Add Graph.

examples/dom/graph.cpp

@@ -0,0 +1,65 @@
+#include "ftxui/dom/elements.hpp"
+#include "ftxui/dom/graph.hpp"
+#include "ftxui/screen/screen.hpp"
+#include "ftxui/screen/string.hpp"
+#include <chrono>
+#include <cmath>
+#include <iostream>
+#include <thread>
+
+class Graph : public ftxui::GraphFunction {
+ public:
+  std::vector<int> operator()(int width, int height) {
+    std::vector<int> output(width);
+    for (int i = 0; i < width; ++i) {
+      float v = 0;
+      v += 0.1 * sin((i + shift) * 0.1);
+      v += 0.2 * sin((i + shift+10) * 0.15);
+      v += 0.1 * sin((i + shift) * 0.03);
+      // v += 0.2*sin((i+shift)*0.3);
+      // v += 0.1*sin((i+shift)*0.9);
+      v *= height;
+      v += 0.5 * height;
+      output[i] = v;
+    }
+    return output;
+  }
+  int shift = 0;
+};
+
+int main(int argc, const char* argv[]) {
+  using namespace ftxui;
+  using namespace std::chrono_literals;
+
+  Graph my_graph;
+
+  std::string reset_position;
+  for (int i = 0;; ++i) {
+    auto document =
+      window(text(L"Your graphs"),
+        hbox(
+          vbox(
+            graph(my_graph), separator(),
+            graph(my_graph) | inverted
+          ) | flex,
+          separator(),
+          vbox(
+            graph(my_graph) | color(Color::BlueLight), separator(),
+            graph(my_graph) | color(Color::RedLight), separator(),
+            graph(my_graph) | color(Color::YellowLight)
+          ) | flex
+        )
+      ) | size(HEIGHT, GREATER_THAN, 40);
+
+    auto screen = Screen::Create(Dimension::Full(), Dimension::Fit(document));
+    Render(screen, document.get());
+    std::cout << reset_position << screen.ToString() << std::flush;
+
+    reset_position = screen.ResetPosition();
+
+    std::this_thread::sleep_for(0.03s);
+    my_graph.shift++;
+  }
+
+  return 0;
+}