Making menu bar overlap central widget in QMainWindow

[J.B. Langston]

I'm trying to implement an auto-hiding menu bar when my application is in full screen mode. I am using a QMainWindow with a menubar and a central widget. I have implemented this code, and it works after I setMouseTracking(true).

void MainWindow::mouseMoveEvent(QMouseEvent *event)
{
    if (isFullScreen()) {
        if (event->pos().y() < menuBar()->sizeHint().height())
            menuBar()->show();
        else
            menuBar()->hide();
    }
}

The problem is that when the menu bar appears, the central widget moves down to accommodate it and it's jarring. I would rather have the menu bar overlap the central widget so that it doesn't move. Is this possible? If so, how?

[mrjj]

Hi
Try this in ctor
ui->menubar->setParent( centralWidget() );
and add
void MainWindow::resizeEvent(QResizeEvent *event)
{
ui->menubar->resize(width(), ui->menubar->height());
}

Tested fast with full screen and seems to work.

[J.B. Langston]

@mrjj Thanks, this pointed me in the right direction. Here is what I ultimately ended up doing: https://github.com/xaos-project/XaoS/blob/master/src/ui/mainwindow.cpp#L954

Note that my centralWidget can optionally be a QGLWidget, which complicates things. The menubar won't display over it properly and I also had other problems when the QGLWidget completely filled the screen, such as popup menus not displaying, so I just disabled the autohiding menu if the compile-time USE_OPENGL flag is set.