Changeset 78

Timestamp:

03/20/08 13:24:03 (4 years ago)

Author:

lgs

Message:

Automatically adjust the light of the color scheme based on the number of keys. Patch based on the patch by jae_AT_zhar.net. Fixes #8

Location:

trunk

Files:

• src/color.py (modified) (1 diff)
• tests/color.py (modified) (2 diffs)

trunk/src/color.py

@@ -49 +49 @@
             clamp(0.0, 1.0, b + amount))
     
-def generateColorscheme(masterColor, keys, light=0.098):
+def generateColorscheme(masterColor, keys):
     """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 is a lighter version of masterColor. This difference is
+    computed based on the number of keys.
 
     The masterColor is given in a hex string format.
     """
     r, g, b = hex2rgb(masterColor)
+    light = 1.0 / (len(keys)*2)
     return dict([(key, lighten(r, g, b, light * i))
                  for i, key in enumerate(keys)])

trunk/tests/color.py

@@ -68 +68 @@
         scheme = pycha.color.generateColorscheme(color, keys)
 
-
         self._assertColors(scheme['k1'], (1, 0, 0), 3)
-        self._assertColors(scheme['k2'], (1, 0.098, 0.098), 3)
-        self._assertColors(scheme['k3'], (1, 0.196, 0.196), 3)
-        self._assertColors(scheme['k4'], (1, 0.294, 0.294), 3)
-
-        scheme = pycha.color.generateColorscheme(color, keys, 0.1)
-        self._assertColors(scheme['k1'], (1, 0, 0), 1)
-        self._assertColors(scheme['k2'], (1, 0.1, 0.1), 1)
-        self._assertColors(scheme['k3'], (1, 0.2, 0.2), 1)
-        self._assertColors(scheme['k4'], (1, 0.3, 0.3), 1)
+        self._assertColors(scheme['k2'], (1, 0.125, 0.125), 3)
+        self._assertColors(scheme['k3'], (1, 0.250, 0.250), 3)
+        self._assertColors(scheme['k4'], (1, 0.375, 0.375), 3)
 
     def test_defaultColorScheme(self):
@@ -92 +85 @@
             self.assert_(pycha.color.colorSchemes.has_key(color))
 
+    def test_autoLighting(self):
+        """This test ensures that the colors don't get to white too fast.
+        
+        See bug #8.
+        """
+        # we have a lot of keys
+        n = 50
+        keys = range(n)
+        color = '#ff0000'
+        scheme = pycha.color.generateColorscheme(color, keys)
+        
+        # ensure that the last color is not completely white
+        color = scheme[n-1]
+        self.assertAlmostEqual(color[0], 1.0, 4) # the red component was already 1
+        self.assertNotAlmostEqual(color[1], 1.0, 4)
+        self.assertNotAlmostEqual(color[2], 1.0, 4)
+        
 def test_suite():
     return unittest.TestSuite((