Question

I am using a QVBoxLayout to arrange a vertical stack of widgets. The QVBoxLayout is contained within a QScrollArea. I want some of the widgets to be initially hidden and only show up when a check box is checked. Here is an example of the code I’m using.

MyWidget::MyWidget(QWidget *parent) : QWidget(parent)
{
    QVBoxLayout *layout = new QVBoxLayout(this);

    QLabel *labelLogTypes = new QLabel(tr("Log Types"));

    m_checkBoxCsv = new QCheckBox(tr("&Delimited File (CSV)"));
    m_labelDelimiter = new QLabel(tr("Delimiter:"));
    m_lineEditDelimiter = new QLineEdit(",");
    checkBoxCsv_Toggled(m_checkBoxCsv->isChecked());
    connect(m_checkBoxCsv, SIGNAL(toggled(bool)), SLOT(checkBoxCsv_Toggled(bool)));

    QHBoxLayout *layoutDelimitedChar = new QHBoxLayout();
    layoutDelimitedChar->addWidget(m_labelDelimiter);
    layoutDelimitedChar->addWidget(m_lineEditDelimiter);


    m_checkBoxXml = new QCheckBox(tr("&XML File"));
    m_checkBoxText = new QCheckBox(tr("Plain &Text File"));


    // Now that everything is constructed, put it all together
    // in the main layout.
    layout->addWidget(labelLogTypes);

    layout->addWidget(m_checkBoxCsv);
    layout->addLayout(layoutDelimitedChar);

    layout->addWidget(m_checkBoxXml);
    layout->addWidget(m_checkBoxText);

    layout->addStretch();
}


MyWidget::checkBoxCsv_Toggled(bool checked)
{
    m_labelDelimiter->setVisible(checked);
    m_lineEditDelimiter->setVisible(checked);
}

I want m_labelDelimiter and m_lineEditDelimiter both to be initially invisible and I want their visibility to toggle with the state of m_checkBoxCsv. When they become visible, I would like the layout to expand vertically to accommodate them.

This code achieves the functionality I desire, but it doesn’t seem to reserve space for the two initially hidden widgets. When I check the checkbox, they become visible, but everything is kind of scrunched to accommodate them.

If I leave them initially visible, everything is laid out just the way I would like it. Is there any way to make the QVBoxLayout reserve space for these widgets even if they’re initially invisible?

If I don’t put this widget into a QScrollArea, then this code works exactly as I want it to. What is the deal with the QScrollArea?

Answer 1

I apologize for not being totally clear in my original question. It turns out that the problem seems to have been related to this widget having been contained within a QScrollArea. When I called scrollArea->setWidgetResizable(true), things started to work perfectly.

Thanks for your suggestions, serge and Caleb.