142 lines
5.0 KiB
Python
142 lines
5.0 KiB
Python
""" Handle PDF
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"""
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import os
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import re
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import logging
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import tempfile
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import io
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from distutils.version import LooseVersion
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import cairo
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import gi
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gi.require_version('Poppler', '0.18')
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from gi.repository import Poppler, GLib
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from . import abstract
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poppler_version = Poppler.get_version()
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if LooseVersion(poppler_version) < LooseVersion('0.46'): # pragma: no cover
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raise ValueError("MAT2 needs at least Poppler version 0.46 to work. \
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The installed version is %s." % poppler_version) # pragma: no cover
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class PDFParser(abstract.AbstractParser):
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mimetypes = {'application/pdf', }
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meta_list = {'author', 'creation-date', 'creator', 'format', 'keywords',
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'metadata', 'mod-date', 'producer', 'subject', 'title',
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'viewer-preferences'}
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def __init__(self, filename):
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super().__init__(filename)
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self.uri = 'file://' + os.path.abspath(self.filename)
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self.__scale = 2 # how much precision do we want for the render
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try: # Check now that the file is valid, to avoid surprises later
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Poppler.Document.new_from_file(self.uri, None)
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except GLib.GError: # Invalid PDF
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raise ValueError
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def remove_all_lightweight(self):
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"""
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Load the document into Poppler, render pages on a new PDFSurface.
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"""
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document = Poppler.Document.new_from_file(self.uri, None)
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pages_count = document.get_n_pages()
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tmp_path = tempfile.mkstemp()[1]
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pdf_surface = cairo.PDFSurface(tmp_path, 10, 10) # resized later anyway
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pdf_context = cairo.Context(pdf_surface) # context draws on the surface
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for pagenum in range(pages_count):
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logging.info("Rendering page %d/%d", pagenum + 1, pages_count)
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page = document.get_page(pagenum)
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page_width, page_height = page.get_size()
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pdf_surface.set_size(page_width, page_height)
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pdf_context.save()
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page.render_for_printing(pdf_context)
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pdf_context.restore()
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pdf_context.show_page() # draw pdf_context on pdf_surface
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pdf_surface.finish()
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self.__remove_superficial_meta(tmp_path, self.output_filename)
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os.remove(tmp_path)
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return True
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def remove_all(self):
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"""
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Load the document into Poppler, render pages on PNG,
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and shove those PNG into a new PDF.
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"""
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document = Poppler.Document.new_from_file(self.uri, None)
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pages_count = document.get_n_pages()
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_, tmp_path = tempfile.mkstemp()
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pdf_surface = cairo.PDFSurface(tmp_path, 32, 32) # resized later anyway
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pdf_context = cairo.Context(pdf_surface)
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for pagenum in range(pages_count):
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page = document.get_page(pagenum)
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page_width, page_height = page.get_size()
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logging.info("Rendering page %d/%d", pagenum + 1, pages_count)
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width = int(page_width) * self.__scale
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height = int(page_height) * self.__scale
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img_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
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img_context = cairo.Context(img_surface)
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img_context.scale(self.__scale, self.__scale)
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page.render_for_printing(img_context)
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img_context.show_page()
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buf = io.BytesIO()
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img_surface.write_to_png(buf)
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img_surface.finish()
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buf.seek(0)
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img = cairo.ImageSurface.create_from_png(buf)
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pdf_surface.set_size(page_width*self.__scale, page_height*self.__scale)
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pdf_context.set_source_surface(img, 0, 0)
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pdf_context.paint()
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pdf_context.show_page() # draw pdf_context on pdf_surface
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pdf_surface.finish()
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# Removes metadata added by Poppler
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self.__remove_superficial_meta(tmp_path, self.output_filename)
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os.remove(tmp_path)
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return True
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@staticmethod
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def __remove_superficial_meta(in_file: str, out_file: str) -> bool:
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document = Poppler.Document.new_from_file('file://' + in_file)
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document.set_producer('')
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document.set_creator('')
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document.set_creation_date(-1)
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document.save('file://' + os.path.abspath(out_file))
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return True
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@staticmethod
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def __parse_metadata_field(data: str) -> dict:
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metadata = {}
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for (_, key, value) in re.findall(r"<(xmp|pdfx|pdf|xmpMM):(.+)>(.+)</\1:\2>", data, re.I):
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metadata[key] = value
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return metadata
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def get_meta(self):
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""" Return a dict with all the meta of the file
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"""
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metadata = {}
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document = Poppler.Document.new_from_file(self.uri, None)
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for key in self.meta_list:
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if document.get_property(key):
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metadata[key] = document.get_property(key)
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if 'metadata' in metadata:
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parsed_meta = self.__parse_metadata_field(metadata['metadata'])
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for key, value in parsed_meta.items():
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metadata[key] = value
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return metadata
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