Add fxtui example

cli/CMakeLists.txt

@@ -1,3 +1,35 @@
 
 include_directories(thirdparty)
-add_executable(cryptor cryptor.cpp)
+add_executable(cryptor cryptor.cpp)
+
+include(FetchContent)
+
+FetchContent_Declare(ftxui
+  GIT_REPOSITORY https://github.com/ArthurSonzogni/ftxui
+  GIT_TAG v5.0.0
+  GIT_PROGRESS TRUE
+  GIT_SHALLOW FALSE
+  EXCLUDE_FROM_ALL
+  FIND_PACKAGE_ARGS NAMES ftxui
+)
+
+FetchContent_Declare(nlohmann_json
+  URL https://github.com/nlohmann/json/releases/download/v3.10.5/json.tar.xz
+  EXCLUDE_FROM_ALL
+  FIND_PACKAGE_ARGS NAMES nlohmann_json
+)
+
+FetchContent_GetProperties(ftxui)
+FetchContent_GetProperties(nlohmann_json)
+
+FetchContent_MakeAvailable(ftxui)
+FetchContent_MakeAvailable(nlohmann_json)
+
+add_executable(test_protocol_ui test_protocol_ui.cpp)
+# target_include_directories(test_protocol_ui ${ftxui_INCLUDE})
+target_link_libraries(test_protocol_ui
+  PRIVATE ftxui::screen
+  PRIVATE ftxui::dom
+  PRIVATE ftxui::component
+  PUBLIC nlohmann_json::nlohmann_json
+)

cli/test_protocol_ui.cpp

@@ -0,0 +1,29 @@
+#include <functional>  // for function
+#include <iostream>  // for basic_ostream::operator<<, operator<<, endl, basic_ostream, basic_ostream<>::__ostream_type, cout, ostream
+#include <string>    // for string, basic_string, allocator
+#include <vector>    // for vector
+
+#include "ftxui/component/captured_mouse.hpp"      // for ftxui
+#include "ftxui/component/component.hpp"           // for Menu
+#include "ftxui/component/component_options.hpp"   // for MenuOption
+#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+
+int main() {
+  using namespace ftxui;
+  auto screen = ScreenInteractive::TerminalOutput();
+
+  std::vector<std::string> entries = {
+      "entry 1",
+      "entry 2",
+      "entry 3",
+  };
+  int selected = 0;
+
+  MenuOption option;
+  option.on_enter = screen.ExitLoopClosure();
+  auto menu = Menu(&entries, &selected, option);
+
+  screen.Loop(menu);
+
+  std::cout << "Selected element = " << selected << std::endl;
+}