--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/grease/color.py	Tue Jul 12 10:16:48 2011 +0200
@@ -0,0 +1,64 @@
+
+class RGBA(object):
+	"""Four channel color representation.
+
+	RGBA colors are floating point color representations with color channel
+	values between (0..1). Colors may be initialized from 3 or 4 floating
+	point numbers or a hex string::
+
+		RGBA(1.0, 1.0, 1.0) # Alpha defaults to 1.0
+		RGBA(1.0, 1.0, 0, 0.5)
+		RGBA("#333")
+		RGBA("#7F7F7F")
+	
+	Individual color channels can be accessed by attribute name, or the
+	color object can be treated as a sequence of 4 floats.
+	"""
+
+	def __init__(self, r_or_colorstr, g=None, b=None, a=None):
+		if isinstance(r_or_colorstr, str):
+			assert g is b is a is None, "Ambiguous color arguments" 
+			self.r, self.g, self.b, self.a = self._parse_colorstr(r_or_colorstr)
+		elif g is b is a is None:
+			try:
+				self.r, self.g, self.b, self.a = r_or_colorstr
+			except ValueError:
+				self.r, self.g, self.b = r_or_colorstr
+				self.a = 1.0
+		else:
+			self.r = r_or_colorstr
+			self.g = g
+			self.b = b
+			self.a = a
+		if self.a is None:
+			self.a = 1.0
+	
+	def _parse_colorstr(self, colorstr):
+		length = len(colorstr)
+		if not colorstr.startswith("#") or length not in (4, 5, 7, 9):
+			raise ValueError("Invalid color string: " + colorstr)
+		if length <= 5:
+			parsed = [int(c*2, 16) / 255.0 for c in colorstr[1:]]
+		else:
+			parsed = [int(colorstr[i:i+2], 16) / 255.0 for i in range(1, length, 2)]
+		if len(parsed) == 3:
+			parsed.append(1.0)
+		return parsed
+	
+	def __len__(self):
+		return 4
+	
+	def __getitem__(self, item):
+		return (self.r, self.g, self.b, self.a)[item]
+	
+	def __iter__(self):
+		return iter((self.r, self.g, self.b, self.a))
+	
+	def __eq__(self, other):
+		return tuple(self) == tuple(other)
+	
+	def __repr__(self):
+		return "%s(%.2f, %.2f, %.2f, %.2f)" % (self.__class__.__name__, 
+			self.r, self.g, self.b, self.a)
+			
+