Question

I have a simple QGraphicsWidget, MyGraphicsWidget. Here’s my mouseMoveEvent(), which seems to work fine :

void MyGraphicsWidget::mouseMoveEvent (QGraphicsSceneMouseEvent *event)
{
    QPointF p = event->scenePos() - m_StartPos;
    if(p.manhattanLength() < 20)
        return;
    //omitted drawing a rounded rect on the drag
    QDrag *drag = new QDrag(event->widget());
    drag->start(Qt::MoveAction);
}

The scene’s dropEvent() just moves this widget to its new position, and I don’t have a press/move event for the scene itself, so those should get passed on correctly to the widgets within.

However, once the drag completes, the next mouse press will be on this widget. So if I try to click and drag another widget, I’ll be stuck dragging this one on accident, despite the fact that my cursor is not on this widget. I’ve printed out the event->pos() and event->scenePos(), and both reported that the cursor is where it appears to be (not on the widget at all). If I click once before trying to click and drag, everything works normally. Is there maybe something I need to implement within mouseReleaseEvent() or my mouseMoveEvent() ?

Thanks.

Answer 1

It’s working now. I’m pretty sure this was the issue:
MyGraphicsWidget had another custom GraphicsWidget sitting on top of it, and in its mousePressEvent, I was calling QGraphicsWidget::mousePressEvent(event); at the start of the event. The rest of the event was never getting triggered, which was messing it all up. I moved that line to the end of the method, and everything seems okay now.