Resize window to fit content

问题

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.

回答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.

回答2:

I have an app that needed to be very similar to your requirements, so I'll post my solution here. An image covering the window which is freely expandable and shrinkable, and can be changed to the original size, and remain expandable / shrinkable after that.

I used a QLabel widget to display the image, but it should work with other widget types too. I created the widget with an initial size and the QSizePolicy::Ignored.

label->resize (w, h); // initial size
label->setSizePolicy (QSizePolicy::Ignored, QSizePolicy::Ignored);

The label widget was in a QVBoxLayout with a few buttons in the window, but this may work with other layout types too.

The window and image widget can be resized to the image's original size with this code:

label->resize (w, h); // change to original size
label->setMinimumSize (w, h); // prevent it from collapsing to zero immediately
window->adjustSize (); // resize the window
label->setMinimumSize (0, 0); // allow shrinking afterwards

来源：https://stackoverflow.com/questions/16468235/resize-window-to-fit-content

标签

qlayout