Fix Qt on Mac bundle generation

src/qt/CMakeLists.txt

@@ -189,6 +189,71 @@ if (WIN32)
     qt_import_plugins(plat INCLUDE Qt${QT_MAJOR}::QWindowsIntegrationPlugin Qt${QT_MAJOR}::QICOPlugin QWindowsVistaStylePlugin)
 endif()
 
+# loads a macro to install Qt5 plugins on macOS
+# based on https://stackoverflow.com/questions/35612687/cmake-macos-x-bundle-with-bundleutiliies-for-qt-application
+macro(install_qt5_plugin _qt_plugin_name _qt_plugins_var _prefix)
+    get_target_property(_qt_plugin_path "${_qt_plugin_name}" LOCATION)
+    if(EXISTS "${_qt_plugin_path}")
+        get_filename_component(_qt_plugin_file "${_qt_plugin_path}" NAME)
+        get_filename_component(_qt_plugin_type "${_qt_plugin_path}" PATH)
+        get_filename_component(_qt_plugin_type "${_qt_plugin_type}" NAME)
+        set(_qt_plugin_dest "${_prefix}/PlugIns/${_qt_plugin_type}")
+        install(FILES "${_qt_plugin_path}"
+            DESTINATION "${_qt_plugin_dest}")
+        set(${_qt_plugins_var}
+            "${${_qt_plugins_var}};\$ENV{DEST_DIR}\${CMAKE_INSTALL_PREFIX}/${_qt_plugin_dest}/${_qt_plugin_file}")
+    else()
+        message(FATAL_ERROR "QT plugin ${_qt_plugin_name} not found")
+    endif()
+endmacro()
+
+if (APPLE AND CMAKE_MACOSX_BUNDLE)
+    set(prefix "$<TARGET_FILE_NAME:86Box>/Contents")
+    set(INSTALL_RUNTIME_DIR "${prefix}/MacOS")
+    set(INSTALL_CMAKE_DIR "${prefix}/Resources")
+
+    # using the install_qt5_plugin to add Qt plugins into the macOS app bundle
+    if (USE_QT6)
+        install_qt5_plugin("Qt6::QCocoaIntegrationPlugin" QT_PLUGINS ${prefix})
+    else()
+        install_qt5_plugin("Qt5::QCocoaIntegrationPlugin" QT_PLUGINS ${prefix})
+        install_qt5_plugin("Qt5::QMacStylePlugin" QT_PLUGINS ${prefix})
+        install_qt5_plugin("Qt5::QICOPlugin" QT_PLUGINS ${prefix})
+        install_qt5_plugin("Qt5::QICNSPlugin" QT_PLUGINS ${prefix})
+    endif()
+    
+    file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/qt.conf"
+        "[Paths]\nPlugins = ${_qt_plugin_dir}\n")
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/qt.conf"
+        DESTINATION "${INSTALL_CMAKE_DIR}")
+
+    # Note Mac specific extension .app
+    set(APPS "\$ENV{DESTDIR}\${CMAKE_INSTALL_PREFIX}/$<TARGET_FILE_NAME:86Box>")
+
+    # Directories to look for dependencies
+    set(DIRS "${CMAKE_BINARY_DIR}")
+
+    # Path used for searching by FIND_XXX(), with appropriate suffixes added
+    if(CMAKE_PREFIX_PATH)
+        foreach(dir ${CMAKE_PREFIX_PATH})
+            list(APPEND DIRS "${dir}/bin" "${dir}/lib")
+        endforeach()
+    endif()
+
+    # Append Qt's lib folder which is two levels above Qt5Widgets_DIR
+    list(APPEND DIRS "${Qt5Widgets_DIR}/../..")
+
+    include(InstallRequiredSystemLibraries)
+
+    message(STATUS "APPS: ${APPS}")
+    message(STATUS "QT_PLUGINS: ${QT_PLUGINS}")
+    message(STATUS "DIRS: ${DIRS}")
+
+    install(CODE "
+        include(BundleUtilities)
+        fixup_bundle(\"${APPS}\" \"${QT_PLUGINS}\" \"${DIRS}\")")
+endif()
+
 if (UNIX AND NOT APPLE)
     find_package(X11 REQUIRED)
     target_link_libraries(ui PRIVATE X11::X11)