[Qt-interest] [Solved] Screen coordinates inQGraphicsItem::hoverEnterEvent() ?

[bd.anon at free.fr]

On Mon, 30 May 2011 14:11:13 +1000, "Ross Bencina"
<rossb-lists at audiomulch.com> said :

>The solution I use only works when there is a single view.

Ross, based on your suggestion, this seems to work for me in a
multi-view environment :

void myQGraphicsItem::hoverEnterEvent(QGraphicsSceneHoverEvent*
pEvent)
{
    QString text("tooltip text");
    
    // We need a way to turn QGraphicsItem's bounding rectangle into
screen coordinates, even though
    // we do not know which of several potential views generated the
QGraphicsSceneHoverEvent

    // 1) Determine which view generated the event
    QWidget* pViewport = QApplication::widgetAt(pEvent->screenPos());
    QWidget* pView = pViewport->parentWidget();

    // 2) As this is a hack, check that we indeed got a QGraphicsView
    QGraphicsView* pGraphicsView =
qobject_cast<QGraphicsView*>(pView);
    // If not, show transient tooltip
    if (pGraphicsView == 0)
    {
        QToolTip::showText(pEvent->screenPos(), text,
pEvent->widget());
        return;
    }

    // 3) Here we indeed have a QGraphicsView
    //    Use it to map the QGraphicsItem's bounding rectangle into
screen coordinates and enjoy a semi permanent tooltip
    QRectF itemRect = boundingRect();
    QRect screenRect(

pGraphicsView->mapToGlobal(pGraphicsView->mapFromScene(mapToScene(itemRect.topLeft()))),

pGraphicsView->mapToGlobal(pGraphicsView->mapFromScene(mapToScene(itemRect.bottomRight())))
    );

    QToolTip::showText(pEvent->screenPos(), text, pEvent->widget(),
screenRect);
}

Bertrand Anon