QListWidget::setStyleSheet() and QListWidgetItem::setBackgroundColor() relation

Question

So I have a QListWidget object, and I set this:

ui.myQListWidget->setStyleSheet("QListWidget::item { border-bottom: 1px solid black; }")

Right before the object is constructed.

Then I want to add some QListWidgetItem objects in my new created QListWidget list.

I have something like this:

if(stuff) {
    myqlistwidgetitem->setBackgroundColor(Qt::GlobalColor::darkGray);
}
else if(other_stuff) {
    myQListWidgetItem->setBackgroundColor(Qt::GlobalColor::lightGray);
}

ui.myQListWidget->addItem(myQListWidgetItem);

The problem is that all the elements will be white (and not darkGray or greenDark as I specified).

The elements will be colored in the specified colors only if I omit the QListWidget::setStyleSheet() call (but then I don't have the border between items).

How I solve this? (I need colored items and border between them).

Answer 1

if this is the result you want

you can subclass QStyledItemDelegate, overwrite the paint() method and set it as itemDelegate to your listWidget. I don't know c++, but i think, you can see the way from my python3/ pyqt5 example:

class myDelegate(QtWidgets.QStyledItemDelegate):
    def __init__(self, parent=None):
        QtWidgets.QStyledItemDelegate.__init__(self)  
        self.setParent(parent)
        # offset item.rect - colored rect
        self.offset = 2 
        # different backgroundcolors
        self.brush = QtGui.QBrush(QtGui.QColor('white'))
        self.brush1 = QtGui.QBrush(QtGui.QColor('darkGray'))
        self.brush2 = QtGui.QBrush(QtGui.QColor('lightGray')) 
        # textcolor
        self.textpen = QtGui.QPen(QtGui.QColor(0,0,0))
        # linecolor and -width
        self.linePen = QtGui.QPen(QtGui.QColor(0,0,0))
        self.linePen.setWidth(2)
        # Alignment
        self.AlignmentFlag = QtCore.Qt.AlignHCenter | QtCore.Qt.AlignVCenter

    def paint(self, painter, option, index):
        # rect to fill with backgroundcolor
        itemRect = option.rect.adjusted(self.offset, self.offset, -self.offset, -self.offset)
        # text of the item to be painted
        text = self.parent().item(index.row()).text() 
        painter.save()
        # conditions for different backgroundcolors
        if text[0] == 'a':
            color = self.brush1
        elif text[0] == 'C':
            color = self.brush2
        else:
            color = self.brush
        # paint backgroundcolor
        painter.fillRect(itemRect,color)
        # paint text
        painter.setPen(self.textpen)
        painter.drawText(itemRect, self.AlignmentFlag, text)
        # paint bottom border
        painter.setPen(self.linePen)
        painter.drawLine(option.rect.bottomLeft(), option.rect.bottomRight())
        painter.restore()