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""" Handle PDF
"""
import os
import re
import logging
import tempfile
import io
import cairo
import gi
gi.require_version('Poppler', '0.18')
from gi.repository import Poppler, GLib
from . import abstract
logging.basicConfig(level=logging.DEBUG)
class PDFParser(abstract.AbstractParser):
mimetypes = {'application/pdf', }
meta_list = {'author', 'creation-date', 'creator', 'format', 'keywords',
'metadata', 'mod-date', 'producer', 'subject', 'title',
'viewer-preferences'}
def __init__(self, filename):
super().__init__(filename)
self.uri = 'file://' + os.path.abspath(self.filename)
self.__scale = 2 # how much precision do we want for the render
try: # Check now that the file is valid, to avoid surprises later
Poppler.Document.new_from_file(self.uri, None)
except GLib.GError: # Invalid PDF
raise ValueError
def remove_all_lightweight(self):
"""
Load the document into Poppler, render pages on a new PDFSurface.
"""
document = Poppler.Document.new_from_file(self.uri, None)
pages_count = document.get_n_pages()
tmp_path = tempfile.mkstemp()[1]
pdf_surface = cairo.PDFSurface(tmp_path, 10, 10)
pdf_context = cairo.Context(pdf_surface) # context draws on the surface
for pagenum in range(pages_count):
logging.info("Rendering page %d/%d", pagenum + 1, pages_count)
page = document.get_page(pagenum)
page_width, page_height = page.get_size()
pdf_surface.set_size(page_width, page_height)
pdf_context.save()
page.render_for_printing(pdf_context)
pdf_context.restore()
pdf_context.show_page() # draw pdf_context on pdf_surface
pdf_surface.finish()
self.__remove_superficial_meta(tmp_path, self.output_filename)
os.remove(tmp_path)
return True
def remove_all(self):
"""
Load the document into Poppler, render pages on PNG,
and shove those PNG into a new PDF.
"""
document = Poppler.Document.new_from_file(self.uri, None)
pages_count = document.get_n_pages()
_, tmp_path = tempfile.mkstemp()
pdf_surface = cairo.PDFSurface(tmp_path, 32, 32) # resized later anyway
pdf_context = cairo.Context(pdf_surface)
for pagenum in range(pages_count):
page = document.get_page(pagenum)
page_width, page_height = page.get_size()
logging.info("Rendering page %d/%d", pagenum + 1, pages_count)
img_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, int(page_width) * self.__scale, int(page_height) * self.__scale)
img_context = cairo.Context(img_surface)
img_context.scale(self.__scale, self.__scale)
page.render_for_printing(img_context)
img_context.show_page()
buf = io.BytesIO()
img_surface.write_to_png(buf)
img_surface.finish()
buf.seek(0)
img = cairo.ImageSurface.create_from_png(buf)
pdf_surface.set_size(page_width*self.__scale, page_height*self.__scale)
pdf_context.set_source_surface(img, 0, 0)
pdf_context.paint()
pdf_context.show_page()
pdf_surface.finish()
# Removes metadata added by Poppler
self.__remove_superficial_meta(tmp_path, self.output_filename)
os.remove(tmp_path)
return True
@staticmethod
def __remove_superficial_meta(in_file: str, out_file: str) -> bool:
document = Poppler.Document.new_from_file('file://' + in_file)
document.set_producer('')
document.set_creator('')
document.set_creation_date(-1)
document.save('file://' + os.path.abspath(out_file))
return True
@staticmethod
def __parse_metadata_field(data: str) -> dict:
metadata = {}
for (_, key, value) in re.findall(r"<(xmp|pdfx|pdf|xmpMM):(.+)>(.+)</\1:\2>", data, re.I):
metadata[key] = value
return metadata
def get_meta(self):
""" Return a dict with all the meta of the file
"""
metadata = {}
document = Poppler.Document.new_from_file(self.uri, None)
for key in self.meta_list:
if document.get_property(key):
metadata[key] = document.get_property(key)
if 'metadata' in metadata:
parsed_meta = self.__parse_metadata_field(metadata['metadata'])
return {**metadata, **parsed_meta}
return metadata
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