Add scrollbar example.

examples/component/scrollbar.cpp

@@ -0,0 +1,112 @@
+// Copyright 2023 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
+#include <ftxui/component/component.hpp>
+#include <ftxui/component/screen_interactive.hpp>
+
+using namespace ftxui;
+
+Component DummyWindowContent() {
+  class Impl : public ComponentBase {
+   private:
+    float scroll_x = 0.9;
+    float scroll_y = 0.1;
+
+   public:
+    Impl() {
+      auto content = Renderer([=] {
+        const std::string lorem =
+            "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed "
+            "do eiusmod tempor incididunt ut labore et dolore magna "
+            "aliqua. Ut enim ad minim veniam, quis nostrud exercitation "
+            "ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis "
+            "aute irure dolor in reprehenderit in voluptate velit esse "
+            "cillum dolore eu fugiat nulla pariatur. Excepteur sint "
+            "occaecat cupidatat non proident, sunt in culpa qui officia "
+            "deserunt mollit anim id est laborum.";
+        return vbox({
+            text(lorem.substr(0, -1)),   text(lorem.substr(5, -1)),
+            text(lorem.substr(10, -1)),  text(lorem.substr(15, -1)),
+            text(lorem.substr(20, -1)),  text(lorem.substr(25, -1)),
+            text(lorem.substr(30, -1)),  text(lorem.substr(35, -1)),
+            text(lorem.substr(40, -1)),  text(lorem.substr(45, -1)),
+            text(lorem.substr(50, -1)),  text(lorem.substr(55, -1)),
+            text(lorem.substr(60, -1)),  text(lorem.substr(65, -1)),
+            text(lorem.substr(70, -1)),  text(lorem.substr(75, -1)),
+            text(lorem.substr(80, -1)),  text(lorem.substr(85, -1)),
+            text(lorem.substr(90, -1)),  text(lorem.substr(95, -1)),
+            text(lorem.substr(100, -1)), text(lorem.substr(105, -1)),
+            text(lorem.substr(110, -1)), text(lorem.substr(115, -1)),
+            text(lorem.substr(120, -1)), text(lorem.substr(125, -1)),
+            text(lorem.substr(130, -1)), text(lorem.substr(135, -1)),
+            text(lorem.substr(140, -1)),
+        });
+      });
+
+      auto scrollable_content = Renderer(content, [&, content] {
+        return content->Render() |
+               focusPositionRelative(1.f - scroll_x, scroll_y) | frame | flex;
+      });
+
+      SliderOption<float> option_x;
+      option_x.value = &scroll_x;
+      option_x.min = 0.f;
+      option_x.max = 1.f;
+      option_x.increment = 0.1f;
+      option_x.direction = Direction::Left;
+      option_x.color_active = Color::Blue;
+      option_x.color_inactive = Color::BlueLight;
+      auto scrollbar_x = Slider(option_x);
+
+      SliderOption<float> option_y;
+      option_y.value = &scroll_y;
+      option_y.min = 0.f;
+      option_y.max = 1.f;
+      option_y.increment = 0.1f;
+      option_y.direction = Direction::Down;
+      option_y.color_active = Color::Yellow;
+      option_y.color_inactive = Color::YellowLight;
+      auto scrollbar_y = Slider(option_y);
+
+      Add(Container::Vertical({
+          Container::Horizontal({
+              scrollable_content,
+              scrollbar_y,
+          }) | flex,
+          Container::Horizontal({
+              scrollbar_x,
+              Renderer([] { return text(L"x"); }),
+          }),
+      }));
+    }
+  };
+  return Make<Impl>();
+}
+
+int main() {
+  auto window_1 = Window({
+      .inner = DummyWindowContent(),
+      .title = "First window",
+      .width = 80,
+      .height = 30,
+  });
+
+  auto window_2 = Window({
+      .inner = DummyWindowContent(),
+      .title = "My window",
+      .left = 40,
+      .top = 20,
+      .width = 80,
+      .height = 30,
+  });
+
+  auto window_container = Container::Stacked({
+      window_1,
+      window_2,
+  });
+
+  auto screen = ScreenInteractive::Fullscreen();
+  screen.Loop(window_container);
+
+  return EXIT_SUCCESS;
+}