Qt - QPushButton text formatting

You really don't need to subclass to change the formatting of your button, rather use stylesheets e.g.

QPushButton {
    font-size: 18pt;
    font-weight: bold;
    color: #ff0000;
}

Applying this to the button that you want to change will make the buttons text 18pt, bold and red. You can apply via widget->setStyleSheet()

Applying this to a widget in the hierarchy above will style all the buttons underneath, the QT stylesheet mechanism is very flexible and fairly well documented.

You can set stylesheets in the designer too, this will style the widget that you are editing immediately

you make the subclass of "QPushbutton", then override the paint event, there you modify the text to your wish.

here it is,

class button : public QPushButton
    {
    Q_OBJECT

public:
    button(QWidget *parent = 0)
        {

        }
    ~button()
        {

        }

    void paintEvent(QPaintEvent *p2)
        {

        QPushButton::paintEvent(p2);

            QPainter paint(this);
            paint.save();
            QFont sub(QApplication::font());
            sub.setPointSize(sub.pointSize() + 7);
            paint.setFont(sub);
            paint.drawText(QPoint(300,300),"Hi");
            paint.restore();

        }
    };

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


    button b1;
    b1.showMaximized();
    return a.exec();
}

Note:
My answer is inspired by the idea from @Петър Петров and the comment from @mjwach.

You can subclass QPushButton and give it two private fields:

• self.__lbl: A QLabel() instance to hold the rich text. Its background is made transparent and it doesn't catch mouse events.
• self.__lyt: A QHBoxLayout() to hold the label. The layout margins are set to zero, such that the label's borders touch the button's borders. In other words: we ensure that the label has the exact same size as the button, and is positioned right on top of it.

Finally you have to override the setText() method, such that the text ends up in the label instead of the button.

class RichTextPushButton(QPushButton):
    def __init__(self, parent=None, text=None):
        if parent is not None:
            super().__init__(parent)
        else:
            super().__init__()
        self.__lbl = QLabel(self)
        if text is not None:
            self.__lbl.setText(text)
        self.__lyt = QHBoxLayout()
        self.__lyt.setContentsMargins(0, 0, 0, 0)
        self.__lyt.setSpacing(0)
        self.setLayout(self.__lyt)
        self.__lbl.setAttribute(Qt.WA_TranslucentBackground)
        self.__lbl.setAttribute(Qt.WA_TransparentForMouseEvents)
        self.__lbl.setSizePolicy(
            QSizePolicy.Expanding,
            QSizePolicy.Expanding,
        )
        self.__lbl.setTextFormat(Qt.RichText)
        self.__lyt.addWidget(self.__lbl)
        return

    def setText(self, text):
        self.__lbl.setText(text)
        self.updateGeometry()
        return

    def sizeHint(self):
        s = QPushButton.sizeHint(self)
        w = self.__lbl.sizeHint()
        s.setWidth(w.width())
        s.setHeight(w.height())
        return s