Signal Slot is missing in moc file

Question

I cannot use the button, which I have connected with the correct slot.

Here the infoPage.cpp file:

#include "infoPage.h"

InfoPage::InfoPage(QWidget *parent)
    : QDialog(parent)
{
    ui.setupUi(this);
    bool working = false;
    working = QObject::connect(ui.b_showReleaseNotes, SIGNAL(clicked()), this, SLOT(openReleaseNotes()));
    working = QObject::connect(ui.ok_button, SIGNAL(clicked()), this, SLOT(closeInfoPage()));
}

void InfoPage::openReleaseNotes()
{

    QString prog = "C:\\Windows\\System32\\";

    const char *args[3];

    //get full path of file to use it in cmd 

    QString currentAppPath = QCoreApplication::applicationDirPath();

    QString releaseNotePath = currentAppPath + "release_notes.txt";

    args[0] = "notepad.exe";
    args[1] = _strdup(releaseNotePath.toAscii());
    args[2] = NULL;

    prog += args[0];
    //LOG_DEBUG("starting external program '%s' with file '%s'", prog.toAscii(), docPath.toAscii());

    int errorCode = _spawnv(_P_NOWAIT , _strdup(prog.toAscii()),args);

    if (errorCode == -1)
    {
        QMessageBox::information(NULL, "Error:","An error occured while starting process. The call was\n\""+prog+" "+releaseNotePath+"\"");
    }


}

void InfoPage::closeInfoPage()
{
    QString test = "ABC";
    this->close();
    return;
}


InfoPage::~InfoPage()
{

}

Here the depend .h file:

#ifndef INFOPAGE_H
#define INFOPAGE_H

#include <QDialog>
#include "ui_infoPage.h"
#include <QProcess>
#include <process.h>
#include <QtDebug>
#include <QtGui/QMessageBox>

class InfoPage : public QDialog
{

 Q_OBJECT


public:
    InfoPage(QWidget *parent = 0);
    ~InfoPage();
    void openReleaseNotes();
    void closeInfoPage();


//private:
    Ui::InfoPage ui;

private:
    //void openReleaseNotes();
    QString programPath;

};

#endif // INFOPAGE_H

At least, the moc file:

/****************************************************************************
** Meta object code from reading C++ file 'infoPage.h'
**
** Created: Mon 24. Jul 10:41:32 2017
**      by: The Qt Meta Object Compiler version 62 (Qt 4.7.0)
**
** WARNING! All changes made in this file will be lost!
*****************************************************************************/

#include "../../infoPage.h"
#if !defined(Q_MOC_OUTPUT_REVISION)
#error "The header file 'infoPage.h' doesn't include <QObject>."
#elif Q_MOC_OUTPUT_REVISION != 62
#error "This file was generated using the moc from 4.7.0. It"
#error "cannot be used with the include files from this version of Qt."
#error "(The moc has changed too much.)"
#endif

QT_BEGIN_MOC_NAMESPACE
static const uint qt_meta_data_InfoPage[] = {

 // content:
       5,       // revision
       0,       // classname
       0,    0, // classinfo
       0,    0, // methods
       0,    0, // properties
       0,    0, // enums/sets
       0,    0, // constructors
       0,       // flags
       0,       // signalCount

       0        // eod
};

static const char qt_meta_stringdata_InfoPage[] = {
    "InfoPage\0"
};

const QMetaObject InfoPage::staticMetaObject = {
    { &QDialog::staticMetaObject, qt_meta_stringdata_InfoPage,
      qt_meta_data_InfoPage, 0 }
};

#ifdef Q_NO_DATA_RELOCATION
const QMetaObject &InfoPage::getStaticMetaObject() { return staticMetaObject; }
#endif //Q_NO_DATA_RELOCATION

const QMetaObject *InfoPage::metaObject() const
{
    return QObject::d_ptr->metaObject ? QObject::d_ptr->metaObject : &staticMetaObject;
}

void *InfoPage::qt_metacast(const char *_clname)
{
    if (!_clname) return 0;
    if (!strcmp(_clname, qt_meta_stringdata_InfoPage))
        return static_cast<void*>(const_cast< InfoPage*>(this));
    return QDialog::qt_metacast(_clname);
}

int InfoPage::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{
    _id = QDialog::qt_metacall(_c, _id, _a);
    if (_id < 0)
        return _id;
    return _id;
}
QT_END_MOC_NAMESPACE

During the run of the application, I get the following message:

Object::connect: No such slot InfoPage::openReleaseNotes() in infoPage.cpp:8
Object::connect:  (sender name:   'b_showReleaseNotes')
Object::connect:  (receiver name: 'InfoPage')
Object::connect: No such slot InfoPage::closeInfoPage() in infoPage.cpp:9
Object::connect:  (sender name:   'ok_button')
Object::connect:  (receiver name: 'InfoPage')

I have read in other threads, that the moc file is responsible to create a "relation" between the signal and slot.

But the moc file does not contain any list of signal slots. I know, it has to contain something like that in qt_meta_data_InfoPage[]:

 // slots: signature, parameters, type, tag, flags
      10,    9,    9,    9, 0x08,
      54,   50,    9,    9, 0x08,

  0    //end

If I removes the content of the moc file, the new generated moc file contains the same code.

Is there any possibility to add the signal/slot to the moc file manually?

Regards,

Samir

Answer 1

The reason for the lack of slots in the moc file is the fact that the two methods are not declared as slots, they are declared as simple methods:

public:
    InfoPage(QWidget *parent = 0);
    ~InfoPage();
    void openReleaseNotes();
    void closeInfoPage();

Instead, they should be declared as slots:

public:
        InfoPage(QWidget *parent = 0);
        ~InfoPage();

public slots:
        void openReleaseNotes();
        void closeInfoPage();