Changeset 169 for trunk/pycha

Timestamp:

03/17/09 05:27:31 (3 years ago)

Author:

lgs

Message:

Big refactor about how the colors scheme are created and used. See #29

Location:

trunk/pycha

Files:

• bar.py (modified) (1 diff)
• chart.py (modified) (5 diffs)
• color.py (modified) (3 diffs)
• line.py (modified) (2 diffs)
• pie.py (modified) (1 diff)
• scatter.py (modified) (1 diff)

trunk/pycha/bar.py

@@ -86 +86 @@
 
                 if self.options.shouldFill:
-                    cx.set_source_rgb(*self.options.colorScheme[bar.name])
+                    cx.set_source_rgb(*self.colorScheme[bar.name])
                     cx.fill_preserve()
 

trunk/pycha/chart.py

@@ -21 +21 @@
 import cairo
 
-from pycha.color import (defaultColorscheme, getColorscheme, hex2rgb,
-                         DEFAULT_COLOR)
+from pycha.color import ColorScheme, hex2rgb, DEFAULT_COLOR
 
 
@@ -57 +56 @@
         self._initSurface(surface)
 
+        self.colorScheme = None
+
     def addDataset(self, dataset):
         """Adds an object containing chart data to the storage hash"""
@@ -113 +114 @@
 
     def _setColorscheme(self):
-        """Sets the colorScheme used for the chart using the color in the
+        """Sets the colorScheme used for the chart using the
         options.colorScheme option
         """
-        scheme = self.options.colorScheme
+        name = self.options.colorScheme.name
         keys = self._getDatasetsKeys()
-        if isinstance(scheme, dict):
-            if not scheme:
-                self.options.colorScheme = defaultColorscheme(keys)
-        elif isinstance(scheme, basestring):
-            self.options.colorScheme = getColorscheme(scheme, keys)
-        else:
-            raise TypeError("Color scheme is invalid!")
+        colorSchemeClass = ColorScheme.getColorScheme(name, None)
+        if colorSchemeClass is None:
+            raise ValueError('Color scheme is invalid!')
+
+        kwargs = dict(self.options.colorScheme.args)
+        self.colorScheme = colorSchemeClass(keys, **kwargs)
 
     def _initSurface(self, surface):
@@ -552 +552 @@
         def drawKey(key, x, y, text_height):
             cx.rectangle(x, y, bullet, bullet)
-            cx.set_source_rgb(*self.options.colorScheme[key])
+            cx.set_source_rgb(*self.colorScheme[key])
             cx.fill_preserve()
             cx.set_source_rgb(0, 0, 0)
@@ -670 +670 @@
     barWidthFillFraction=0.75,
     pieRadius=0.4,
-    colorScheme=DEFAULT_COLOR,
+    colorScheme=Option(
+        name='gradient',
+        args=Option(initialColor=DEFAULT_COLOR),
+    ),
     title=None,
     titleFont='Tahoma',

trunk/pycha/color.py

@@ -1 +1 @@
 # Copyright(c) 2007-2009 by Lorenzo Gil Sanchez <lorenzo.gil.sanchez@gmail.com>
+#              2009 by Yaco S.L. <lgs@yaco.es>
 #
 # This file is part of PyCha.
@@ -53 +54 @@
 
 
-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. 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)])
-
-
-def defaultColorscheme(keys):
-    """Return the default color scheme (derived from a dark green)"""
-    return generateColorscheme(DEFAULT_COLOR, keys)
-
-
-def getColorscheme(color, keys):
-    """Get a color scheme from the six predefined ones or makes another
-    one if the color is not found
-    """
-    return generateColorscheme(colorSchemes.get(color, color), keys)
-
-
-# default colors for color schemes
-colorSchemes = dict(
+basicColors = dict(
     red='#6d1d1d',
     green=DEFAULT_COLOR,
@@ -89 +62 @@
     darkcyan='#305755',
     )
+
+
+class ColorSchemeMetaclass(type):
+    """This metaclass is used to autoregister all ColorScheme classes"""
+
+    def __new__(mcs, name, bases, dict):
+        klass = type.__new__(mcs, name, bases, dict)
+        klass.registerColorScheme()
+        return klass
+
+
+class ColorScheme(dict):
+    """A color scheme is a dictionary where the keys match the keys
+    constructor argument and the values are colors"""
+
+    __metaclass__ = ColorSchemeMetaclass
+    __registry__ = {}
+
+    def __init__(self, keys):
+        super(ColorScheme, self).__init__()
+
+    @classmethod
+    def registerColorScheme(cls):
+        key = cls.__name__.replace('ColorScheme', '').lower()
+        if key:
+            cls.__registry__[key] = cls
+
+    @classmethod
+    def getColorScheme(cls, name, default=None):
+        return cls.__registry__.get(name, default)
+
+
+class GradientColorScheme(ColorScheme):
+    """In this color scheme each color is a lighter version of initialColor.
+
+    This difference is computed based on the number of keys.
+
+    The initialColor is given in a hex string format.
+    """
+
+    def __init__(self, keys, initialColor=DEFAULT_COLOR):
+        super(GradientColorScheme, self).__init__(keys)
+        if initialColor in basicColors:
+            initialColor = basicColors[initialColor]
+
+        r, g, b = hex2rgb(initialColor)
+        light = 1.0 / (len(keys) * 2)
+
+        for i, key in enumerate(keys):
+            self[key] = lighten(r, g, b, light * i)

trunk/pycha/line.py

@@ -74 +74 @@
                 cx.close_path()
             else:
-                cx.set_source_rgb(*self.options.colorScheme[storeName])
+                cx.set_source_rgb(*self.colorScheme[storeName])
                 cx.stroke()
 
@@ -93 +93 @@
 
                 # fill the line
-                cx.set_source_rgb(*self.options.colorScheme[storeName])
+                cx.set_source_rgb(*self.colorScheme[storeName])
                 preparePath(storeName)
                 cx.fill()

trunk/pycha/pie.py

@@ -112 +112 @@
         for slice in self.slices:
             if slice.isBigEnough():
-                cx.set_source_rgb(*self.options.colorScheme[slice.name])
+                cx.set_source_rgb(*self.colorScheme[slice.name])
                 if self.options.shouldFill:
                     slice.draw(cx, self.centerx, self.centery, self.radius)

trunk/pycha/scatter.py

@@ -44 +44 @@
         # TODO: self.options.stroke.shadow
         for key in self._getDatasetsKeys():
-            cx.set_source_rgb(*self.options.colorScheme[key])
+            cx.set_source_rgb(*self.colorScheme[key])
             preparePath(key)
             cx.stroke()