def test_image_direct_embed(infile):
img = Image.open(os.path.join(IMG_DIR, infile))
w = IncrementalPdfFileWriter(BytesIO(MINIMAL))
image_ref = images.pil_image(img, w)
page_ref, resources = w.find_page_for_modification(0)
resources[pdf_name('/XObject')] = generic.DictionaryObject(
{pdf_name('/Img'): image_ref})
w.update_container(resources)
content_stream: generic.StreamObject = page_ref.get_object()['/Contents']
content_stream._data = \
content_stream.data + b' q 50 0 0 50 5 5 cm /Img Do Q'
content_stream._encoded_data = None
w.update_container(content_stream)
w.write_in_place()
# TODO flatten and do a visual comparison
image_obj = image_ref.get_object()
if 'indexed' in infile:
assert '/SMask' not in image_obj
else:
assert '/SMask' in image_obj
def append_signature_field(pdf_out: IncrementalPdfFileWriter,
sig_field_spec: SigFieldSpec):
"""
Append signature fields to a PDF file.
:param pdf_out:
Incremental writer to house the objects.
:param sig_field_spec:
A :class:`.SigFieldSpec` object describing the signature field
to add.
"""
root = pdf_out.root
page_ref = pdf_out.find_page_for_modification(sig_field_spec.on_page)[0]
# use default appearance
field_created, sig_field_ref = _prepare_sig_field(
sig_field_spec.sig_field_name,
root,
update_writer=pdf_out,
existing_fields_only=False,
box=sig_field_spec.box,
include_on_page=page_ref,
lock_sig_flags=False)
if not field_created:
raise PdfWriteError('Signature field with name %s already exists.' %
sig_field_spec.sig_field_name)
sig_field = sig_field_ref.get_object()
if sig_field_spec.seed_value_dict is not None:
# /SV must be an indirect reference as per the spec
sv_ref = pdf_out.add_object(
sig_field_spec.seed_value_dict.as_pdf_object())
sig_field[pdf_name('/SV')] = sv_ref
lock = sig_field_spec.format_lock_dictionary()
if lock is not None:
sig_field[pdf_name('/Lock')] = pdf_out.add_object(lock)
def _prepare_sig_field(sig_field_name,
root,
update_writer: IncrementalPdfFileWriter,
existing_fields_only=False,
lock_sig_flags=True,
**kwargs):
"""
Returns a tuple of a boolean and a reference to a signature field.
The boolean is ``True`` if the field was created, and ``False`` otherwise.
"""
if sig_field_name is None: # pragma: nocover
raise ValueError
try:
form = root['/AcroForm']
try:
fields = form['/Fields']
except KeyError:
raise ValueError('/AcroForm has no /Fields')
candidates = enumerate_sig_fields_in(fields, with_name=sig_field_name)
sig_field_ref = None
try:
field_name, value, sig_field_ref = next(candidates)
if value is not None:
raise SigningError(
'Signature field with name %s appears to be filled already.'
% sig_field_name)
except StopIteration:
if existing_fields_only:
raise SigningError(
'No empty signature field with name %s found.' %
sig_field_name)
form_created = False
except KeyError:
# we have to create the form
if existing_fields_only:
raise SigningError('This file does not contain a form.')
# no AcroForm present, so create one
form = generic.DictionaryObject()
root[pdf_name('/AcroForm')] = update_writer.add_object(form)
fields = generic.ArrayObject()
form[pdf_name('/Fields')] = fields
# now we need to mark the root as updated
update_writer.update_root()
form_created = True
sig_field_ref = None
if sig_field_ref is not None:
return False, sig_field_ref
if '.' in sig_field_name:
raise NotImplementedError(
"Creating fields deep in the form hierarchy is not supported"
"right now.")
# no signature field exists, so create one
# default: grab a reference to the first page
page_ref = update_writer.find_page_for_modification(0)[0]
sig_form_kwargs = {'include_on_page': page_ref}
sig_form_kwargs.update(**kwargs)
sig_field = SignatureFormField(sig_field_name,
writer=update_writer,
**sig_form_kwargs)
sig_field_ref = sig_field.reference
fields.append(sig_field_ref)
# make sure /SigFlags is present. If not, create it
sig_flags = 3 if lock_sig_flags else 1
form.setdefault(pdf_name('/SigFlags'), generic.NumberObject(sig_flags))
# if a field was added to an existing form, register an extra update
if not form_created:
update_writer.update_container(fields)
return True, sig_field_ref
