drawing antialiasing line still looks jagged on IPad mini

I'm drawing a line using the antialiasing flag. This works fine when running my app on MacOS and Windows but looks jagged when running on a tablet (Ipad mini or IPad 2). I'm using Qt 5.2.1

Any ideas?

Code:

---

if (GetShow())
{
		QColor penColor = mFocused ? mFocusedFillColor : mNotFocusedFillColor;
		penColor.setAlpha( mFocused ? mFocusedOpacity : mNotFocusedOpacity);
		QPen pen(penColor, 0, Qt::SolidLine);
		if (mOverrideDefualtLineStyle)
			pen.setStyle(mLineStyle);
 
		int lineWidth = mFocused ? mLineWidthFocused : mLineWidthNotFocused;
		pen.setWidth(lineWidth);
 
		pen.setCapStyle(Qt::RoundCap);
 
		painter->setPen(pen);
		painter->setRenderHint(QPainter::Antialiasing, true);
		painter->drawLine(mBoxPositionToDraw, mAnchorPositionToDraw);
}

---

I thought it might be a Qt bug and updated to Qt 5.3.0 but I still see jagged lines. Does anybody else see this?

There's a bug in Qt: https://bugreports.qt-project.org/browse/QTBUG-35271