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 = folding.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(QtCore.QRectF(0, top, w, h), painter)
