Define custom signals and slots

Same effect of the last exercise "signals and slots". In this exercise we create a new class, InterClass, with custom signals and slots. In main.cpp, the emited signals will be sent to the InterClass and re-direct to the receiver.



create a new class, InterClass.

interclass.h

#ifndef INTERCLASS_H
#define INTERCLASS_H

#include <QtGui>
#include <QObject>

class InterClass : public QObject
{
    Q_OBJECT
public:
    explicit InterClass(QObject *parent, QSlider *slider, QSpinBox *spinBox);

signals:
    void spinBoxValueChanged(int value);
    void sliderValueChanged(int value);
public slots:
    void setValue(int value);

private:
    QSlider *parentSlider;
    QSpinBox *parentSpinBox;

};

#endif // INTERCLASS_H

interclass.cpp

#include <QtGui>
#include "interclass.h"

InterClass::InterClass(QObject *parent, QSlider *slider, QSpinBox *spinBox) :
    QObject(parent)
{
    parentSlider = slider;
    parentSpinBox = spinBox;
    QObject::connect(this, SIGNAL(sliderValueChanged(int)), parentSpinBox, SLOT(setValue(int)));
    QObject::connect(this, SIGNAL(spinBoxValueChanged(int)), parentSlider, SLOT(setValue(int)));
}

void InterClass::setValue(int value)
{
    if((QObject::sender()) == parentSlider){
        emit sliderValueChanged(value);
    }
    else{
        emit spinBoxValueChanged(value);
    }
}

main.cpp

#include <QtGui>
#include "interclass.h"

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);

    QWidget* mainwindow = new QWidget();
    QVBoxLayout* mainlayout = new QVBoxLayout();

    QSlider* slider = new QSlider(Qt::Horizontal, mainwindow);
    slider->setRange(0, 100);

    QSpinBox* spinBox = new QSpinBox(mainwindow);
    spinBox->setRange(0, 100);

    InterClass* interClass =  new InterClass(mainwindow, slider, spinBox);

    QObject::connect(slider, SIGNAL(valueChanged(int)), interClass, SLOT(setValue(int)));
    QObject::connect(spinBox, SIGNAL(valueChanged(int)), interClass, SLOT(setValue(int)));

    mainlayout->addWidget(slider);
    mainlayout->addWidget(spinBox);

    mainwindow->setLayout(mainlayout);
    mainwindow->show();
    return app.exec();
}