Changing the border of a QRubberBand

[Sergex]

Hello,

In my program I draw rectangle rubberbands on a QGraphicsView with the mouse and I now I want to have the border of the rubber band have a marching ant kind of effect.
The first thing I am trying to to is subclassing the QRubberband and re-implementing the paintEvent. And also set the effect using a QTimer.
The QTimer is in my QGV class.

I simply set the timer up there.

...
   m_timer = new QTimer(this);
    connect(m_timer, SIGNAL(timeout()), this, SLOT(updateBorder()));
    m_timer->start(400);
...
 
void WaveObject::updateBorder()
{
    m_rubberBand->update(); //MyRubberBand object
}

...
   m_timer = new QTimer(this);
    connect(m_timer, SIGNAL(timeout()), this, SLOT(updateBorder()));
    m_timer->start(400);
...

void WaveObject::updateBorder()
{
    m_rubberBand->update(); //MyRubberBand object
}

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Then in my QRubberband subclass I am trying a few things:

void MyRubberBand::paintEvent(QPaintEvent *event)
{
    QPen pen;
    QVector<qreal> dashes;
    qreal space = 2;
    dashes << 1 << space << 3 << space << 9 << space
           << 2 << space << 2 << space;
    pen.setDashPattern(dashes);
    pen.setDashOffset(m_offset);
 
    QStylePainter painter(this);
    QStyleOptionRubberBand option;
    initStyleOption(&option);
    painter.setPen(pen);
    painter.drawControl(QStyle::CE_RubberBand, option);
}

void MyRubberBand::paintEvent(QPaintEvent *event)
{
    QPen pen;
    QVector<qreal> dashes;
    qreal space = 2;
    dashes << 1 << space << 3 << space << 9 << space
           << 2 << space << 2 << space;
    pen.setDashPattern(dashes);
    pen.setDashOffset(m_offset);

    QStylePainter painter(this);
    QStyleOptionRubberBand option;
    initStyleOption(&option);
    painter.setPen(pen);
    painter.drawControl(QStyle::CE_RubberBand, option);
}

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This doesn't do anything yet, which si expected because I don't really understand very well how the offset and setting patterns work. Can someone point in the right direction ?? Any help much appreciated.
Thanks!

[d_stranz]

Seems like all you need to do is to change "m_offset" in the timeout slot by incrementing it with each timeout (mod( pattern length) so it cycles from 0 to pattern length). Otherwise it looks to me like you have interpreted the dash pattern and offset methods correctly.