Make point, line and two-point linestrip shapes selectable

[Ynjxsjmh]

Currenly, point, line and two-point linestrip won't be selected by mouse left click, which leads to hard deletion. The main problem is that self.makePath().contains(point) doesn't consider these three special condition. These three shapes don't possess enclosing structures like rectangle and circle.

labelme/labelme/shape.py

Lines 326 to 355 in b9c83ff

	def containsPoint(self, point):
	if self.mask is not None:
	y = np.clip(
	int(round(point.y() - self.points[0].y())),
	0,
	self.mask.shape[0] - 1,
	)
	x = np.clip(
	int(round(point.x() - self.points[0].x())),
	0,
	self.mask.shape[1] - 1,
	)
	return self.mask[y, x]
	return self.makePath().contains(point)
	def makePath(self):
	if self.shape_type in ["rectangle", "mask"]:
	path = QtGui.QPainterPath()
	if len(self.points) == 2:
	path.addRect(QtCore.QRectF(self.points[0], self.points[1]))
	elif self.shape_type == "circle":
	path = QtGui.QPainterPath()
	if len(self.points) == 2:
	raidus = labelme.utils.distance(self.points[0] - self.points[1])
	path.addEllipse(self.points[0], raidus, raidus)
	else:
	path = QtGui.QPainterPath(self.points[0])
	for p in self.points[1:]:
	path.lineTo(p)
	return path

To solve this, I add judgement to check if the clicked point is near these shapes.

[Ynjxsjmh]

@wkentaro Hi, could you take some time to view my two prs? I don't know how to trigger checks on github, but they pass the test on my local machine.