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troggle/imagekit/specs.py
substantialnoninfringinguser b509390575 [svn] Switch from photologue to imagekit. Less bloat.
Copied from http://cucc@cucc.survex.com/svn/trunk/expoweb/troggle/, rev. 8338 by cucc @ 5/11/2009 3:08 AM
2009-05-13 06:24:52 +01:00

120 lines
3.4 KiB
Python

""" ImageKit image specifications
All imagekit specifications must inherit from the ImageSpec class. Models
inheriting from ImageModel will be modified with a descriptor/accessor for each
spec found.
"""
import os
from StringIO import StringIO
from imagekit.lib import *
from imagekit.utils import img_to_fobj
from django.core.files.base import ContentFile
class ImageSpec(object):
pre_cache = False
quality = 70
increment_count = False
processors = []
@classmethod
def name(cls):
return getattr(cls, 'access_as', cls.__name__.lower())
@classmethod
def process(cls, image, obj):
processed_image = image.copy()
for proc in cls.processors:
processed_image = proc.process(processed_image, obj)
return processed_image
class Accessor(object):
def __init__(self, obj, spec):
self._img = None
self._obj = obj
self.spec = spec
def _get_imgfile(self):
format = self._img.format or 'JPEG'
if format != 'JPEG':
imgfile = img_to_fobj(self._img, format)
else:
imgfile = img_to_fobj(self._img, format,
quality=int(self.spec.quality),
optimize=True)
return imgfile
def _create(self):
if self._exists():
return
# process the original image file
fp = self._obj._imgfield.storage.open(self._obj._imgfield.name)
fp.seek(0)
fp = StringIO(fp.read())
try:
self._img = self.spec.process(Image.open(fp), self._obj)
# save the new image to the cache
content = ContentFile(self._get_imgfile().read())
self._obj._imgfield.storage.save(self.name, content)
except IOError:
pass
def _delete(self):
self._obj._imgfield.storage.delete(self.name)
def _exists(self):
return self._obj._imgfield.storage.exists(self.name)
def _basename(self):
filename, extension = \
os.path.splitext(os.path.basename(self._obj._imgfield.name))
return self._obj._ik.cache_filename_format % \
{'filename': filename,
'specname': self.spec.name(),
'extension': extension.lstrip('.')}
@property
def name(self):
return os.path.join(self._obj._ik.cache_dir, self._basename())
@property
def url(self):
self._create()
if self.spec.increment_count:
fieldname = self._obj._ik.save_count_as
if fieldname is not None:
current_count = getattr(self._obj, fieldname)
setattr(self._obj, fieldname, current_count + 1)
self._obj.save(clear_cache=False)
return self._obj._imgfield.storage.url(self.name)
@property
def file(self):
self._create()
return self._obj._imgfield.storage.open(self.name)
@property
def image(self):
if self._img is None:
self._create()
if self._img is None:
self._img = Image.open(self.file)
return self._img
@property
def width(self):
return self.image.size[0]
@property
def height(self):
return self.image.size[1]
class Descriptor(object):
def __init__(self, spec):
self._spec = spec
def __get__(self, obj, type=None):
return Accessor(obj, self._spec)