Custom QObject derived class as a parent in constructor definition

[enemyofthedawn]

I have a class constructor like this(expecting MainWindow as a parent and deriving from QObject)

class ActionManager : public QObject
{
    Q_OBJECT
public:
    ActionManager(MainWindow *mainWindow, Settings *settings);

ActionManager::ActionManager(MainWindow *mainWindow, Settings *settings) : QObject(mainWindow)

This however, shows an error:

error: C2664: 'QObject::QObject(const QObject &)': cannot convert argument 1 from 'MainWindow *' to 'QObject *'

Should I reinterpret_cast this or it's a wrong way of doing this?

[ambershark]

@enemyofthedawn It's the wrong way to do it. Typically your constructor would take either a QWidget * or a QObject * depending on your needs. Since QMainWindow is derived from both of those you can go either way (I would usually do QWidget for a widget since it's derived from QObject).

So here is how it would normally be:

// .h
ActionManager(Settings *settings, QWidget *parent=nullptr);

// .cpp
ActionManager::ActionManager(Settings *settings, QWidget *parent) : QWidget(parent)
{
}

Optionally if you need MainWindow* somewhere else in your ActionManager class (i.e. you are going to store it) then you can go ahead and use a qobject_cast<QWidget*> to pass it to QWidget's constructor.

[enemyofthedawn]

@ambershark Thanks!