How to visualize an edge of a QT graph?

Question

Qt

There is a task to visualize the graph. Everything is fine with the vertices, but there is a problem with the edge, I don’t know how to make an arrow from QGraphicsLineItem. The code below takes the coordinates of the vertex from which the arrow should be built, then the coordinates of the vertex where the arrow should be built and the name of the edge. But he just draws a line, but you need a line with an arrow. How to implement????
void MainWindow::getrebro(float x, float y, float xx, float yy, QString s)
{
QGraphicsLineItem *line = new QGraphicsLineItem(x+5,y+5,xx+5,yy+5);
line->setZValue(-1);
float xt = (x+xx)/2;
float yt = (y+yy)/2;
QGraphicsTextItem *text = new QGraphicsTextItem(s);
text->setX(xt);
text->setY(yt);
scene->addItem(line);
scene->addItem(text);
}
vertices are built like this:
void MainWindow::getsubject(float x, float y, QString s)
{
QGraphicsEllipseItem *ellips = new QGraphicsEllipseItem(0,0,10,10);
ellips->setY(y);
ellips->setX(x);
ellips->setBrush(Qt::black);
QGraphicsTextItem *text = new QGraphicsTextItem(s);
text->setY(y+5);
text->setX(x);
scene->addItem(ellipses);
scene->addItem(text);
}
void MainWindow::getobject(float x, float y, QString s)
{
QGraphicsEllipseItem *ellips = new QGraphicsEllipseItem(0,0,10,10);
ellips->setY(y);
ellips->setX(x);
ellips->setBrush(Qt::white);
QGraphicsTextItem *text = new QGraphicsTextItem(s);
text->setY(y+5);
text->setX(x);
scene->addItem(ellipses);
scene->addItem(text);
}

Answer 1

Write the drawing of the arrow yourself: https://doc.qt.io/qt-5/qtwidgets-graphicsview-diag...
Here is the whole example: https://doc.qt.io/qt-5/qtwidgets-graphicsview-diag ...