def get_arrow_polygon(self, scaling: float = 1., offset: int = 0, base: int = 35,
height: int = 10, colour: str = "white") -> Polygon:
""" Returns an SVG polygon shaped like an arrow that represents the Gene """
if self.reversed:
start = int((offset - self.get_start()) * scaling)
end = int((offset - self.get_end()) * scaling)
else:
start = int((self.get_start() + offset) * scaling)
end = int((self.get_end() + offset) * scaling)
start, end = sorted([start, end])
builder = ShapeBuilder()
arrow_size = height // 2
if abs(start - end) < arrow_size:
if self.strand > -1:
points = [(start, base),
(end, base - arrow_size),
(start, base - height),
(start, base)]
else:
points = [(start, base - arrow_size),
(end, base - height),
(end, base),
(start, base - arrow_size)]
else:
if self.strand > -1:
arrowstart = end - arrow_size
points = [(start, base),
(arrowstart, base),
(end, base - arrow_size),
(arrowstart, base - height),
(start, base - height),
(start, base)]
else:
arrowstart = start + arrow_size
points = [(start, base - arrow_size),
(arrowstart, base - height),
(end, base - height),
(end, base),
(arrowstart, base),
(start, base - arrow_size)]
arrow = builder.createPolygon(strokewidth=1, stroke='black', fill=colour,
points=builder.convertTupleArrayToPoints(points))
locus_tag = self.name
if self.protein:
locus_tag = self.protein.get_id()
arrow.setAttribute('description', self._get_description())
arrow.setAttribute('locus_tag', locus_tag)
arrow.set_class('clusterblast-orf')
return arrow
