QML element positioning works unexpectedly - qt

Question

This is my custom control. It draws background. I want it to occupy the whole header. But none of methods works, expect setting width and height explicitly, using some numbers. Even parent.width and parent.height does not work.
Control - TabViewHeaderBg.
Code:
import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.0
import MyControls 1.0
Item
{
property int preInfoColumnWidth
property int nameColumnWidth
property int progressColumnWidth
property int sizeColumnWidth
property int columnSpacing
height: 40
TabViewHeaderBg
{
anchors.fill: parent
}
Row
{
spacing: columnSpacing
Row
{
width: preInfoColumnWidth
CheckBox
{
}
}
Text
{
text: "Name"
width: nameColumnWidth
anchors.verticalCenter: parent.verticalCenter
}
Text
{
text: "Status"
width: progressColumnWidth
anchors.verticalCenter: parent.verticalCenter
}
Text
{
text: "Size"
width: sizeColumnWidth
anchors.verticalCenter: parent.verticalCenter
}
}
}
This whole control is used as the header control in ListView.
Addition #1.
TabViewHeaderBgQc code:
class TabViewHeaderBgQc :
public QQuickPaintedItem
{
Q_OBJECT
public:
TabViewHeaderBgQc(
QQuickItem *parent = 0);
void paint(QPainter *painter) override;
signals:
public slots:
};
TabViewHeaderBgQc::TabViewHeaderBgQc(
QQuickItem *parent) :
QQuickPaintedItem(parent)
{
}
void TabViewHeaderBgQc::paint(QPainter *painter)
{
QPen pen(QColor(229,229,229), 1);
painter->setPen(pen);
painter->drawRect(boundingRect());
}
Imports with the following code:
qmlRegisterType<TabViewHeaderBgQc>("MyControls", 1, 0, "TabViewHeaderBg");
Addition #2.
Qt 5.8, Windows 10, Visual Studio 2015.