more spacing fine-tuning

1 files changed, 98 insertions, 19 deletions

diff --git a/src/jarabe/desktop/favoriteslayout.py b/src/jarabe/desktop/favoriteslayout.py
index 85e1b59..14c1d68 100644
--- a/src/jarabe/desktop/favoriteslayout.py
+++ b/src/jarabe/desktop/favoriteslayout.py
@@ -1,4 +1,5 @@
 # Copyright (C) 2008 One Laptop Per Child
+# Copyright (C) 2010 Sugar Labs
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -32,6 +33,10 @@ _logger = logging.getLogger('FavoritesLayout')
 
 _CELL_SIZE = 4
 _BASE_SCALE = 1000
+_INTERMEDIATE_B = (style.STANDARD_ICON_SIZE + style.SMALL_ICON_SIZE) / 2
+_INTERMEDIATE_A = (style.STANDARD_ICON_SIZE + _INTERMEDIATE_B) / 2
+_INTERMEDIATE_C = (_INTERMEDIATE_B + style.SMALL_ICON_SIZE) / 2
+
 
 class FavoritesLayout(gobject.GObject, hippo.CanvasLayout):
     """Base class of the different layout types."""
@@ -185,6 +190,12 @@ _MINIMUM_RADIUS = style.XLARGE_ICON_SIZE / 2 + style.DEFAULT_SPACING + \
         style.STANDARD_ICON_SIZE * 2
 _MAXIMUM_RADIUS = (gtk.gdk.screen_height() - style.GRID_CELL_SIZE) / 2 - \
         style.STANDARD_ICON_SIZE - style.DEFAULT_SPACING
+_ICON_SIZES = [style.MEDIUM_ICON_SIZE, style.STANDARD_ICON_SIZE,
+               _INTERMEDIATE_A, _INTERMEDIATE_B, _INTERMEDIATE_C,
+               style.SMALL_ICON_SIZE]
+_ICON_SPACING_FACTOR = [1.5, 1.4, 1.3, 1.2, 1.1, 1.0]
+_SPIRAL_SPACING_FACTOR = [1.5, 1.5, 1.5, 1.4, 1.3, 1.2]
+_MIMIMUM_RADIUS_ENCROACHMENT = 0.75
 
 class RingLayout(FavoritesLayout):
     """Lay out icons in a ring around the XO man."""
@@ -201,6 +212,13 @@ class RingLayout(FavoritesLayout):
     def __init__(self):
         FavoritesLayout.__init__(self)
         self._locked_children = {}
+        self._spiral = False
+        self._radius = _MINIMUM_RADIUS
+        self._orientation = math.pi
+        self._icon_size = style.MEDIUM_ICON_SIZE
+        self._icon_spacing_factor = _ICON_SPACING_FACTOR[0]
+        self._spiral_spacing_factor = _SPIRAL_SPACING_FACTOR[0]
+        self._count = -1
 
     def append(self, icon, locked=False):
         FavoritesLayout.append(self, icon, locked)
@@ -221,31 +239,92 @@ class RingLayout(FavoritesLayout):
             self._locked_children[child] = (x, y)
 
     def _calculate_radius_and_icon_size(self, children_count):
-        # what's the radius required without downscaling?
-        distance = style.STANDARD_ICON_SIZE + style.DEFAULT_SPACING
-        icon_size = style.STANDARD_ICON_SIZE
-        # circumference is 2*pi*r; we want this to be at least
-        # 'children_count * distance'
+        """ Determine if we are drawing a ring with MEDIUM- or STANDARD-size
+        icons or a spiral with STANDARD-, INTERMEDIATE-, or SMALL-size
+        icons."""
+        self._spiral = True
+        distance = style.MEDIUM_ICON_SIZE + style.DEFAULT_SPACING
         radius = children_count * distance / (2 * math.pi)
-        # limit computed radius to reasonable bounds.
         radius = max(radius, _MINIMUM_RADIUS)
-        radius = min(radius, _MAXIMUM_RADIUS)
-        # recompute icon size from limited radius
-        if children_count > 0:
-            icon_size = (2 * math.pi * radius / children_count) \
-                        - style.DEFAULT_SPACING
-        # limit adjusted icon size.
-        icon_size = max(icon_size, style.SMALL_ICON_SIZE)
-        icon_size = min(icon_size, style.MEDIUM_ICON_SIZE)
-        return radius, icon_size
+        if radius < _MAXIMUM_RADIUS:
+            self._spiral = False
+            self._icon_size = style.MEDIUM_ICON_SIZE
+        if self._spiral:
+            distance = style.STANDARD_ICON_SIZE + style.DEFAULT_SPACING
+            radius = children_count * distance / (2 * math.pi)
+            radius = max(radius, _MINIMUM_RADIUS)
+            if radius < _MAXIMUM_RADIUS:
+                self._spiral = False
+                self._icon_size = style.STANDARD_ICON_SIZE
+            else:
+                self._spiral = True
+                radius = _MINIMUM_RADIUS - \
+                    (self._icon_size * _MIMIMUM_RADIUS_ENCROACHMENT)
+
+        # If there are fewer children, try increasing icon_size.
+        if self._count > children_count:
+            i = _ICON_SIZES.index(self._icon_size)
+            if i > 0:
+                self._icon_size = _ICON_SIZES[i - 1]
+                self._icon_spacing_factor = _ICON_SPACING_FACTOR[i - 1]
+                self._spiral_spacing_factor = _SPIRAL_SPACING_FACTOR[i - 1]
+        self._count = children_count
+
+        # If the radius exceeds the minimun, try decreasing icon_size.
+        if self._radius > _MAXIMUM_RADIUS:
+            i = _ICON_SIZES.index(self._icon_size)
+            if i < len(_ICON_SIZES) - 1:
+                self._icon_size = _ICON_SIZES[i + 1]
+                self._icon_spacing_factor = _ICON_SPACING_FACTOR[i + 1]
+                self._spiral_spacing_factor = _SPIRAL_SPACING_FACTOR[i + 1]
+
+        return radius, self._icon_size
+
+    def _calculate_xy(self, icon_size, width, height):
+        """ Convert r, o to x, y """
+        x = -math.sin(self._orientation) * self._radius
+        y = math.cos(self._orientation) * self._radius
+        self._calculate_new_radius_orientation(icon_size + \
+                             self._icon_spacing_factor * style.DEFAULT_SPACING)
+
+        x = int(x) + (width - icon_size) / 2
+        y = int(y) + (height - icon_size - (style.GRID_CELL_SIZE / 2) ) / 2
+        return x, y
+
+    def _calculate_new_radius_orientation(self, icon_size):
+        """ Based upon current radius, calculate new increments """
+        circumference = self._radius * 2 * math.pi
+        n = circumference / icon_size
+        self._orientation += 2 * math.pi / n
+        self._radius += float(icon_size * self._spiral_spacing_factor) / n
 
     def _calculate_position(self, radius, icon_size, index, children_count,
                             sin=math.sin, cos=math.cos):
+        """ Try fitting a circle or a spiral """
         width, height = self.box.get_allocation()
-        angle = index * (2 * math.pi / children_count) - math.pi / 2
-        x = radius * cos(angle) + (width - icon_size) / 2
-        y = radius * sin(angle) + (height - icon_size -
-                                   (style.GRID_CELL_SIZE/2) ) / 2
+        if not self._spiral:
+            angle = index * (2 * math.pi / children_count) - math.pi / 2
+            x = radius * cos(angle) + (width - icon_size) / 2
+            y = radius * sin(angle) + (height - icon_size - \
+                                       (style.GRID_CELL_SIZE/2) ) / 2
+        else:
+            min_width_, box_width = self.box.get_width_request()
+            min_height_, box_height = self.box.get_height_request(box_width)
+            if index == 0:
+                self._radius = _MINIMUM_RADIUS - \
+                    (self._icon_size * _MIMIMUM_RADIUS_ENCROACHMENT)
+                self._orientation = math.pi
+            x, y = self._calculate_xy(icon_size, width, height)
+            # If we are off the screen, keep going...
+            while x < min_width_ or x > box_width - icon_size or \
+                    y < min_height_ or y > box_height - icon_size:
+                x, y = self._calculate_xy(icon_size, width, height)
+                # If we run past a corner, we will never return, so break
+                if (x < min_height_ and \
+                        (y < min_width_ or y > box_height - icon_size)) or \
+                        (x > box_width - icon_size and \
+                             (y < min_width_ or y > box_height - icon_size)):
+                    break
         return x, y
 
     def _get_children_in_ring(self):