Add RadioBox.

ftxui/CMakeLists.txt

@@ -36,6 +36,7 @@ add_library(component
   src/ftxui/component/event.cpp
   src/ftxui/component/input.cpp
   src/ftxui/component/menu.cpp
+  src/ftxui/component/radiobox.cpp
   src/ftxui/component/screen_interactive.cpp
   src/ftxui/component/toggle.cpp
 )

ftxui/include/ftxui/component/checkbox.hpp

@@ -15,8 +15,10 @@ class CheckBox : public Component {
   bool state = false;
   std::wstring label = L"label";
 
-  std::wstring checked = L"[X] ";
-  std::wstring unchecked = L"[ ] ";
+  //std::wstring checked = L"[X] ";
+  //std::wstring unchecked = L"[ ] ";
+  std::wstring checked = L"☑ ";
+  std::wstring unchecked = L"☐ ";
 
   // State update callback.
   std::function<void()> on_change = [](){};

ftxui/include/ftxui/component/radiobox.hpp

@@ -0,0 +1,38 @@
+#ifndef FTXUI_COMPONENT_RADIOBOX_HPP
+#define FTXUI_COMPONENT_RADIOBOX_HPP
+
+#include "ftxui/component/component.hpp"
+#include <functional>
+
+namespace ftxui {
+
+class RadioBox : public Component {
+ public:
+  // Constructor.
+  RadioBox() = default;
+  ~RadioBox() override = default;
+
+  int selected = 0;
+  int focused = 0;
+  std::vector<std::wstring> entries;
+
+  std::wstring checked = L"◉ ";
+  std::wstring unchecked = L"○ ";
+
+  Decorator focused_style = inverted;
+  Decorator unfocused_style = nothing;
+
+  // State update callback.
+  std::function<void()> on_change = [](){};
+
+  // Component implementation.
+  Element Render() override;
+  bool OnEvent(Event) override;
+
+ private:
+  int cursor_position = 0;
+};
+
+}  // namespace ftxui
+
+#endif /* end of include guard: FTXUI_COMPONENT_RADIOBOX_HPP */

ftxui/src/ftxui/component/radiobox.cpp

@@ -0,0 +1,41 @@
+#include "ftxui/component/radiobox.hpp"
+#include <functional>
+
+namespace ftxui {
+
+Element RadioBox::Render() {
+  std::vector<Element> elements;
+  bool is_focused = Focused();
+  for (size_t i = 0; i < entries.size(); ++i) {
+    auto style =
+        (focused == int(i) && is_focused) ? focused_style : unfocused_style;
+    const std::wstring& symbol = selected == int(i) ? checked : unchecked;
+    elements.push_back(hbox(text(symbol), text(entries[i]) | style));
+  }
+  return vbox(std::move(elements));
+}
+
+bool RadioBox::OnEvent(Event event) {
+  if (!Focused())
+    return false;
+
+  int new_focused = focused;
+  if (event == Event::ArrowUp || event == Event::Character('k'))
+    new_focused--;
+  if (event == Event::ArrowDown || event == Event::Character('j'))
+    new_focused++;
+  new_focused = std::max(0, std::min(int(entries.size()) - 1, new_focused));
+  if (focused != new_focused) {
+    focused = new_focused;
+    return true;
+  }
+
+  if (event == Event::Character(' ')) {
+    selected = focused;
+    on_change();
+  }
+
+  return false;
+}
+
+}  // namespace ftxui