QTcpSocket - Events

[Skorpien126]

Hi,
i´ve a strange problem. I try to implement some kind of permanent event for an object deriving from QTcpSocket. My first idea was to use a simple timer be called all x-msecs. The problem is that I can´t connect to slots defined in my subclass - I checked out the internet and found this http://stackoverflow.com/questions/1389680/why-is-qt-looking-for-my-slot-in-the-base-class-instead-of-derived-one. All the points of the solution are applied but it´s still not working - any idea why it´s not working?

Furthermore I tried it with the timer of QObject-Baseclass - call startTimer() and implementing timerEvent(QEvent* event) - but the function is never called!??!

Is there a reason for this behaviour - do I miss something?!?!?

[tbscope]

Can you please post your code?
There can be tons of possible errors and without seeing the code it's not easy to pin them down.

[Skorpien126]

Sure.... here a simple example.



#ifndef MYTCPSOCKET_H
#define MYTCPSOCKET_H

#include <QDebug>
#include <QHostInfo>
#include <QHostAddress>
#include <QTcpSocket>
#include "Definitions.h"

class myTCPSocket: public QTcpSocket
{
Q_OBJECT

public:
myTCPSocket(QObject* in_Parent = NULL);
~myTCPSocket(void);

// init the object (startTimer)
void init()
{
startTimer();
}

// reads a package
bool readPackage(tNetworkTcpData* in_NetworkTcpData);

// writes a package
bool writePackage(tNetworkTcpData in_NetworkTcpData);

// handle event
void timerEvent(QTimerEvent *event)
{
qDebug()<< "timerEventFired";
}

private:
};
#endif //MYTCPSOCKET_H


My Socket is initialized like that....

myTCPSocket m_TcpSocket = static_cast<myTCPSocket*>(in_TcpSocket);
m_TcpSocket->init();

Thx for the help..

[tbscope]

Quoting the documentation:


If interval is 0, then the timer event occurs once every time there are no more window system events to process.

So, try setting a real interval and see what happens.

Also:

Note that QTimer's accuracy depends on the underlying operating system and hardware. Most platforms support an accuracy of 20 milliseconds; some provide more. If Qt is unable to deliver the requested number of timer events, it will silently discard some.
It's not a good idea to use timers to receive or send data (at least I don't think so)

[Skorpien126]

Nothing happens at all.... I set the value to 1000 and 5000 milliseconds.

I know that the accuracy depends on the system - but this not the crititcal point in my case - I just want that the events is emitted when the process has to time to handle it. An update every 500msecs would be satisfying for me too.

[numbat]

myTCPSocket m_TcpSocket = static_cast<myTCPSocket*>(in_TcpSocket);

I don't think this works like you think it does. In particular, I think the vtable still points to the QTcpSocket vtable rather than your subclass vtable. In short, you don't want to do this.

[Skorpien126]

Ok... it´s obvisously whats wrong. Thx....
P.S. Everyone with the same problem. I create a normal QTcpSocket now and connecting it. Afterwards I use the socketDescriptor to initialize my myTcpSocket-object. not sure if this the best way - but it works fine for me. :)