Source Code for Module AccessEngine.AccessEngineAPI.Utils

  1  ''' 
  2  Provides utility methods that assist L{AEScript <AEScript.AEScript>} developers 
  3  in processing accessibility information, but do not touch accessible objects, do 
  4  output, handle input, manage the SUE system, etc. 
  5   
  6  @author: Brett Clippingdale 
  7  @author: Peter Parente 
  8  @organization: IBM Corporation 
  9  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
 10   
 11  @author: Frank Zenker 
 12  @author: Ramona Bunk 
 13  @organization: IT Science Center Ruegen gGmbH, Germany 
 14  @copyright: Copyright (c) 2007, 2008 ITSC Ruegen 
 15   
 16  @license: I{The BSD License} 
 17  All rights reserved. This program and the accompanying materials are made  
 18  available under the terms of the BSD license which accompanies 
 19  this distribution, and is available at 
 20  U{http://www.opensource.org/licenses/bsd-license.php} 
 21  ''' 
 22   
 23  from AccessEngine import AEConstants 
 24   
 25 -def getColorString(val): 
 26    ''' 
 27    Tries to map a given RGB string (if in form "u,u,u") to a nearby color  
 28    name. 
 29     
 30    @param val: Representation of an RGB color in form "u,u,u" 
 31    @type val: string 
 32    @return: Localized color name if val param is valid format, otherwise None 
 33    @rtype: string 
 34    ''' 
 35    # if color value an RGB 3-tuple, map it to a string value 
 36    try: 
 37      r, g, b = val.split(',') 
 38      r, g, b = int(r), int(g), int(b) 
 39    except (ValueError, TypeError, AttributeError): 
 40      return val 
 41    WORD = 256 # 8-bit word size 
 42       
 43    VISIBLE = 64 
 44    LOW_COLORATION = 4  
 45    LOW_SATURATION = 192 
 46    HIGH_SATURATION = 240 
 47     
 48    # normalize values into three 8-bit values to reprent RGB color 
 49    if r >= WORD or g >= WORD or b >= WORD: 
 50      r = int(r / WORD) # can't guarantee apps will have modulo 256 color 
 51      g = int(g / WORD) 
 52      b = int(b / WORD) 
 53     
 54    # if all values of RGB 3-tuple have low saturation, amplify them 
 55    while r < VISIBLE and g < VISIBLE and b < VISIBLE and \ 
 56          (r > LOW_COLORATION or g > LOW_COLORATION or b > LOW_COLORATION): 
 57      r = r << 1 
 58      g = g << 1 
 59      b = b << 1 
 60     
 61    # attenuation algo #1   
 62    ## if all values of RGB 3-tuple have high saturation, attenuate them 
 63    #while r >= LOW_SATURATION and g >= LOW_SATURATION and b >= LOW_SATURATION and \ 
 64           #(r < HIGH_SATURATION or g < HIGH_SATURATION or b < HIGH_SATURATION): 
 65      #print "high saturation: shifting rgb from:", r, g, b 
 66      #r = r >> 1 
 67      #g = g >> 1 
 68      #b = b >> 1 
 69      #print "shifted rgb to:" , r, g, b 
 70     
 71    # attenuation algo #2 
 72    # if all values of RGB 3-tuple have high saturation, attenuate them 
 73    if r >= LOW_SATURATION and g >= LOW_SATURATION and b >= LOW_SATURATION and \ 
 74       (r < HIGH_SATURATION or g < HIGH_SATURATION or b < HIGH_SATURATION): 
 75      if r < g and r < b: 
 76        r = r - 64 
 77      elif g < r and g < b: 
 78        g = g - 64 
 79      elif b < r and b < g: 
 80        b = b - 64 
 81      elif r == g == b: 
 82        # assign levels of grey based on saturation 
 83        if r > 250: 
 84          return AEConstants.COLOR_MAP[63] #'white' 
 85        elif r > 200: 
 86          return AEConstants.COLOR_MAP[41] # light grey 
 87        elif r > 96: 
 88          return AEConstants.COLOR_MAP[21] # medium grey 
 89        else: 
 90          return AEConstants.COLOR_MAP[42] # dark grey 
 91        pass 
 92      elif r == g: 
 93        r = r - 64 
 94        g = g - 64 
 95      elif r == b: 
 96        r = r - 64 
 97        b = b - 64 
 98      elif g == b: 
 99        g = g - 64 
100        b = b - 64 
101       
102    # place high 2-bits of each color into bitfield: rrggbb for value 0..63 
103    r = r >> 6 << 4 
104    g = g >> 6 << 2 
105    b = b >> 6 
106    rgb = r+g+b # add into 6-bit bitfield (rrggbb) for integer value 0..63 
107    name = AEConstants.COLOR_MAP[rgb] # get the color value from dictionary 
108    return name 
109   
110 -def convertPOSIXToIANA(lang): 
111    ''' 
112    Converts a POSIX language string to a IANA language tag following RFC 4646 
113    U{http://www.ietf.org/rfc/rfc4646.txt}, the format recommended for  
114    L{AEOutput <AccessEngine.AEDevice.AEOutput.AEOutput>} device language settings. 
115     
116    The POSIX format is language[_territory][.codeset] 
117     
118    Some examples include "en", "fr_CA", "en_US.UTF-8". Ambiguous conversions  
119    such as "zh_CN" are allowed, but do not pinpoint specific spoken dialects  
120    (i.e. Mandarin, Cantonese, Pinyin, Taiwanese Mandarin, etc.) The code set 
121    is currently ignored, though may serve as a hint for the dialect in the 
122    future. 
123     
124    @param lang: POSIX locale string 
125    @type lang: string 
126    @return: IANA language tag 
127    @rtype: string 
128    ''' 
129    tag = [] 
130    lang = lang.split('_') 
131    try: 
132      # if first element is there, it's the language code 
133      tag.append(lang[0]) 
134    except IndexError: 
135      pass 
136    try: 
137      # if the second element is there, it's the territory code 
138      t = lang[1].split('.')[0] 
139    except IndexError: 
140      pass 
141    else: 
142      # if there was no language code, backfill using the territory 
143      if len(tag) == 0: 
144        tag.append(t) 
145      tag.append(t)  
146    # make lowercase for comparison 
147    return '-'.join(tag).lower() 
148