Separate hue color of scheme by golden angle

issue4257
review12631002

CHANGELOG

@@ -1,3 +1,4 @@
+* New color scheme for graph
 * Replace img_{width,height} by width and height attributes
 
 Version 3.4.0 - 2014-10-20

tryton/common/common.py

@@ -11,6 +11,7 @@ import subprocess
 import re
 import logging
 import unicodedata
+import colorsys
 from functools import partial
 from tryton.config import CONFIG
 from tryton.config import TRYTON_ICON, PIXMAPS_DIR
@@ -1177,33 +1178,26 @@ def hex2rgb(hexstring, digits=2):
     return r / top, g / top, b / top
 
 
-def clamp(minValue, maxValue, value):
-    """Make sure value is between minValue and maxValue"""
-    if value < minValue:
-                return minValue
-    if value > maxValue:
-                return maxValue
-    return value
+def highlight_rgb(r, g, b, amount=0.1):
+    h, s, v = colorsys.rgb_to_hsv(r, g, b)
+    return colorsys.hsv_to_rgb(h, s, (v + amount) % 1)
 
 
-def lighten(r, g, b, amount):
-    """Return a lighter version of the color (r, g, b)"""
-    return (clamp(0.0, 1.0, r + amount),
-            clamp(0.0, 1.0, g + amount),
-            clamp(0.0, 1.0, b + amount))
-
-
-def generateColorscheme(masterColor, keys, light=0.06):
+def generateColorscheme(masterColor, keys, light=0.1):
     """
     Generates a dictionary where the keys match the keys argument and
     the values are colors derivated from the masterColor.
-    Each color is a lighter version of masterColor separated by a difference
-    given by the light argument.
+    Each color has a value higher then the previous of `light`.
+    Each color has a hue separated from the previous by the golden angle.
     The masterColor is given in a hex string format.
     """
     r, g, b = hex2rgb(COLOR_SCHEMES.get(masterColor, masterColor))
-    return dict([(key, lighten(r, g, b, light * i))
-        for i, key in enumerate(keys)])
+    h, s, v = colorsys.rgb_to_hsv(r, g, b)
+    if keys:
+        light = min(light, (1. - v) / len(keys))
+    golden_angle = 0.618033988749895
+    return {key: colorsys.hsv_to_rgb((h + golden_angle * i) % 1,
+            s, (v + light * i) % 1) for i, key in enumerate(keys)}
 
 
 class DBProgress(object):

tryton/gui/window/view_form/view/graph_gtk/bar.py

@@ -3,7 +3,7 @@
 #This code is inspired by the pycha project
 #(http://www.lorenzogil.com/projects/pycha/)
 from graph import Graph
-from tryton.common import float_time_to_text
+from tryton.common import float_time_to_text, highlight_rgb
 import locale
 import math
 import cairo
@@ -37,7 +37,7 @@ class Bar(Graph):
             self.drawRectangle(cr, x, y, w, h)
             r, g, b = self.colorScheme[bar.yname]
             if bar.highlight:
-                r, g, b = self.colorScheme['__highlight']
+                r, g, b = highlight_rgb(r, g, b)
             cr.set_source(self.sourceRectangle(x, y, w, h, r, g, b))
             cr.fill_preserve()
             cr.stroke()

tryton/gui/window/view_form/view/graph_gtk/graph.py

@@ -454,7 +454,7 @@ class Graph(gtk.DrawingArea):
         color = self.attrs.get('color', 'blue')
         r, g, b = hex2rgb(COLOR_SCHEMES.get(color, color))
         maxcolor = max(max(r, g), b)
-        self.colorScheme = generateColorscheme(color, keys + ['__highlight'],
+        self.colorScheme = generateColorscheme(color, keys,
                 maxcolor / (len(keys) or 1))
         for yfield in self.yfields:
             if yfield.get('color'):

tryton/gui/window/view_form/view/graph_gtk/line.py

@@ -3,7 +3,7 @@
 #This code is inspired by the pycha project
 #(http://www.lorenzogil.com/projects/pycha/)
 from graph import Graph
-from tryton.common import hex2rgb, float_time_to_text
+from tryton.common import hex2rgb, highlight_rgb, float_time_to_text
 import locale
 import math
 import cairo
@@ -146,7 +146,8 @@ class Line(Graph):
                     point.y * self.area.h + self.area.y,
                     3, 0, 2 * math.pi)
                 cr.stroke()
-                cr.set_source_rgb(*self.colorScheme['__highlight'])
+                cr.set_source_rgb(*highlight_rgb(
+                        *self.colorScheme[point.yname]))
                 cr.arc(point.x * self.area.w + self.area.x,
                     point.y * self.area.h + self.area.y,
                     3, 0, 2 * math.pi)

tryton/gui/window/view_form/view/graph_gtk/pie.py

@@ -5,7 +5,7 @@
 from graph import Graph, Area
 import math
 import cairo
-from tryton.common import hex2rgb, float_time_to_text
+from tryton.common import hex2rgb, highlight_rgb, float_time_to_text
 import locale
 import tryton.rpc as rpc
 
@@ -94,7 +94,7 @@ class Pie(Graph):
                 if bool(int(self.yfields[0].get('fill', 1))):
                     color = self.colorScheme[slice.xname]
                     if slice.highlight:
-                        color = self.colorScheme['__highlight']
+                        color = highlight_rgb(*color)
                     cr.set_source_rgba(*color)
                     slice.draw(cr, self.centerx, self.centery, self.radius)
                     cr.fill()