parent() heirarchy misunderstanding?

[KShots]

Hello all... I've been getting confused on the parent() heirarchy. Here's what I've got:

formMainWindow, parent of QMdiArea, parent of QMdiSubWindow, parent of subWidget

I can use this code to initialize (from within the formMainWindow):

QMdiArea * ws = new QMdiArea(this);
subWidget * w = new subWidget;
QMdiSubWindow * sw = ws->addSubWindow(w);   // Should set w->parent() to sw

QMdiArea * ws = new QMdiArea(this);
subWidget * w = new subWidget;
QMdiSubWindow * sw = ws->addSubWindow(w);   // Should set w->parent() to sw

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I *think* this works all right... but traversing the heirarchy is another matter. From within subWidget:

QMdiSubWindow * sw = dynamic_cast<QMdiSubWindow *>(parent());   // Returns a valid pointer
QMdiArea * ws = dynamic_cast<QMdiArea *>(sw->parent());   // Returns NULL
formMainWindow * mw = dynamic_cast<formMainWindow *>(sw->parent());   // Also returns NULL

QMdiSubWindow * sw = dynamic_cast<QMdiSubWindow *>(parent());   // Returns a valid pointer
QMdiArea * ws = dynamic_cast<QMdiArea *>(sw->parent());   // Returns NULL
formMainWindow * mw = dynamic_cast<formMainWindow *>(sw->parent());   // Also returns NULL

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So... what is the parent of a QMdiSubWindow? How can I traverse the heirarchy back to the formMainWindow?

[marcel]

The parent of all subwindows in a mdi area is QMdiArea::viewport(). This is inherited from abstract scroll area.
The viewport is a QWidget so you should write the cast accordingly.

[KShots]

Thanks, I was able to replace that with a simple

static_cast<formMainWindow *>(parent()->parent()->parent()->parent())->subWindowDestroyed(this);

static_cast<formMainWindow *>(parent()->parent()->parent()->parent())->subWindowDestroyed(this);

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within the closeEvent(QCloseEvent *) of the subwindow (to clean up before the thing is actually destroyed).