Draw the fold region when the mouse is over and non collapsed
        indicator.

        :param top: Top position
        :param block: Current block.
        :param painter: QPainter

def _draw_fold_region_background(self, block, painter):
        """
        Draw the fold region when the mouse is over and non collapsed
        indicator.

        :param top: Top position
        :param block: Current block.
        :param painter: QPainter
        """
        r = FoldScope(block)
        th = TextHelper(self.editor)
        start, end = r.get_range(ignore_blank_lines=True)
        if start > 0:
            top = th.line_pos_from_number(start)
        else:
            top = 0
        bottom = th.line_pos_from_number(end + 1)
        h = bottom - top
        if h == 0:
            h = self.sizeHint().height()
        w = self.sizeHint().width()
        self._draw_rect(QRectF(0, top, w, h), painter)