app/django/core/files/images.py
author Pawel Solyga <Pawel.Solyga@gmail.com>
Mon, 17 Nov 2008 22:12:34 +0000
changeset 501 be89bf307478
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Fix not working feed display for home settings public view. Modify blog javascript so that we can define how many feed entries we want to display. Change default number of entries to 3 as suggested by Leslie and Chris. Patch by: Pawel Solyga

"""
Utility functions for handling images.

Requires PIL, as you might imagine.
"""

from django.core.files import File

class ImageFile(File):
    """
    A mixin for use alongside django.core.files.base.File, which provides
    additional features for dealing with images.
    """
    def _get_width(self):
        return self._get_image_dimensions()[0]
    width = property(_get_width)

    def _get_height(self):
        return self._get_image_dimensions()[1]
    height = property(_get_height)

    def _get_image_dimensions(self):
        if not hasattr(self, '_dimensions_cache'):
            self._dimensions_cache = get_image_dimensions(self)
        return self._dimensions_cache

def get_image_dimensions(file_or_path):
    """Returns the (width, height) of an image, given an open file or a path."""
    from PIL import ImageFile as PILImageFile
    p = PILImageFile.Parser()
    if hasattr(file_or_path, 'read'):
        file = file_or_path
    else:
        file = open(file_or_path, 'rb')
    while 1:
        data = file.read(1024)
        if not data:
            break
        p.feed(data)
        if p.image:
            return p.image.size
    return None