+
+ /**
+ * @brief Update anchor position from given number of inserted characters.
+ *
+ * @param[in] controller The controller
+ * @param[in] numberOfCharacters The number of inserted characters.
+ * @param[in] previousCursorIndex A cursor position before event occurs.
+ */
+ static void InsertTextAnchor(Controller& controller, int numberOfCharacters, CharacterIndex previousCursorIndex);
+
+ /**
+ * @brief Update anchor position from given number of removed characters.
+ *
+ * @param[in] controller The controller
+ * @param[in] cursorOffset Start position from the current cursor position to start deleting characters.
+ * @param[in] numberOfCharacters The number of removed characters.
+ * @param[in] previousCursorIndex A cursor position before event occurs.
+ */
+ static void RemoveTextAnchor(Controller& controller, int cursorOffset, int numberOfCharacters, CharacterIndex previousCursorIndex);