apps/picture/templatetags/picture_tags.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 from django import template
   6 from catalogue.utils import split_tags
   7 from ..engine import CustomCroppingEngine
   8 import sorl.thumbnail.default
   9 import logging
  10
  11 register = template.Library()
  12
  13 cropper = CustomCroppingEngine()
  14
  15 @register.inclusion_tag('picture/picture_wide.html', takes_context=True)
  16 def picture_wide(context, picture):
  17     context.update({
  18         'picture': picture,
  19         'main_link': picture.get_absolute_url(),
  20         'request': context.get('request'),
  21         'tags': split_tags(picture.tags),
  22         })
  23     return context
  24
  25
  26 @register.simple_tag()
  27 def area_thumbnail_url(area, geometry):
  28     def to_square(coords):
  29         w = coords[1][0] - coords[0][0]
  30         h = coords[1][1] - coords[0][1]
  31         if w == h:
  32             return coords
  33         elif w > h:
  34             return [[coords[0][0] + w/2 - h/2, coords[0][1]],
  35                     [coords[1][0] - w/2 + h/2, coords[1][1]]]
  36         else:
  37             return [[coords[0][0], coords[0][1] + h/2 - w/2],
  38                     [coords[1][0], coords[1][1] - h/2 + w/2, ]]
  39
  40     # so much for sorl extensibility.
  41     # what to do about this?
  42     _engine = sorl.thumbnail.default.engine
  43     sorl.thumbnail.default.engine = cropper
  44     coords = to_square(area.area)
  45
  46     try:
  47         th = sorl.thumbnail.default.backend.get_thumbnail(
  48             area.picture.image_file,
  49             geometry,
  50             crop="%dpx %dpx %dpx %dpx" % tuple(map(lambda d: max(0, d), tuple(coords[0] + coords[1]))))
  51     except Exception, e:
  52         logging.exception("Error creating a thumbnail for PictureArea")
  53         return ''
  54
  55     sorl.thumbnail.default.engine = _engine
  56
  57     return th.url