feat(linux): 新增基于 GDBus 的 StatusNotifierItem 托盘后端，替代失效的 libappindicator 链条

3rd/dependencies.cmake

@@ -549,9 +549,36 @@ if(EUI_ENABLE_MARKDOWN)
 endif()
 
 if(UNIX AND NOT APPLE)
+    # eui_begin/end_quiet_third_party_config above replaces PKG_CONFIG_EXECUTABLE
+    # with a stub and then FORCE-restores the (usually empty) pre-stub value
+    # into the cache, which poisons find_program for the rest of the run.
+    # Platform tray detection below genuinely needs the real pkg-config, so
+    # drop the poisoned cache entry and let FindPkgConfig search again.
+    unset(PKG_CONFIG_EXECUTABLE CACHE)
     find_package(PkgConfig QUIET)
     if(PkgConfig_FOUND)
+        # SNI (StatusNotifierItem) backend: only glib/gio, present on every
+        # desktop Linux. Preferred over the GTK + libappindicator chain.
+        # gobject-2.0 is listed explicitly: gio-2.0.pc normally pulls it in
+        # via Requires, but naming it keeps the link line complete even with
+        # stripped-down or pkgconf-incompatible .pc files.
+        pkg_check_modules(EUI_GIO QUIET gio-2.0 gobject-2.0 glib-2.0)
+        # Legacy chain. libappindicator upstream is unmaintained and the
+        # Ayatana fork renamed the module, so this only fires on hosts that
+        # still ship the old build. Kept as a fallback; the SNI branch takes
+        # precedence in CMakeLists.txt.
         pkg_check_modules(EUI_APPINDICATOR QUIET appindicator3-0.1)
         pkg_check_modules(EUI_GTK3 QUIET gtk+-3.0)
     endif()
+    # Fail loudly instead of silently compiling the empty tray stub: a Linux
+    # build with EUI_TRAY_HAS_BACKEND=0 looks successful but has no tray.
+    if(EUI_ENABLE_TRAY AND NOT EUI_GIO_FOUND
+       AND NOT (EUI_APPINDICATOR_FOUND AND EUI_GTK3_FOUND))
+        message(FATAL_ERROR
+            "Linux tray support requires glib/gio (gio-2.0, preferred, SNI backend) "
+            "or GTK3 + libappindicator (legacy fallback), detected via pkg-config, "
+            "but none of them were found. Install your distribution's glib2 development "
+            "package (e.g. glib2-devel / libglib2.0-dev), or configure with "
+            "-DEUI_ENABLE_TRAY=OFF to build without tray support.")
+    endif()
 endif()

CMakeLists.txt

@@ -20,6 +20,7 @@ option(EUI_BUILD_SHARED "Build eui_neo as a shared library instead of a static l
 option(EUI_ENABLE_INSTALL "Install EUI-NEO library, headers, and CMake package files." ${EUI_NEO_TOP_LEVEL_DEFAULT})
 option(EUI_ENABLE_MODULES "Build optional EUI-NEO modules when their directories are present." ON)
 option(EUI_VULKAN_LOW_LATENCY_PRESENT "Prefer low-latency Vulkan presentation when available." OFF)
+option(EUI_ENABLE_TRAY "Enable the system tray backend. On Linux, configuration fails when neither glib/gio (SNI) nor GTK3 + libappindicator is available; turn this OFF to build without tray support." ON)
 
 set(EUI_DEFAULT_WINDOW_BACKEND "glfw")
 set(EUI_DEFAULT_RENDER_BACKEND "opengl")
@@ -336,7 +337,18 @@ if(WIN32)
 elseif(APPLE)
     target_compile_definitions(eui_neo PUBLIC EUI_TRAY_APPKIT=1)
     target_link_libraries(eui_neo PUBLIC "-framework Cocoa" objc)
-elseif(UNIX AND EUI_APPINDICATOR_FOUND AND EUI_GTK3_FOUND)
+elseif(UNIX AND EUI_ENABLE_TRAY AND EUI_GIO_FOUND)
+    # StatusNotifierItem backend: speaks the freedesktop SNI + DBusMenu
+    # protocols over GDBus, needing only glib/gio (see tray_bridge.c). This is
+    # the default because glib is ubiquitous and libappindicator is dead.
+    target_compile_definitions(eui_neo PUBLIC EUI_TRAY_SNI=1)
+    target_include_directories(eui_neo PUBLIC ${EUI_GIO_INCLUDE_DIRS})
+    target_compile_options(eui_neo PRIVATE ${EUI_GIO_CFLAGS_OTHER})
+    target_link_directories(eui_neo PUBLIC ${EUI_GIO_LIBRARY_DIRS})
+    target_link_libraries(eui_neo PUBLIC ${EUI_GIO_LIBRARIES})
+elseif(UNIX AND EUI_ENABLE_TRAY AND EUI_APPINDICATOR_FOUND AND EUI_GTK3_FOUND)
+    # Legacy fallback: GTK3 + libappindicator. Only reached when glib/gio is
+    # absent but the old stack is present.
     target_compile_definitions(eui_neo PUBLIC EUI_TRAY_APPINDICATOR=1)
     target_include_directories(eui_neo PUBLIC ${EUI_APPINDICATOR_INCLUDE_DIRS} ${EUI_GTK3_INCLUDE_DIRS})
     target_compile_options(eui_neo PRIVATE ${EUI_APPINDICATOR_CFLAGS_OTHER} ${EUI_GTK3_CFLAGS_OTHER})