Q_OBJECT macro problem

[norobro]

Sorry bijan311 I've just been shooting in the dark. I haven't used windows for several years and this is my first stab at using Qt under windows. Heck I had to squirt a little wd40 onto my winxp to get it to boot

Looks to me like the path still isn't right. Notice that my path is set to d:\Qt\4.6.2\qt\bin. That's where moc.exe resides on my system. I have no idea how it was set if changing the path in environment variables didn't change yours.

Fatjuicymole is a windows user so I'd follow his advice.

[squidge]

My post is a complete stab in the dark too, but it just seems weird that since Qt comes with GCC, why it would use the GCC in the Codeblocks directory.

[bijan311]

Maybe because my MinGW installment is in the Codeblocks directory

[bijan311]

Ok I found "main.moc" in the debug folder so I copied that into the folder that main.cpp is in, but when i compiles and i press execute the LCDNumber doesn't change.
here is my code

#include <QApplication>
#include <QPushButton>
#include <QLabel>
#include <QSpinBox>
#include <QLCDNumber>
#include <QHBoxLayout>
#include <QVBoxLayout>
 
class Calculator : public QWidget {
    Q_OBJECT
public:
  Calculator(QWidget *parent = 0) : QWidget(parent){
    minus = new QLabel("-");
    equal = new QPushButton("&Execute");
    num1 = new QSpinBox;
    num2 = new QSpinBox;
    answer = new QLCDNumber(3);
 
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(num1);
    layout->addWidget(minus);
    layout->addWidget(num2);
    layout->addWidget(answer);
    QHBoxLayout *buttons = new QHBoxLayout;
    buttons->addStretch();
    buttons->addWidget(equal);
    buttons->addStretch();
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addLayout(layout);
    mainLayout->addLayout(buttons);
    QObject::connect(equal, SIGNAL(clicked()), answer, SLOT(calculate()));
      }
public slots:
  void calculate() {
    answer->display(num1->value()-num2->value());
    disconnect();
  }
private:
  QLabel *minus;
  QPushButton *equal;
  QPushButton *help;
  QSpinBox *num1;
  QSpinBox *num2;
  QLCDNumber *answer;
};
 
int main(int argc, char **argv){
  QApplication app(argc, argv);
  Calculator w;
  w.show();
  return app.exec();
}
#include "main.moc"

#include <QApplication>
#include <QPushButton>
#include <QLabel>
#include <QSpinBox>
#include <QLCDNumber>
#include <QHBoxLayout>
#include <QVBoxLayout>

class Calculator : public QWidget {
    Q_OBJECT
public:
  Calculator(QWidget *parent = 0) : QWidget(parent){
    minus = new QLabel("-");
    equal = new QPushButton("&Execute");
    num1 = new QSpinBox;
    num2 = new QSpinBox;
    answer = new QLCDNumber(3);

    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(num1);
    layout->addWidget(minus);
    layout->addWidget(num2);
    layout->addWidget(answer);
    QHBoxLayout *buttons = new QHBoxLayout;
    buttons->addStretch();
    buttons->addWidget(equal);
    buttons->addStretch();
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addLayout(layout);
    mainLayout->addLayout(buttons);
    QObject::connect(equal, SIGNAL(clicked()), answer, SLOT(calculate()));
      }
public slots:
  void calculate() {
    answer->display(num1->value()-num2->value());
    disconnect();
  }
private:
  QLabel *minus;
  QPushButton *equal;
  QPushButton *help;
  QSpinBox *num1;
  QSpinBox *num2;
  QLCDNumber *answer;
};

int main(int argc, char **argv){
  QApplication app(argc, argv);
  Calculator w;
  w.show();
  return app.exec();
}
#include "main.moc"

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[squidge]

Your connect call is still wrong. Your answer object doesn't have a slot called calculate.

[bijan311]

but its in public slots

[Archimedes]

It's in the public slots of class Calculator and NOT of class QLCDNumber. So change your connect statement to this:

QObject::connect(equal, SIGNAL(clicked()), this, SLOT(calculate()));

QObject::connect(equal, SIGNAL(clicked()), this, SLOT(calculate()));

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[bijan311]

thanks so much

[bijan311]

wait... now I changed the code up a bit and I think need to update the .moc file but can't find out how
he is main.cpp

#include <QApplication>
#include "calc.h"
 
int main(int argc, char **argv){
  QApplication app(argc, argv);
  Calculator w;
  w.show();
  return app.exec();
}
#include "main.moc"

#include <QApplication>
#include "calc.h"

int main(int argc, char **argv){
  QApplication app(argc, argv);
  Calculator w;
  w.show();
  return app.exec();
}
#include "main.moc"

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and calc.h

#ifndef CALC_H
#define CALC_H
 
#include <QPushButton>
#include <QLabel>
#include <QSpinBox>
#include <QLCDNumber>
#include <QHBoxLayout>
#include <QVBoxLayout>
 
class Calculator : public QWidget {
    Q_OBJECT
public:
  Calculator(QWidget *parent = 0) : QWidget(parent){
    minus = new QPushButton("&-");
    add = new QPushButton("&+");
    multiply = new QPushButton("&X");
    divide = new QPushButton("&/");
    num1 = new QSpinBox;
    num2 = new QSpinBox;
    answer = new QLCDNumber(3);
 
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(num1);
    layout->addWidget(num2);
    layout->addWidget(answer);
 
    QHBoxLayout *button1 = new QHBoxLayout;
    button1->addStretch();
    button1->addWidget(add);
    button1->addWidget(minus);
    button1->addStretch();
 
    QHBoxLayout *button2 = new QHBoxLayout;
    button2->addStretch();
    button2->addWidget(multiply);
    button2->addWidget(divide);
    button2->addStretch();
 
 
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addLayout(layout);
    mainLayout->addLayout(button1);
    mainLayout->addLayout(button2);
 
    connect(minus, SIGNAL(clicked()), this, SLOT(subtract()));
 
      }
public slots:
  void subtract(){
    answer->display(num1->value()-num2->value());
    disconnect();
  }
  void plus(){
      answer->display(num1->value()+num2->value());
  }
  void times(){
      answer->display(num1->value()*num2->value());
  }
  void divider(){
      answer->display(num1->value()/num2->value());
  }
private:
  QPushButton *minus;
  QPushButton *add;
  QPushButton *multiply;
  QPushButton *divide;
  QPushButton *help;
  QSpinBox *num1;
  QSpinBox *num2;
  QLCDNumber *answer;
};
#endif CALC_H

#ifndef CALC_H
#define CALC_H

#include <QPushButton>
#include <QLabel>
#include <QSpinBox>
#include <QLCDNumber>
#include <QHBoxLayout>
#include <QVBoxLayout>

class Calculator : public QWidget {
    Q_OBJECT
public:
  Calculator(QWidget *parent = 0) : QWidget(parent){
    minus = new QPushButton("&-");
    add = new QPushButton("&+");
    multiply = new QPushButton("&X");
    divide = new QPushButton("&/");
    num1 = new QSpinBox;
    num2 = new QSpinBox;
    answer = new QLCDNumber(3);

    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(num1);
    layout->addWidget(num2);
    layout->addWidget(answer);

    QHBoxLayout *button1 = new QHBoxLayout;
    button1->addStretch();
    button1->addWidget(add);
    button1->addWidget(minus);
    button1->addStretch();

    QHBoxLayout *button2 = new QHBoxLayout;
    button2->addStretch();
    button2->addWidget(multiply);
    button2->addWidget(divide);
    button2->addStretch();


    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addLayout(layout);
    mainLayout->addLayout(button1);
    mainLayout->addLayout(button2);

    connect(minus, SIGNAL(clicked()), this, SLOT(subtract()));

      }
public slots:
  void subtract(){
    answer->display(num1->value()-num2->value());
    disconnect();
  }
  void plus(){
      answer->display(num1->value()+num2->value());
  }
  void times(){
      answer->display(num1->value()*num2->value());
  }
  void divider(){
      answer->display(num1->value()/num2->value());
  }
private:
  QPushButton *minus;
  QPushButton *add;
  QPushButton *multiply;
  QPushButton *divide;
  QPushButton *help;
  QSpinBox *num1;
  QSpinBox *num2;
  QLCDNumber *answer;
};
#endif CALC_H

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[squidge]

You don't need the #include anymore as your class is in a header file now. Just run qmake.

[bijan311]

but if i take out

#include "main.moc"

#include "main.moc"

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I get this error

C:\MinGW\include\c++\3.4.5\bits\stl_algobase.h:(.text$_ZN10CalculatorD1Ev[Calculator::~Calculator()]+0xb)||undefined reference to `vtable for Calculator'|

C:\MinGW\include\c++\3.4.5\bits\stl_algobase.h:(.text$_ZN10CalculatorD1Ev[Calculator::~Calculator()]+0xb)||undefined reference to `vtable for Calculator'|

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[squidge]

Yes, which is why you need to run qmake, to update the project file to resolve that error.