Adding creating app bundle for cmake script on MacOS

[meoow]

Prior to 3.0.0, the qmake build script had the ability to create the app bundle, while the cmake script didn't included the clauses for doing the same - as of now it still simply creates an executable just like it on Linux.

Since 3.x has dropped the qmake script, I think it'd be nice to add that feature back and put it into cmake script. I already figured out how to do it and I have tested it on my machine. But I'm not a cmake expert, so I think I'd better just post the code here instead of creating a pull request.

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index b75ea5d..70ddc66 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -28,7 +28,19 @@ if (WIN32)
     list(APPEND SOURCE ss-qt5.rc)
 endif()

-add_executable(${APP_NAME} ${SOURCE})
+if (APPLE)
+    set(MACOSX_BUNDLE_BUNDLE_NAME ${PROJECT_NAME})
+    set(MACOSX_BUNDLE_GUI_IDENTIFIER "org.shadowsocks.shadowsocks-qt5")
+    set(MACOSX_BUNDLE_INFO_STRING "A cross-platform shadowsocks GUI client")
+    set(MACOSX_BUNDLE_ICON_FILE "shadowsocks-qt5.icns")
+    set(MACOSX_BUNDLE_LONG_VERSION_STRING ${PROJECT_VERSION})
+    set(MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION})
+    set(MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION})
+    add_executable(${APP_NAME} MACOSX_BUNDLE ${SOURCE}
+        "icons/shadowsocks-qt5.icns")
+else()
+    add_executable(${APP_NAME} ${SOURCE})
+endif()

 target_link_libraries(${APP_NAME}
     PUBLIC Qt5::Core
@@ -47,10 +59,24 @@ if (UNIX AND NOT APPLE)
     target_link_libraries(${APP_NAME} PRIVATE Qt5::DBus)
 endif()

-install(TARGETS ${APP_NAME}
+if (APPLE)
+    set_target_properties(
+        ${APP_NAME}
+        PROPERTIES
+        RESOURCE "icons/shadowsocks-qt5.icns"
+        )
+    add_custom_command(
+        TARGET ${APP_NAME}
+        POST_BUILD
+        COMMAND macdeployqt ${APP_NAME}.app
+        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/src
+        )
+else()
+    install(TARGETS ${APP_NAME}
     RUNTIME DESTINATION bin)
+endif()

-if (UNIX)
+if (UNIX AND NOT APPLE)
     install(FILES shadowsocks-qt5.desktop DESTINATION share/applications)
     install(FILES icons/shadowsocks-qt5.png DESTINATION share/icons/hicolor/512x512/apps)
 endif()

[librehat]

I'm not familiar with Mac OS. Is macdeployqt part of official Qt offer? I think you can create a PR so others can also comment, thanks