app/django/core/files/images.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sat, 22 Nov 2008 14:53:23 +0000
changeset 555 3cdfb42d941b
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Split the list view code up in three pieces 1. getListContents which returns the required contents dictionary 2. _list which returns the response for a specified list of contents 3. list which constructs just one content dict and passes it to _list This way it is easier to do step 1 and 2 in other code than list(), which makes it possible to display multiple list pages (by calling getListContents multiple times and passing the result to _list).

"""
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