feat: add Sparkle framework support for app updater on macOS

Author: mfisher31

CMakeLists.txt

@@ -7,6 +7,9 @@ set(PROJECT_VERSION_SUFFIX "b2")
 set(PROJECT_VERSION_FULL "${PROJECT_VERSION}${PROJECT_VERSION_SUFFIX}")
 
 include(cmake/Element.cmake)
+if(ELEMENT_ENABLE_UPDATER)
+    include(cmake/FindSparkle.cmake)
+endif()
 include(cmake/FindJack.cmake)
 
 add_subdirectory(deps/sol2 EXCLUDE_FROM_ALL)
@@ -79,6 +82,15 @@ target_link_libraries(element_app PRIVATE kv::element)
 if(NOT APPLE)
     install(TARGETS element_app DESTINATION ${CMAKE_INSTALL_BINDIR})
 else()
+    if(ELEMENT_ENABLE_UPDATER)
+        target_link_libraries(element_app PRIVATE ${SPARKLE_FRAMEWORK})
+        add_custom_command(TARGET element_app POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy_directory
+                "${SPARKLE_FRAMEWORK}"
+                "$<TARGET_BUNDLE_CONTENT_DIR:element_app>/Frameworks/Sparkle.framework"
+        COMMENT "Copying Sparkle.framework into app bundle"
+    )
+    endif()
     install(TARGETS element_app
         BUNDLE DESTINATION "Applications"
         COMPONENT "Standalone")

cmake/FindSparkle.cmake

@@ -0,0 +1,18 @@
+if(APPLE)    
+    set(SPARKLE_VERSION "2.8.1" CACHE STRING "Sparkle version to download")
+    
+    FetchContent_Declare(
+        sparkle
+        URL https://github.com/Sparkle-project/Sparkle/releases/download/${SPARKLE_VERSION}/Sparkle-${SPARKLE_VERSION}.tar.xz
+        DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+    )
+    
+    FetchContent_MakeAvailable(sparkle)
+    message(STATUS "Searching for Sparkle in: ${sparkle_SOURCE_DIR}")
+    find_library(SPARKLE_FRAMEWORK Sparkle HINTS ${sparkle_SOURCE_DIR})
+    if(SPARKLE_FRAMEWORK)
+        message(STATUS "Found Sparkle: ${SPARKLE_FRAMEWORK}")
+    else()
+        message(FATAL_ERROR "Sparkle framework not found")
+    endif()
+endif()