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 django.template import Node, Variable, Template, Context
   7 from catalogue.utils import split_tags
   8 from itertools import chain
   9 from ..engine import CustomCroppingEngine
  10 import sorl.thumbnail.default
  11 import logging
  12
  13 register = template.Library()
  14
  15 cropper = CustomCroppingEngine()
  16
  17 @register.inclusion_tag('picture/picture_short.html', takes_context=True)
  18 def picture_short(context, picture):
  19     context.update({
  20         'picture': picture,
  21         'main_link': picture.get_absolute_url(),
  22         # 'related': picture.related_info(),
  23         'request': context.get('request'),
  24         'tags': split_tags(picture.tags),
  25         })
  26     return context
  27
  28 @register.inclusion_tag('picture/picture_wide.html', takes_context=True)
  29 def picture_wide(context, picture):
  30     context.update({
  31         'picture': picture,
  32         'main_link': picture.get_absolute_url(),
  33         # 'related': picture.related_info(),
  34         'request': context.get('request'),
  35         'tags': split_tags(picture.tags),
  36         })
  37     return context
  38
  39
  40 @register.simple_tag()
  41 def area_thumbnail_url(area, geometry):
  42     def to_square(coords):
  43         w = coords[1][0] - coords[0][0]
  44         h = coords[1][1] - coords[0][1]
  45         if w == h:
  46             return coords
  47         elif w > h:
  48             return [[coords[0][0] + w/2 - h/2, coords[0][1]],
  49                     [coords[1][0] - w/2 + h/2, coords[1][1]]]
  50         else:
  51             return [[coords[0][0], coords[0][1] + h/2 - w/2],
  52                     [coords[1][0], coords[1][1] - h/2 + w/2, ]]
  53
  54     # so much for sorl extensibility.                                                                                                                           # what to do about this?
  55     _engine = sorl.thumbnail.default.engine
  56     sorl.thumbnail.default.engine = cropper
  57     coords = to_square(area.area)
  58
  59     try:
  60         th = sorl.thumbnail.default.backend.get_thumbnail(
  61             area.picture.image_file,
  62             geometry,
  63             crop="%dpx %dpx %dpx %dpx" % tuple(map(lambda d: max(0, d), tuple(coords[0] + coords[1]))))
  64     except Exception, e:
  65         logging.exception("Error creating a thumbnail for PictureArea")
  66         return ''
  67
  68     sorl.thumbnail.default.engine = _engine
  69
  70     return th.url
  71
  72
  73
  74