GUI is now in its own unit.

gui.cpp

@@ -0,0 +1,99 @@
+#include "gui.hpp"
+#include <stdlib.h>                   // for EXIT_SUCCESS
+#include <chrono>                     // for milliseconds
+#include <fmt/core.h>
+#include <ftxui/component/event.hpp>  // for Event
+#include <ftxui/component/mouse.hpp>  // for ftxui
+#include <ftxui/dom/elements.hpp>  // for text, separator, Element, operator|, vbox, border
+#include <memory>                  // for allocator, shared_ptr
+#include <string>                  // for operator+, to_string
+#include <thread>                  // for sleep_for
+
+#include "ftxui/component/component.hpp"  // for CatchEvent, Renderer, operator|=
+#include "ftxui/component/loop.hpp"       // for Loop
+#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+#include <vector>
+
+using namespace ftxui;
+using namespace std;
+using namespace fmt;
+namespace fs = std::filesystem;
+
+vector<string> lines;
+
+void output(const string &msg) {
+  lines.push_back(msg);
+}
+
+ButtonOption Style() {
+  auto option = ButtonOption::Animated();
+  option.transform = [](const EntryState& s) {
+    auto element = paragraph(s.label);
+    if (s.focused) {
+      element |= bold;
+    }
+    return element | center | borderEmpty | flex;
+  };
+  return option;
+}
+
+int main_loop(GameEngine &game, std::function<bool()> runner) {
+  auto screen = ScreenInteractive::Fullscreen();
+  screen.TrackMouse(true);
+
+  // Create a component counting the number of frames drawn and event handled.
+  float scroll_x = 0.1;
+  float scroll_y = 1.0;
+
+  auto status = Renderer([&] {
+      return vbox({
+        paragraph(fmt::format("HP {}", game.hit_points)),
+        separator(),
+        hbox({
+            text("HP"),
+            gauge(game.hit_points / 100.0f),
+          }),
+      });
+  });
+
+  auto content = Renderer([&] {
+      vector<Element> output;
+
+      for(const auto line : lines) {
+        output.push_back(text(line));
+      }
+
+      return vbox(output);
+    });
+
+  auto scrollable_content = Renderer(content,
+      [&, content] {
+      return content->Render()
+        | focusPositionRelative(scroll_x, scroll_y)
+        | frame | flex;
+  });
+
+  auto component = Renderer(scrollable_content, [&] {
+    return vbox({
+        status->Render(),
+        separator(),
+        scrollable_content->Render() | vscroll_indicator | yframe | size(HEIGHT, LESS_THAN, 20),
+        }) |
+    border;
+  });
+
+  component |= CatchEvent([&](Event) -> bool {
+    return false;
+  });
+
+  Loop loop(&screen, component);
+
+  while (!loop.HasQuitted()) {
+    int run_error = runner();
+    loop.RunOnce();
+    screen.Post(Event::Custom);
+    std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+
+  return EXIT_SUCCESS;
+}