~osomon/pyexiv2/pyexiv2-0.3

# -*- coding: utf-8 -*-

# ******************************************************************************

#

# Copyright (C) 2010 Olivier Tilloy <olivier@tilloy.net>

#

# This file is part of the pyexiv2 distribution.

#

# pyexiv2 is free software; you can redistribute it and/or

# modify it under the terms of the GNU General Public License

# as published by the Free Software Foundation; either version 2

# of the License, or (at your option) any later version.

#

# pyexiv2 is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with pyexiv2; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.

#

# Author: Olivier Tilloy <olivier@tilloy.net>

#

# ******************************************************************************

import unittest

import os.path

import hashlib

from datetime import datetime

from pyexiv2.metadata import ImageMetadata

import testutils

class TestBuffer(unittest.TestCase):

    def setUp(self):

        filename = os.path.join('data', 'smiley1.jpg')

        self.filepath = testutils.get_absolute_file_path(filename)

        self.md5sum = 'c066958457c685853293058f9bf129c1'

        self.assert_(testutils.CheckFileSum(self.filepath, self.md5sum))

    def _metadata_from_buffer(self):

        fd = open(self.filepath, 'rb')

        data = fd.read()

        fd.close()

        return ImageMetadata.from_buffer(data)

    def test_from_file_and_from_buffer(self):

        # from file

        m1 = ImageMetadata(self.filepath)

        m1.read()

        self.assertEqual(hashlib.md5(m1.buffer).hexdigest(), self.md5sum)

        # from buffer

        m2 = self._metadata_from_buffer()

        self.assertEqual(hashlib.md5(m2.buffer).hexdigest(), self.md5sum)

    def test_buffer_not_updated_until_write_called(self):

        m = self._metadata_from_buffer()

        m.read()

        self.assertEqual(hashlib.md5(m.buffer).hexdigest(), self.md5sum)

        # Modify the value of an EXIF tag

        m['Exif.Image.DateTime'].value = datetime.today()

        # Check that the buffer is unchanged until write() is called

        self.assertEqual(hashlib.md5(m.buffer).hexdigest(), self.md5sum)

        # Write back the changes

        m.write()

        # Check that the buffer has changed

        self.failIfEqual(hashlib.md5(m.buffer).hexdigest(), self.md5sum)

    def test_from_original_buffer(self):

        m1 = self._metadata_from_buffer()

        m2 = ImageMetadata.from_buffer(m1.buffer)

        self.assertEqual(hashlib.md5(m2.buffer).hexdigest(), self.md5sum)

    def test_from_modified_buffer(self):

        m1 = self._metadata_from_buffer()

        m1.read()

        key = 'Exif.Image.ImageDescription'

        value = 'my kingdom for a semiquaver'

        m1[key] = value

        m1.write()

        m2 = ImageMetadata.from_buffer(m1.buffer)

        m2.read()

        self.assertEqual(m2[key].value, value)