import random import math import cairo import hippo _DISTANCE_THRESHOLD = 120.0 class SpreadBox(hippo.CanvasBox, hippo.CanvasItem): __gtype_name__ = 'SugarSpreadBox' def __init__(self, **kwargs): hippo.CanvasBox.__init__(self, **kwargs) self._items_to_position = [] self._spread_on_add = False def add(self, item): self._items_to_position.append(item) self.append(item, hippo.PACK_FIXED) if self._spread_on_add: self.spread() def spread(self): self._spread_on_add = True [width, height] = self.get_allocation() for item in self._items_to_position: x = int(random.random() * width) y = int(random.random() * height) [x, y] = self._clamp_position(item, x, y) self.move(item, x, y) self._items_to_position = [] def _get_distance(self, icon1, icon2): [icon1_x, icon1_y] = self.get_position(icon1) [icon2_x, icon2_y] = self.get_position(icon2) a = icon1_x - icon2_x b = icon1_y - icon2_y return math.sqrt(a * a + b * b) def _get_repulsion(self, icon1, icon2): [icon1_x, icon1_y] = self.get_position(icon1) [icon2_x, icon2_y] = self.get_position(icon2) f_x = icon1_x - icon2_x f_y = icon1_y - icon2_y return [f_x, f_y] def _clamp_position(self, icon, x, y): x = max(0, x) y = max(0, y) [item_w, item_h] = icon.get_allocation() [box_w, box_h] = self.get_allocation() x = min(box_w - item_w, x) y = min(box_h - item_h, y) return [x, y] def _spread_icons(self): stable = True for icon1 in self.get_children(): vx = 0 vy = 0 [x, y] = self.get_position(icon1) for icon2 in self.get_children(): if icon1 != icon2: distance = self._get_distance(icon1, icon2) if distance <= _DISTANCE_THRESHOLD: stable = False [f_x, f_y] = self._get_repulsion(icon1, icon2) vx += f_x vy += f_y new_x = x + vx new_y = y + vy [new_x, new_y] = self._clamp_position(icon1, new_x, new_y) self.move(icon1, new_x, new_y) return stable def do_allocate(self, width, height): hippo.CanvasBox.do_allocate(self, width, height) tries = 10 stable = self._spread_icons() while not stable and tries > 0: stable = self._spread_icons() tries -= 1