ci: add AppImage build workflow

.github/workflows/build.yml

@@ -180,7 +180,7 @@ jobs:
       - name: Extract build artifacts
         run: |
           ARTIFACT_DIR=$(find temp_artifacts -maxdepth 1 -type d -name "gswatcher_${{ env.APP_VERSION }}+${{ matrix.image }}.*" | head -n 1)
-          mkdir ${{ env.OUTDIR }}
+          mkdir -p ${{ env.OUTDIR }}
           cp -r "$ARTIFACT_DIR"/* ${{ env.OUTDIR }}/
           rm -rf temp_artifacts
 
@@ -220,11 +220,79 @@ jobs:
             }}
           path: ${{ env.OUTDIR }}
 
+  build-appimage:
+    strategy:
+      matrix:
+        include:
+          - { image: ubuntu-24.04,     arch: x86_64  }
+          - { image: ubuntu-24.04-arm, arch: aarch64 }
+
+    runs-on: ${{ matrix.image }}
+
+    needs: build-linux
+
+    env:
+      OUTDIR: AppDir
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Extract version
+        run: |
+          VERSION=$(grep -oP "version: '\K[0-9]+\.[0-9]+\.[0-9]+" meson.build)
+          echo "APP_VERSION=$VERSION" >> $GITHUB_ENV
+
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: gswatcher_${{ env.APP_VERSION }}+${{ matrix.image }}.*
+          path: temp_artifacts
+
+      - name: Extract build artifacts
+        run: |
+          ARTIFACT_DIR=$(find temp_artifacts -maxdepth 1 -type d -name "gswatcher_${{ env.APP_VERSION }}+${{ matrix.image }}.*" | head -n 1)
+          mkdir -p ${{ env.OUTDIR }}/usr
+          cp -r "$ARTIFACT_DIR"/* ${{ env.OUTDIR }}/usr/
+          rm -rf temp_artifacts
+
+      - name: Setup dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libfuse2t64 libgee-0.8-dev libgtk-4-dev libadwaita-1-dev liblua5.4-dev libgeoip-dev
+
+      - name: Get linuxdeploy
+        run: |
+          wget -c "https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-${{ matrix.arch }}.AppImage" -O linuxdeploy.AppImage
+          chmod +x linuxdeploy.AppImage
+          wget -c "https://raw.githubusercontent.com/linuxdeploy/linuxdeploy-plugin-gtk/master/linuxdeploy-plugin-gtk.sh"
+          chmod +x linuxdeploy-plugin-gtk.sh
+
+      - name: Build AppImage
+        run: |
+          export OUTPUT="gswatcher-${{ env.APP_VERSION }}-${{ matrix.arch }}.AppImage"
+          export DEPLOY_GTK_VERSION=4
+          ./linuxdeploy.AppImage --appdir ${{ env.OUTDIR }} --plugin gtk --output appimage --icon-file "${{ env.OUTDIR }}/usr/share/icons/hicolor/512x512/apps/io.github.lxndr.gswatcher.png" --desktop-file "${{ env.OUTDIR }}/usr/share/applications/io.github.lxndr.gswatcher.desktop"
+          chmod +x "${{ env.OUTDIR }}/AppRun"
+          chmod +x "${{ env.OUTDIR }}/AppRun.wrapped"
+
+      - name: Upload AppImage artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: >-
+            ${{
+              (github.event_name == 'pull_request' &&
+                format('gswatcher_{0}+{1}.pr{2}.appimage.{3}.build{4}', env.APP_VERSION, matrix.image, github.event.number, matrix.arch, github.run_number)) ||
+                format('gswatcher_{0}+{1}.appimage.{2}.build{3}', env.APP_VERSION, matrix.image, matrix.arch, github.run_number)
+            }}
+          path: gswatcher-${{ env.APP_VERSION }}-${{ matrix.arch }}.AppImage
+
   release:
     runs-on: ubuntu-24.04
 
     needs:
       - create-windows-portable
+      - build-appimage
 
     if: ${{ github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') }}
 
@@ -235,6 +303,12 @@ jobs:
           pattern: gswatcher_*+windows-portable.*
           path: ./artifacts
 
+      - name: Download AppImage artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: gswatcher_*+*.appimage.*
+          path: ./artifacts
+
       - name: Release
         uses: softprops/action-gh-release@v1
         with:

gswatcher.code-workspace

@@ -8,6 +8,7 @@
 		"cSpell.words": [
 			"absindex",
 			"ADWAITA",
+			"APPDIR",
 			"appimage",
 			"appimagetool",
 			"APPNAME",
@@ -32,6 +33,7 @@
 			"checkstring",
 			"checktype",
 			"checkudata",
+			"clangarm",
 			"cmpint",
 			"cmpmem",
 			"cmpstr",
@@ -105,10 +107,12 @@
 			"launchable",
 			"lauxlib",
 			"libadwaita",
+			"libfuse",
 			"libgee",
 			"libgeoip",
 			"liblua",
 			"LIGHTUSERDATA",
+			"linuxdeploy",
 			"listitem",
 			"loadstring",
 			"lstring",