Maximize a widget (to fill its parent

[Ohman]

hi,

I have a QglWidget which I would like to be 100% of the size of his parent QMainWindow.

When I create the QglWidget he is the right size (parent auto-created), but now I tried to maximize it with :

QSizePolicy sizePolicy;
	sizePolicy.setHorizontalPolicy(QSizePolicy::Expanding);
	sizePolicy.setVerticalPolicy(QSizePolicy::Expanding);
	qglWidget.setSizePolicy(sizePolicy);

QSizePolicy sizePolicy;
	sizePolicy.setHorizontalPolicy(QSizePolicy::Expanding);
	sizePolicy.setVerticalPolicy(QSizePolicy::Expanding);
	qglWidget.setSizePolicy(sizePolicy);

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but it doesn't seem to work

Any idea ?