QFileOpenEvent connecting to QMainWindow

[BrianNorman]

Looking into auto file open on a a Mac.

I have a standard Qt app where I have subclassed QApplication adding an event filter. Here I capture the QEvent::FileOpen and I can debug message the filename. All good.

What I want to do now is to connect a signal to my MainWindow to tell it to do something with the filename. I thought the route would be to connect a signal from the my QApplication to the MainWindow but I am struggling to do this.

Any ideas?

Thanks

[d_stranz]

If you have subclassed QApplication already, then just add a signal to it:

// MyApplication.h
 
class MyApplication : public QApplication
{
 
//...
signals:
  void openFile( const QString & fileName );
 
};

// MyApplication.h

class MyApplication : public QApplication
{

//...
signals:
  void openFile( const QString & fileName );

};

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and in your event handler, emit that signal with the file name after you have verified that the file is of the right type for your app, etc.

In your MainWindow class, add a public slot and connect to it in main(). Implement the slot in MainWindow.cpp to do whatever it needs to do.

// MainWindow.h
 
class MainWindow : public QMainWIndow
{
// ...
 
public slots:
  void onOpenFile( const QString & fileName );
 
};
 
// main.cpp
 
int main( /* ... */ )
{
 
  MyApplication myApp;
  MainWindow  myMain;
 
  connect ( &myApp, &MyApplication::openFile, &myMain, &MainWindow::onOpenFile );
 
  myMain.show();
  return myApp.exec();
}

// MainWindow.h

class MainWindow : public QMainWIndow
{
// ...

public slots:
  void onOpenFile( const QString & fileName );

};

// main.cpp

int main( /* ... */ )
{

  MyApplication myApp;
  MainWindow  myMain;

  connect ( &myApp, &MyApplication::openFile, &myMain, &MainWindow::onOpenFile );

  myMain.show();
  return myApp.exec();
}

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[BrianNorman]

Thanks for your prompt reply.

I was trying this route but where I get stuck is when I add the emit line to the code. I get an error

error: symbol(s) not found for architecture x86_64

Any ideas where I am going wrong here?

Thanks

class MyApplication : public QApplication
{
public:
MyApplication(int &argc, char **argv)
: QApplication(argc, argv)
{
}

bool event(QEvent *event)
{
if (event->type() == QEvent::FileOpen)
{
QFileOpenEvent *openEvent = static_cast<QFileOpenEvent *>(event);

qDebug() << "Open file in QApplication" << openEvent->file();

emit openFile(openEvent->file());
}

return QApplication::event(event);
}

signals:
void openFile( const QString & fileName );

};

[d_stranz]

If this is your actual code, then you are missing the Q_OBJECT macro at the start of the class definition:

class MyApplication : public QApplication
{
    Q_OBJECT
 
public:
MyApplication(int &argc, char **argv)
: QApplication(argc, argv)
{
}

class MyApplication : public QApplication
{
    Q_OBJECT

public:
MyApplication(int &argc, char **argv)
: QApplication(argc, argv)
{
}

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