setStyleSheet sometimes not working

Jakob Clausen

Thats interesting.

setStyleSheet("Data { font-size: 26pt; }");

or

setStyleSheet("#SMALL { font-size: 26pt; }");

does not work.
Neither does

setStyleSheet("{ font-size: 26pt; }");

But as you suggest

setStyleSheet("* { font-size: 26pt; }");

does.
Does that make any sense?

JonB

@Jakob-Clausen
* is the selector for "anything". This implies to me that none of Data#SMALL, Data or #SMALL correctly address your widget instance, or maybe the right "bit" of it, but I do not know why. What is the ultimate base Qt type of your Data class?

Jakob Clausen

It is derived from QLabel.

JonB

@Jakob-Clausen
setStyleSheet("QLabel { font-size: 26pt; }"); ?

Jakob Clausen

That works! :-)
What does that mean?

JonB

@Jakob-Clausen
One outside thought is: does your Data class use the Q_OBJECT macro in its definition? That is usually required for signals, I have no idea whether that just might be required for stylesheet-widget-inheritance to work, worth checking.

Otherwise, produce the absolute minimum standalone program which creates a QLabel and show setStyleSheet("QLabel { font-size: 26pt; }") working, together with the minimum for a derived MyLabel and show that setStyleSheet("MyLabel { font-size: 26pt; }") does not work.

P.S.
Your Data class does not reside in a namespace, does it??

P.P.S.
I don't know whether this applies to deriving from QLabel, but for deriving from QWidget read https://forum.qt.io/topic/55983/inheritance-from-qwidget-stylesheet-problem & https://stackoverflow.com/questions/7276330/qt-stylesheet-for-custom-widget. But I'm really thinking/pretty sure that applies to QWidget only....

Jakob Clausen

I use Q_OBJECT and it is not in a namespace.
I have also tried to reimplement the event callback without any luck.
Now I will try to create a minimal standalone example.

Jakob Clausen

Ok. I have not yet created the absolute minimum standalone program, but I have something else.
If I do

setStyleSheet("Data QLabel { font-size: 26pt; }")

then it works. :-)
But why? Isn't the stylesheet supposed to be passed along to children automatically? (I guess not).

So Data#SMALL only applies to Data-objects with the name SMALL and not its descendants and Data QLabel applies to all QLabel descendants of Data.
Is what I just wrote correct?

JonB

@Jakob-Clausen
But you said earlier that Data is derived from QLabel (not e.g. that it contains a QLabel)? That's why I asked?

Jakob Clausen

Ah.
Sorry about that.
It does both.

Jakob Clausen

But many thanks for your effort.
I appreciate it.

JonB

@Jakob-Clausen said in setStyleSheet sometimes not working:

It does both.

It is a QLabel, and it also contains (another) QLabel?

P.S.
As a tip/suggestion, don't pick Data as a class name, and certainly not for some GUI element like labels.

Jakob Clausen

Yes.
In a layout.
Is that bad?

Jakob Clausen

@JonB Ok. Thank you.

JonB

@Jakob-Clausen said in setStyleSheet sometimes not working:

Is that bad?

[Nested QLabels.] I don't know, I've never done it!