mouse move and mouse release events don't respond

[AngelicTiger]

Hello, QT! I am a begginer in QT and I wanted to drag the scene with mouse move event, but i faced some troubles. I don't really understand, what should I do.

Part of .cpp code

void Widget::mousePressEvent(QMouseEvent* event)
{
    if (event->button() == Qt::MiddleButton)
    {
        QApplication::setOverrideCursor(Qt::SizeAllCursor);
        midMousePressed = true;
        m_originX = event->x();
        m_originY = event->y();
        event->accept();
        return;
    }
}

void Widget::mouseReleaseEvent(QMouseEvent *event){
    if (event->button() == Qt::MiddleButton)
    {
        midMousePressed = false;
        QApplication::restoreOverrideCursor();
        event->accept();
        return;
    }
    event->ignore();
}

void Widget::mouseMoveEvent(QMouseEvent* event)
{
    if (midMousePressed == true)
    {
        QPointF oldp = ui->graphicsView->mapToScene(m_originX, m_originY);
        QPointF newp = ui->graphicsView->mapToScene(event->pos());
        QPointF translation = newp - oldp;
        ui->graphicsView->translate(translation.x(), translation.y());
        m_originX = event->x();
        m_originY = event->y();
        event->accept();
        return;
    }
    event->ignore();
}

Working in QT 5.15.2

[SGaist]

Hi and welcome to devnet,

You should rather do that at the view level.

See here for a possible implementation.