1
0
mirror of https://github.com/Llewellynvdm/pdflayers.git synced 2024-11-21 11:25:09 +00:00

Add pdflayers script

Rough initial version of script. Only tested with
a few PDF files. There's a lot of things that could
be improved:
* Add options to list layer names
* Add options for trying to loacate and modify JavaScript
  that might affect layer visibility (in Adobe Reader).
* Error handling...
* Cleanup... better ways of using pikedpdf..?
This commit is contained in:
Simon Segerblom Rex 2019-05-16 19:39:29 +02:00
parent 15184a4dc3
commit afae3e9b07

95
pdflayers.py Normal file
View File

@ -0,0 +1,95 @@
#!/usr/bin/env python3
"""Script for editing PDF to change layer (OCG) visibility.
The output should display correctly in the PDF viwer in google-chrome,
evince, okular, and Adobe Reader (with JavaScript disabled).
pdf.js in firefox might not work: https://github.com/mozilla/pdf.js/issues/4841
Requirements:
Install pikepdf:
pip3 install --user pikepdf
and run the script with python3.
References:
https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdf_reference_archive/PDFReference16.pdf
https://pikepdf.readthedocs.io/
"""
import argparse
import logging
import sys
import pikepdf
def set_layer_visibility(pdf, layers_to_show):
"""Set visibility of layers."""
try:
ocgs = pdf.root.OCProperties.OCGs
except (AttributeError, KeyError):
logging.error("Unable to locate layers in PDF.")
sys.exit(1)
ocgs_on = []
ocgs_off = []
for ocg in ocgs:
if ocg.Name in layers_to_show:
logging.info("Layer %s will be visible.", ocg.Name)
ocgs_on.append(ocg)
else:
logging.info("Layer %s will be hidden.", ocg.Name)
ocgs_off.append(ocg)
ocgs_config = pikepdf.Dictionary(
BaseState=pikepdf.Name('/OFF'),
ON=ocgs_on,
)
pdf.root.OCProperties = pikepdf.Dictionary(
D=ocgs_config,
OCGs=ocgs,
)
# Needed for the PDF viwer in google-chrome (at least):
# TODO: Set PrintState and ExportState too..? Exception+ handling...
# Check PDF reference. Maybe better to just delete ViewState..?
for ocg in ocgs_on:
ocg.Usage.View.ViewState = pikepdf.Name('/ON')
for ocg in ocgs_off:
ocg.Usage.View.ViewState = pikepdf.Name('/OFF')
def main():
"""Main."""
logging.basicConfig(level=logging.INFO)
parser = argparse.ArgumentParser(
description='Tool for changing default visibility of PDF layers.'
)
parser.add_argument('input',
help='input file')
parser.add_argument('output',
help='output file')
parser.add_argument('--password', default='',
help='user password (for encrypted files)')
parser.add_argument('--show', nargs='+', default=(),
help='layers to be visible in output')
parser.add_argument('--qdf', action='store_true',
help='Use qdf to save the output. (Debug option)')
args = parser.parse_args()
pdf = pikepdf.open(args.input, password=args.password)
set_layer_visibility(pdf, args.show)
pdf.remove_unreferenced_resources()
save_options = {
'compress_streams': False,
'qdf': True,
} if args.qdf else {
}
pdf.save(args.output, **save_options)
if __name__ == "__main__":
main()