Qt's application wide stylesheet not overwritten by local default stylesheet

Question

I have an application which loads a .qss styling file and apply the stylesheet to the whole application. My problem is that it modifies the default QGroupBox styling instead of a subclass of it, and I would like a default-style QGroupBox in one place.
Here is an example of the styling applied application wide that I'm trying to replace by the default one.

QGroupBox {
    border: 0px solid gray;
    border-bottom: 1px solid block;
}

I have tried to reset the stylesheet by using

_ui->setupUi(this);
_ui->myGroupBox->setStylesheet("");

But this does not work. From what I've gathered, the application-wide styling should have happened duing the setupUi() phase though, and thus be overwritten by the empty (default) stylesheet. This does not seem to be the case.

I have also tried without success to set it directly from Qt Designer, or from the qss file using.

myGroupBox {
}

However, if I put border-bottom: 1px solid red; in the qss file, it is correctly registered and overrule the default style. I do not now the default parameters though, so I cannot set them all by hand if needed.

If I remove the annoying qss rule, it works fine, but it breaks the application ui in 50 other places and I sadly do not have the time to refactor it right now.

Am I missing something when it comes to resetting to the default stylesheet?

Thanks.

Answer 1

You seem to be mixing up the styles with stylesheets. These are different beasts. When a widget has a stylesheet, it is not styled by the style mechanism anymore, because the styles in general aren't flexible enough to be modified by stylesheets, since they e.g. depend on platform-provided images etc. The two mechanisms are exclusive of each other: either one can control the appearance of the widget, but once you use a stylesheet, it's all-or-nothing: the style mechanism is out of the picture.

Simply fix your stylesheet to apply only to the group boxes it should apply to - you can select them by name or name path.