app/django/core/files/images.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sun, 01 Feb 2009 22:48:48 +0000
changeset 1166 558bd62ee9d4
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Fix get args construction when there are multiple lists on the page It is now possible to go back and forward through the liast, and specify the limit (both offset and limit can be done per list). The JS driving the list boxes is buggy, if visiting an url like: http://localhost:8080/notification/list?limit_0=10 And then change the limit in the second checkbox, it directs to: http://localhost:8080/notification/list?limit_1=25 Whereas it should redirect to: http://localhost:8080/notification/list?limit_0=10&limit_1=25 The logic _does_ work properly when the limit of the changed list is already present in the url. Patch by: Sverre Rabbelier

"""
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