Add Linux release (AppImage) + native build smoke test

.github/workflows/ci.yml

@@ -119,3 +119,45 @@ jobs:
       - name: Build macOS (debug, no codesign)
         working-directory: patch_app
         run: flutter build macos --debug
+
+  # Linux counterpart of build-macos: compiles patch_core as a cdylib and links
+  # it into the GTK app the same way a release build does, so Linux-specific
+  # link/plugin regressions fail the PR instead of first surfacing at
+  # release-tag time. Also the only CI job that compiles patch_core's Linux
+  # `cfg(target_os = "linux")` paths (ALSA/midir). Keep the apt deps in step
+  # with release.yml's "Install Linux build deps".
+  build-linux:
+    name: Linux — native build smoke test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Linux build deps
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang cmake ninja-build pkg-config \
+            libgtk-3-dev libasound2-dev \
+            libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
+
+      # cargokit invokes cargo during `flutter build`, so the same pinned Rust
+      # as the `rust` job must be present.
+      - name: Install Rust 1.95.0
+        uses: dtolnay/rust-toolchain@1.95.0
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: Install Flutter 3.44.1
+        uses: subosito/flutter-action@v2
+        with:
+          flutter-version: 3.44.1
+          channel: stable
+          cache: true
+
+      - name: Pub get
+        working-directory: patch_app
+        run: flutter pub get
+
+      # Debug build: we only need compile-and-link to succeed, not an artifact.
+      - name: Build Linux (debug)
+        working-directory: patch_app
+        run: flutter build linux --debug

.github/workflows/release.yml

@@ -11,7 +11,8 @@ name: Release
 # (CODE_SIGN_IDENTITY = "-"), so first launch after opening the DMG shows a
 # Gatekeeper warning (right-click → Open, or
 # `xattr -dr com.apple.quarantine Patch.app`); Windows is unsigned, so the
-# installer trips SmartScreen ("More info → Run anyway"). Real codesigning/
+# installer trips SmartScreen ("More info → Run anyway"); Linux ships a
+# portable AppImage (`chmod +x` then run — no install step). Real codesigning/
 # notarization would need certs added as repo secrets — out of scope here.
 #
 # NB the release name comes from the tag. Keep the tag aligned with
@@ -40,10 +41,24 @@ jobs:
             platform: macos
           - os: windows-latest
             platform: windows
+          - os: ubuntu-latest
+            platform: linux
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
 
+      # Flutter Linux desktop needs GTK + the CMake/Ninja toolchain; patch-core
+      # links ALSA (midir) and audioplayers_linux links GStreamer. macOS/Windows
+      # get their MIDI/audio backends from the OS (CoreMIDI/WinMM), so this is
+      # Linux-only. Keep in step with ci.yml's build-linux job.
+      - name: Install Linux build deps
+        if: matrix.platform == 'linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang cmake ninja-build pkg-config \
+            libgtk-3-dev libasound2-dev \
+            libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
+
       # cargokit compiles patch-core (cdylib/staticlib) during `flutter build`,
       # so the Rust toolchain must be present. macOS links CoreMIDI, Windows
       # WinMM — neither needs an extra system package (ALSA is Linux-only).
@@ -125,13 +140,56 @@ jobs:
             /DMyOutputDir="${{ github.workspace }}" `
             patch_app\windows\installer\patch.iss
 
+      # ── Linux ────────────────────────────────────────────────────────────
+      - name: Build Linux
+        if: matrix.platform == 'linux'
+        working-directory: patch_app
+        run: flutter build linux --release
+
+      - name: Package Linux (AppImage)
+        if: matrix.platform == 'linux'
+        working-directory: patch_app
+        # A portable AppImage (single executable, no install) mirrors the
+        # "download & run" UX of the macOS .dmg / Windows .exe. appimagetool is
+        # itself an AppImage; APPIMAGE_EXTRACT_AND_RUN avoids needing FUSE on the
+        # runner.
+        env:
+          APPIMAGE_EXTRACT_AND_RUN: 1
+        run: |
+          BUNDLE=build/linux/x64/release/bundle
+          APPDIR=AppDir
+          rm -rf "$APPDIR"
+          mkdir -p "$APPDIR/usr/bin"
+          cp -r "$BUNDLE"/. "$APPDIR/usr/bin/"
+          cp assets/icon/icon_master.png "$APPDIR/patch.png"
+          cat > "$APPDIR/patch.desktop" <<'EOF'
+          [Desktop Entry]
+          Type=Application
+          Name=Patch
+          Exec=patch_app
+          Icon=patch
+          Categories=AudioVideo;Network;Utility;
+          Terminal=false
+          EOF
+          cat > "$APPDIR/AppRun" <<'EOF'
+          #!/bin/bash
+          HERE="$(dirname "$(readlink -f "$0")")"
+          exec "$HERE/usr/bin/patch_app" "$@"
+          EOF
+          chmod +x "$APPDIR/AppRun"
+          wget -q https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-x86_64.AppImage
+          chmod +x appimagetool-x86_64.AppImage
+          ARCH=x86_64 ./appimagetool-x86_64.AppImage "$APPDIR" \
+            "$GITHUB_WORKSPACE/Patch-${{ steps.version.outputs.version }}-linux-x86_64.AppImage"
+
       - name: Upload build artifact
         uses: actions/upload-artifact@v4
         with:
           name: patch-${{ matrix.platform }}
           path: |
             Patch-*.dmg
             Patch-*.exe
+            Patch-*.AppImage
           if-no-files-found: error
 
   release:
@@ -152,5 +210,6 @@ jobs:
           files: |
             artifacts/*.dmg
             artifacts/*.exe
+            artifacts/*.AppImage
           generate_release_notes: true
           draft: true

README.md

@@ -87,11 +87,12 @@ flutter run -d macos
 # iOS / iPad (device or simulator)
 flutter run -d <device-id>
 
-# Windows / Linux — generate the platform folder first if missing
-flutter create --platforms=windows .   # or linux
+# Windows / Linux (platform folders are committed, like macOS/iOS)
 flutter run -d windows                 # or linux
 ```
 
+Prebuilt downloads for tagged releases are attached to the [GitHub Releases](https://github.com/vk0eppel/Patch/releases) page: a `.dmg` (macOS), an installer `.exe` (Windows), and a portable `.AppImage` (Linux — `chmod +x` then run, no install step). All are unsigned; see the notes in `.github/workflows/release.yml`.
+
 The first build is slow because Cargokit cross-compiles the Rust engine for the target. Subsequent runs are fast.
 
 The engine generates a `patch.toml` config file on first run in the platform data directory:

patch_app/.metadata

@@ -24,6 +24,9 @@ migration:
     - platform: windows
       create_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
       base_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
+    - platform: linux
+      create_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
+      base_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
 
   # User provided section
 

patch_app/lib/main.dart

@@ -52,6 +52,18 @@ bool _positionOnScreen(Offset pos, Size windowSize) {
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
+  // TEMP DEADZONE PROBE — prints every pointer-down that reaches Flutter's
+  // engine, with window-local coords. If clicking the Audio tab's dead centre
+  // prints nothing, the event is swallowed natively before Flutter. Remove.
+  WidgetsBinding.instance.pointerRouter.addGlobalRoute((event) {
+    if (event is PointerDownEvent) {
+      debugPrint(
+        'PROBE pointerDown  x=${event.position.dx.toStringAsFixed(1)} '
+        'y=${event.position.dy.toStringAsFixed(1)}',
+      );
+    }
+  });
+
   // Lock to landscape on iPad — the fixed-width multi-panel layout is unusable
   // in portrait. Done before runApp so it's in effect for the first frame. No-op
   // on desktop and iPhone (see shouldLockLandscape).

patch_app/linux/.gitignore

@@ -0,0 +1 @@
+flutter/ephemeral

patch_app/linux/CMakeLists.txt

@@ -0,0 +1,128 @@
+# Project-level configuration.
+cmake_minimum_required(VERSION 3.13)
+project(runner LANGUAGES CXX)
+
+# The name of the executable created for the application. Change this to change
+# the on-disk name of your application.
+set(BINARY_NAME "patch_app")
+# The unique GTK application identifier for this application. See:
+# https://wiki.gnome.org/HowDoI/ChooseApplicationID
+set(APPLICATION_ID "com.patch.app")
+
+# Explicitly opt in to modern CMake behaviors to avoid warnings with recent
+# versions of CMake.
+cmake_policy(SET CMP0063 NEW)
+
+# Load bundled libraries from the lib/ directory relative to the binary.
+set(CMAKE_INSTALL_RPATH "$ORIGIN/lib")
+
+# Root filesystem for cross-building.
+if(FLUTTER_TARGET_PLATFORM_SYSROOT)
+  set(CMAKE_SYSROOT ${FLUTTER_TARGET_PLATFORM_SYSROOT})
+  set(CMAKE_FIND_ROOT_PATH ${CMAKE_SYSROOT})
+  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+endif()
+
+# Define build configuration options.
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+  set(CMAKE_BUILD_TYPE "Debug" CACHE
+    STRING "Flutter build mode" FORCE)
+  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS
+    "Debug" "Profile" "Release")
+endif()
+
+# Compilation settings that should be applied to most targets.
+#
+# Be cautious about adding new options here, as plugins use this function by
+# default. In most cases, you should add new options to specific targets instead
+# of modifying this function.
+function(APPLY_STANDARD_SETTINGS TARGET)
+  target_compile_features(${TARGET} PUBLIC cxx_std_14)
+  target_compile_options(${TARGET} PRIVATE -Wall -Werror)
+  target_compile_options(${TARGET} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:-O3>")
+  target_compile_definitions(${TARGET} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:NDEBUG>")
+endfunction()
+
+# Flutter library and tool build rules.
+set(FLUTTER_MANAGED_DIR "${CMAKE_CURRENT_SOURCE_DIR}/flutter")
+add_subdirectory(${FLUTTER_MANAGED_DIR})
+
+# System-level dependencies.
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTK REQUIRED IMPORTED_TARGET gtk+-3.0)
+
+# Application build; see runner/CMakeLists.txt.
+add_subdirectory("runner")
+
+# Run the Flutter tool portions of the build. This must not be removed.
+add_dependencies(${BINARY_NAME} flutter_assemble)
+
+# Only the install-generated bundle's copy of the executable will launch
+# correctly, since the resources must in the right relative locations. To avoid
+# people trying to run the unbundled copy, put it in a subdirectory instead of
+# the default top-level location.
+set_target_properties(${BINARY_NAME}
+  PROPERTIES
+  RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/intermediates_do_not_run"
+)
+
+
+# Generated plugin build rules, which manage building the plugins and adding
+# them to the application.
+include(flutter/generated_plugins.cmake)
+
+
+# === Installation ===
+# By default, "installing" just makes a relocatable bundle in the build
+# directory.
+set(BUILD_BUNDLE_DIR "${PROJECT_BINARY_DIR}/bundle")
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+  set(CMAKE_INSTALL_PREFIX "${BUILD_BUNDLE_DIR}" CACHE PATH "..." FORCE)
+endif()
+
+# Start with a clean build bundle directory every time.
+install(CODE "
+  file(REMOVE_RECURSE \"${BUILD_BUNDLE_DIR}/\")
+  " COMPONENT Runtime)
+
+set(INSTALL_BUNDLE_DATA_DIR "${CMAKE_INSTALL_PREFIX}/data")
+set(INSTALL_BUNDLE_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib")
+
+install(TARGETS ${BINARY_NAME} RUNTIME DESTINATION "${CMAKE_INSTALL_PREFIX}"
+  COMPONENT Runtime)
+
+install(FILES "${FLUTTER_ICU_DATA_FILE}" DESTINATION "${INSTALL_BUNDLE_DATA_DIR}"
+  COMPONENT Runtime)
+
+install(FILES "${FLUTTER_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+  COMPONENT Runtime)
+
+foreach(bundled_library ${PLUGIN_BUNDLED_LIBRARIES})
+  install(FILES "${bundled_library}"
+    DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+    COMPONENT Runtime)
+endforeach(bundled_library)
+
+# Copy the native assets provided by the build.dart from all packages.
+set(NATIVE_ASSETS_DIR "${PROJECT_BUILD_DIR}native_assets/linux/")
+install(DIRECTORY "${NATIVE_ASSETS_DIR}"
+   DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+   COMPONENT Runtime)
+
+# Fully re-copy the assets directory on each build to avoid having stale files
+# from a previous install.
+set(FLUTTER_ASSET_DIR_NAME "flutter_assets")
+install(CODE "
+  file(REMOVE_RECURSE \"${INSTALL_BUNDLE_DATA_DIR}/${FLUTTER_ASSET_DIR_NAME}\")
+  " COMPONENT Runtime)
+install(DIRECTORY "${PROJECT_BUILD_DIR}/${FLUTTER_ASSET_DIR_NAME}"
+  DESTINATION "${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
+
+# Install the AOT library on non-Debug builds only.
+if(NOT CMAKE_BUILD_TYPE MATCHES "Debug")
+  install(FILES "${AOT_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+    COMPONENT Runtime)
+endif()