'Recreates the combobox contents.'

def update_combobox(self):

    index = self.current_scheme_index
    self.schemes_combobox.blockSignals(True)
    names = self.get_option('names')
    try:
        names.pop(names.index(u'Custom'))
    except ValueError:
        pass
    custom_names = self.get_option('custom_names', [])
    for n in (names + custom_names):
        self.scheme_choices_dict[self.get_option('{0}/name'.format(n))] = n
    if custom_names:
        choices = ((names + [None]) + custom_names)
    else:
        choices = names
    combobox = self.schemes_combobox
    combobox.clear()
    for name in choices:
        if (name is None):
            continue
        combobox.addItem(self.get_option('{0}/name'.format(name)), name)
    if custom_names:
        combobox.insertSeparator(len(names))
    self.schemes_combobox.blockSignals(False)
    self.schemes_combobox.setCurrentIndex(index)
