How to receive mouse events in QGraphicsItem derived class? Qt

Question

There are already threads about this, but the solution I could find does not work. Solution: writing QGraphicsView::MousePressEvent(event); at the end of my MousePressEvent class in the QGraphicsView derived class. Both do not work. The QGraphicsItem-class does not receive the mouse events. This is my MousePressEvent in my QGraphicsView class:

void GraphWidget::mousePressEvent(QMouseEvent *event){
    mousePressed = true;

    if (event->button() == Qt::RightButton) // doesn't matter
    {
        rightMousePressed = true;
        _panStartX = event->x();
        _panStartY = event->y();
        setCursor(Qt::ClosedHandCursor);
        event->accept();
        return;
    }

    // And I tried this: QGraphicsView::mousePressEvent(event);
}

This is my MousePressEvent in my QGraphicsItem class:

void Node::mousePressEvent(QGraphicsSceneMouseEvent *event){
    mousePressed = true;
    qDebug() << "mouse trigered!";
}

Any ideas, what I've forgotten?

Do you call "QGraphicsView::mousePressEvent(event);" in mousePressEvent function of your graphicsview class? Also check if the boundingRect() function is implemented properly in your graphicsitem class. — fatma.ekici

mep mep · Accepted Answer · 2017-08-13T10:42:49

ANSWER Never forget to call

QGraphicsView::mousePressEvent(event); /
QGraphicsView::mouseReleaseEvent(event); /
QGraphicsView::mouseMoveEvent(event);
...

at the end of every mouseEvent you overrode in your QGraphicsView derived class (in the mouseMoveEvent use QGraphicsView::mouseMoveEvent(event) and so on). Otherwise really strange things can happen. Also if you even did not use some of these in your QGraphicsItem derived class, call it in every event.

How to receive mouse events in QGraphicsItem derived class? Qt

1 Answers