= Drawing highlighted rows in a calendar widget =

On the Freenode #pyqt channel, rowinggolfer asked if it was possible to highlight the current week in a calendar widget.

{{{
#!python
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class WeekCalendar(QCalendarWidget):

    def __init__(self, *args):
    
        QCalendarWidget.__init__(self, *args)
        self.color = QColor(self.palette().color(QPalette.Highlight))
        self.color.setAlpha(64)
        self.selectionChanged.connect(self.updateCells)
    
    def paintCell(self, painter, rect, date):
    
        QCalendarWidget.paintCell(self, painter, rect, date)
        
        first_day = self.firstDayOfWeek()
        last_day = first_day + 6
        current_date = self.selectedDate()
        current_day = current_date.dayOfWeek()
        
        if first_day <= current_day:
            first_date = current_date.addDays(first_day - current_day)
        else:
            first_date = current_date.addDays(first_day - 7 - current_day)
        last_date = first_date.addDays(6)
        
        if first_date <= date <= last_date:
            painter.fillRect(rect, self.color)
}}}