Drag & QMouseEvent

michelson

Hello,
I have a simple widget which I would like to move with the mouse (one axis only - x in this case). I have implemented three MouseEvents to be able to move widget around:

void MyWidget::mousePressEvent(QMouseEvent *event){
    qDebug() << "click";
    m_is_dragging = true;
}

void MyWidget::mouseMoveEvent(QMouseEvent *event){
    if(m_is_dragging)    {
/* !!!!!!!!!!!!note this one!!!!!!!!!!!!*/
        qDebug() << event->pos();         
        this->move(event->pos().x(), 400);
    }
}

void MyWidget::mouseReleaseEvent(QMouseEvent *event){
    m_is_dragging = false;
    qDebug() << "relese";
}

The output of the program is:

click
...
QPoint(39,27) // 1
QPoint(21,27) // 2
QPoint(40,27) // 1
QPoint(22,27) // 2
QPoint(41,27) // 1
QPoint(23,27) // 2
relese
...

Note that x positions are jumping like every other call was concering totally different pos. Why?

VRonin

form http://doc.qt.io/qt-5/qmouseevent.html#pos

If you move the widget as a result of the mouse event, use the global position returned by globalPos() to avoid a shaking motion.

michelson

Jeez, thanks! :D