Question

I’m adding widget in layout

ui->horizontalLayout->addWidget(tabwidget);

and qmainwindow resizes itself. But then I do

tabwidget->setVisible(false);
qs = sizeHint();
resize(qs);

I get the size like tabwidget was not removed from window.

I’ve made new button

void MainWindow::on_pushButton_2_clicked()
{
    qs = sizeHint();
    resize(qs);
}

and it gives correct size.

Seems I need some update function but I can’t find it. Please advice

Answer 1

If the button slot gives you the correct result then you can always call the sizeHint() and subsequent resize() in a slot which is called by a single shot timer:

void MainWindow::fixSize()
{
    QSize size = sizeHint();
    resize(size);
}

void MainWindow::methodWhereIHideTheTabWidget()
{
    tabwidget->setVisible(false);
    QTimer::singleShot(0, this, SLOT(fixSize()));
}

This timer is set to zero delay. This means that the slot will be called immediatelly when the program returns to the main loop and hopefully after the internal widget state gets updated. If this doesn’t resolve your problem you may try replacing zero with 1.