothSocket, SIGNAL(readyRead()) or, better, using Qt5 syntax: connect(m_bluetoothSocket,&QBluetoothSocket::readyRead,this,&DeviceData::readSocket);

mrjj

@Avtansh-Sharma
Hi
Using a thread will most likely not make any difference with the current issue but
when you use signals from inside a thread , it's sometimes necessary to add Qt::QueuedConnection
to the connect statement.
https://woboq.com/blog/how-qt-signals-slots-work-part3-queuedconnection.html