How to compile single cpp without header file in Qt ?

Dear All,

When I want to compile below script, it shown error like this :

toggle/main.cpp:26: error: undefined reference to `vtable for toggle'

line 26 : toggle::toggle( QWidget *parent ) : QDialog( parent )

and here compile output

/media/DATA/Qt/toggle/main.cpp:26: undefined reference to `vtable for toggle'
/media/DATA/Qt/toggle/main.cpp:26: undefined reference to `vtable for toggle'
/media/DATA/Qt/toggle/main.cpp:26: undefined reference to `vtable for toggle'
/media/DATA/Qt/toggle/main.cpp:26: undefined reference to `vtable for toggle'
collect2: ld returned 1 exit status
make: Leaving directory `/media/DATA/Qt/toggle'
make: *** [toggle] Error 1
The process "/usr/bin/make" exited with code %2.
Error while building project toggle (target: Desktop)
When executing build step 'Make'

Can I compile script w/o .h file ? If I can, how to solve below problem ?

Thanks

alphazero


File :
toggle.pro

Code:

---

#-------------------------------------------------
#
# Project created by QtCreator 2010-12-14T21:46:25
#
#-------------------------------------------------
 
QT       += gui
 
TARGET = toggle
CONFIG   += app_bundle
 
TEMPLATE = app
 
 
SOURCES += main.cpp

---

toggle.cpp

Code:

---

#include <QtGui/QApplication>
#include <QDialog>
#include <QWidget>
#include <QPushButton>
#include <QHBoxLayout>
#include <QMessageBox>
 
class QPushButton;
 
class toggle : public QDialog
{
  Q_OBJECT;
 
public:
toggle( QWidget *parent=0 );
 
private slots:
  void buttonClicked();
  void buttonToggled();
 
private:
  QPushButton *clickButton;
  QPushButton *toggleButton;
};
 
toggle::toggle( QWidget *parent ) : QDialog( parent )
{
    clickButton = new QPushButton( "Click me!", this );
    toggleButton = new QPushButton( "Toggle me!", this );
    toggleButton->setCheckable( true );
    QHBoxLayout *layout = new QHBoxLayout( this );
    layout->addWidget( clickButton );
    layout->addWidget( toggleButton );
 
    connect( clickButton, SIGNAL(clicked()), this, SLOT(buttonClicked()) );
    connect( toggleButton, SIGNAL(clicked()), this, SLOT(buttonToggled()) );
 
};
 
void toggle::buttonClicked()
{
  QMessageBox::information( this, "Clicked!", "The button was clicked!" );
};
 
void toggle::buttonToggled()
{
  QMessageBox::information( this, "Toggled!", QString("The button is %1!").arg(toggleButton->isChecked()?"pressed":"released") );
}
 
 
int main( int argc, char **argv )
{
  QApplication app( argc, argv );
 
  toggle *dlg = new toggle();
  dlg->show();
  return app.exec();
}

---

Hi,

Did you run qmake ?

Regards,
Marc

You need to moc the cpp file, try adding '#include "main.moc' and then running qmake and rebuilding.

The moc-related include should be after the declaration of class toggle as the generated code requires a complete class definition. I usually put it as the last line of the file in these one-file test program or QTestLib tests.

Yesterday, I have run qmake, and I didn't see any main.moc built.
But today, when I add script #include "main.moc" on the last line of main.cpp (main.moc is not exist before), and i try to re-run qmake again.. qcreator create "main.moc" automatically.

thanks.. it's working now..

regards,

alphazero