Add Linux support with Nix packaging, Flatpak, desktop integration, and CI/CD

Author: ndarilek

.envrc

@@ -0,0 +1,4 @@
+# Optional: Automatically load Nix development environment when entering this directory
+# Requires direnv (https://direnv.net/) and nix-direnv for automatic shell activation
+# If you don't use direnv, run 'nix develop' manually instead
+use flake

.github/workflows/build.yml

@@ -5,7 +5,7 @@ on:
 permissions:
   contents: write
 jobs:
-  build:
+  build-windows:
     runs-on: windows-latest
     steps:
     - name: Checkout repository
@@ -57,11 +57,46 @@ jobs:
     - name: Upload artifacts
       uses: actions/upload-artifact@v4
       with:
-        name: paperback-build
+        name: paperback-windows
         path: |
           build/paperback.zip
           build/paperback_setup.exe
         retention-days: 30
+
+  build-linux-flatpak:
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-49
+      options: --privileged
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    - uses: flatpak/flatpak-github-actions/flatpak-builder@v6
+      with:
+        bundle: paperback.flatpak
+        manifest-path: io.github.trypsynth.Paperback.yaml
+        cache-key: flatpak-builder-${{ github.sha }}
+
+  release:
+    needs: [build-windows, build-linux-flatpak]
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push'
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+    - name: Download Windows artifacts
+      uses: actions/download-artifact@v4
+      with:
+        name: paperback-windows
+        path: windows-build
+    - name: Download Linux Flatpak
+      uses: actions/download-artifact@v4
+      with:
+        name: paperback-x86_64.flatpak
+        path: linux-build
     - name: Get latest tag reachable from HEAD
       id: get_tag
       shell: bash
@@ -91,8 +126,9 @@ jobs:
           ## Commits since last release
           ${{ steps.release_notes.outputs.commits }}
         files: |
-          build/paperback.zip
-          build/paperback_setup.exe
+          windows-build/paperback.zip
+          windows-build/paperback_setup.exe
+          linux-build/paperback.flatpak
         prerelease: true
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -1,3 +1,8 @@
 build/
 vcpkg/bin/
 web/_site/
+result
+.direnv/
+.flatpak-builder/
+*.flatpak
+repo-flatpak/

CMakeLists.txt

@@ -1,4 +1,9 @@
 cmake_minimum_required(VERSION 3.21)
+
+# Option to use system libraries instead of vcpkg (for Nix, Linux distros, etc.)
+option(USE_SYSTEM_LIBS "Use system libraries instead of vcpkg" OFF)
+
+if(NOT USE_SYSTEM_LIBS)
 set(CMAKE_TOOLCHAIN_FILE "${CMAKE_SOURCE_DIR}/vcpkg/bin/scripts/buildsystems/vcpkg.cmake" CACHE STRING "Vcpkg toolchain file")
 set(VCPKG_MANIFEST_DIR "${CMAKE_SOURCE_DIR}/vcpkg")
 if(WIN32)
@@ -8,6 +13,7 @@ elseif(APPLE)
 else()
 	set(VCPKG_TARGET_TRIPLET "x64-linux" CACHE STRING "Vcpkg triplet")
 endif()
+endif()
 project(paperback VERSION 0.6.1 LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 20)
@@ -28,15 +34,32 @@ if(CLANG_TIDY_EXE)
 	add_custom_target(lint COMMAND ${CLANG_TIDY_EXE} -warnings-as-errors=* --header-filter=^${CMAKE_SOURCE_DIR}/src/ --extra-arg=/EHsc ${ALL_SOURCE_FILES} WORKING_DIRECTORY ${CMAKE_SOURCE_DIR} USES_TERMINAL)
 endif()
 
-find_package(chmlib CONFIG REQUIRED)
+if(USE_SYSTEM_LIBS)
+	# Find system libraries (for Nix, system package managers, etc.)
+	find_library(CHMLIB_LIBRARY NAMES chm REQUIRED)
+	find_path(CHMLIB_INCLUDE_DIR NAMES chm_lib.h REQUIRED)
+	find_library(LEXBOR_LIBRARY NAMES lexbor REQUIRED)
+	find_path(LEXBOR_INCLUDE_DIR NAMES lexbor/html/html.h REQUIRED)
+	find_library(MBEDCRYPTO_LIBRARY NAMES mbedcrypto REQUIRED)
+	find_path(MBEDTLS_INCLUDE_DIR NAMES mbedtls/md.h REQUIRED)
+	find_library(PDFIUM_LIBRARY NAMES pdfium REQUIRED)
+	find_path(PDFIUM_INCLUDE_DIR NAMES fpdfview.h REQUIRED)
+	find_library(PUGIXML_LIBRARY NAMES pugixml REQUIRED)
+	find_path(PUGIXML_INCLUDE_DIR NAMES pugixml.hpp REQUIRED)
+	find_package(wxWidgets REQUIRED base core net)
+else()
+	# Use vcpkg libraries (default)
+	find_package(chmlib CONFIG REQUIRED)
+	find_package(lexbor CONFIG REQUIRED)
+	find_package(MbedTLS CONFIG REQUIRED)
+	find_package(pdfium CONFIG REQUIRED)
+	find_package(pugixml CONFIG REQUIRED)
+	find_package(wxWidgets CONFIG REQUIRED)
+endif()
+
 find_package(Gettext)
-find_package(lexbor CONFIG REQUIRED)
 find_package(maddy CONFIG REQUIRED)
-find_package(MbedTLS CONFIG REQUIRED)
 find_package(nlohmann_json CONFIG REQUIRED)
-find_package(pdfium CONFIG REQUIRED)
-find_package(pugixml CONFIG REQUIRED)
-find_package(wxWidgets CONFIG REQUIRED)
 
 if(GETTEXT_FOUND)
 	find_program(XGETTEXT_EXECUTABLE NAMES xgettext)
@@ -93,17 +116,42 @@ if(WIN32)
 else()
 	add_executable(paperback ${SRC_FILES})
 endif()
-target_link_libraries(paperback PRIVATE
-	chmlib::chm
-	lexbor::lexbor
-	maddy::maddy
-	MbedTLS::mbedcrypto
-	pdfium::pdfium
-	pugixml::pugixml
-	wx::base
-	wx::core
-	wx::net
-)
+
+if(USE_SYSTEM_LIBS)
+	target_include_directories(paperback PRIVATE
+		${CHMLIB_INCLUDE_DIR}
+		${LEXBOR_INCLUDE_DIR}
+		${MBEDTLS_INCLUDE_DIR}
+		${PDFIUM_INCLUDE_DIR}
+		${PUGIXML_INCLUDE_DIR}
+		${wxWidgets_INCLUDE_DIRS}
+	)
+	target_compile_options(paperback PRIVATE ${wxWidgets_CXX_FLAGS})
+	target_compile_definitions(paperback PRIVATE ${wxWidgets_DEFINITIONS})
+	target_link_libraries(paperback PRIVATE
+		${CHMLIB_LIBRARY}
+		${LEXBOR_LIBRARY}
+		maddy::maddy
+		${MBEDCRYPTO_LIBRARY}
+		nlohmann_json::nlohmann_json
+		${PDFIUM_LIBRARY}
+		${PUGIXML_LIBRARY}
+		${wxWidgets_LIBRARIES}
+	)
+else()
+	target_link_libraries(paperback PRIVATE
+		chmlib::chm
+		lexbor::lexbor
+		maddy::maddy
+		MbedTLS::mbedcrypto
+		nlohmann_json::nlohmann_json
+		pdfium::pdfium
+		pugixml::pugixml
+		wx::base
+		wx::core
+		wx::net
+	)
+endif()
 
 if (MSVC)
 	target_compile_options(paperback PRIVATE /W4 /permissive- /WX)
@@ -172,3 +220,37 @@ if(WIN32)
 else()
 	add_custom_target(release DEPENDS package)
 endif()
+
+# Installation rules (Linux desktop integration)
+if(UNIX AND NOT APPLE)
+	# Install binary
+	install(TARGETS paperback DESTINATION bin)
+
+	# Install desktop file
+	install(FILES ${CMAKE_SOURCE_DIR}/paperback.desktop
+	        DESTINATION share/applications)
+
+	# Install icons
+	foreach(size 16 32 48 64 128 256)
+		install(FILES ${CMAKE_SOURCE_DIR}/icons/hicolor/${size}x${size}/apps/paperback.png
+		        DESTINATION share/icons/hicolor/${size}x${size}/apps)
+	endforeach()
+
+	# Install documentation
+	if(TARGET doc)
+		install(FILES ${CMAKE_BINARY_DIR}/readme.html
+		        DESTINATION share/doc/paperback)
+	endif()
+
+	# Install translations
+	if(MO_FILES)
+		foreach(mo_file ${MO_FILES})
+			get_filename_component(mo_dir ${mo_file} DIRECTORY)
+			get_filename_component(lang_dir ${mo_dir} DIRECTORY)
+			get_filename_component(lang ${lang_dir} NAME)
+			install(FILES ${mo_file}
+			        DESTINATION share/locale/${lang}/LC_MESSAGES
+			        RENAME paperback.mo)
+		endforeach()
+	endif()
+endif()

README.md

@@ -12,6 +12,9 @@ Paperback is a lightweight, fast, and accessible ebook and document reader built
 * Command-line file opening for 'Open With' integration.
 
 ## Building
+
+### Windows (VCPKG)
+
 We use VCPKG for managing dependencies. Currently we manage our own VCPKG installation through a submodule. As such, make sure to clone Paperback recursively:
 
 ```batch
@@ -39,6 +42,50 @@ Optional tools:
 - `pandoc` on your `PATH` to generate the HTML readme during the build.
 - `gettext` tools (`xgettext`, `msgfmt`, `msgmerge`) on your `PATH` to generate the translation template and compile translations.
 
+### Linux
+
+For building with CMake, you'll need CMake 3.21+, a C++20 compiler, and dependencies:
+- wxWidgets 3.2+
+- chmlib, lexbor, mbedtls, pdfium, pugixml, nlohmann-json
+
+```bash
+cmake -B build -DUSE_SYSTEM_LIBS=ON -DCMAKE_BUILD_TYPE=Release
+cmake --build build
+sudo cmake --install build
+```
+
+Optional tools:
+- `pandoc` for HTML readme generation
+- `gettext` tools for translations
+
+### Linux (Nix)
+
+**Run directly:**
+```bash
+nix run github:trypsynth/paperback
+```
+
+**Install to profile:**
+```bash
+nix profile install github:trypsynth/paperback
+```
+
+**Build from source:**
+```bash
+# Clone repository
+git clone --recursive https://github.com/trypsynth/paperback
+cd paperback
+
+# Build and run
+nix run .#paperback
+
+# Or build specific outputs:
+nix build .#paperback  # Nix derivation
+
+# Build Flatpak:
+flatpak-builder --force-clean --repo=repo build io.github.trypsynth.Paperback.yaml
+```
+
 ## Contributing
 Contributions are welcome! Whether through issues, pull requests, discussions, or other means, your interest is appreciated.
 

doc/readme.md

@@ -3,7 +3,9 @@
 Paperback is a lightweight, fast, and accessible ebook/document reader designed to make reading fun and seamless, regardless of the file format being used or the user's preferences.
 
 ## System Requirements
-Paperback currently runs on Windows 7 through Windows 11. It's possible it runs on earlier versions of Windows too and/or can be built in such a way that it will, but this hasn't been tested yet. Support for other platforms is planned for a future version.
+**Windows:** Windows 7 through Windows 11. It's possible it runs on earlier versions of Windows too and/or can be built in such a way that it will, but this hasn't been tested yet.
+
+**Linux:** Any modern distribution with glibc 2.38+ (e.g., Ubuntu 24.04+, Fedora 39+, Arch Linux). Alternatively, use the Flatpak version for broader compatibility with older distributions.
 
 ## Features
 * Incredibly fast and standalone.