snapcraft.yaml

name: ocrthypdf
title: OCRthyPDF Essentials
base: core20 # the base snap is the execution environment for this snap
adopt-info: ocrthypdf
summary: Make your PDF files text-searchable (A GUI for OCRmyPDF)
description: |
  This is a basic user interface for the command line tool OCRmyPDF. 
  It's main purpose is to provide users that are not used to command 
  line tools easy access to OCRmyPDF's basic features.  
  You can use it to make PDF files that contain images with text 
  (e. g. after scanning) searchable by adding an invisible text layer.
  If you like the results created with OCRthyPDF but need more flexibility 
  I suggest you give OCRmyPDF a try on the command line. 
license: AGPL-3.0
icon: gui/ocrthypdf.svg 
compression: lzo 
grade: stable # 'stable' 'devel'
confinement: strict # 'strict' 'devmode'
architectures: [amd64]
package-repositories:
 - type: apt
   ppa: alex-p/tesseract-ocr5
 - type: apt
   ppa: alex-p/jbig2enc      

environment:
    PYTHONPATH: $SNAP/usr/bin/python3.9
    TESSDATA_PREFIX: $SNAP/usr/share/tesseract-ocr/tessdata
    GS_LIB: $SNAP/usr/share/ghostscript/Init 
    GS_FONTPATH: $SNAP/usr/share/ghostscript/Font
    GS_OPTIONS: -sGenericResourceDir=$SNAP/usr/share/ghostscript/ -sICCProfilesDir=$SNAP/usr/share/color/icc/ghostscript/
    SNAPCRAFT_PRELOAD_REDIRECT_ONLY_SHM: 1

apps:
  ocrthypdf:
    command: usr/bin/snapcraft-preload $SNAP/bin/python3.9 $SNAP/code/OCRthyPDF.py
    command-chain: [bin/debian-multiarch-triplet-provider-launch, bin/tcltk-launch]
    desktop: $SNAPCRAFT_PROJECT_DIR/gui/ocrthypdf.desktop
    extensions: [gnome-3-38]
    plugs:
      - home
      - removable-media
      - unity7
     
parts:
  get-source:
    plugin: dump
    source: https://github.com/digidigital/OCRthyPDF-Essentials.git
  
  tcltk-launch:
    plugin: nil
    stage-snaps: [tcltk-launch]
  
  debian-multiarch-triplet-provider-launch:
    plugin: nil
    stage-snaps: [debian-multiarch-triplet-provider-launch]

  snapcraft-preload:
      source: https://github.com/sergiusens/snapcraft-preload.git
      plugin: cmake
      cmake-parameters:
      - -DCMAKE_INSTALL_PREFIX=/usr -DLIBPATH=/lib
      build-packages:
        - gcc-multilib
        - g++-multilib
      stage-packages:
        - lib32stdc++6  
      override-build: |
        snapcraftctl build
        ln -sf ../usr/lib/libsnapcraft-preload.so $SNAPCRAFT_PART_INSTALL/lib/libsnapcraft-preload.so

  pull-parts:
    plugin: nil
    stage-packages: 
      - ghostscript
      - gsfonts      
      - icc-profiles-free 
      - tesseract-ocr-all
    build-packages: 
      - ghostscript
      - curl
    override-prime: |
      snapcraftctl prime

      gslibpath=$(gs -h | grep  Resource/Init | tr -d ' ':)
      ln -s -f ${gslibpath/\/usr\/share\/ghostscript/.} .${gslibpath}/../../../Init

      gsfontpath=$(gs -h | grep  Resource/Font | tr -d ' ':)
      ln -s -f ${gsfontpath/\/usr\/share\/ghostscript/.} .${gsfontpath}/../../../Font

      tessdatapath=$(find ./ -iname tessdata)                                  
      ln -s -f ${tessdatapath/usr\/share\/tesseract-ocr\//} ${tessdatapath}/../../tessdata
      
      curl --output "${tessdatapath}/best-#1.traineddata" "https://raw.githubusercontent.com/tesseract-ocr/tessdata_best/main/{deu,eng,fra,spa,por,ita,rus,ukr,jpn,jpn_vert,ara,hin,pol}.traineddata" 

      # debug
      ls -l ${tessdatapath}

  ocrthypdf:
    plugin: python
    source: https://github.com/digidigital/OCRthyPDF-Essentials.git
    source-type: git

    stage-packages: 
      - python3.9-venv
      - python3-tk
      - fonts-freefont-ttf
      - tcl
      - libxml2 
      - pngquant 
      - unpaper 
      - qpdf 
      - zlib1g 
      - libzbar0
      - libnspr4
      - libnss3
      - libpoppler-cpp0v5
      - libpoppler97
      - jbig2enc
    
    override-pull: |
      snapcraftctl pull  
      snapcraftctl set-version "$(git describe --tags)"
    
    build-packages:
      - build-essential
      - python3.9-venv
      - python3.9-dev
      - libpoppler-cpp-dev  
      - pipenv

    build-environment:
      - SNAPCRAFT_PYTHON_INTERPRETER: python3.9   
      # python3.9 lives in $SNAPCRAFT_PART_INSTALL/bin
      - PATH: $SNAPCRAFT_PART_INSTALL/bin:/usr/lib/gcc/x86_64-linux-gnu/9/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/include/c++/9/:/usr/include/c++/:$PATH   
      - CPATH:  /usr/include/x86_64-linux-gnu/c++/9/:/usr/lib/gcc/x86_64-linux-gnu/9/:usr/lib/gcc/x86_64-linux-gnu/:/usr/include/c++/9/:/usr/include/c++/
      - PYTHONPATH: ''

    override-build: |
      # Work around a bug in snapcraft python plugin / gnome 3.38 extension
      # https://forum.snapcraft.io/t/build-a-snap-with-any-version-of-python-i-want/10420/8
          
      rm -rf $SNAPCRAFT_PART_INSTALL/usr/lib/python3.9/distutils
      cp -r /usr/lib/python3.9/distutils $SNAPCRAFT_PART_INSTALL/usr/lib/python3.9/distutils
      mkdir -p $SNAPCRAFT_PART_INSTALL/usr/include/
      cp -r /usr/include/python3.9 $SNAPCRAFT_PART_INSTALL/usr/include/python3.9    
      
      snapcraftctl build
      
      pip install -U pip wheel setuptools
      # ocrmypdf version >= 15.0.0 has dependecies not available in core20 
      pip install pdftotext ocrmypdf==14.4.0 pikepdf==8.15.1 pyzbar darkdetect rich
      pip uninstall -y wheel 

      # Apply shebang rewrite as done by snapcraft
      
      find $SNAPCRAFT_PART_INSTALL/bin/ -maxdepth 1 -mindepth 1 -type f -executable -exec \
        sed -i                                                                                \
          "s|^#!${SNAPCRAFT_PART_INSTALL}/bin/python3.9$|#!/usr/bin/env python3|" {} \;
      
      # debug
      find $SNAPCRAFT_PART_INSTALL/bin/ -maxdepth 1 -mindepth 1 -type f -executable -exec head -n 1 {} \;