Frame color/palette of QGroupBox?

CJha

Hi, I am trying to figure out the border color of QGroupBox. I have applied a fusion style and black palette to QApplication and my QGroupBox looks like this:

As you can see the border color of QGroupBox is neither black nor white but a shade of gray. I am trying to figure out which color is this.

I have subclassed QProxyStyle and in its drawPrimitive() function when the primitive element is equal to QStyle::PE_FrameGroupBox I am printing all the colors that are available in its current palette in all its states (Active, inactive, and Disabled) but none of the colors seem to be the border color of the QGroupBox.

I tried to figure out the QGroupBox border color using the color picker from QColorDialog, here are the results for different palettes:

qApp->setPalette(QPalette{QColor{0,0,0}}) => QColor(ARGB 1, 0.0901961, 0.0901961, 0.0901961)
qApp->setPalette(QPalette{QColor{10,10,10}}) => QColor(ARGB 1, 0.121569, 0.121569, 0.121569)
qApp->setPalette(QPalette{QColor{20,20,20}}) => QColor(ARGB 1, 0.152941, 0.152941, 0.152941)

As you can see the border color does change with the change in the main color of the palette applied, how is this calculated and how can I get this programmatically from Qt?

Chris Kawa

Fusion style ignores palette for the groupbox frame and uses a hardcoded semi-transparent pixmap.

See the source.

RokeJulianLockhart

@Chris-Kawa, that's horrible. Do you have any idea whether that's deliberate? That seems worth filing a bug about.

Christian Ehrlicher

@RokeJulianLockhart said in Frame color/palette of QGroupBox?:

That seems worth filing a bug about.

A style can do whatever it likes. Here it was decided to paint them through a semi-transparent png. It's maybe not nice but...
if you come up with an equivalent solution which does exactly the same with some palette stuff - feel free to post a patch.