# We will draw some shapes without knowing too much about
# either how the shapes are stored or how the drawing code works.
# We only know their interfaces (APIs).
# 
# For shapes, we need to know how to create them (constructor)
# and get their bounding boxes (bounding_box method).
# For drawing, we need to know how to create the drawing
# (constructor), how to add rectangles (add_rectangle method),
# how to add circles (add_circle method) and how to display (run method).
#
# The show_rectangles and show_shapes functions are polymorphic
# in the sense that they process different types of shapes.
# Because the functions are polymorphic, the main program is
# very simple because it only needs to pass the shape list to
# these functions without knowing anything about shapes at all.
#
# show_rectangles takes advantage of the fact that it only uses
# a portion of the API (bounding_box) that is shared by all
# shapes, and therefore needs no more information.
# 
# show_shapes is distinguishes between quadrilaterals and circles
# by checking whether an instance belongs to the Circle class.
# The shape type determines which Drawing API to use for displaying
# the shape.

def show_rectangles(d, shapes):
	for s in shapes:
		llx, lly, urx, ury = s.bounding_box()
		d.add_rectangle(llx, lly, urx, ury, "red")

def show_shapes(d, shapes):
	for s in shapes:
		llx, lly, urx, ury = s.bounding_box()
		if isinstance(s, Circle):
			d.add_circle(llx, lly, urx, ury, "green")
		else:
			d.add_rectangle(llx, lly, urx, ury, "red")

if __name__ == "__main__":
	from rectangle import Rectangle
	from inheritance import Square, Circle
	from drawing import Drawing
	shape_list = [
		Rectangle(40, 80, 120, 160),
		Square(160, 200, 80),
		Circle(40, 280, 60),
	]
	d = Drawing(400, 400)
	show_rectangles(d, shape_list)
	d.run()
	d = Drawing(400, 400)
	show_shapes(d, shape_list)
	d.run()