class ToggleButtonDelegate(QtWidgets.QStyledItemDelegate):

    def paint(self, painter, option, index):
        value = index.data(QtCore.Qt.EditRole)
        state = QtWidgets.QStyle.State_On if value else QtWidgets.QStyle.State_Off
        checkbox_indicator = QtWidgets.QStyleOptionButton()
        checkbox_indicator.state |= QtWidgets.QStyle.State_Enabled
        checkbox_indicator.state |= state
        checkbox_indicator.rect = QtWidgets.QApplication.style().subElementRect(QtWidgets.QStyle.SE_CheckBoxIndicator, checkbox_indicator, None)

        x = option.rect.center().x() - checkbox_indicator.rect.width() / 2
        y = option.rect.center().y() - checkbox_indicator.rect.height() / 2
        checkbox_indicator.rect.moveTo(x, y)

        #if option.state:
            #painter.fillRect(option.rect, option.palette.highlight())

        QtWidgets.QApplication.style().drawControl(QtWidgets.QStyle.CE_CheckBox, checkbox_indicator, painter)

    def createEditor(self, parent, option, index):
        """Editor for templates and tasks."""
        index.model().setData(index, not index.data())