Support colors in rgb / rgba for parametric styles

CHANGELOG

@@ -3,6 +3,7 @@ V 1.5.0 UNRELEASED
 	Add half pie (thanks philt2001)
 	Make lxml an optionnal dependency (huge speed boost in pypy)
 	Add render_table (WIP)
+	Support colors in rgb / rgba for parametric styles
 
 V 1.4.6
 	Add support for \n separated multiline titles (thanks sirlark)

pygal/colors.py

@@ -79,27 +79,78 @@ def hsl_to_rgb(h, s, l):
     return r, g, b
 
 
-def adjust(color, attribute, percent):
-    assert color[0] == '#', '#rrggbb and #rgb format are supported'
+def parse_color(color):
+    r = g = b = a = type = None
+    if color.startswith('#'):
         color = color[1:]
-    assert len(color) in (3, 6), '#rrggbb and #rgb format are supported'
         if len(color) == 3:
-        color = [a for b in zip(color, color) for a in b]
-
-    bound = lambda x: max(0, min(100, x))
-
-    def _adjust(hsl):
+            type = '#rgb'
+            color = color + 'f'
+        if len(color) == 4:
+            type = type or '#rgba'
+            color = ''.join([c * 2 for c in color])
+        if len(color) == 6:
+            type = type or '#rrggbb'
+            color = color + 'ff'
+        assert len(color) == 8
+        type = type or '#rrggbbaa'
+        r, g, b, a = [
+            int(''.join(c), 16) for c in zip(color[::2], color[1::2])]
+        a /= 255
+    elif color.startswith('rgb('):
+        type = 'rgb'
+        color = color[4:-1]
+        r, g, b, a = [int(c) for c in color.split(',')] + [1]
+    elif color.startswith('rgba('):
+        type = 'rgba'
+        color = color[5:-1]
+        r, g, b, a = [int(c) for c in color.split(',')[:-1]] + [
+            float(color.split(',')[-1])]
+    return r, g, b, a, type
+
+
+def unparse_color(r, g, b, a, type):
+    if type == '#rgb':
+        # Don't lose precision on rgb shortcut
+        if r % 17 == 0 and g % 17 == 0 and b % 17 == 0:
+            return '#%x%x%x' % (r / 17, g / 17, b / 17)
+        type = '#rrggbb'
+
+    if type == '#rgba':
+        if r % 17 == 0 and g % 17 == 0 and b % 17 == 0:
+            return '#%x%x%x%x' % (r / 17, g / 17, b / 17, a * 15)
+        type = '#rrggbbaa'
+
+    if type == '#rrggbb':
+        return '#%02x%02x%02x' % (r, g, b)
+
+    if type == '#rrggbbaa':
+        return '#%02x%02x%02x%02x' % (r, g, b, a * 255)
+
+    if type == 'rgb':
+        return 'rgb(%d, %d, %d)' % (r, g, b)
+
+    if type == 'rgba':
+        return 'rgba(%d, %d, %d, %g)' % (r, g, b, a)
+
+
+_clamp = lambda x: max(0, min(100, x))
+
+
+def _adjust(hsl, attribute, percent):
     hsl = list(hsl)
     if attribute > 0:
-            hsl[attribute] = bound(hsl[attribute] + percent)
+        hsl[attribute] = _clamp(hsl[attribute] + percent)
     else:
         hsl[attribute] += percent
 
     return hsl
-    return '#%02x%02x%02x' % hsl_to_rgb(
-        *_adjust(
-            rgb_to_hsl(*map(lambda x: int(''.join(x), 16),
-                            zip(color[::2], color[1::2])))))
+
+
+def adjust(color, attribute, percent):
+    r, g, b, a, type = parse_color(color)
+    r, g, b = hsl_to_rgb(*_adjust(rgb_to_hsl(r, g, b), attribute, percent))
+    return unparse_color(r, g, b, a, type)
 
 
 def rotate(color, percent):

pygal/ghost.py

@@ -111,8 +111,8 @@ class Ghost(object):
                 .make_instance(overrides=kwargs)
                 .render(is_unicode=is_unicode))
 
-    def render_tree(self):
-        return self.make_instance().render_tree()
+    def render_tree(self, **kwargs):
+        return self.make_instance(overrides=kwargs).render_tree()
 
     def render_table(self, **kwargs):
         # Import here to avoid lxml import
@@ -130,29 +130,29 @@ class Ghost(object):
         from pyquery import PyQuery as pq
         return pq(self.render(), parser='html')
 
-    def render_in_browser(self):
+    def render_in_browser(self, **kwargs):
         """Render the graph, open it in your browser with black magic"""
         try:
             from lxml.html import open_in_browser
         except ImportError:
             raise ImportError('You must install lxml to use render in browser')
-        open_in_browser(self.render_tree(), encoding='utf-8')
+        open_in_browser(self.render_tree(**kwargs), encoding='utf-8')
 
-    def render_response(self):
+    def render_response(self, **kwargs):
         """Render the graph, and return a Flask response"""
         from flask import Response
-        return Response(self.render(), mimetype='image/svg+xml')
+        return Response(self.render(**kwargs), mimetype='image/svg+xml')
 
-    def render_to_file(self, filename):
+    def render_to_file(self, filename, **kwargs):
         """Render the graph, and write it to filename"""
         with io.open(filename, 'w', encoding='utf-8') as f:
-            f.write(self.render(is_unicode=True))
+            f.write(self.render(is_unicode=True, **kwargs))
 
-    def render_to_png(self, filename=None, dpi=72):
+    def render_to_png(self, filename=None, dpi=72, **kwargs):
         """Render the graph, convert it to png and write it to filename"""
         import cairosvg
         return cairosvg.svg2png(
-            bytestring=self.render(), write_to=filename, dpi=dpi)
+            bytestring=self.render(**kwargs), write_to=filename, dpi=dpi)
 
     def render_sparktext(self, relative_to=None):
         """Make a mini text sparkline from chart"""

pygal/test/test_colors.py

@@ -1,21 +1,55 @@
+from __future__ import division
+
 from pygal.colors import (
+    parse_color, unparse_color,
     rgb_to_hsl, hsl_to_rgb, darken, lighten, saturate, desaturate, rotate)
 
 
+def test_parse_color():
+    assert parse_color('#123') == (17, 34, 51, 1., '#rgb')
+    assert parse_color('#cdf') == (204, 221, 255, 1., '#rgb')
+    assert parse_color('#a3d7') == (170, 51, 221, 119 / 255, '#rgba')
+    assert parse_color('#584b4f') == (88, 75, 79, 1., '#rrggbb')
+    assert parse_color('#8cbe22') == (140, 190, 34, 1., '#rrggbb')
+    assert parse_color('#16cbf055') == (22, 203, 240, 1 / 3, '#rrggbbaa')
+    assert parse_color('rgb(134, 67, 216)') == (134, 67, 216, 1., 'rgb')
+    assert parse_color('rgb(0, 111, 222)') == (0, 111, 222, 1., 'rgb')
+    assert parse_color('rgba(237, 83, 48, .8)') == (237, 83, 48, .8, 'rgba')
+    assert parse_color('rgba(0, 1, 0, 0.1223)') == (0, 1, 0, .1223, 'rgba')
+
+
+def test_unparse_color():
+    assert unparse_color(17, 34, 51, 1., '#rgb') == '#123'
+    assert unparse_color(204, 221, 255, 1., '#rgb') == '#cdf'
+    assert unparse_color(170, 51, 221, 119 / 255, '#rgba') == '#a3d7'
+    assert unparse_color(88, 75, 79, 1., '#rrggbb') == '#584b4f'
+    assert unparse_color(140, 190, 34, 1., '#rrggbb') == '#8cbe22'
+    assert unparse_color(22, 203, 240, 1 / 3, '#rrggbbaa') == '#16cbf055'
+    assert unparse_color(134, 67, 216, 1., 'rgb') == 'rgb(134, 67, 216)'
+    assert unparse_color(0, 111, 222, 1., 'rgb') == 'rgb(0, 111, 222)'
+    assert unparse_color(237, 83, 48, .8, 'rgba') == 'rgba(237, 83, 48, 0.8)'
+    assert unparse_color(0, 1, 0, .1223, 'rgba') == 'rgba(0, 1, 0, 0.1223)'
+
+
 def test_darken():
-    assert darken('#800', 20) == '#220000'
-    assert darken('#800', 0) == '#880000'
+    assert darken('#800', 20) == '#200'
+    assert darken('#800e', 20) == '#200e'
+    assert darken('#800', 0) == '#800'
     assert darken('#ffffff', 10) == '#e6e6e6'
     assert darken('#000000', 10) == '#000000'
     assert darken('#f3148a', 25) == '#810747'
+    assert darken('#f3148aab', 25) == '#810747ab'
     assert darken('#121212', 1) == '#0f0f0f'
     assert darken('#999999', 100) == '#000000'
+    assert darken('#99999999', 100) == '#00000099'
     assert darken('#1479ac', 8) == '#105f87'
+    assert darken('rgb(136, 0, 0)', 20) == 'rgb(34, 0, 0)'
+    assert darken('rgba(20, 121, 172, .13)', 8) == 'rgba(16, 95, 135, 0.13)'
 
 
 def test_lighten():
-    assert lighten('#800', 20) == '#ee0000'
-    assert lighten('#800', 0) == '#880000'
+    assert lighten('#800', 20) == '#e00'
+    assert lighten('#800', 0) == '#800'
     assert lighten('#ffffff', 10) == '#ffffff'
     assert lighten('#000000', 10) == '#1a1a1a'
     assert lighten('#f3148a', 25) == '#f98dc6'
@@ -25,26 +59,26 @@ def test_lighten():
 
 
 def test_saturate():
-    assert saturate('#000', 20) == '#000000'
-    assert saturate('#fff', 20) == '#ffffff'
-    assert saturate('#8a8', 100) == '#33ff33'
+    assert saturate('#000', 20) == '#000'
+    assert saturate('#fff', 20) == '#fff'
+    assert saturate('#8a8', 100) == '#3f3'
     assert saturate('#855', 20) == '#9e3f3f'
 
 
 def test_desaturate():
-    assert desaturate('#000', 20) == '#000000'
-    assert desaturate('#fff', 20) == '#ffffff'
-    assert desaturate('#8a8', 100) == '#999999'
+    assert desaturate('#000', 20) == '#000'
+    assert desaturate('#fff', 20) == '#fff'
+    assert desaturate('#8a8', 100) == '#999'
     assert desaturate('#855', 20) == '#726b6b'
 
 
 def test_rotate():
-    assert rotate('#000', 45) == '#000000'
-    assert rotate('#fff', 45) == '#ffffff'
+    assert rotate('#000', 45) == '#000'
+    assert rotate('#fff', 45) == '#fff'
     assert rotate('#811', 45) == '#886a11'
-    assert rotate('#8a8', 360) == '#88aa88'
-    assert rotate('#8a8', 0) == '#88aa88'
-    assert rotate('#8a8', -360) == '#88aa88'
+    assert rotate('#8a8', 360) == '#8a8'
+    assert rotate('#8a8', 0) == '#8a8'
+    assert rotate('#8a8', -360) == '#8a8'
 
 
 def test_hsl_to_rgb_part_0():