Is there a way to pair 2 top level windows?

[Naveed]

Hi all,

I'm new to Qt programming so please bare with me. I'm currently working with some code that has 2 top level windows open simultaneously (lets name them window 1 and window 2). The control flow of the software design demands that window 1 acts as a pseudo parent to window 2 and therefore window 2 should close every time window 1 is closed. However, the opposite will not be true. Since both windows are independent of each other, is there a way of achieving this or am I banging my head against a wall here?

Note: Unfortunately making window a child widget to window one is not possible due to the way the code has already been developed.

Thanks in advance.

[aamer4yu]

You can make use of signals and slots.
Just inform one another about the events you are interested in and decide upon the action

[Naveed]

Thanks for the response. What signal should I be using to determine if the X (close) button on window 1 has been clicked?

[hobbyist]

Install an event filter to detect QEvent::Close, e.g.

#include <QtGui>
 
class EventSignaller : public QObject
{
 Q_OBJECT
 
 signals:
  void closing();
 
 protected:
  bool eventFilter(QObject *object, QEvent *event)
  {
    if(event->type() == QEvent::Close)
      emit(closing());
 
    return QObject::eventFilter(object, event);
  }
};
 
int main(int argc, char *argv[])
{
  QApplication app(argc, argv);
 
  QWidget w1;
  w1.setWindowTitle("w1");
  w1.show();
 
  QWidget w2;
  w2.setWindowTitle("w2");
  w2.show();
 
  EventSignaller s;
  w1.installEventFilter(&s);
  w2.connect(&s, SIGNAL(closing()), SLOT(close()));
 
  return app.exec();
}
 
#include "main.moc"

#include <QtGui>

class EventSignaller : public QObject
{
 Q_OBJECT
  
 signals:
  void closing();
  
 protected:
  bool eventFilter(QObject *object, QEvent *event)
  {
    if(event->type() == QEvent::Close)
      emit(closing());
    
    return QObject::eventFilter(object, event);
  }
};

int main(int argc, char *argv[])
{
  QApplication app(argc, argv);
  
  QWidget w1;
  w1.setWindowTitle("w1");
  w1.show();
  
  QWidget w2;
  w2.setWindowTitle("w2");
  w2.show();
  
  EventSignaller s;
  w1.installEventFilter(&s);
  w2.connect(&s, SIGNAL(closing()), SLOT(close()));
  
  return app.exec();
}

#include "main.moc"

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