Implement very simple spread out logic for the IconLayout

shell/view/home/IconLayout.py

@@ -1,10 +1,16 @@
 import random
+import math
 
 class IconLayout:
+	DISTANCE_THRESHOLD = 120.0
+
 	def __init__(self, grid):
 		self._icons = []
 		self._grid = grid
 
+		[self._x1, self._y1] = self._grid.convert_to_canvas(1, 1)
+		[self._x2, self._y2] = self._grid.convert_to_canvas(78, 59)
+
 	def add_icon(self, icon):
 		self._icons.append(icon)
 		self._layout_icon(icon)
@@ -12,13 +18,47 @@ class IconLayout:
 	def remove_icon(self, icon):
 		self._icons.remove(icon)
 
+	def _distance(self, icon1, icon2):
+		a = icon2.props.x - icon1.props.x
+		b = icon2.props.y - icon1.props.y
+		return math.sqrt(a * a  + b * b)
+
+	def _spread_icons(self):
+		self._stable = True
+
+		for icon1 in self._icons:
+			vx = 0
+			vy = 0
+
+			for icon2 in self._icons:
+				if icon1 != icon2:
+					distance = self._distance(icon1, icon2)
+					if distance <= IconLayout.DISTANCE_THRESHOLD:
+						self._stable = False
+						vx += icon1.props.x - icon2.props.x
+						vy += icon1.props.y - icon2.props.y
+
+			new_x = icon1.props.x + vx
+			new_y = icon1.props.y + vy
+
+			new_x = max(self._x1, new_x)
+			new_y = max(self._y1, new_y)
+
+			new_x = min(self._x2 - icon1.props.size, new_x)
+			new_y = min(self._y2 - icon1.props.size, new_y)
+
+			icon1.props.x = new_x
+			icon1.props.y = new_y
+
 	def _layout_icon(self, icon):
-		[x1, y1] = self._grid.convert_to_canvas(1, 1)
+		x = random.random() * (self._x2 - self._x1 - icon.props.size) 
-		[x2, y2] = self._grid.convert_to_canvas(78, 59)
+		y = random.random() * (self._y2 - self._y1 - icon.props.size)
-		size = icon.props.size
 
-		x = random.random() * (x2 - x1 - size) 
+		icon.props.x = x + self._x1
-		y = random.random() * (y2 - y1 - size)
+		icon.props.y = y + self._y1
 
-		icon.props.x = x + x1
+		tries = 10
-		icon.props.y = y + y1
+		self._spread_icons()
+		while not self._stable and tries > 0:
+			self._spread_icons()
+			tries -= 1

tests/test-icon-layout.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python
 import pygtk
 pygtk.require('2.0')
+import gobject
 
 from sugar.session.UITestSession import UITestSession
 
@@ -19,6 +20,17 @@ from sugar.canvas.IconItem import IconItem
 from sugar.canvas.CanvasView import CanvasView
 from sugar.canvas.Grid import Grid
 
+def _create_icon():
+	color = IconColor.IconColor()
+
+	icon = IconItem(size=125, color=color,
+					icon_name='stock-buddy')
+	root.add_child(icon)
+
+	icon_layout.add_icon(icon)
+
+	return (root.get_n_children() < 20)
+
 window = gtk.Window()
 window.connect("destroy", lambda w: gtk.main_quit())
 window.show()
@@ -36,14 +48,7 @@ root.add_child(item)
 
 icon_layout = IconLayout(Grid())
 
-for i in range(0, 200):
+gobject.timeout_add(500, _create_icon)
-	color = IconColor.IconColor()
-
-	icon = IconItem(size=125, color=color,
-					icon_name='stock-buddy')
-	root.add_child(icon)
-
-	icon_layout.add_icon(icon)
 
 canvas.set_model(canvas_model)