How to remove the horizontal line in a QWizard with a stylesheet?

Question

I am working on stylesheet of a QWizard and I would like to remove the horizontal line just above the push button.

I've already posted a minimal example here, the question was solved by scopchanov from the minimal example, but I have some lines of code in my project that avoids the solution to work, so I post another question here.

Screenshot

Here is my code (the complete buildable example can be downloaded from the gist here):

licensewizard.h

#include <QWizard>

class LicenseWizard : public QWizard {
  Q_OBJECT
public:
  LicenseWizard(QWidget *parent = 0);
};

licensewizard.cpp

#include <QApplication>
#include <QtWidgets>
#include "licensewizard.h"

LicenseWizard::LicenseWizard(QWidget *parent) : QWizard(parent) {
    setWizardStyle(ModernStyle);

    // solution from @scopchanov https://stackoverflow.com/a/52541248/8570451
    QPalette p(palette());
    p.setColor(QPalette::Mid, p.color(QPalette::Base));
    setPalette(p);
}

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    // this line breaks @scopchanov solution.
    // replace QLabel by QPushButton, or anything else... still broken.
    qApp->setStyleSheet("QLabel { color:black; }");

    LicenseWizard wizard;
    wizard.show();

    return app.exec();
}

As scopchanov said, I used the QPalette trick. But I have a big style sheet defined on the qApp and this is the cause of my problem. Using a very small style give the same problem.

The step to reproduce is to add this line after the declaration of the QApplication:

qApp->setStyleSheet("QLabel { color:black; }");

I hope someone could help me.

scopchanov · Accepted Answer · 2018-10-06T00:05:46.010

2

To fix this, set the palette of the whole application, instead of just the LicenseWizard class, like this:

LicenseWizard::LicenseWizard(QWidget *parent) : QWizard(parent) {
    setWizardStyle(ModernStyle);
}

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    QPalette p(qApp->palette());

    p.setColor(QPalette::Mid, p.color(QPalette::Base));
    qApp->setPalette(p);
    qApp->setStyleSheet("QLabel { color:black; }");

    LicenseWizard wizard;
    wizard.show();

    return app.exec();
}

Note: As mentioned in my answer to the linked question, if this color role is used by any other item, its color would be affected as well.

edited Oct 06 '18 at 00:05

answered Oct 05 '18 at 15:34

scopchanov

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Will not that affect other widgets? – eyllanesc Oct 05 '18 at 15:38
@eyllanesc, most certainly. I cannot think of other solution, though. In my answer to the linked question I've explicitly mentioned that. – scopchanov Oct 05 '18 at 15:40
1

So I recommend placing it as a warning in your question. It is always good to indicate the limitations of the answers. – eyllanesc Oct 05 '18 at 15:41
2

I recommend placing it here, I assure you that very few will review your linked question. – eyllanesc Oct 05 '18 at 15:43
1

@eyllanesc, I already did. Thank you for the remark! I appreciate it. – scopchanov Oct 05 '18 at 15:43
1

Using qApp->setStyleSheet, why do I need to define the palette for the whole appication? The line is painted inside of the QWizard. Thanks you again, this is the accepted answer. – matt Oct 05 '18 at 15:49
@matt, I know it does not sound logical. I have dug in the Qt sources the whole last night without much success for finding a reasonable explanation. The closest I get is that `QApplication::setStyleSheet` resets the palette [along the way](https://code.woboq.org/qt5/qtbase/src/widgets/kernel/qapplication.cpp.html#_ZN12QApplication8setStyleEP6QStyle) and of course the warning in the [documentation](http://doc.qt.io/qt-5/qapplication.html#setPalette) not to use `QApplication::setPalette` in conjunction with stylesheets. – scopchanov Oct 06 '18 at 11:36

How to remove the horizontal line in a QWizard with a stylesheet?

1 Answers1

Linked