QScrollArea transparent background on MacOS X

Question

I have a problem with making contents of QScrollArea to not draw a background.

So here is the initial picture, when I apply no stylesheet: You can see, that the contents of scroll area are darker then the overall frame.

I have found the stylesheet that I can apply to scroll area, so the background is transparent. Here's the stylesheet I use:

QScrollArea { background: transparent; }
QScrollArea > QWidget > QWidget { background: transparent; }

Problem is that when I do that, the scrollbar of scrollarea gets messed up:

You see? The scrollbar is now always visible and is ugly and transparent.

How can I make my stylesheet not to affect the scrollbar, while still applying it to the QScrollArea ? Or what different stylesheet should I apply instead?

Answer 1

try to set an object name for the scroll area viewport:

pScrollArea->viewport()->setObjectName("myViewport");

then address it using the hashtag property in the stylesheet (also add the groupbox since the way I see it in your screenshot, your goal is to make them transparent as well):

QScrollArea, #myViewport, QGroupBox { 
  background: transparent;
}

Answer 2

The problem is that QScrollBar is a subclass of QWidget, so just target the viewport with that rule:

pScrollArea->setStyleSheet("QScrollArea { background: transparent; }");
pScrollArea->viewport()->setStyleSheet(".QWidget { background: transparent; }");

Notice the dot before QWidget, so to not target any children of the viewport (ie, any viewport content that's a QWidget subclass).