i18n: Add wxGUI screenshot capture and Weblate uploader

.github/workflows/periodic_update.yml

@@ -171,3 +171,9 @@ jobs:
         env:
           STEPS_CPR_OUTPUTS_PULL_REQUEST_NUMBER: ${{ steps.cpr.outputs.pull-request-number }}
           STEPS_CPR_OUTPUTS_PULL_REQUEST_URL: ${{ steps.cpr.outputs.pull-request-url }}
+  wxgui-screenshots:
+    # The update-i18n job builds without the GUI, so the screenshots are
+    # captured in a separate workflow (also run for changes to it).
+    permissions:
+      contents: read
+    uses: $/.github/workflows/wxgui_screenshots.yml

.github/workflows/wxgui_screenshots.yml

@@ -0,0 +1,59 @@
+---
+name: wxGUI screenshots
+
+# Captures wxGUI screenshots with the translatable strings they show, for
+# example to give translators visual context on Weblate. The result is only
+# uploaded as an artifact; see utils/weblate_screenshots/weblate_upload.py for
+# synchronizing it to Weblate.
+on:
+  workflow_call:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - ".github/workflows/wxgui_screenshots.yml"
+      - "utils/weblate_screenshots/**"
+
+permissions: {}
+
+jobs:
+  capture:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - name: Install dependencies
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y ninja-build gettext python3-wxgtk4.0 \
+            xvfb imagemagick librsvg2-common
+          LC_ALL=C.UTF-8 sudo add-apt-repository -y ppa:ubuntugis/ubuntugis-unstable
+          sudo apt-get update -y
+          xargs -a <(awk '! /^ *(#|$)/' ".github/workflows/apt.txt") -r -- \
+              sudo apt-get install -y --no-install-recommends --no-install-suggests
+      - name: Configure
+        run: |
+          cmake -S "${GITHUB_WORKSPACE}" -B "${GITHUB_WORKSPACE}/build" -G Ninja -DWITH_DOCS=OFF
+      - name: Build
+        run: cmake --build build -j"$(nproc)"
+      - name: Capture screenshots
+        env:
+          GRASS_CONFIG_DIR: ${{ runner.temp }}/grass-config
+          LANG: C.UTF-8
+        run: |
+          export PATH="${GITHUB_WORKSPACE}/build/output/bin:${PATH}"
+          mkdir -p "${GRASS_CONFIG_DIR}"
+          # A fixed project path keeps the screenshots identical between runs.
+          grass -e -c XY /tmp/grassdata/screenshots
+          xvfb-run -s "-screen 0 1600x1200x24" \
+            grass /tmp/grassdata/screenshots/PERMANENT --exec \
+            python3 utils/weblate_screenshots/wxgui_capture.py \
+            --pot locale/templates/grasswxpy.pot --output wxgui-screenshots
+      - name: Upload screenshots
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: wxgui-screenshots
+          path: wxgui-screenshots
+          retention-days: 30