Question

I know there’s no support for QCalendarWidget QSS styling but does anyone know some workarounds for changing the color of sections 1 and 2 of the QCalendarWidget? (the light blue for section 1 and white for section 2)

Thanks!

Answer 1

I’ve examined QCalendarWidget source code and found the solution.

QCalendarWidget internally has a model and a view to display days. QCalendarModel has a formatForCell(int, int) function that returns QTextCharFormat for a given cell. Returning format is the result of merging QCalendarView palette data, a format for current day (saturday and sunday are shown in red) and a format for current date, which can be set using QCalendarWidget::setDateTextFormat function.

Actually an item’s background is:

format.setBackground(pal.brush(cg, header ? QPalette::AlternateBase : QPalette::Base));

• pal is a QCalendarView‘s palette;
• cg is a color group;
• header is true when the current cell is a header cell (section 1 in your example)

So, all you need is to set your custom palette to that internal QCalendarView. In the source code we can find that QCalendarView object has a name “qt_calendar_calendarview” which we can use:

QCalendarWidget *c = new QCalendarWidget;

QTableView *view = c->findChild<QTableView*>("qt_calendar_calendarview");
if (view)
{
    QPalette pal = view->palette();
    pal.setColor(QPalette::Base, Qt::red);
    pal.setColor(QPalette::AlternateBase, Qt::green);
    view->setPalette(pal);
}

In my example section 1 will be red and section 2 will be green.
Additionally you can set colors for every color group of you palette to get the widget you like when it’s active, inactive etc.