Files
mayan-edms/mayan/apps/converter/classes.py

338 lines
10 KiB
Python

from __future__ import unicode_literals
import base64
import logging
import os
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
from PIL import Image
import sh
from django.utils.translation import string_concat, ugettext_lazy as _
from common.settings import setting_temporary_directory
from common.utils import fs_cleanup, mkstemp
from mimetype.api import get_mimetype
from .exceptions import InvalidOfficeFormat, OfficeConversionError
from .literals import DEFAULT_PAGE_NUMBER, DEFAULT_FILE_FORMAT
from .settings import setting_libreoffice_path
CHUNK_SIZE = 1024
logger = logging.getLogger(__name__)
try:
LIBREOFFICE = sh.Command(
setting_libreoffice_path.value
).bake('--headless', '--convert-to', 'pdf')
except sh.CommandNotFound:
LIBREOFFICE = None
CONVERTER_OFFICE_FILE_MIMETYPES = (
'application/msword',
'application/mswrite',
'application/mspowerpoint',
'application/msexcel',
'application/pgp-keys',
'application/vnd.ms-excel',
'application/vnd.ms-excel.addin.macroEnabled.12',
'application/vnd.ms-excel.sheet.binary.macroEnabled.12',
'application/vnd.ms-powerpoint',
'application/vnd.oasis.opendocument.chart',
'application/vnd.oasis.opendocument.chart-template',
'application/vnd.oasis.opendocument.formula',
'application/vnd.oasis.opendocument.formula-template',
'application/vnd.oasis.opendocument.graphics',
'application/vnd.oasis.opendocument.graphics-template',
'application/vnd.oasis.opendocument.image',
'application/vnd.oasis.opendocument.image-template',
'application/vnd.oasis.opendocument.presentation',
'application/vnd.oasis.opendocument.presentation-template',
'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
'application/vnd.openxmlformats-officedocument.spreadsheetml.template',
'application/vnd.openxmlformats-officedocument.presentationml.template',
'application/vnd.openxmlformats-officedocument.presentationml.slideshow',
'application/vnd.openxmlformats-officedocument.presentationml.presentation',
'application/vnd.openxmlformats-officedocument.presentationml.slide',
'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
'application/vnd.openxmlformats-officedocument.wordprocessingml.template',
'application/vnd.oasis.opendocument.spreadsheet',
'application/vnd.oasis.opendocument.spreadsheet-template',
'application/vnd.oasis.opendocument.text',
'application/vnd.oasis.opendocument.text-master',
'application/vnd.oasis.opendocument.text-template',
'application/vnd.oasis.opendocument.text-web',
'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
'application/vnd.ms-office',
'application/xml',
'text/x-c',
'text/x-c++',
'text/x-pascal',
'text/x-msdos-batch',
'text/x-python',
'text/x-shellscript',
'text/plain',
'text/rtf',
)
class ConverterBase(object):
def __init__(self, file_object, mime_type=None):
self.file_object = file_object
self.image = None
self.mime_type = mime_type or get_mimetype(
file_object=file_object, mimetype_only=False
)[0]
self.soffice_file = None
def to_pdf(self):
if self.mime_type in CONVERTER_OFFICE_FILE_MIMETYPES:
return self.soffice()
else:
raise InvalidOfficeFormat(_('Not an office file format.'))
def seek(self, page_number):
# Starting with #0
self.file_object.seek(0)
try:
self.image = Image.open(self.file_object)
except IOError:
# Cannot identify image file
self.image = self.convert(page_number=page_number)
else:
self.image.seek(page_number)
self.image.load()
def soffice(self):
"""
Executes LibreOffice as a subprocess
"""
if not os.path.exists(setting_libreoffice_path.value):
raise OfficeConversionError(
_(
'LibreOffice not installed or not found at path: %s'
) % setting_libreoffice_path.value
)
new_file_object, input_filepath = mkstemp()
self.file_object.seek(0)
os.write(new_file_object, self.file_object.read())
self.file_object.seek(0)
os.lseek(new_file_object, 0, os.SEEK_SET)
os.close(new_file_object)
libreoffice_filter = None
if self.mime_type == 'text/plain':
libreoffice_filter = 'Text (encoded):UTF8,LF,,,'
args = (input_filepath, '--outdir', setting_temporary_directory.value)
kwargs = {'_env': {'HOME': setting_temporary_directory.value}}
if libreoffice_filter:
kwargs.update({'infilter': libreoffice_filter})
try:
LIBREOFFICE(*args, **kwargs)
except sh.ErrorReturnCode as exception:
raise OfficeConversionError(exception)
finally:
fs_cleanup(input_filepath)
filename, extension = os.path.splitext(
os.path.basename(input_filepath)
)
logger.debug('filename: %s', filename)
logger.debug('extension: %s', extension)
converted_output = os.path.join(
setting_temporary_directory.value, os.path.extsep.join(
(filename, 'pdf')
)
)
logger.debug('converted_output: %s', converted_output)
with open(converted_output) as converted_file_object:
while True:
data = converted_file_object.read(CHUNK_SIZE)
if not data:
break
yield data
fs_cleanup(input_filepath)
fs_cleanup(converted_output)
def get_page(self, output_format=DEFAULT_FILE_FORMAT, as_base64=False):
if not self.image:
self.seek(0)
image_buffer = StringIO()
new_mode = self.image.mode
if output_format.upper() == 'JPEG':
if self.image.mode == 'P':
new_mode = 'RGB'
if 'transparency' in self.image.info:
new_mode = 'RGBA'
self.image.convert(new_mode).save(image_buffer, format=output_format)
if as_base64:
return 'data:{};base64,{}'.format(Image.MIME[output_format], base64.b64encode(image_buffer.getvalue()))
else:
image_buffer.seek(0)
return image_buffer
def convert(self, page_number=DEFAULT_PAGE_NUMBER):
self.page_number = page_number
def transform(self, transformation):
if not self.image:
self.seek(0)
self.image = transformation.execute_on(self.image)
def transform_many(self, transformations):
if not self.image:
self.seek(0)
for transformation in transformations:
self.image = transformation.execute_on(self.image)
def get_page_count(self):
try:
self.soffice_file = self.to_pdf()
except InvalidOfficeFormat as exception:
logger.debug('Is not an office format document; %s', exception)
class BaseTransformation(object):
name = 'base_transformation'
arguments = ()
_registry = {}
@classmethod
def register(cls, transformation):
cls._registry[transformation.name] = transformation
@classmethod
def get_transformation_choices(cls):
return [
(name, klass.get_label()) for name, klass in cls._registry.items()
]
@classmethod
def get(cls, name):
return cls._registry[name]
@classmethod
def get_label(cls):
return string_concat(cls.label, ': ', ', '.join(cls.arguments))
def __init__(self, **kwargs):
for argument_name in self.arguments:
setattr(self, argument_name, kwargs.get(argument_name))
def execute_on(self, image):
self.image = image
self.aspect = 1.0 * image.size[0] / image.size[1]
class TransformationResize(BaseTransformation):
name = 'resize'
arguments = ('width', 'height')
label = _('Resize')
def execute_on(self, *args, **kwargs):
super(TransformationResize, self).execute_on(*args, **kwargs)
fit = False
width = int(self.width)
height = int(self.height or 1.0 * width / self.aspect)
factor = 1
while self.image.size[0] / factor > 2 * width and self.image.size[1] * 2 / factor > 2 * height:
factor *= 2
if factor > 1:
self.image.thumbnail(
(self.image.size[0] / factor, self.image.size[1] / factor),
Image.NEAREST
)
# calculate the cropping box and get the cropped part
if fit:
x1 = y1 = 0
x2, y2 = self.image.size
wRatio = 1.0 * x2 / width
hRatio = 1.0 * y2 / height
if hRatio > wRatio:
y1 = y2 / 2 - height * wRatio / 2
y2 = y2 / 2 + height * wRatio / 2
else:
x1 = x2 / 2 - width * hRatio / 2
x2 = x2 / 2 + width * hRatio / 2
self.image = self.image.crop((x1, y1, x2, y2))
# Resize the image with best quality algorithm ANTI-ALIAS
self.image.thumbnail((width, height), Image.ANTIALIAS)
return self.image
class TransformationRotate(BaseTransformation):
name = 'rotate'
arguments = ('degrees',)
label = _('Rotate')
def execute_on(self, *args, **kwargs):
super(TransformationRotate, self).execute_on(*args, **kwargs)
return self.image.rotate(
360 - self.degrees, resample=Image.BICUBIC, expand=True
)
class TransformationZoom(BaseTransformation):
name = 'zoom'
arguments = ('percent',)
label = _('Zoom')
def execute_on(self, *args, **kwargs):
super(TransformationZoom, self).execute_on(*args, **kwargs)
decimal_value = float(self.percent) / 100
return self.image.resize(
(
int(self.image.size[0] * decimal_value),
int(self.image.size[1] * decimal_value)
), Image.ANTIALIAS
)
class TransformationCrop(BaseTransformation):
name = 'crop'
arguments = ('left', 'top', 'right', 'bottom',)
label = _('Crop')
def execute_on(self, *args, **kwargs):
super(TransformationCrop, self).execute_on(*args, **kwargs)
return self.image.crop(
(self.left, self.top, self.right, self.bottom)
)
BaseTransformation.register(TransformationResize)
BaseTransformation.register(TransformationRotate)
BaseTransformation.register(TransformationZoom)
BaseTransformation.register(TransformationCrop)