CODEWITHSUNDEEP
c++qt
K. Barresi
K. Barresi

Reputation: 1315

Dragging a QGraphicsSvgItem in Qt

I'm trying to move a single object subclassed from a QGraphicsSvgItem around a scene. I've looked at the Qt Drag and Drop example, but my goal isn't to drag and drop like the way they have it. Rather, I want the entire object's location to follow the mouse until it is dropped.

Is there a simple way of doing this in Qt? Thanks!

This is what I have so far: 

mouseMoveEvent(QGraphicsSceneMouseEvent *event) {
    if (QLineF(event->screenPos(), event->buttonDownScreenPos(Qt::LeftButton)).length() <     QApplication::startDragDistance()) {
        return;
    }

    QDrag *drag = new QDrag(event->widget());
    QMimeData *mime = new QMimeData;
    drag->setMimeData(mime);

    QPixmap pixmap(100, 100);
    pixmap.fill(Qt::white);
    QPainter painter(&pixmap);
    painter.translate(15,15);
    painter.setRenderHint(QPainter::Antialiasing);
    paint(&painter, 0, 0);
    painter.end();
    pixmap.setMask(pixmap.createHeuristicMask());

    drag->setPixmap(pixmap);
    drag->setHotSpot(QPoint(50, 50));
    drag->exec();
    setCursor(Qt::OpenHandCursor);
}

Upvotes: 0

Views: 422

Answers (1)

Jeremy Friesner
Jeremy Friesner

Reputation: 73081

If all you want is to have the object draggable by the user, you don't need to override mouseMoveEvent or anything; instead just do this:

   theSVGItem->setFlag(ItemIsMovable, true);

... and the QGraphicsView will handle it for you.

Upvotes: 2

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