def original(self):
"""(:class:`Image`) The original image. It could be ``None``
if there are no stored images yet.
"""
if Session.object_session(self.instance) is None:
for image, store in self._stored_images:
if image.original:
return image
state = instance_state(self.instance)
try:
added = state.committed_state[self.attr.key].added_items
except KeyError:
pass
else:
for image in added:
if image.original:
return image
if self.session:
for image in self.session.new:
if image.original:
return image
return
query = self.filter_by(original=True)
try:
return query.one()
except NoResultFound:
pass
def original(self):
"""(:class:`Image`) The original image. It could be ``None``
if there are no stored images yet.
"""
if Session.object_session(self.instance) is None:
for image, store in self._stored_images:
if image.original:
return image
state = instance_state(self.instance)
try:
added = state.committed_state[self.attr.key].added_items
except KeyError:
pass
else:
for image in added:
if image.original:
return image
if self.session:
for image in self.session.new:
if image.original:
return image
return
query = self.filter_by(original=True)
try:
return query.one()
except NoResultFound:
pass
def _original_images(self, **kwargs):
"""A list of the original images.
:returns: A list of the original images.
:rtype: :class:`collections.Image`
"""
def test(image):
if not image.original:
return False
for filter, value in kwargs.items():
if getattr(image, filter) != value:
return False
return True
if Session.object_session(self.instance) is None:
images = []
for image, store in self._stored_images:
if test(image):
images.append(image)
state = instance_state(self.instance)
try:
added = state.committed_state[self.attr.key].added_items
except KeyError:
pass
else:
for image in added:
if test(image):
images.append(image)
if self.session:
for image in self.session.new:
if test(image):
images.append(image)
else:
query = self.filter_by(original=True, **kwargs)
images = query.all()
return images
def _original_images(self, **kwargs):
"""A list of the original images.
:returns: A list of the original images.
:rtype: :class:`typing.Sequence`\ [:class:`Image`]
"""
def test(image):
if not image.original:
return False
for filter, value in kwargs.items():
if getattr(image, filter) != value:
return False
return True
if Session.object_session(self.instance) is None:
images = []
for image, store in self._stored_images:
if test(image):
images.append(image)
state = instance_state(self.instance)
try:
added = state.committed_state[self.attr.key].added_items
except KeyError:
pass
else:
for image in added:
if test(image):
images.append(image)
if self.session:
for image in self.session.new:
if test(image):
images.append(image)
else:
query = self.filter_by(original=True, **kwargs)
images = query.all()
return images
def generate_thumbnail(self, ratio=None, width=None, height=None,
filter='undefined', store=current_store,
_preprocess_image=None, _postprocess_image=None):
"""Resizes the :attr:`original` (scales up or down) and
then store the resized thumbnail into the ``store``.
:param ratio: resize by its ratio. if it's greater than 1
it scales up, and if it's less than 1 it scales
down. exclusive for ``width`` and ``height``
parameters
:type ratio: :class:`numbers.Real`
:param width: resize by its width. exclusive for ``ratio``
and ``height`` parameters
:type width: :class:`numbers.Integral`
:param height: resize by its height. exclusive for ``ratio``
and ``width`` parameters
:type height: :class:`numbers.Integral`
:param filter: a filter type to use for resizing. choose one in
:const:`wand.image.FILTER_TYPES`. default is
``'undefined'`` which means ImageMagick will try
to guess best one to use
:type filter: :class:`basestring`, :class:`numbers.Integral`
:param store: the storage to store the resized image file.
:data:`~sqlalchemy_imageattach.context.current_store`
by default
:type store: :class:`~sqlalchemy_imageattach.store.Store`
:param _preprocess_image: internal-use only option for preprocessing
original image before resizing.
it has to be callable which takes
a :class:`wand.image.Image` object
and returns a new :class:`wand.image.Image`
object
:type _preprocess_image: :class:`collections.Callable`
:param _postprocess_image: internal-use only option for preprocessing
original image before resizing.
it has to be callable which takes
a :class:`wand.image.Image` object
and returns a new :class:`wand.image.Image`
object
:type _postprocess_image: :class:`collections.Callable`
:returns: the resized thumbnail image. it might be an already
existing image if the same size already exists
:rtype: :class:`Image`
:raises exceptions.IOError: when there's no :attr:`original`
image yet
"""
params = ratio, width, height
param_count = sum(p is not None for p in params)
if not param_count:
raise TypeError('pass an argument ratio, width, or height')
elif param_count > 1:
raise TypeError('pass only one argument in ratio, width, or '
'height; these parameters are exclusive for '
'each other')
query = self.query
transient = Session.object_session(query.instance) is None
state = instance_state(query.instance)
try:
added = state.committed_state[query.attr.key].added_items
except KeyError:
added = []
if width is not None:
if not isinstance(width, numbers.Integral):
raise TypeError('width must be integer, not ' + repr(width))
elif width < 1:
raise ValueError('width must be natural number, not ' +
repr(width))
# find the same-but-already-generated thumbnail
for image in added:
if image.width == width:
return image
if not transient:
q = query.filter_by(width=width)
try:
return q.one()
except NoResultFound:
pass
def height(sz):
return sz[1] * (width / sz[0])
elif height is not None:
if not isinstance(height, numbers.Integral):
raise TypeError('height must be integer, not ' + repr(height))
elif height < 1:
raise ValueError('height must be natural number, not ' +
repr(height))
# find the same-but-already-generated thumbnail
for image in added:
if image.height == height:
return image
if not transient:
q = query.filter_by(height=height)
try:
return q.one()
except NoResultFound:
pass
def width(sz):
return sz[0] * (height / sz[1])
elif ratio is not None:
if not isinstance(ratio, numbers.Real):
raise TypeError('ratio must be an instance of numbers.Real, '
'not ' + repr(ratio))
def width(sz):
return sz[0] * ratio
def height(sz):
return sz[1] * ratio
data = io.BytesIO()
image = self.require_original()
with image.open_file(store=store) as f:
if _preprocess_image is None:
img = WandImage(file=f)
else:
with WandImage(file=f) as img:
img = _preprocess_image(img)
with img:
if img.mimetype in VECTOR_TYPES:
img.format = 'png'
original_size = img.size
if callable(width):
width = width(original_size)
if callable(height):
height = height(original_size)
width = int(width)
height = int(height)
# find the same-but-already-generated thumbnail
for image in added:
if image.width == width and image.height == height:
return image
if not transient:
q = query.filter_by(width=width, height=height)
try:
return q.one()
except NoResultFound:
pass
if len(img.sequence) > 1:
img_ctx = img.sequence[0].clone()
img_ctx.resize(width, height, filter=filter)
else:
img_ctx = NoopContext(img)
with img_ctx as single_img:
single_img.resize(width, height, filter=filter)
if _postprocess_image is None:
mimetype = img.mimetype
single_img.save(file=data)
else:
with _postprocess_image(img) as img:
mimetype = img.mimetype
single_img.save(file=data)
return self.from_raw_file(data, store,
size=(width, height),
mimetype=mimetype,
original=False)
def generate_thumbnail(self,
ratio=None,
width=None,
height=None,
filter='undefined',
store=current_store,
_preprocess_image=None,
_postprocess_image=None):
"""Resizes the :attr:`original` (scales up or down) and
then store the resized thumbnail into the ``store``.
:param ratio: resize by its ratio. if it's greater than 1
it scales up, and if it's less than 1 it scales
down. exclusive for ``width`` and ``height``
parameters
:type ratio: :class:`numbers.Real`
:param width: resize by its width. exclusive for ``ratio``
and ``height`` parameters
:type width: :class:`numbers.Integral`
:param height: resize by its height. exclusive for ``ratio``
and ``width`` parameters
:type height: :class:`numbers.Integral`
:param filter: a filter type to use for resizing. choose one in
:const:`wand.image.FILTER_TYPES`. default is
``'undefined'`` which means ImageMagick will try
to guess best one to use
:type filter: :class:`basestring`, :class:`numbers.Integral`
:param store: the storage to store the resized image file.
:data:`~sqlalchemy_imageattach.context.current_store`
by default
:type store: :class:`~sqlalchemy_imageattach.store.Store`
:param _preprocess_image: internal-use only option for preprocessing
original image before resizing.
it has to be callable which takes
a :class:`wand.image.Image` object
and returns a new :class:`wand.image.Image`
object
:type _preprocess_image: :class:`collections.Callable`
:param _postprocess_image: internal-use only option for preprocessing
original image before resizing.
it has to be callable which takes
a :class:`wand.image.Image` object
and returns a new :class:`wand.image.Image`
object
:type _postprocess_image: :class:`collections.Callable`
:returns: the resized thumbnail image. it might be an already
existing image if the same size already exists
:rtype: :class:`Image`
:raises exceptions.IOError: when there's no :attr:`original`
image yet
"""
params = ratio, width, height
param_count = sum(p is not None for p in params)
if not param_count:
raise TypeError('pass an argument ratio, width, or height')
elif param_count > 1:
raise TypeError('pass only one argument in ratio, width, or '
'height; these parameters are exclusive for '
'each other')
query = self.query
transient = Session.object_session(query.instance) is None
state = instance_state(query.instance)
try:
added = state.committed_state[query.attr.key].added_items
except KeyError:
added = []
if width is not None:
if not isinstance(width, numbers.Integral):
raise TypeError('width must be integer, not ' + repr(width))
elif width < 1:
raise ValueError('width must be natural number, not ' +
repr(width))
# find the same-but-already-generated thumbnail
for image in added:
if image.width == width:
return image
if not transient:
q = query.filter_by(width=width)
try:
return q.one()
except NoResultFound:
pass
def height(sz):
return sz[1] * (width / sz[0])
elif height is not None:
if not isinstance(height, numbers.Integral):
raise TypeError('height must be integer, not ' + repr(height))
elif height < 1:
raise ValueError('height must be natural number, not ' +
repr(height))
# find the same-but-already-generated thumbnail
for image in added:
if image.height == height:
return image
if not transient:
q = query.filter_by(height=height)
try:
return q.one()
except NoResultFound:
pass
def width(sz):
return sz[0] * (height / sz[1])
elif ratio is not None:
if not isinstance(ratio, numbers.Real):
raise TypeError('ratio must be an instance of numbers.Real, '
'not ' + repr(ratio))
def width(sz):
return sz[0] * ratio
def height(sz):
return sz[1] * ratio
data = io.BytesIO()
image = self.require_original()
with image.open_file(store=store) as f:
if _preprocess_image is None:
img = WandImage(file=f)
else:
with WandImage(file=f) as img:
img = _preprocess_image(img)
with img:
if img.mimetype in VECTOR_TYPES:
img.format = 'png'
original_size = img.size
if callable(width):
width = width(original_size)
if callable(height):
height = height(original_size)
width = int(width)
height = int(height)
# find the same-but-already-generated thumbnail
for image in added:
if image.width == width and image.height == height:
return image
if not transient:
q = query.filter_by(width=width, height=height)
try:
return q.one()
except NoResultFound:
pass
if len(img.sequence) > 1:
img_ctx = img.sequence[0].clone()
img_ctx.resize(width, height, filter=filter)
else:
img_ctx = NoopContext(img)
with img_ctx as single_img:
single_img.resize(width, height, filter=filter)
if _postprocess_image is None:
mimetype = img.mimetype
single_img.save(file=data)
else:
with _postprocess_image(img) as img:
mimetype = img.mimetype
single_img.save(file=data)
return self.from_raw_file(data,
store,
size=(width, height),
mimetype=mimetype,
original=False)
