File:Spiral.png

    def _calculate_position(self, radius, icon_size, index, children_count):
        width, height = self.box.get_allocation()
        # angle decreases as the radius increases
        inc = 12.0 + index / 6.0
        angle = index * (2 * math.pi / inc) - math.pi / 2
        # radius is proportional to index/children_count
        myminimum = _MINIMUM_RADIUS * .667
        newradius = ((radius - myminimum) * (index * 1.1) / children_count) +
                                        myminimum
        x = newradius * math.cos(angle) + (width - icon_size) / 2
        y = newradius * math.sin(angle) + (height - icon_size -
                                        style.GRID_CELL_SIZE) / 2
        return x, y