QGraphicsView update/paint issues

[emanuel]

Hi,

I have trouble with QGraphicsView update.

Screenshot:

image1.jpg

Code:

GraphicsViewExample.tar.bz2

I belive there is a problem with AssociItem :: Line :: paint() where I'm setting position of QGraphicsTextItem, but I have no clue how to fix it:

void AssociItem::Line::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);
 
    painter->setPen(pen());
 
    setLine(QLineF(start->mapToScene(start->boundingRect().center()),
                   end->mapToScene(end->boundingRect().center())));
 
    QPointF endPoint;
 
    QPolygonF polygon = QPolygonF(end->boundingRect());
    QPointF p1 = polygon.first() + end->pos();
    QPointF p2;
    QLineF polyLine;
 
    int count = polygon.count();
    for(int i = 1; i < count; ++i)
    {
        p2 = polygon[i] + end->pos();
        polyLine = QLineF(p1, p2);
        QLineF::IntersectType intersectType = polyLine.intersect(line(), &endPoint);
        if(intersectType == QLineF::BoundedIntersection)
            break;
 
        p1 = p2;
    }
 
    QGraphicsTextItem *text = static_cast<AssociItem *>(parentItem())->leftText;
    text->setPos(endPoint);
 
    QPointF startPoint;
 
    polygon = QPolygonF(start->boundingRect());
    p1 = polygon.first() + start->pos();
 
    count = polygon.count();
    for(int i = 1; i < count; ++i)
    {
        p2 = polygon[i] + start->pos();
        polyLine = QLineF(p1, p2);
        QLineF::IntersectType intersectType = polyLine.intersect(line(), &startPoint);
        if(intersectType == QLineF::BoundedIntersection)
            break;
 
        p1 = p2;
    }
 
    text = static_cast<AssociItem *>(parentItem())->rightText;
    text->setPos(startPoint);
 
    setLine(QLineF(startPoint, endPoint));
 
    painter->drawLine(line());
}

void AssociItem::Line::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);

    painter->setPen(pen());

    setLine(QLineF(start->mapToScene(start->boundingRect().center()),
                   end->mapToScene(end->boundingRect().center())));

    QPointF endPoint;

    QPolygonF polygon = QPolygonF(end->boundingRect());
    QPointF p1 = polygon.first() + end->pos();
    QPointF p2;
    QLineF polyLine;

    int count = polygon.count();
    for(int i = 1; i < count; ++i)
    {
        p2 = polygon[i] + end->pos();
        polyLine = QLineF(p1, p2);
        QLineF::IntersectType intersectType = polyLine.intersect(line(), &endPoint);
        if(intersectType == QLineF::BoundedIntersection)
            break;

        p1 = p2;
    }

    QGraphicsTextItem *text = static_cast<AssociItem *>(parentItem())->leftText;
    text->setPos(endPoint);

    QPointF startPoint;

    polygon = QPolygonF(start->boundingRect());
    p1 = polygon.first() + start->pos();

    count = polygon.count();
    for(int i = 1; i < count; ++i)
    {
        p2 = polygon[i] + start->pos();
        polyLine = QLineF(p1, p2);
        QLineF::IntersectType intersectType = polyLine.intersect(line(), &startPoint);
        if(intersectType == QLineF::BoundedIntersection)
            break;

        p1 = p2;
    }

    text = static_cast<AssociItem *>(parentItem())->rightText;
    text->setPos(startPoint);

    setLine(QLineF(startPoint, endPoint));

    painter->drawLine(line());
}

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Any ideas?

[wysota]

paint() is supposed to paint the item inside the area specified by boundingRect(). Nothing more and certainly should not modify the object state.