plugins/thumbnailer/thumbnailer.py

   1 import os
   2 import os.path as path
   3 import re
   4 from pelican import signals
   5
   6 import logging
   7 logger = logging.getLogger(__name__)
   8
   9 try:
  10     from PIL import Image, ImageOps
  11     enabled = True
  12 except ImportError:
  13     logger.warning("Unable to load PIL, disabling thumbnailer")
  14     enabled = False
  15
  16 DEFAULT_IMAGE_DIR = "pictures"
  17 DEFAULT_THUMBNAIL_DIR = "thumbnails"
  18 DEFAULT_THUMBNAIL_SIZES = {
  19     'thumbnail_square': '150',
  20     'thumbnail_wide': '150x?',
  21     'thumbnail_tall': '?x150',
  22 }
  23 DEFAULT_TEMPLATE = """<a href="{url}" rel="shadowbox" title="{filename}"><img src="{thumbnail}" alt="{filename}"></a>"""
  24 DEFAULT_GALLERY_THUMB = "thumbnail_square"
  25
  26 class Resizer(object):
  27     """ Resizes based on a text specification, see readme """
  28
  29     REGEX = re.compile(r'(\d+|\?)x(\d+|\?)')
  30
  31     def __init__(self, name, spec, root):
  32         self._name = name
  33         self._spec = spec
  34         # The location of input images from _image_path.
  35         self._root = root
  36
  37     def _null_resize(self, w, h, image):
  38         return image
  39
  40     def _exact_resize(self, w, h, image):
  41         retval = ImageOps.fit(image, (w,h), Image.BICUBIC)
  42         return retval
  43
  44     def _aspect_resize(self, w, h, image):
  45         retval = image.copy()
  46         retval.thumbnail((w, h), Image.ANTIALIAS)
  47
  48         return retval
  49
  50     def resize(self, image):
  51         resizer = self._null_resize
  52
  53         # Square resize and crop
  54         if 'x' not in self._spec:
  55             resizer = self._exact_resize
  56             targetw = int(self._spec)
  57             targeth = targetw
  58         else:
  59             matches = self.REGEX.search(self._spec)
  60             tmpw = matches.group(1)
  61             tmph = matches.group(2)
  62
  63             # Full Size
  64             if tmpw == '?' and tmph == '?':
  65                 targetw = image.size[0]
  66                 targeth = image.size[1]
  67                 resizer = self._null_resize
  68
  69             # Set Height Size
  70             if tmpw == '?':
  71                 targetw = image.size[0]
  72                 targeth = int(tmph)
  73                 resizer = self._aspect_resize
  74
  75             # Set Width Size
  76             elif tmph == '?':
  77                 targetw = int(tmpw)
  78                 targeth = image.size[1]
  79                 resizer = self._aspect_resize
  80
  81             # Scale and Crop
  82             else:
  83                 targetw = int(tmpw)
  84                 targeth = int(tmph)
  85                 resizer = self._exact_resize
  86
  87         logger.debug("Using resizer {0}".format(resizer.__name__))
  88         return resizer(targetw, targeth, image)
  89
  90     def get_thumbnail_name(self, in_path):
  91         # Find the partial path + filename beyond the input image directory.
  92         prefix = path.commonprefix([in_path, self._root])
  93         new_filename = in_path[len(prefix):]
  94         if new_filename.startswith('/'):
  95             new_filename = new_filename[1:]
  96
  97         # Generate the new filename.
  98         (basename, ext) = path.splitext(new_filename)
  99         return "{0}_{1}{2}".format(basename, self._name, ext)
 100
 101     def resize_file_to(self, in_path, out_path, keep_filename=False):
 102         """ Given a filename, resize and save the image per the specification into out_path
 103
 104         :param in_path: path to image file to save.  Must be supported by PIL
 105         :param out_path: path to the directory root for the outputted thumbnails to be stored
 106         :return: None
 107         """
 108         if keep_filename:
 109             filename = path.join(out_path, path.basename(in_path))
 110         else:
 111             filename = path.join(out_path, self.get_thumbnail_name(in_path))
 112         out_path = path.dirname(filename)
 113         if not path.exists(out_path):
 114             os.makedirs(out_path)
 115         if not path.exists(filename):
 116             try:
 117                 image = Image.open(in_path)
 118                 thumbnail = self.resize(image)
 119                 thumbnail.save(filename)
 120                 logger.info("Generated Thumbnail {0}".format(path.basename(filename)))
 121             except IOError:
 122                 logger.info("Generating Thumbnail for {0} skipped".format(path.basename(filename)))
 123
 124
 125 def resize_thumbnails(pelican):
 126     """ Resize a directory tree full of images into thumbnails
 127
 128     :param pelican: The pelican instance
 129     :return: None
 130     """
 131     global enabled
 132     if not enabled:
 133         return
 134
 135     in_path = _image_path(pelican)
 136
 137     include_regex = pelican.settings.get('THUMBNAIL_INCLUDE_REGEX')
 138     if include_regex:
 139         pattern = re.compile(include_regex)
 140         is_included = lambda name: pattern.match(name)
 141     else:
 142         is_included = lambda name: not name.startswith('.')
 143
 144     sizes = pelican.settings.get('THUMBNAIL_SIZES', DEFAULT_THUMBNAIL_SIZES)
 145     resizers = dict((k, Resizer(k, v, in_path)) for k,v in sizes.items())
 146     logger.debug("Thumbnailer Started")
 147     for dirpath, _, filenames in os.walk(in_path):
 148         for filename in filenames:
 149             if is_included(filename):
 150                 for name, resizer in resizers.items():
 151                     in_filename = path.join(dirpath, filename)
 152                     out_path = get_out_path(pelican, in_path, in_filename, name)
 153                     resizer.resize_file_to(
 154                         in_filename,
 155                         out_path, pelican.settings.get('THUMBNAIL_KEEP_NAME'))
 156
 157
 158 def get_out_path(pelican, in_path, in_filename, name):
 159     base_out_path = path.join(pelican.settings['OUTPUT_PATH'],
 160                          pelican.settings.get('THUMBNAIL_DIR', DEFAULT_THUMBNAIL_DIR))
 161     logger.debug("Processing thumbnail {0}=>{1}".format(in_filename, name))
 162     if pelican.settings.get('THUMBNAIL_KEEP_NAME', False):
 163         if pelican.settings.get('THUMBNAIL_KEEP_TREE', False):
 164             return path.join(base_out_path, name, path.dirname(path.relpath(in_filename, in_path)))
 165         else:
 166             return path.join(base_out_path, name)
 167     else:
 168         return base_out_path
 169
 170
 171 def _image_path(pelican):
 172     return path.join(pelican.settings['PATH'],
 173         pelican.settings.get("IMAGE_PATH", DEFAULT_IMAGE_DIR)).rstrip('/')
 174
 175
 176 def expand_gallery(generator, metadata):
 177     """ Expand a gallery tag to include all of the files in a specific directory under IMAGE_PATH
 178
 179     :param pelican: The pelican instance
 180     :return: None
 181     """
 182     if "gallery" not in metadata or metadata['gallery'] is None:
 183         return  # If no gallery specified, we do nothing
 184
 185     lines = [ ]
 186     base_path = _image_path(generator)
 187     in_path = path.join(base_path, metadata['gallery'])
 188     template = generator.settings.get('GALLERY_TEMPLATE', DEFAULT_TEMPLATE)
 189     thumbnail_name = generator.settings.get("GALLERY_THUMBNAIL", DEFAULT_GALLERY_THUMB)
 190     thumbnail_prefix = generator.settings.get("")
 191     resizer = Resizer(thumbnail_name, '?x?', base_path)
 192     for dirpath, _, filenames in os.walk(in_path):
 193         for filename in filenames:
 194             if not filename.startswith('.'):
 195                 url = path.join(dirpath, filename).replace(base_path, "")[1:]
 196                 url = path.join('/static', generator.settings.get('IMAGE_PATH', DEFAULT_IMAGE_DIR), url).replace('\\', '/')
 197                 logger.debug("GALLERY: {0}".format(url))
 198                 thumbnail = resizer.get_thumbnail_name(filename)
 199                 thumbnail = path.join('/', generator.settings.get('THUMBNAIL_DIR', DEFAULT_THUMBNAIL_DIR), thumbnail).replace('\\', '/')
 200                 lines.append(template.format(
 201                     filename=filename,
 202                     url=url,
 203                     thumbnail=thumbnail,
 204                 ))
 205     metadata['gallery_content'] = "\n".join(lines)
 206
 207
 208 def register():
 209     signals.finalized.connect(resize_thumbnails)
 210     signals.article_generator_context.connect(expand_gallery)