Add instructions for wasm build.

PR:ArthurSonzogni/ftxui-starter#3
author: Guerout-Arnaud

CMakeLists.txt

@@ -6,7 +6,7 @@ include(FetchContent)
 set(FETCHCONTENT_UPDATES_DISCONNECTED TRUE)
 FetchContent_Declare(ftxui
   GIT_REPOSITORY https://github.com/ArthurSonzogni/ftxui
-  GIT_TAG v2.0.0
+  GIT_TAG v3.0.0
 )
 
 FetchContent_GetProperties(ftxui)
@@ -31,4 +31,12 @@ target_link_libraries(ftxui-starter
   PRIVATE ftxui::component # Not needed for this example.
 )
 
-install(TARGETS ftxui-starter RUNTIME DESTINATION "bin")
+if (EMSCRIPTEN) 
+  string(APPEND CMAKE_CXX_FLAGS " -s USE_PTHREADS") 
+  string(APPEND CMAKE_EXE_LINKER_FLAGS " -s ASYNCIFY") 
+  string(APPEND CMAKE_EXE_LINKER_FLAGS " -s PROXY_TO_PTHREAD") 
+
+  foreach(file "index.html" "run_webassembly.py")
+    configure_file("src/${file}" ${file})
+  endforeach(file)
+endif() 

README.md

@@ -13,8 +13,18 @@ Minimal starter project using the [FTXUI library](https://github.com/ArthurSonzo
 mkdir build
 cd build
 cmake ..
-make -j3
-./ftxuistarter
+make -j
+cd ../target
+./ftxui-starter
+~~~
+
+## Webassembly build:
+~~~bash
+mkdir build_emscripten && cd build_emscripten
+emcmake cmake ..
+make -j
+./run_webassembly.py
+(visit localhost:8000)
 ~~~
 
 ## Linux snap build:

src/index.html

@@ -76,6 +76,23 @@ <h1>ftxui-starter example </h1>
       text-decoration: underline;
     }
 
+    select {
+      display:block;
+      padding: .6em 1.4em .5em .8em;
+      border-radius: 20px 20px 0px 0px;
+      font-size: 16px;
+      font-family: sans-serif;
+      font-weight: 700;
+
+      color: #444;
+      line-height: 1.3;
+      background-color:black;
+      border:0px;
+      color:white;
+      transition: color 0.2s linear;
+      transition: background-color 0.2s linear;
+    }
+
     #terminal {
       padding:10px;
       border:none;

src/main.cpp

@@ -33,7 +33,7 @@ int main(void) {
   auto screen = Screen::Create(Dimension::Full(), Dimension::Fit(document));
   Render(screen, document);
 
-  std::cout << screen.ToString() << std::endl;
+  std::cout << screen.ToString() << '\0' << std::endl;
 
   return EXIT_SUCCESS;
 }