feat: doxygen docs include hyperlinks to Qt docs

.github/workflows/build.yml

@@ -17,6 +17,7 @@ concurrency:
 env:
   do_vatsim_key: ${{ github.event_name == 'push' }}
   do_symbols:    ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+  do_doxygen:    ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
   qt_version:    6.8.0
   bitrock_version: qt-professional-24.7.0
   bitrock_url:     https://releases.installbuilder.com/installbuilder
@@ -81,16 +82,25 @@ jobs:
           cppcheck --template=gcc --inline-suppr --std=c++17 --enable=style,unusedFunction \
                    -i src/plugins/weatherdata/gfs/g2clib -DCPPCHECK --force --suppressions-list=cppcheck.supp \
                    --library=qt.cfg --library=posix.cfg .
+      - name: Install Qt docs
+        if: ${{ env.do_doxygen == 'true' }}
+        uses: jurplel/install-qt-action@v4
+        with:
+          version: ${{ env.qt_version }}
+          no-qt-binaries: true
+          documentation: true
+          cache: true
       - name: Run doxygen
-        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+        if: ${{ env.do_doxygen == 'true' }}
         working-directory: docs
         run: |
           sudo apt-get -y install doxygen graphviz
           doxygen Doxyfile
         env:
           DOXY_SRC_ROOT: ..
+          DOXY_TAGFILES: ${{ runner.workspace }}/Qt/Docs/Qt-${{ env.qt_version }}
       - name: Upload doxygen
-        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+        if: ${{ env.do_doxygen == 'true' }}
         uses: actions/upload-pages-artifact@v3
         with:
           path: docs/html/

docs/Doxyfile

@@ -2199,6 +2199,25 @@ SKIP_FUNCTION_MACROS   = YES
 # the path). If a tag file is not located in the directory in which doxygen is
 # run, you must also specify the path to the tagfile here.
 
+TAGFILES               = $(DOXY_TAGFILES)/qdoc/qdoc.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qmake/qmake.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtconcurrent/qtconcurrent.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtcore/qtcore.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtdbus/qtdbus.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtgui/qtgui.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtnetwork/qtnetwork.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtopengl/qtopengl.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqml/qtqml.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqmlcore/qtqmlcore.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqmlmodels/qtqmlmodels.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqmltest/qtqmltest.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqmlworkerscript/qtqmlworkerscript.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtqmlxmllistmodel/qtqmlxmllistmodel.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtsvg/qtsvg.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qttestlib/qttestlib.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtwidgets/qtwidgets.tags=http://doc.qt.io/qt-6/ \
+                         $(DOXY_TAGFILES)/qtxml/qtxml.tags=http://doc.qt.io/qt-6/
+
 # When a file name is specified after GENERATE_TAGFILE, doxygen will create a
 # tag file that is based on the input files it reads. See section "Linking to
 # external documentation" for more information about the usage of tag files.