dynamically change qpushbuttons font size

[hobbyProgrammer]

I have a grid of pushbuttons, and the size of the buttons vary depending on the size of the window.
I would like to change the font-size dynamiccaly depending on the buttons size.

Does anyone know how to do that?

[mrjj]

Hi
Do you mean to make text as large as will fit in button ?

Unless you also scale the height of the buttons (normally fixed)
there won't be much scaling possible.

However, if you really got a bigger area (width and height) then you can use
https://doc.qt.io/qt-5/qfontmetrics.html#details
To know the size of the text and then change the font size and recheck
if it can fit. If not use the point size before.

Update: Some very fast made code to play with.
Disclaimer. Will have bugs for corner cases.

void scalerFontSizeToFitBB(QPushButton *Button)
{
    qreal oldFontSize, newFontSize;

    oldFontSize = Button->font().pointSizeF();
    QFont font;

    int h = Button->rect().height() - 8;
    int w = Button->rect().width() - 8;
    qreal step = 0.5;    
    for (int i = 0 ; i < 25 ; i++) {
        QRect textRect = Button->fontMetrics().boundingRect(Button->text());
        if ( textRect.height() < h  && textRect.width() <  w ) {
            newFontSize = oldFontSize += step;
            font.setPointSizeF(newFontSize);
            Button->setFont(font);
            oldFontSize = newFontSize;
            qDebug() << i;
        } else continue; // skip rest
    }

    // set result
    oldFontSize -= step; // use the size before we didnt fit
    font.setPointSizeF(oldFontSize);
    Button->setFont(font);
}


void MainWindow::ButtonClicked()
{
    // scale all buttons
    QList<QPushButton *> buttonList = findChildren<QPushButton *>();
    for (QPushButton  *button : buttonList) {
        scalerFontSizeToFitBB(button);
    }
}

And do not put in unmodified in
void MainWindow::resizeEvent(QResizeEvent *event)
as it might lead to infinite recursion and crash.

Fast test

[hobbyProgrammer]

@mrjj that looks like what I need. Thank you so much.