Enable libsyncthing by default on mobile platforms

* Users are likely most likely not running Syncthing outside the app on
  mobile platforms.
* Also use libsyncthing by default when it is being built so this is
  actually effectively enabling support for libsyncthing.

CMakeLists.txt

@@ -21,11 +21,13 @@ set(NETWORK_INFORMATION_SUPPORT ON)
 project(${META_PROJECT_NAME})
 enable_testing()
 
-# disable experimental Qt Quick GUI by default except on mobile platforms
+# disable experimental Qt Quick GUI by default except on mobile platforms, enable libsyncthing by default
 if (ANDROID OR IOS)
     set(QUICK_GUI_ENABLED_BY_DEFAULT ON)
+    set(LIBSYNCTHING_DISABLED_BY_DEFAULT OFF)
 else ()
     set(QUICK_GUI_ENABLED_BY_DEFAULT OFF)
+    set(LIBSYNCTHING_DISABLED_BY_DEFAULT ON)
 endif ()
 
 # disable KDE integration under Android, Windows and MacOS by default
@@ -54,7 +56,7 @@ if (KF_PACKAGE_PREFIX MATCHES ".*KF([0-9]+).*")
 endif ()
 
 # add options for partial build
-option(NO_LIBSYNCTHING "whether building Syncthing itself as a library should be skipped" ON)
+option(NO_LIBSYNCTHING "whether building Syncthing itself as a library should be skipped" "${LIBSYNCTHING_DISABLED_BY_DEFAULT}")
 option(NO_CLI "whether building CLI should be skipped" OFF)
 option(NO_TRAY "whether building the tray should be skipped" OFF)
 option(NO_FILE_ITEM_ACTION_PLUGIN "whether building the file item action plugin should be skipped" "${FILE_ITEM_ACTION_PLUGIN_DISABLED_BY_DEFAULT}")

syncthingwidgets/CMakeLists.txt

@@ -113,7 +113,12 @@ find_package(syncthingtesthelper ${META_APP_VERSION} REQUIRED)
 list(APPEND PRIVATE_INCLUDE_DIRS "${CMAKE_CURRENT_BINARY_DIR}/../testhelper/include")
 
 # configure libsyncthing
-option(USE_LIBSYNCTHING "whether libsyncthing should be included for the launcher" OFF)
+if (NO_LIBSYNCTHING)
+    set(USE_LIBSYNCTHING_DEFAULT OFF)
+else ()
+    set(USE_LIBSYNCTHING_DEFAULT ON)
+endif ()
+option(USE_LIBSYNCTHING "whether libsyncthing should be included for the launcher" ${USE_LIBSYNCTHING_DEFAULT})
 if (USE_LIBSYNCTHING)
     find_package(syncthing ${META_APP_VERSION} REQUIRED)
     use_syncthing(VISIBILITY PUBLIC)