Qt resize widget inside another widget

Question

I have the following layout:

The black rectangles are QVBoxLayouts, the red one is a generic widget container and the blue little rectangle is my custom openGL widget.

I already set the resize policies for all layouts and widgets, but I can't get the openGL little widget to resize to the extent of his parent's area (the red rectangle in the image).

I'm a Qt beginner, perhaps I need to use signals and slots to resize the little blue openGL widget to the red one? But how?

Answer 1

In Qt5.4 (i didn't test others) new QOpenGLWidget (inside layout) do not resized automatically in my case. I call

LayoutWidget->setGeometry(QRect(0, 0, event->size().width(), event->size().height()));

in resizeEvent(QResizeEvent *event) of parent widget.

Answer 2

The QGLWidget should also be in a layout (of any layout type) to resize itself automatically when its parent is resized.

So, for instance, in the designer, left-click on the red "generic widget container", and choose a vertical layout.