"""turtledemo/sorting_animation.py

A minimal sorting algorithm animation:
Sorts a shelf of 10 blocks using insertion
sort, selection sort and quicksort.

Shelves are implemented using builtin lists.

Blocks are turtles with shape "square", but
stretched to rectangles by shapesize()
"""
from turtle import *
import random


class Block(Turtle):

    def __init__(self, size):
        self.size = size
        Turtle.__init__(self, shape="square", visible=False)
        self.pu()
        self.shapesize(size * 1.5, 1.5, 2) # square-->rectangle
        self.fillcolor("black")
        self.st()

    def glow(self):
        self.fillcolor("red")

    def unglow(self):
        self.fillcolor("black")

    def __repr__(self):
        return "Block size: {0}".format(self.size)


class Shelf(list):

    def __init__(self, y):
        "create a shelf. y is y-position of first block"
        self.y = y
        self.x = -150

    def push(self, d):
        width, _, _ = d.shapesize()
        # align blocks by the bottom edge
        y_offset = width / 2 * 20
        d.sety(self.y + y_offset)
        d.setx(self.x + 34 * len(self))
        self.append(d)
