SC 24/02/2005

Steve Chaplin · Steve Chaplin · commit 8761974eca5d · 2005-02-24T12:38:07.000Z
svn path=/trunk/matplotlib/; revision=984
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,5 +1,11 @@
 New entries should be added at the top
 
+2005-02-24 colors.py change ColorConverter.to_rgb() so it always returns rgb 
+           (and not rgba), allow cnames keys to be cached, change the exception
+           raised from RuntimeError to ValueError (like hex2color())
+	   hex2color() use a regular expression to check the color string is
+           valid  - SC
+
 2005-02-23 Added rc param ps.useafm so backend ps can use native afm
            fonts or truetype.  afme breaks mathtext but causes much
            smaller font sizes and may result in images that display
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -28,6 +28,7 @@
 Finally, legal html names for colors, like 'red', 'burlywood' and
 'chartreuse' are supported.
 """
+import re
 
 from numerix import array, arange, take, put, Float, Int, where, \
      zeros, asarray, sort, searchsorted, sometrue, ravel, divide
@@ -336,10 +337,14 @@ def rgb2hex(rgb):
     'Given a len 3 rgb tuple of 0-1 floats, return the hex string'
     return '#%02x%02x%02x' % tuple([round(val*255) for val in rgb])
     
+hexColorPattern = re.compile("\A#[a-fA-F0-9]{6}\Z")
+
 def hex2color(s):
-    "Convert hex string (like html uses, eg, #efefef) to a r,g,b tuple"
-    if s[0]!='#' or len(s)!=7:
-        raise ValueError('s must be a hex string like "#efefef"')
+    "Convert hex string 's' (like html uses, eg, #efefef) to a r,g,b tuple"
+    if not isinstance(s, str):
+        raise TypeError('hex2color requires a string argument')
+    if not hexColorPattern.match(s):
+        raise ValueError('invalid hex color string "%s"' % s)
     return tuple([int(n, 16)/255.0 for n in (s[1:3], s[3:5], s[5:7])])
 
 class ColorConverter:
@@ -368,28 +373,29 @@ def to_rgb(self, arg):
             try: self.cache[arg]
             except KeyError: pass
 
-        color = None
-        try: float(arg)
-        except: 
+        try:
             if is_string_like(arg):
-                hex = cnames.get(arg)
-                if hex is not None: arg = hex
-                if len(arg)==7 and arg[0]=='#':
-                    color =   hex2color(arg)
-            if color is None:
-                # see if it looks like rgb.  If so, just return arg
-                try: float(arg[2])
-                except: color = self.colors.get(arg, (0.0, 0.0, 0.0))
-                else: color =  tuple(arg)
-        else:
-            if arg>=0 and arg<=1:
-                color =  (arg,arg,arg)
-            else:
-                msg = 'Floating point color arg must be between 0 and 1\n' +\
-                      'Found %1.2f' % arg
-                raise RuntimeError(msg)
-
-        self.cache[arg] = color
+                str1 = cnames.get(arg, arg)
+                if str1.startswith('#'):
+                    color = hex2color(str1)
+                else:
+                    color = self.colors[arg]
+            elif isinstance(arg, float):
+                if 0<=arg<=1:
+                    color = (arg,arg,arg)
+                else:
+                    raise ValueError('Floating point color arg must be between 0 and 1')
+            else: # assume tuple (or list)
+                assert isinstance(arg[2], (float,int))
+                color = tuple(arg[:3])           
+
+            self.cache[arg] = color # raise exception if color not set
+
+        except KeyError:            
+            raise ValueError('to_rgb: Invalid rgb arg "%s"' % (str(arg)))
+        except Exception, exc:
+            raise ValueError('to_rgb: Invalid rgb arg "%s"\n%s' % (str(arg), exc))
+                
         return color
 
     def to_rgba(self, arg, alpha=1.0):
