Prevent widgets stretching in QVBoxLayout and have scrollbar appear in QScrollArea?

Question

Making my way up the Qt learning curve, I've seen many questions about dynamic layouts but the solutions aren't working for me or I don't quite understand them.

Reference questions:: Qt Scroll Area does not add in scroll bars, How can i make widgets overflow to make a scrollbar appear in Qt?

Question:: I want to have a dynamic layout of a set of widgets within a QScrollArea. I've been able to do this manually in Qt Creator and now I am trying to do it through code.

• How do I prevent the widgets from stretching/force the area to scroll?

• How do I have the added widgets start from the top? I have a vertical spacer in my QVBoxLayout but that pushes everything to the bottom.

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Simple test code::

void MainWindow::on_pushButton_clicked()
{
    ui->myScroll->setWidgetResizable(true); //making sure this is set
    QPushButton *b = new QPushButton(this);
    b->setText(QString("Hello Button"));
    QHBoxLayout *h = new QHBoxLayout();
    h->addWidget(b,0);
    ui->myVBoxLayout->addLayout(h,0);

}

Result:: Left side squished (dynamic) – Right side Ok (set up manually)

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Qt Creator Setup:: Left side: dynamic – Right side set up manually

Properties::

Answer 1

You can set use setMinimumHeight() on your buttons for preventing squished buttons. The layout can be configured with setContentsMargin() for space between item-border and item-content (QtDesigner has all four directions set to 9 IIRC) and setSpacing() for space between items (QtDesigner uses a default of 6). Also setWidgetResizable(true) allows your scrollarea to resize the view widgeth inside the area (this is where your layout and children are being placed).

This works for me:

In constructor or code set scrollArea->widget() to hold the QVBoxLayout:

v = new QVBoxLayout;
ui->scrollArea->widget()->setLayout(v);

In Button Slot:

void MainWindow::pushButtonPressed()
{
    ui->scrollArea->setWidgetResizable(true);
    QPushButton *b = new QPushButton(this);
    b->setText(QString("Hello Button"));
    QHBoxLayout *h = new QHBoxLayout();
    h->addWidget(b,0);
    v->addLayout(h);
}