Add the Renderer component.

src/ftxui/component/renderer.cpp

@@ -0,0 +1,44 @@
+#include <functional>  // for function
+#include <memory>      // for shared_ptr
+
+#include "ftxui/component/component.hpp"       // for Make
+#include "ftxui/component/component_base.hpp"  // for ComponentBase
+#include "ftxui/dom/elements.hpp"              // for Element
+
+namespace ftxui {
+
+/// @brief A component rendering Element from a function.
+/// @ingroup component.
+class RendererBase : public ComponentBase {
+ public:
+  // Access this interface from a Component
+  static RendererBase* From(Component component) {
+    return static_cast<RendererBase*>(component.get());
+  }
+
+  // Constructor.
+  RendererBase(std::function<Element()> render) : render_(std::move(render)) {}
+  ~RendererBase() override = default;
+
+  // Component implementation.
+  Element Render() override { return render_(); }
+
+ protected:
+  std::function<Element()> render_;
+};
+
+Component Renderer(std::function<Element()> render) {
+  return Make<RendererBase>(std::move(render));
+}
+
+Component Renderer(Component child, std::function<Element()> render) {
+  Component renderer = Renderer(std::move(render));
+  renderer->Add(std::move(child));
+  return renderer;
+}
+
+}  // namespace ftxui
+
+// Copyright 2021 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.