Question

Although Qt’s docs indicate that these two functions are different (the first doesn’t include the frame) no matter what widget I choose – including the main window of my application – someWidget->frameGeometry().height() always returns the same value as someWidget->geometry.height().

What am I missing here?

Answer 1

I think, you don’t give enough time to widget to be painted. There is little example:

#include <QApplication>
#include <QMainWindow>
#include <QDebug>

class MainWindow : public QMainWindow
{
public:
    MainWindow() {
        startTimer(500);
    }

    void timerEvent(QTimerEvent *e) {
        // Here values are different
        qDebug() << geometry().height() << frameGeometry().height();
    }
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    MainWindow mainWin;
    mainWin.show();

    // Here values are equals
    qDebug() << mainWin.geometry().height() << mainWin.frameGeometry().height();

    return app.exec();
}

First debug output will produce the same values for geometry and frameGeometry, but the second (in timerEvent) will produce different.