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_short.html', takes_context=True)
  16 def picture_short(context, picture):
  17     context.update({
  18         'picture': picture,
  19         'main_link': picture.get_absolute_url(),
  20         # 'related': picture.related_info(),
  21         'request': context.get('request'),
  22         'tags': split_tags(picture.tags),
  23         })
  24     return context
  25
  26 @register.inclusion_tag('picture/picture_wide.html', takes_context=True)
  27 def picture_wide(context, picture):
  28     context.update({
  29         'picture': picture,
  30         'main_link': picture.get_absolute_url(),
  31         # 'related': picture.related_info(),
  32         'request': context.get('request'),
  33         'tags': split_tags(picture.tags),
  34         })
  35     return context
  36
  37
  38 @register.simple_tag()
  39 def area_thumbnail_url(area, geometry):
  40     def to_square(coords):
  41         w = coords[1][0] - coords[0][0]
  42         h = coords[1][1] - coords[0][1]
  43         if w == h:
  44             return coords
  45         elif w > h:
  46             return [[coords[0][0] + w/2 - h/2, coords[0][1]],
  47                     [coords[1][0] - w/2 + h/2, coords[1][1]]]
  48         else:
  49             return [[coords[0][0], coords[0][1] + h/2 - w/2],
  50                     [coords[1][0], coords[1][1] - h/2 + w/2, ]]
  51
  52     # so much for sorl extensibility.
  53     # what to do about this?
  54     _engine = sorl.thumbnail.default.engine
  55     sorl.thumbnail.default.engine = cropper
  56     coords = to_square(area.area)
  57
  58     try:
  59         th = sorl.thumbnail.default.backend.get_thumbnail(
  60             area.picture.image_file,
  61             geometry,
  62             crop="%dpx %dpx %dpx %dpx" % tuple(map(lambda d: max(0, d), tuple(coords[0] + coords[1]))))
  63     except Exception, e:
  64         logging.exception("Error creating a thumbnail for PictureArea")
  65         return ''
  66
  67     sorl.thumbnail.default.engine = _engine
  68
  69     return th.url