How to remove this effect?

[A Former User]

When I hover over the items, the top line becomes thinner or is restored to original style like this:

The code is almost same as this, I've added a UserRole for those Total. In the Delegate, I've these:

Delegate::Delegate(){ }
void Delegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const{   
    painter->setRenderHints(QPainter::Antialiasing|QPainter::TextAntialiasing);
    QStyledItemDelegate::paint(painter, option, index);
    if(index.siblingAtColumn(0).data(Qt::UserRole) == "Aggregate" && index.column() > 0){
        painter->drawLine(option.rect.topLeft(), option.rect.topRight());
        painter->drawLine(option.rect.bottomLeft(), option.rect.bottomRight());
    }
}

[raven-worx]

@Emon-Haque
your line overlaps indexes and i guess you used a (default) pen with a width of 2px.
So the half of the line is overdrawn when the index/row is repainted without the highlighting.

you need to translate the line by the half of the line/pen width to ensure that it is inside the index boundaries.

[A Former User]

@raven-worx, this translation works:

void Delegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const{   
    painter->setRenderHints(QPainter::Antialiasing|QPainter::TextAntialiasing);
    QStyledItemDelegate::paint(painter, option, index);
    if(index.siblingAtColumn(0).data(Qt::UserRole) == "Aggregate" && index.column() > 0){
        painter->save();
        painter->translate(0,1);
        painter->drawLine(option.rect.topLeft(), option.rect.topRight());
        painter->restore();
        painter->drawLine(option.rect.bottomLeft(), option.rect.bottomRight());
    }
}

Is there an extra 1 px/pt gap at the end of last child of each node or at the end of each Total?

[raven-worx]

@Emon-Haque
just a tip:

• QPainter save/restore is rather costly and should be avoided if you are after performance. Better just translate the line coordiantes
• the generic way would be to calculate the translation based on the pen width: int translate = qCeil(painter->pen().width() * 0.5)

Is there an extra 1 px/pt gap at the end of last child of each node or at the end of each Total?

i dont understand your question

[A Former User]

@raven-worx, the top line is now 1 px/pt below the original position so there's an extra 1px/pt gap between those top lines and last Some Text -1,000 1000 of each node, right? And all those Total 1,000 1000 is 1 px/pt closer to the top line.

[raven-worx]

@Emon-Haque
i dont see an additional gap.
you may want to read this: https://doc.qt.io/qt-5/coordsys.html