Add webassembly support (#79)

src/ftxui/screen/screen.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <sstream>
+#include <iostream>
 
 #include "ftxui/dom/node.hpp"
 #include "ftxui/screen/string.hpp"
@@ -149,6 +150,7 @@ Screen::Screen(int dimx, int dimy)
 }
 
 /// Produce a std::string that can be used to print the Screen on the terminal.
+/// Don't forget to flush stdout. Alternatively, you can use Screen::Print();
 std::string Screen::ToString() {
   std::wstringstream ss;
 
@@ -158,7 +160,7 @@ std::string Screen::ToString() {
   for (int y = 0; y < dimy_; ++y) {
     if (y != 0) {
       UpdatePixelStyle(ss, previous_pixel, final_pixel);
-      ss << '\n';
+      ss << L"\r\n";
     }
     for (int x = 0; x < dimx_;) {
       auto& pixel = pixels_[y][x];
@@ -181,6 +183,10 @@ std::string Screen::ToString() {
   return to_string(ss.str());
 }
 
+void Screen::Print() {
+  std::cout << ToString() << std::flush << (char)0;
+}
+
 /// @brief Access a character a given position.
 /// @param x The character position along the x-axis.
 /// @param y The character position along the y-axis.
@@ -254,6 +260,7 @@ void Screen::ApplyShader() {
     }
   }
 }
+
 // clang-format on
 
 }  // namespace ftxui

src/ftxui/screen/terminal.cpp

@@ -19,7 +19,7 @@ namespace ftxui {
 
 Terminal::Dimensions Terminal::Size() {
 #if defined(__EMSCRIPTEN__)
-  return Dimensions{80, 43};
+  return Dimensions{140, 43};
 #elif defined(_WIN32)
   CONSOLE_SCREEN_BUFFER_INFO csbi;
   int columns, rows;
@@ -48,6 +48,10 @@ bool Contains(const std::string& s, const char* key) {
 static bool cached = false;
 Terminal::Color cached_supported_color;
 Terminal::Color ComputeColorSupport() {
+#if defined(__EMSCRIPTEN__)
+  return Terminal::Color::TrueColor;
+#endif
+
   std::string COLORTERM = Safe(std::getenv("COLORTERM"));
   if (Contains(COLORTERM, "24bit") || Contains(COLORTERM, "truecolor"))
     return Terminal::Color::TrueColor;