QBoxLayout misplacing

[GrassHopper90]

Hello everyone

I'm writing a class (ButtonArray) that inherits QWidget and uses a QBoxLayout to display a series of buttons.

what i've wrote:

//=========================================================
void UGButtonArray::paintEvent(QPaintEvent* event)//just for debug
{
    QPainter painter(this);
    painter.fillRect(rect(), QColor(255, 0, 0, 20));
    QWidget::paintEvent(event);
}
//=========================================================
UGButtonArray::UGButtonArray(QWidget* parent)
    : QWidget{parent},
      m_layout(QBoxLayout::Direction::LeftToRight, this)
{
    setLayout(&m_layout);
    m_layout.setSpacing(0);
    m_layout.setContentsMargins(0, 0, 0, 0);
}
//=========================================================
void UGButtonArray::setArrayDir(ArrayDirection dir)
{
    if (dir == AD_Horizontal)
        m_layout.setDirection(QBoxLayout::Direction::LeftToRight);
    else
        m_layout.setDirection(QBoxLayout::Direction::TopToBottom);
}
//=========================================================
void UGButtonArray::addButton(const UltraEntry& entry)
{
    auto b = new UGButton(this);
    b->setVisible(!entry.hidden);
    b->setSizePolicy(QSizePolicy(QSizePolicy::Policy::Ignored, QSizePolicy::Policy::Ignored));
    b->setText(entry.entryText);
    b->drawBorder();
    b->setBorderRadius(5);

    m_layout.addWidget(b);
    m_buttons.push_back({b, entry});
}
//=========================================================

The array of button is a QVector of button, that's another class i wrote that inherits QPushButton and simply display a button with some other features. I don't paste it for now because it's a long piece of code.

What i see:

As you can see in the picture, the three buttons don't have the same height. I mean, they HAVE the same height but it's like they have been placed from the first (Button 1) to the last (Button 3) overlapping (the 2 goes partially on top of 1 and the same with 3 and 2). I am sure of this because i rounded the corners and i cannot see the rounded lower corners of button 1 and 2.

Is there something i missed? (ofc there is :D)

[JonB]

@GrassHopper90
Don't you get to see everything if you remove the m_layout.setSpacing(0);? Are you saying you don't expect any overlap with 0 spacing? I assume this does not only happen when go for rounded corners?

[artwaw]

@GrassHopper90 said in QBoxLayout misplacing:

m_layout.setSpacing(0);
m_layout.setContentsMargins(0, 0, 0, 0);

What if you start sensibly increasing values?

[GrassHopper90]

@JonB This. You fixed it. But why? Spacing is the space between elements, correct? Why if i set it to zero the elements overlap?

[artwaw]

@GrassHopper90 I'd wager that sizeHint() for the buttons doesn't return proper value.

[GrassHopper90]

@JonB Now i have the other test array (horizontal) like this:

On the left there is the horizontal array and on the righ you can see the vertical one that now is correctly placed

[GrassHopper90]

@artwaw I've reimplemented that method to return a small size, and set the layout to ignore the hint.

[GrassHopper90]

up .