drawtext doesn't work in Qt - c++

Question

i m working on a project that consist on creating an uml tool with qt and for now i have a problem with drawingtext on an arrow so this is my code :
void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem * ,QWidget *)
{
if (myStartItem->collidesWithItem(myEndItem))
return;
QPen myPen = pen();
myPen.setColor(myColor);
qreal arrowSize = 20;
painter->setPen(myPen);
painter->setBrush(myColor);
QLineF centerLine(myStartItem->pos(), myEndItem->pos());
QPolygonF endPolygon = myEndItem->polygon();
QPointF p1 = endPolygon.first() + myEndItem->pos();
QPointF p2;
QPointF intersectPoint;
QLineF polyLine;
for (int i = 1; i < endPolygon.count(); ++i)
{
p2 = endPolygon.at(i) + myEndItem->pos();
polyLine = QLineF(p1, p2);
QLineF::IntersectType intersectType =
polyLine.intersect(centerLine, &intersectPoint);
if (intersectType == QLineF::BoundedIntersection)
break;
p1 = p2;
}
setLine(QLineF(intersectPoint, myStartItem->pos()));
double angle = ::acos(line().dx() / line().length());
if (line().dy() >= 0)
angle = (Pi * 2) - angle;
QPointF arrowP1 = line().p1() + QPointF(sin(angle + Pi / 3) * arrowSize,
cos(angle + Pi / 3) * arrowSize);
QPointF arrowP2 = line().p1() + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
cos(angle + Pi - Pi / 3) * arrowSize);
arrowHead.clear();
arrowHead << line().p1() << arrowP1 << arrowP2;
painter->drawLine(line());
//painter->drawPolygon(arrowHead);
if (isSelected())
{
painter->setPen(QPen(myColor, 1, Qt::DashLine));
QLineF myLine = line();
myLine.translate(0, 4.0);
painter->drawLine(myLine);
myLine.translate(0,-8.0);
painter->drawLine(myLine);
QPoint point = QPoint( 10, 20 );
painter->drawText( point, "You can draw text from a point..." );
}
}
and nothing happens i can draw the arrow but the text does not appear on the arrow what should i do ? please i need some help

Answer 1

IMO you did that wrong.
You should compose your graphics item using QGraphicsPathItem, QGraphicsPolygonItem, QGraphicsRectItem, and QGraphicsSimpleTextItem instead drawing everything yourself.
Just provide some root item responsible for managing children (lines text and polygons). It will be easier to do this properly.
Secondly your paint method is faulty. You should restore initial state of the painter!
And finally I'm pretty sure your problem is caused by incorrect implementation of boundingRect. It is quite common mistake when performing such complex drawing in paint method.