drawPrimitive does not draw over all primitive elements

[ateek.ujjawal]

Hi,

I have been trying to draw some primitive elements for a custom styled scrollbar. A snippet of my code:

void CustomStyle::drawPrimitive(PrimitiveElement pe, const QStyleOption* opt,
                                QPainter* p, const QWidget* widget) const {
  if (pe == PE_IndicatorArrowUp || pe == PE_IndicatorArrowDown) {
    QImage img;
    if (pe == PE_IndicatorArrowUp) {
      img = QImage(":/resources/ui/upward_arrow.png");
    } else if (pe == PE_IndicatorArrowDown) {
      img = QImage(":/resources/ui/downward_arrow.png");
    }

    QRect topPortion = QRect(QPoint(-2, -2), QSize(1.7 * opt->rect.width(),
                                                   1.7 * opt->rect.height()));

    QPixmap pixmap = QPixmap::fromImage(img);

    QSize size = pixmap.size().scaled(topPortion.size(), Qt::KeepAspectRatio);
    p->drawPixmap(topPortion.x(), topPortion.y(), size.width(), size.height(),
                  pixmap);
  } else {
    QProxyStyle::drawPrimitive(pe, opt, p, widget);
  }
}

Although I wanted to draw to separate primitive elements, only the PE_IndicatorArrowUp is drawn. What is even more surprising, is that the image for the downward arrow is drawn in place of the PE_IndicatorArrowUp primitive element while the PE_IndicatorArrowDown is left blank.

I have attached a screenshot of how it looks like.

I want to know why this behavior takes place and how to resolve it.

[Christian Ehrlicher]

Use a debugger and see what is drawn when on which place. Also make sure you added the correct images.

[SGaist]

Hi,

From a quick look at your code, aren't you always painting the image at the same place ?

[Christian Ehrlicher]

@SGaist said in drawPrimitive does not draw over all primitive elements:

Hi,

From a quick look at your code, aren't you always painting the image at the same place ?

You're correct - opt.rect is not honored...

[ateek.ujjawal]

@Christian-Ehrlicher Thank you, I figured it out, using opt->rect's x and y attributes draws it in the correct place.