Add focusable Renderer. (#173)

examples/component/CMakeLists.txt

@@ -12,12 +12,13 @@ example(menu2)
 example(menu_multiple)
 example(menu_style)
 example(modal_dialog)
+example(print_key_press)
 example(radiobox)
 example(radiobox_in_frame)
+example(renderer)
+example(resizable_split)
 example(slider)
 example(slider_rgb)
 example(tab_horizontal)
 example(tab_vertical)
 example(toggle)
-example(resizable_split)
-example(print_key_press)

examples/component/input.cpp

@@ -1,11 +1,12 @@
 #include <memory>  // for allocator, __shared_ptr_access
-#include <string>  // for operator+, char_traits, wstring
+#include <string>  // for char_traits, operator+, wstring, basic_string
 
 #include "ftxui/component/captured_mouse.hpp"  // for ftxui
 #include "ftxui/component/component.hpp"       // for Input, Renderer, Vertical
 #include "ftxui/component/component_base.hpp"  // for ComponentBase
+#include "ftxui/component/component_options.hpp"  // for InputOption
 #include "ftxui/component/screen_interactive.hpp"  // for Component, ScreenInteractive
-#include "ftxui/dom/elements.hpp"  // for text, hbox, Element, separator, operator|, vbox, border
+#include "ftxui/dom/elements.hpp"  // for text, hbox, separator, Element, operator|, vbox, border
 
 int main(int argc, const char* argv[]) {
   using namespace ftxui;
@@ -14,7 +15,6 @@ int main(int argc, const char* argv[]) {
   std::wstring last_name;
   std::wstring password;
 
-
   Component input_first_name = Input(&first_name, "first name");
   Component input_last_name = Input(&last_name, "last name");
 

examples/component/renderer.cpp

@@ -0,0 +1,49 @@
+#include <memory>  // for shared_ptr, allocator, __shared_ptr_access
+
+#include "ftxui/component/captured_mouse.hpp"  // for ftxui
+#include "ftxui/component/component.hpp"       // for Renderer, Button, Vertical
+#include "ftxui/component/component_base.hpp"  // for ComponentBase
+#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+#include "ftxui/dom/elements.hpp"  // for operator|, Element, text, bold, border, center, color
+#include "ftxui/screen/color.hpp"  // for Color, Color::Red
+
+int main(int argc, const char* argv[]) {
+  using namespace ftxui;
+  auto screen = ScreenInteractive::FitComponent();
+
+  // A Renderer() is a component using a lambda function as a parameter to
+  // render itself.
+
+  // 1. Example of focusable renderer:
+  auto renderer_focusable = Renderer([](bool focused) {
+    if (focused)
+      return text(L"FOCUSABLE RENDERER()") | center | bold | border;
+    else
+      return text(L" Focusable renderer() ") | center | border;
+  });
+
+  // 2. Examples of a non focusable renderer.
+  auto renderer_non_focusable = Renderer([&] {
+    return text(L"~~~~~ Non Focusable renderer() ~~~~~");  //
+  });
+
+  // 3. Renderer can wrap other components to redefine their Render() function.
+  auto button = Button(L"Wrapped quit button", screen.ExitLoopClosure());
+  auto renderer_wrap = Renderer(button, [&] {
+    if (button->Focused())
+      return button->Render() | bold | color(Color::Red);
+    else
+      return button->Render();
+  });
+
+  // Let's renderer everyone:
+  screen.Loop(Container::Vertical({
+      renderer_focusable,
+      renderer_non_focusable,
+      renderer_wrap,
+  }));
+}
+
+// Copyright 2020 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

@@ -51,6 +51,7 @@ Component ResizableSplitTop(Component main, Component back, int* main_size);
 Component ResizableSplitBottom(Component main, Component back, int* main_size);
 Component Renderer(Component child, std::function<Element()>);
 Component Renderer(std::function<Element()>);
+Component Renderer(std::function<Element(bool /* focused */)>);
 Component CatchEvent(Component child, std::function<bool(Event)>);
 
 namespace Container {

include/ftxui/screen/screen.hpp

@@ -2,12 +2,12 @@
 #define FTXUI_SCREEN_SCREEN
 
 #include <memory>
-#include <string>
+#include <string>  // for allocator, wstring, string, basic_string
-#include <vector>
+#include <vector>  // for vector
 
-#include "ftxui/screen/box.hpp"
+#include "ftxui/screen/box.hpp"       // for Box
-#include "ftxui/screen/color.hpp"
+#include "ftxui/screen/color.hpp"     // for Color, Color::Default
-#include "ftxui/screen/terminal.hpp"
+#include "ftxui/screen/terminal.hpp"  // for Dimensions
 
 namespace ftxui {
 

src/ftxui/component/button.cpp

@@ -53,9 +53,7 @@ class ButtonBase : public ComponentBase {
     return false;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return true; }
-    return true;
-  }
 
  private:
   ConstStringRef label_;

src/ftxui/component/checkbox.cpp

@@ -71,9 +71,7 @@ class CheckboxBase : public ComponentBase {
     return false;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return true; }
-    return true;
-  }
 
   ConstStringRef label_;
   bool* const state_;

src/ftxui/component/input.cpp

@@ -56,8 +56,7 @@ class InputBase : public ComponentBase {
     std::wstring part_at_cursor = cursor_position() < (int)content.size()
                                       ? content.substr(cursor_position(), 1)
                                       : L" ";
-    std::wstring part_after_cursor =
+    std::wstring part_after_cursor = cursor_position() < (int)content.size() - 1
-        cursor_position() < (int)content.size() - 1
                                          ? content.substr(cursor_position() + 1)
                                          : L"";
     auto focused = is_focused ? focus : select;
@@ -164,9 +163,7 @@ class InputBase : public ComponentBase {
     return true;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return true; }
-    return true;
-  }
 
   StringRef content_;
   ConstStringRef placeholder_;

src/ftxui/component/input_test.cpp

@@ -4,10 +4,13 @@
 #include <string>  // for wstring
 
 #include "ftxui/component/captured_mouse.hpp"  // for ftxui
-#include "ftxui/component/component.hpp"          // for Input, Component
+#include "ftxui/component/component.hpp"       // for Input
-#include "ftxui/component/component_base.hpp"     // for ComponentBase
+#include "ftxui/component/component_base.hpp"  // for ComponentBase, Component
 #include "ftxui/component/component_options.hpp"  // for InputOption
 #include "ftxui/component/event.hpp"  // for Event, Event::ArrowLeft, Event::ArrowRight, Event::Backspace, Event::Delete, Event::End, Event::Home
+#include "ftxui/dom/elements.hpp"     // for Fit
+#include "ftxui/dom/node.hpp"         // for Render
+#include "ftxui/screen/screen.hpp"    // for Screen, Pixel
 #include "ftxui/util/ref.hpp"         // for Ref
 #include "gtest/gtest_pred_impl.h"    // for Test, EXPECT_EQ, TEST
 

src/ftxui/component/menu.cpp

@@ -106,9 +106,7 @@ class MenuBase : public ComponentBase {
     return false;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return entries_->size(); }
-    return entries_->size();
-  }
 
   int& focused_entry() { return option_->focused_entry(); }
 

src/ftxui/component/radiobox.cpp

@@ -119,9 +119,7 @@ class RadioboxBase : public ComponentBase {
     return false;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return entries_->size(); }
-    return entries_->size();
-  }
 
   int& focused_entry() { return option_->focused_entry(); }
 

src/ftxui/component/renderer.cpp

@@ -1,31 +1,17 @@
 #include <functional>  // for function
-#include <memory>      // for __shared_ptr_access
+#include <memory>      // for __shared_ptr_access, shared_ptr
 #include <utility>     // for move
 
-#include "ftxui/component/component.hpp"       // for Component, Make, Renderer
+#include "ftxui/component/captured_mouse.hpp"  // for CapturedMouse
-#include "ftxui/component/component_base.hpp"  // for ComponentBase
+#include "ftxui/component/component.hpp"       // for Make, Renderer
-#include "ftxui/dom/elements.hpp"              // for Element
+#include "ftxui/component/component_base.hpp"  // for Component, ComponentBase
+#include "ftxui/component/event.hpp"           // for Event
+#include "ftxui/component/mouse.hpp"           // for Mouse
+#include "ftxui/dom/elements.hpp"  // for Element, operator|, reflect
+#include "ftxui/screen/box.hpp"    // for Box
 
 namespace ftxui {
 
-// @brief A component rendering Element from a function.
-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)) {}
-
-  // Component implementation.
-  Element Render() override { return render_(); }
-
- protected:
-  std::function<Element()> render_;
-};
-
 /// @brief Return a component, using |render| to render its interface.
 /// @param render The function drawing the interface.
 /// @ingroup component
@@ -40,7 +26,14 @@ class RendererBase : public ComponentBase {
 /// screen.Loop(renderer);
 /// ```
 Component Renderer(std::function<Element()> render) {
-  return Make<RendererBase>(std::move(render));
+  class Impl : public ComponentBase {
+   public:
+    Impl(std::function<Element()> render) : render_(std::move(render)) {}
+    Element Render() override { return render_(); }
+    std::function<Element()> render_;
+  };
+
+  return Make<Impl>(std::move(render));
 }
 
 /// @brief Return a new Component, similar to |child|, but using |render| as the
@@ -69,6 +62,48 @@ Component Renderer(Component child, std::function<Element()> render) {
   return renderer;
 }
 
+/// @brief Return a focusable component, using |render| to render its interface.
+/// @param render The function drawing the interface, taking a boolean telling
+/// whether the component is focused or not.
+/// @ingroup component
+///
+/// ### Example
+///
+/// ```cpp
+/// auto screen = ScreenInteractive::TerminalOutput();
+/// auto renderer = Renderer([] (bool focused) {
+///   if (focused)
+///     return text("My interface") | inverted;
+///   else
+///     return text("My interface") | inverted;
+/// });
+/// screen.Loop(renderer);
+/// ```
+Component Renderer(std::function<Element(bool)> render) {
+  class Impl : public ComponentBase {
+   public:
+    Impl(std::function<Element(bool)> render) : render_(std::move(render)) {}
+
+   private:
+    Element Render() override { return render_(Focused()) | reflect(box_); }
+    bool Focusable() const override { return true; }
+    bool OnEvent(Event event) override {
+      if (event.is_mouse() && box_.Contain(event.mouse().x, event.mouse().y)) {
+        if (!CaptureMouse(event))
+          return false;
+
+        TakeFocus();
+      }
+
+      return false;
+    }
+    Box box_;
+
+    std::function<Element(bool)> render_;
+  };
+  return Make<Impl>(std::move(render));
+}
+
 }  // namespace ftxui
 
 // Copyright 2021 Arthur Sonzogni. All rights reserved.

src/ftxui/component/slider.cpp

@@ -84,9 +84,7 @@ class SliderBase : public ComponentBase {
     return false;
   }
 
-  bool Focusable() const final {
+  bool Focusable() const final { return true; }
-    return true;
-  }
 
  private:
   StringRef label_;

src/ftxui/dom/util.cpp

@@ -1,8 +1,14 @@
+#include <algorithm>   // for min
 #include <functional>  // for function
+#include <memory>      // for __shared_ptr_access
 #include <utility>     // for move
 #include <vector>      // for vector
 
-#include "ftxui/dom/elements.hpp"  // for Decorator, Element, Elements, operator|, nothing
+#include "ftxui/dom/elements.hpp"  // for Element, Decorator, Elements, operator|, Fit, nothing
+#include "ftxui/dom/node.hpp"         // for Node
+#include "ftxui/dom/requirement.hpp"  // for Requirement
+#include "ftxui/screen/screen.hpp"    // for Full
+#include "ftxui/screen/terminal.hpp"  // for Dimensions
 
 namespace ftxui {
 

src/ftxui/screen/screen.cpp

@@ -1,10 +1,11 @@
-#include <algorithm>  // for min
+#include <algorithm>  // for max
 #include <iostream>  // for operator<<, basic_ostream, wstringstream, stringstream, flush, cout, ostream
+#include <memory>    // for allocator
 #include <sstream>   // IWYU pragma: keep
 
 #include "ftxui/screen/screen.hpp"
 #include "ftxui/screen/string.hpp"    // for to_string, wchar_width
-#include "ftxui/screen/terminal.hpp"  // for Terminal::Dimensions, Terminal
+#include "ftxui/screen/terminal.hpp"  // for Dimensions, Size
 
 #if defined(_WIN32)
 #define WIN32_LEAN_AND_MEAN