# # Copyright (c) 2002, 2003, 2004, 2005 Art Haas # # This file is part of PythonCAD. # # PythonCAD is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # PythonCAD is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with PythonCAD; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # # classes for colors # from PythonCAD.Generic import globals # # a seemingly good way to convert from string to integer # for a couple of common ways of expressing colors ... # def color_str_to_int(cstr): if cstr.startswith('0x') or cstr.startswith('0X'): _val = int(cstr, 16) elif cstr.startswith('#'): _val = int(cstr[1:], 16) else: _val = int(cstr) return _val class Color(object): """An object representing an RGB color. The class purpose is self evident. A Color object has three attributes: r: Red (0-255) g: Green (0-255) b: Blue (0-255) There is no alpha-channel attribute (yet)... A Color object has the following methods: getRed(): Get the Red value in the Color. getBlue(): Get the Blue value in the Color. getGreen(): Get the Green value in the Color. clone(): Return an identical copy of a Color. Once a color object is created, the values it contains may not be changed. """ def __init__(self, r=None, g=None, b=None): """Initialize a Color object. There are several ways to create a color object: Color(r,g,b) => r, g, and b values are all integers 0 <= value <= 255 Color(0xxxxx) => A hexidecimal value - it must begin with 0x. The color is computed as follows: r = (0xff0000 & value) >> 16 g = (0xff00 & value) >> 8 b = (0xff & value) Color('#hexvalue') => A string prefixed with '#', with the remaining characters representing a hexidecimal value. Color() => A default color with r = g = b = 255. """ _r = r _g = g _b = b if isinstance(_r, str): _val = color_str_to_int(_r) _r = (0xff0000 & _val) >> 16 _g = (0xff00 & _val) >> 8 _b = (0xff & _val) elif isinstance(_r, int) and _g is None and _b is None: _r = (0xff0000 & r) >> 16 _g = (0xff00 & r) >> 8 _b = (0xff & r) elif (isinstance(_r, int) and isinstance(_g, int) and isinstance(_b, int)): if _r < 0 or _r > 255: raise ValueError, "Invalid Red value: %d" % _r if _g < 0 or _g > 255: raise ValueError, "Invalid Green value: %d" % _g if _b < 0 or _b > 255: raise ValueError, "Invalid Blue value: %d" % _b elif _r is None and _g is None and _b is None: _r = 255 _g = 255 _b = 255 else: raise SyntaxError, "Invalid call to Color()." self.__color = (_r << 16) | (_g << 8) | _b def __eq__(self, obj): """Compare two Color objects for equivalence. """ if not isinstance(obj, Color): return False return self.getColors() == obj.getColors() def __ne__(self, obj): """Compare two Color objects for equivalence. """ if not isinstance(obj, Color): return True return self.getColors() != obj.getColors() def __cmp__(self, obj): """Compare two Color objects. The comparison is done based on the RGB values. red value of C1 < red value of C2 ==> return -1 red value of C1 > red value of C2 ==> return 1 Then green values are compared, then blue. If all values are equal, return 0. """ if not isinstance(obj, Color): raise TypeError, "Invalid object for color comparison: " + `obj` _val = self.__color _objval = hash(obj) return cmp(_val, _objval) def __hash__(self): """Return a hash value for the Color object. Providing this method means that Color objects can be used as keys in dictionaries. """ return self.__color def __repr__(self): _val = self.__color _r = (_val & 0xff0000) >> 16 _g = (_val & 0xff00) >> 8 _b = (_val & 0xff) return "Color(%d,%d,%d)" % (_r, _g, _b) def __str__(self): return "#%06x" % self.__color def getColors(self): """Return a three-item tuple with the values comprising this color. getColors() """ _val = self.__color _r = (_val & 0xff0000) >> 16 _g = (_val & 0xff00) >> 8 _b = (_val & 0xff) return _r, _g, _b def getRed(self): """Return the red value of the color. getRed() """ return (self.__color & 0xff0000) >> 16 r = property(getRed, None, None, "Red value of the color.") def getGreen(self): """Return the green value of the color. getGreen() """ return (self.__color & 0xff00) >> 8 g = property(getGreen, None, None, "Green value of the color.") def getBlue(self): """Return the blue value of the color. getBlue() """ return (self.__color & 0xff) b = property(getBlue, None, None, "Blue value of the color.") def clone(self): """Return a new Color object with the same color values. clone() """ _val = self.__color return Color(_val) # # ColorDict Class # # The ColorDict is built from the dict object. Using instances # of this class will guarantee than only Color objects will be # stored in the instance # class ColorDict(dict): def __init__(self): super(ColorDict, self).__init__() def __setitem__(self, key, value): if not isinstance(key, Color): raise TypeError, "ColorDict keys must be color objects: " + `key` if not isinstance(value, Color): raise TypeError, "ColorDict values must be Color objects: " + `value` super(ColorDict, self).__setitem__(key, value) # # find a Color object stored in the global color dictionary # or make a new one and store it # def get_color(r, g, b): if not isinstance(r, int): raise TypeError, "Invalid red value:" + `r` if r < 0 or r > 255: raise ValueError, "Invalid red value: %d" % r if not isinstance(g, int): raise TypeError, "Invalid green value:" + `g` if g < 0 or g > 255: raise ValueError, "Invalid green value: %d" % g if not isinstance(b, int): raise TypeError, "Invalid blue value:" + `b` if b < 0 or b > 255: raise ValueError, "Invalid blue value: %d" % b _color = Color(r, g, b) if _color in globals.colors: _color = globals.colors[_color] else: globals.colors[_color] = _color return _color