Implementing c++ Callback using Qt Signal and Slot - c++

Question

I have created a library which has following interface and callback.
I wanted to Implent it using QT Signal and Slot.
Is is possible to replace IWifiCameraDiscovery with Signal and slot
class IWifiCameraDiscovery
{
public:
virtual int InitialiseWiFiDiscovery(IWifiCameraEnumerationCallback*) = 0;
virtual void UnInitialiseWiFiDiscovery() = 0;
virtual int EnumerateWiFiDevice() = 0;
};
class IWifiCameraEnumerationCallback
{
public:
virtual void onWiFiDeviceDiscovered( WiFiDeviceInfo* pDeviceInfo,unsigned short nNoOfDevice) = 0;
virtual void onDiscoveryTimeout() = 0;
};

Answer 1

Yes, in a quite straightforward way.
class IWifiCameraDiscovery
{
public:
virtual int InitialiseWiFiDiscovery() = 0;
virtual void UnInitialiseWiFiDiscovery() = 0;
virtual int EnumerateWiFiDevice() = 0;
signals:
void onWiFiDeviceDiscovered(WiFiDeviceInfo* pDeviceInfo, unsigned short nNoOfDevice);
void onDiscoveryTimeout();
};
In your implementation, instead of calling the callbacks directly:
callback.onWiFiDeviceDiscovered(pDevInfo, x);
You would emit a signal:
emit onWiFiDeviceDiscovered(pDevInfo, x);
And you would use QObject::connect to connect these signals to your actual receivers (slots) on the other end. Be aware that emitting a signal is more expensive than calling a virtual function.

Answer 2

try this simple example
#include <QApplication>
#include <QFont>
#include <QPushButton>
#include <QWidget>
class MyWidget : public QWidget
{
public:
MyWidget(QWidget *parent = 0);
};
MyWidget::MyWidget(QWidget *parent)
: QWidget(parent)
{
setFixedSize(200, 120);
QPushButton *quit = new QPushButton(tr("Quit"), this);
quit->setGeometry(62, 40, 75, 30);
quit->setFont(QFont("Times", 18, QFont::Bold));
connect(quit, SIGNAL(clicked()), qApp, SLOT(quit()));
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyWidget widget;
widget.show();
return app.exec();
}
you can use like this
class IWifiCameraDiscovery
{
public slots:
void UnInitialiseWiFiDiscovery();
signals:
void EnumerateWiFiDevice();
}