@
void MainWindow::keyPressEvent(QKeyEvent *event) {
if (event->key() == Qt::Key_Escape) {
neki->setParent(this);
neki->showNormal();
event->accept();
} else {
MainWindow::keyPressEvent(event);
}
}

void MainWindow::fS() {
neki->setParent(0);
neki->showFullScreen();
}
@

But if i try this on QWidget which is child of QMainWindow it fails.

I use the following code to toggle between states
@
MainWindow::enterFullScreen()
{
// Hide all elements that I don't need in full screen
ui->toolBar->hide();
ui->menuBar->hide();
ui->statusBar->hide();
// ....

m_windowState = windowState();
setWindowState(m_windowState | Qt::WindowFullScreen);
ui->actionLeaveFullScreen->setEnabled(true);
ui->actionEnterFullScreen->setEnabled(false);

}

MainWindow::leaveFullScreen()
{
ui->toolBar->show();
ui->menuBar->show();
ui->statusBar->show();
// ....

setWindowState(m_windowState);

ui->actionLeaveFullScreen->setEnabled(false);
ui->actionEnterFullScreen->setEnabled(true);

}
@

@
w->setWindowState(w->windowState() ^ Qt::WindowFullScreen);
@

Have anybody had this problem?
Does anybody have an idea how to solve this?

There is my slot for full screen:

@
void Player::showFullScreenVideo() {
if (player->state() != QMediaPlayer::StoppedState) {
videoWidget->setParent(0);
videoWidget->showFullScreen();
}
}
@

And event handler for exit from full screen:

@
void VideoWidget::keyPressEvent(QKeyEvent *event) {
if (event->key() == Qt::Key_Escape && isFullScreen()) {
showNormal();
setParent(myParentWidget);
myParent->vertical->insertWidget(0, this);

    event->accept();
} else {
    VideoWidget::keyPressEvent(event);
}

}
@

Regards