sugar-toolkit-gtk3/shell/home/IconLayout.py

import random

class IconLayout:
	def __init__(self, width, height):
		self._icons = []
		self._width = width
		self._height = height

	def add_icon(self, icon):
		self._icons.append(icon)
		self._layout_icon(icon)

	def remove_icon(self, icon):
		self._icons.remove(icon)

	def _is_valid_position(self, icon, x, y):
		icon_size = icon.props.size
		border = 20

		if not (border < x < self._width - icon_size - border and \
		        border < y < self._height - icon_size - border):
			return False
		
		return True

	def _layout_icon(self, icon):
		while True:
			x = random.random() * self._width
			y = random.random() * self._height
			if self._is_valid_position(icon, x, y):
				break

		icon.props.x = x
		icon.props.y = y