VuoActivityIndicator.cc

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#include "VuoActivityIndicator.hh"
 
VuoActivityIndicator::VuoActivityIndicator(unsigned int ticks)
{
    this->ticks = ticks;
}
 
QPixmap VuoActivityIndicator::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
{
    QPixmap pixmap(size);
 
    // Allow paint() to set a transparent background.
    QBitmap bitmap(size);
    bitmap.clear();
    pixmap.setMask(bitmap);
 
    QPainter painter(&pixmap);
    paint(&painter, QRect(QPoint(0,0),size), mode, state);
    return pixmap;
}
 
void VuoActivityIndicator::paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state)
{
    painter->setRenderHint(QPainter::Antialiasing, true);
 
    painter->setBackground(Qt::transparent);
    painter->eraseRect(rect);
 
    float outerRadius = 0.7f * std::min(rect.width(), rect.height()) / 2;
    float innerRadius = 0.7f * outerRadius;
    float penWidth = 0.3f * innerRadius;
    int numLines = 12;
 
    for (int i = 0; i < numLines; ++i)
    {
        int alpha = (i + 1) / (float)numLines * 255.0f;
        QPen pen(QColor(0, 0, 0, alpha), penWidth);
        painter->setPen(pen);
 
        float radiansForSpoke = (i + ticks) / (float)numLines * 2.0f * M_PI;
        QPointF innerRectCenter(innerRadius * cos(radiansForSpoke), innerRadius * sin(radiansForSpoke));
        QPointF outerRectCenter(outerRadius * cos(radiansForSpoke), outerRadius * sin(radiansForSpoke));
        painter->drawLine(rect.center() + innerRectCenter, rect.center() + outerRectCenter);
    }
}
 
QIconEngine * VuoActivityIndicator::clone() const
{
    return NULL;
}