qt - Resize window to fit content

Question

I have a QGLWidget, which I want to resize to a given resolution (bigger than the containing window). My intention is, that the window expands until the widget fits inside, but can't find a way to do it.

I tried several commands after resizing the QGLWidget to make it work without success. I will list the results here:

• do nothing else: The Widget overlaps the whole window. Eventually it will be resized to fit back into the smaller window
• mainWindow.adjustSize(): The widget gets resized to (0, 0)
• mainWindow.resize(mainWindow.sizeHint()): see above
• mainWindow.resize(mainWindow.minimumSizeHint()): see above

I also read in this thread, that before doing the mainWindow resize I the event loop needs to be run to recalculate the new sizes, so I inserted QCoreApplication::processEvents to do so, without any visible effect.

So how do I resize the window via the widget?

Edit

The GLWidget is not the only widget of the window. It is embedded in splitter together with a group box.

Answer 1

http://qt-project.org/doc/qt-4.8/qwidget.html#sizePolicy-prop

http://qt-project.org/doc/qt-4.8/qsizepolicy.html#Policy-enum

http://qt-project.org/doc/qt-4.8/qwidget.html#setFixedSize

So assuming that you have your QGLWidget nested inside your QMainWindow as the central widget, you need to set the size policy of your QGLWidget.

For example:

QGLWidget * glw; // in your header for QMainWindow

...

// In your constructor for QMainWindow
glw = new QGLWidget;
this->setCentralWidget(glw);
glw->setFixedSize(500, 500);

this->adjustSize();

Hope that helps.