Designing a user interface. input/output , changing images

I want to design a program, a sort of game.
I want to use some pictures and when they get clicked replacing them with another picture. I have done this:

void MainWindow::on_pushButton_clicked(bool checked)
{

if(checked)
checked = false;
else
checked = true;

}

The problem that I have is that I want to replace the pictures not only once and back, I want to swap between 4 images. The data when a image is clicked I must send to my main program who does al the calculations if that's legit or not. I also want to update my user interface after my main program has done a few stuff. (input and output)

How should I do this with code or with the user interface... I'm totally new to Qt

I am not exactly sure what it is you want to do, but if you want the current image to be changed to a new one each time the button is clicked, you can do something like this:

Code:

---

// MainWindow.h:
 
class MainWindow : public QMainWindow
{
  Q_OBJECT;
 
public:
  // usual constructor / destructor stuff
 
protected slots:
  void onButtonClicked( bool );
 
protected:
  void showImage( int index );
 
private:
  QVector< QPixmap * >  images;
  int currentImageIndex;
};
 
// MainWindow.cpp:
 
MainWindow::MainWindow( QWidget * parent ) 
:  QMainWindow( parent )
{
 
    // ... load your images from a file or whatever and put the pixmaps into the vector
 
    currentImageIndex = 0;
 
    showImage( currentImageIndex );
}
 
MainWindow::onButtonClicked( bool )
{
    // increment the image index each time the button is clicked.  The bool argument is irrelevant and ignored
 
    int nImages = images.size();
    currentImageIndex = (currentImageIndex + 1) % nImages;
 
    showImage( currentImageIndex );
}
 
// Assumes your main window uses a QLabel named "label"to display the image
MainWindow::showImage( int index )
{
    if ( index >= 0 && index < images.size() )
       label->setPixmap( *(images[ index ]) );
}

---

NB: Not compiled, not tested.

Please use CODE tags (as I have done) when posting source code.