apps/sponsors/models.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 import json
   6 import time
   7 from StringIO import StringIO
   8 from django.db import models
   9 from django.utils.translation import ugettext_lazy as _
  10 from django.template.loader import render_to_string
  11 from PIL import Image
  12
  13 from jsonfield import JSONField
  14 from django.core.files.base import ContentFile
  15
  16 THUMB_WIDTH = 120
  17 THUMB_HEIGHT = 120
  18
  19
  20 class Sponsor(models.Model):
  21     name = models.CharField(_('name'), max_length=120)
  22     _description = models.CharField(_('description'), blank=True, max_length=255)
  23     logo = models.ImageField(_('logo'), upload_to='sponsorzy/sponsor/logo')
  24     url = models.URLField(_('url'), blank=True)
  25
  26     def __unicode__(self):
  27         return self.name
  28
  29     def description(self):
  30         if len(self._description):
  31             return self._description
  32         else:
  33             return self.name
  34
  35
  36 class SponsorPage(models.Model):
  37     name = models.CharField(_('name'), max_length=120)
  38     sponsors = JSONField(_('sponsors'), default='{}')
  39     _html = models.TextField(blank=True, editable=False)
  40     sprite = models.ImageField(upload_to='sponsorzy/sprite', blank=True)
  41
  42     def populated_sponsors(self):
  43         result = []
  44         offset = 0
  45         for column in self.sponsors:
  46             result_group = {'name': column['name'], 'sponsors': []}
  47             sponsor_objects = Sponsor.objects.in_bulk(column['sponsors'])
  48             for sponsor_pk in column['sponsors']:
  49                 try:
  50                     result_group['sponsors'].append((offset, sponsor_objects[sponsor_pk]))
  51                     offset -= THUMB_HEIGHT
  52                 except KeyError:
  53                     pass
  54             result.append(result_group)
  55         return result
  56
  57     def render_sprite(self):
  58         sponsor_ids = []
  59         for column in self.sponsors:
  60             sponsor_ids.extend(column['sponsors'])
  61         sponsors = Sponsor.objects.in_bulk(sponsor_ids)
  62         sprite = Image.new('RGBA', (THUMB_WIDTH, len(sponsors) * THUMB_HEIGHT))
  63         for i, sponsor_id in enumerate(sponsor_ids):
  64             simg = Image.open(sponsors[sponsor_id].logo.path)
  65             if simg.size[0] > THUMB_WIDTH or simg.size[1] > THUMB_HEIGHT:
  66                 size = (
  67                     min(THUMB_WIDTH,
  68                         simg.size[0] * THUMB_HEIGHT / simg.size[1]),
  69                     min(THUMB_HEIGHT,
  70                         simg.size[1] * THUMB_WIDTH / simg.size[0])
  71                 )
  72                 simg = simg.resize(size, Image.ANTIALIAS)
  73             sprite.paste(simg, (
  74                     (THUMB_WIDTH - simg.size[0]) / 2,
  75                     i * THUMB_HEIGHT + (THUMB_HEIGHT - simg.size[1]) / 2,
  76                     ))
  77         imgstr = StringIO()
  78         sprite.save(imgstr, 'png')
  79
  80         if self.sprite:
  81             self.sprite.delete(save=False)
  82         self.sprite.save('sponsorzy/sprite/%s-%d.png' % (self.name, time.time()), ContentFile(imgstr.getvalue()), save=False)
  83
  84     def html(self):
  85         return self._html
  86     html = property(fget=html)
  87
  88     def save(self, *args, **kwargs):
  89         if isinstance(self.sponsors, basestring):
  90             # Walkaround for weird jsonfield 'no-decode' optimization.
  91             self.sponsors = json.loads(self.sponsors)
  92         self.render_sprite()
  93         self._html = render_to_string('sponsors/page.html', {
  94             'sponsors': self.populated_sponsors(),
  95             'page': self
  96         })
  97         return super(SponsorPage, self).save(*args, **kwargs)
  98
  99     def __unicode__(self):
 100         return self.name
 101