[kiwidude]

The font selection combos:

class FontFamilyModel(QAbstractListModel):

    def __init__(self, *args):
        QAbstractListModel.__init__(self, *args)
        from calibre.utils.fonts.scanner import font_scanner
        try:
            self.families = font_scanner.find_font_families()
        except:
            self.families = []
            print('WARNING: Could not load fonts')
            traceback.print_exc()
        # Restrict to Qt families as Qt tends to crash
        self.font = QFont('Arial' if iswindows else 'sansserif')

    def rowCount(self, *args):
        return len(self.families)

    def data(self, index, role):
        try:
            family = self.families[index.row()]
        except:
            traceback.print_exc()
            return None
        if role == Qt.DisplayRole:
            return family
        if role == Qt.FontRole:
            # If a user chooses some non standard font as the interface font,
            # rendering some font names causes Qt to crash, so return what is
            # hopefully a "safe" font
            return self.font
        return None

    def index_of(self, family):
        return self.families.index(family.strip())


class FontComboBox(QComboBox):
    def __init__(self, parent):
        QComboBox.__init__(self, parent)
        self.font_family_model = FontFamilyModel()
        self.setModel(self.font_family_model)

    def select_value(self, value):
        idx = self.findText(value) if value else -1
        self.setCurrentIndex(idx)

    def get_value(self):
        if self.currentIndex() < 0:
            return None
        return unicode(self.currentText()).strip()

Then the code for drawing making use of the font...

class TextLine(object):

    def __init__(self, text, font_name, font_size,
                 bottom_margin=30, align='center'):
        self.text = force_unicode(text)
        self.bottom_margin = bottom_margin
        try:
            from qt.core import QFont, Qt
        except ImportError:
            from PyQt5.Qt import QFont, Qt
        self.font = QFont(font_name) if font_name else QFont()
        self.font.setPixelSize(font_size)
        self._align = {'center': Qt.AlignHCenter,
                       'left': Qt.AlignLeft, 'right': Qt.AlignRight}[align]