splinext/users/model/__init__.py

   1 # encoding: utf8
   2 import colorsys
   3 from math import sin, pi
   4 import random
   5
   6 from sqlalchemy import Column, ForeignKey
   7 from sqlalchemy.orm import relation
   8 from sqlalchemy.types import Integer, Unicode
   9
  10 from spline.model.meta import TableBase
  11
  12 class User(TableBase):
  13     __tablename__ = 'users'
  14     id = Column(Integer, primary_key=True)
  15     name = Column(Unicode(length=20), nullable=False)
  16     unique_identifier = Column(Unicode(length=32), nullable=False)
  17
  18     def __init__(self, *args, **kwargs):
  19         # Generate a unique hash if one isn't provided (which it shouldn't be)
  20         if 'unique_identifier' not in kwargs:
  21             ident = u''.join(random.choice(u'0123456789abcdef')
  22                              for _ in range(32))
  23             kwargs['unique_identifier'] = ident
  24
  25         super(User, self).__init__(*args, **kwargs)
  26
  27     @property
  28     def unique_colors(self):
  29         """Returns a list of (width, '#rrggbb') tuples that semi-uniquely
  30         identify this user.
  31         """
  32         width_blob, colors_blob = self.unique_identifier[0:8], \
  33                                   self.unique_identifier[8:32]
  34
  35         widths = []
  36         for i in range(4):
  37             width_hex = width_blob[i*2:i*2+2]
  38             widths.append(int(width_hex, 16))
  39         total_width = sum(widths)
  40
  41         ret = []
  42         last_hue = None
  43         for i in range(4):
  44             raw_hue = int(colors_blob[i*6:i*6+2], 16) / 256.0
  45             if last_hue:
  46                 # Make adjacent hues relatively close together, to avoid green
  47                 # + purple sorts of clashes.
  48                 # Minimum distance is 0.1; maximum is 0.35.  Leaves half the
  49                 # spectrum available for any given color.
  50                 # Change 0.0–0.1 to -0.35–-0.1, 0.1–0.35
  51                 hue_offset = raw_hue * 0.5 - 0.25
  52                 if raw_hue < 0:
  53                     raw_hue -= 0.1
  54                 else:
  55                     raw_hue += 0.1
  56
  57                 h = last_hue + raw_hue
  58             else:
  59                 h = raw_hue
  60             last_hue = h
  61
  62             l = int(colors_blob[i*6+2:i*6+4], 16) / 256.0
  63             s = int(colors_blob[i*6+4:i*6+6], 16) / 256.0
  64
  65             # Secondary colors are extremely biased against when picking
  66             # randomly from the hue spectrum.
  67             # To alleviate this, try to bias hue towards secondary colors.
  68             # This adjustment is based purely on experimentation; sin() works
  69             # well because hue is periodic, * 6 means each period is 1/3 the
  70             # hue spectrum, and the final / 24 is eyeballed
  71             h += sin(h * pi * 6) / 24
  72
  73             # Cap lightness to 0.4 to 0.95, so it's not too close to white or
  74             # black
  75             l = l * 0.6 + 0.3
  76
  77             # Cap saturation to 0.5 to 1.0, so the color isn't too gray
  78             s = s * 0.6 + 0.3
  79
  80             r, g, b = colorsys.hls_to_rgb(h, l, s)
  81             color = "#{0:02x}{1:02x}{2:02x}".format(
  82                 int(r * 256),
  83                 int(g * 256),
  84                 int(b * 256),
  85             )
  86
  87             ret.append((1.0 * widths[i] / total_width, color))
  88
  89         return ret
  90
  91
  92 class OpenID(TableBase):
  93     __tablename__ = 'openid'
  94     openid = Column(Unicode(length=255), primary_key=True)
  95     user_id = Column(Integer, ForeignKey('users.id'))
  96     user = relation(User, lazy=False, backref='openids')