Refactor directory structure.

The goal is to increase the separation in between:

 * ftxui::screen
 * ftxui::dom
 * ftxui::component

ftxui/CMakeLists.txt

@@ -5,8 +5,10 @@ add_library(ftxui
   src/ftxui/component/component_direction.cpp
   src/ftxui/component/component_horizontal.cpp
   src/ftxui/component/component_vertical.cpp
+  src/ftxui/component/event.cpp
   src/ftxui/component/input.cpp
   src/ftxui/component/menu.cpp
+  src/ftxui/component/screen_interactive.cpp
   src/ftxui/component/toggle.cpp
   src/ftxui/dom/blink.cpp
   src/ftxui/dom/bold.cpp
@@ -26,9 +28,7 @@ add_library(ftxui
   src/ftxui/dom/underlined.cpp
   src/ftxui/dom/util.cpp
   src/ftxui/dom/vbox.cpp
-  src/ftxui/event.cpp
-  src/ftxui/screen.cpp
-  src/ftxui/screen_interactive.cpp
+  src/ftxui/screen/screen.cpp
   src/ftxui/terminal.cpp
   src/ftxui/util/string.cpp
 )

ftxui/include/ftxui/box.hpp

@@ -1,11 +0,0 @@
-#ifndef FTX_UI_CORE_BOX
-#define FTX_UI_CORE_BOX
-
-struct Box {
-  int left;
-  int right;
-  int top;
-  int bottom;
-};
-
-#endif /* end of include guard: FTX_UI_CORE_BOX */

ftxui/include/ftxui/component/component.hpp

@@ -2,11 +2,10 @@
 #define FTXUI_COMPONENT_COMPONENT_HPP
 
 #include "ftxui/component/delegate.hpp"
+#include "ftxui/component/event.hpp"
 #include "ftxui/dom/elements.hpp"
-#include "ftxui/event.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 class Delegate;
 class Focus;
@@ -39,7 +38,6 @@ class Component {
   Delegate* delegate_;
 };
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component
 
 #endif /* end of include guard: FTXUI_COMPONENT_COMPONENT_HPP */

ftxui/include/ftxui/component/component_horizontal.hpp

@@ -3,8 +3,7 @@
 
 #include "ftxui/component/component_direction.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 // A component where focus and events are automatically handled for you.
 // It assumes its children are put in the horizontal direction.
@@ -14,7 +13,6 @@ class ComponentHorizontal : public ComponentDirection {
   bool HandleDirection(Event) override;
 };
 
-} // namespace component
-} // namespace ftxui
+} // namespace ftxui::component
 
 #endif /* end of include guard: FTXUI_COMPONENT_COMPONENT_HORIZONTAL_H_ */

ftxui/include/ftxui/component/component_vertical.hpp

@@ -3,8 +3,7 @@
 
 #include "ftxui/component/component_direction.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 // A component where focus and events are automatically handled for you.
 // It assumes its children are put in the vertical direction.
@@ -14,7 +13,6 @@ class ComponentVertical : public ComponentDirection {
   bool HandleDirection(Event) override;
 };
 
-} // namespace component
-} // namespace ftxui
+} // namespace ftxui::component
 
 #endif /* end of include guard: FTXUI_COMPONENT_COMPONENT_VERTICAL_H_ */

ftxui/include/ftxui/component/delegate.hpp

@@ -3,8 +3,7 @@
 
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 class Component;
 
@@ -28,7 +27,6 @@ class Delegate {
   virtual Delegate* Root() = 0;
 };
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component
 
 #endif /* end of include guard: FTXUI_COMPONENT_DELEGATE_HPP */

ftxui/include/ftxui/component/event.hpp

@@ -1,10 +1,10 @@
-#ifndef FTXUI_EVENT_H_
-#define FTXUI_EVENT_H_
+#ifndef FTXUI_COMPONENT_EVENT_HPP
+#define FTXUI_COMPONENT_EVENT_HPP
 
 #include <vector>
 #include <array>
 
-namespace ftxui {
+namespace ftxui::component {
 
 struct Event{
  public:
@@ -31,7 +31,7 @@ struct Event{
 };
 
 
-} // namespace ftxui
+} // namespace ftxui::component
 
 
-#endif /* end of include guard: FTXUI_EVENT_H_ */
+#endif /* end of include guard: FTXUI_COMPONENT_EVENT_HPP */

ftxui/include/ftxui/component/input.hpp

@@ -4,8 +4,7 @@
 #include "ftxui/component/component.hpp"
 #include <functional>
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 class Input : public Component {
  public:
@@ -29,7 +28,6 @@ class Input : public Component {
   int cursor_position = 0;
 };
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component
 
 #endif /* end of include guard: FTXUI_COMPONENT_INPUT_H_ */

ftxui/include/ftxui/component/menu.hpp

@@ -5,8 +5,7 @@
 #include "ftxui/dom/elements.hpp"
 #include <functional>
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 class Menu : public Component {
  public:
@@ -30,7 +29,6 @@ class Menu : public Component {
   bool OnEvent(Event) override;
 };
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::Component
 
 #endif /* end of include guard: FTXUI_COMPONENT_MENU */

ftxui/include/ftxui/component/screen_interactive.hpp

@@ -1,18 +1,16 @@
-#ifndef FTXUI_SCREEN_INTERACTIVE
-#define FTXUI_SCREEN_INTERACTIVE
+#ifndef FTXUI_COMPONENT_SCREEN_INTERACTIVE_HPP
+#define FTXUI_COMPONENT_SCREEN_INTERACTIVE_HPP
 
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include <functional>
 #include <memory>
 
-namespace ftxui {
+namespace ftxui::component {
 
-namespace component {
-  class Delegate;
-  class Component;
-} // namespace component
+class Delegate;
+class Component;
 
-class ScreenInteractive : public Screen {
+class ScreenInteractive : public ftxui::screen::Screen {
   public:
     static ScreenInteractive FixedSize(size_t dimx, size_t dimy);
     static ScreenInteractive Fullscreen();
@@ -21,15 +19,15 @@ class ScreenInteractive : public Screen {
     ~ScreenInteractive();
     component::Delegate* delegate();
     void Loop();
-		std::function<void()> ExitLoopClosure();
+    std::function<void()> ExitLoopClosure();
 
   private:
    class Delegate;
    std::unique_ptr<Delegate> delegate_;
 
-	 void Clear();
-	 void Draw();
-	 bool quit_ = false;
+   void Clear();
+   void Draw();
+   bool quit_ = false;
 
    enum class Dimension {
      Fixed,
@@ -41,6 +39,6 @@ class ScreenInteractive : public Screen {
    ScreenInteractive(size_t dimx, size_t dimy, Dimension dimension);
 };
 
-}  // namespace ftxui
+}  // namespace ftxui::component
 
-#endif /* end of include guard: FTXUI_SCREEN_INTERACTIVE */
+#endif /* end of include guard: FTXUI_COMPONENT_SCREEN_INTERACTIVE_HPP */

ftxui/include/ftxui/component/toggle.hpp

@@ -5,8 +5,7 @@
 #include <functional>
 #include <string>
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 class Toggle : public Component {
  public:
@@ -25,7 +24,6 @@ class Toggle : public Component {
   bool OnEvent(Event) override;
 };
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::Component
 
 #endif /* end of include guard: FTXUI_COMPONENT_TOGGLE_H_ */

ftxui/include/ftxui/dom/box.hpp

@@ -0,0 +1,15 @@
+#ifndef FTXUI_DOM_BOX_HPP
+#define FTXUI_DOM_BOX_HPP
+
+namespace ftxui::dom {
+
+struct Box {
+  int left;
+  int right;
+  int top;
+  int bottom;
+};
+
+}; // namespace ftxui::dom
+
+#endif /* end of include guard: FTXUI_DOM_BOX_HPP */

ftxui/include/ftxui/dom/elements.hpp

@@ -3,16 +3,16 @@
 
 #include <functional>
 
-#include "ftxui/color.hpp"
 #include "ftxui/dom/node.hpp"
+#include "ftxui/screen/color.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 using Element = std::unique_ptr<Node>;
 using Decorator = std::function<Element(Element)>;
 using Child = std::unique_ptr<Node>;
 using Children = std::vector<Child>;
+using Color = ftxui::screen::Color;
 
 // --- Layout ----
 Element vbox(Children);
@@ -58,7 +58,6 @@ TAKE_ANY_ARGS(vbox)
 TAKE_ANY_ARGS(hbox)
 TAKE_ANY_ARGS(dbox)
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom
 
 #endif /* end of include guard: FTXUI_DOM_ELEMENTS_HPP */

ftxui/include/ftxui/dom/node.hpp

@@ -1,15 +1,14 @@
-#ifndef DOM_NODE_HPP
-#define DOM_NODE_HPP
+#ifndef FTXUI_DOM_NODE_HPP
+#define FTXUI_DOM_NODE_HPP
 
 #include <memory>
 #include <vector>
 
-#include "ftxui/requirement.hpp"
-#include "ftxui/screen.hpp"
-#include "ftxui/box.hpp"
+#include "ftxui/dom/box.hpp"
+#include "ftxui/dom/requirement.hpp"
+#include "ftxui/screen/screen.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class Node {
  public:
@@ -28,7 +27,7 @@ class Node {
   virtual void SetBox(Box box);
 
   // Step 3: Draw this element.
-  virtual void Render(Screen& screen);
+  virtual void Render(screen::Screen& screen);
 
   std::vector<std::unique_ptr<Node>> children;
  protected:
@@ -36,9 +35,8 @@ class Node {
   Box box_;
 };
 
-void Render(Screen& screen, Node* node);
+void Render(screen::Screen& screen, Node* node);
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom
 
-#endif /* end of include guard: DOM_NODE_HPP */
+#endif /* end of include guard: FTXUI_DOM_NODE_HPP */

ftxui/include/ftxui/dom/requirement.hpp

@@ -1,7 +1,7 @@
-#ifndef FTXUI_REQUIREMENT_HPP
-#define FTXUI_REQUIREMENT_HPP
+#ifndef FTXUI_DOM_REQUIREMENT_HPP
+#define FTXUI_DOM_REQUIREMENT_HPP
 
-namespace ftxui {
+namespace ftxui::dom {
 
 struct Requirement {
   // The required size to fully draw the element.
@@ -11,6 +11,6 @@ struct Requirement {
   struct { int x = 0; int y = 0; } flex;
 };
 
-};  // namespace ftxui
+}; // namespace ftxui::dom
 
 #endif /* end of include guard: FTXUI_REQUIREMENT_HPP */

ftxui/include/ftxui/screen/color.hpp

@@ -1,9 +1,9 @@
-#ifndef FTXUI_COLOR_H_
-#define FTXUI_COLOR_H_
+#ifndef FTXUI_SCREEN_COLOR
+#define FTXUI_SCREEN_COLOR
 
 #include <cstdint>
 
-namespace ftxui {
+namespace ftxui::screen {
 
 enum class Color : uint8_t {
   // --- Transparent -----
@@ -35,6 +35,6 @@ enum class Color : uint8_t {
   YellowLight = 93,
 };
 
-};  // namespace ftxui
+}; // namespace ftxui::screen
 
 #endif /* end of include guard: FTXUI_COLOR_H_ */

ftxui/include/ftxui/screen/screen.hpp

@@ -1,17 +1,18 @@
-#ifndef FTXUI_SCREEN
-#define FTXUI_SCREEN
+#ifndef FTXUI_SCREEN_SCREEN
+#define FTXUI_SCREEN_SCREEN
 
 #include <string>
 #include <vector>
 #include <memory>
 
-#include <ftxui/color.hpp>
+#include "ftxui/screen/color.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
   class Node;
 }
 
+namespace ftxui::screen {
+
 struct Pixel {
   wchar_t character = U' ';
   bool blink = false;
@@ -55,6 +56,6 @@ class Screen {
   std::vector<std::vector<Pixel>> pixels_;
 };
 
-};  // namespace ftxui
+};  // namespace ftxui::screen
 
-#endif /* end of include guard: FTXUI_SCREEN */
+#endif /* end of include guard: FTXUI_SCREEN_SCREEN */

ftxui/src/ftxui/component/component.cpp

@@ -2,8 +2,7 @@
 #include "ftxui/component/delegate.hpp"
 #include <assert.h>
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 Component::Component(Delegate* delegate) {
   delegate_ = delegate;
@@ -55,5 +54,4 @@ Component* Component::Parent() {
   return parent_delegate->component();
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/component/component_direction.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/component/component_direction.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 ComponentDirection::ComponentDirection(Delegate* delegate)
     : Component(delegate), active_child_(nullptr) {}
@@ -27,5 +26,4 @@ void ComponentDirection::Focus(Component* child) {
   active_child_ = child;
 }
 
-} // namespace component
-} // namespace ftxui
+} // namespace ftxui::Component

ftxui/src/ftxui/component/component_horizontal.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/component/component_horizontal.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 ComponentHorizontal::ComponentHorizontal(Delegate* delegate)
     : ComponentDirection(delegate) {}
@@ -28,5 +27,4 @@ bool ComponentHorizontal::HandleDirection(Event event) {
   return false;
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/component/component_vertical.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/component/component_vertical.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 ComponentVertical::ComponentVertical(Delegate* delegate)
     : ComponentDirection(delegate) {}
@@ -28,5 +27,4 @@ bool ComponentVertical::HandleDirection(Event event) {
   return false;
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/component/event.cpp

@@ -1,6 +1,6 @@
-#include "ftxui/event.hpp"
+#include "ftxui/component/event.hpp"
 
-namespace ftxui {
+namespace ftxui::component {
 
 constexpr int ESC = int(27);
 
@@ -34,4 +34,4 @@ Event Event::F10{ESC, '[', '2', '1', '~'};
 Event Event::F11{ESC, '[', '2', '1', '~'};  // Same as F10 ?
 Event Event::F12{ESC, '[', '2', '4', '~'};
 
-} // namespace ftxui
+} // namespace ftxui::component

ftxui/src/ftxui/component/input.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/component/input.hpp"
 #include "ftxui/util/string.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 Input::Input(Delegate* delegate): Component(delegate) {}
 Input::~Input() {}
@@ -76,5 +75,4 @@ bool Input::OnEvent(Event event) {
   return false;
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/component/menu.cpp

@@ -2,8 +2,7 @@
 #include <algorithm>
 #include <iostream>
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 Menu::Menu(Delegate* delegate) : Component(delegate) {}
 
@@ -50,5 +49,4 @@ bool Menu::OnEvent(Event event) {
   return false;
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/component/screen_interactive.cpp

@@ -1,48 +1,48 @@
-#include "ftxui/screen_interactive.hpp"
+#include "ftxui/component/screen_interactive.hpp"
 
-#include "ftxui/component/component.hpp"
-#include "ftxui/component/delegate.hpp"
-#include "ftxui/terminal.hpp"
-#include <iostream>
 #include <stdio.h>
 #include <termios.h>
 #include <unistd.h>
+#include <iostream>
+#include "ftxui/component/component.hpp"
+#include "ftxui/component/delegate.hpp"
+#include "ftxui/terminal.hpp"
 
-namespace ftxui {
+namespace ftxui::component {
 
 namespace {
-  constexpr int ESC = 27;
-  constexpr int WAT = 195;
-  constexpr int WAT2 = 194;
-  constexpr int WATWAIT = 91;
+constexpr int ESC = 27;
+constexpr int WAT = 195;
+constexpr int WAT2 = 194;
+constexpr int WATWAIT = 91;
 
-  Event GetEvent() {
-    int v1 = getchar();
-    if (v1 == ESC) {
-      int v2 = getchar();
-      int v3 = getchar();
+Event GetEvent() {
+  int v1 = getchar();
+  if (v1 == ESC) {
+    int v2 = getchar();
+    int v3 = getchar();
 
-      //if (v2 == WATWAIT) {
-        //int v4 = getchar();
-        //int v5 = getchar();
-        //return Event{v1, v2, v3, v4, v5};
-      //}
-      return Event{v1, v2, v3};
-    }
+    // if (v2 == WATWAIT) {
+    // int v4 = getchar();
+    // int v5 = getchar();
+    // return Event{v1, v2, v3, v4, v5};
+    //}
+    return Event{v1, v2, v3};
+  }
 
-    if (v1 == WAT) {
-      int v2 = getchar();
-      return Event{v1, v2};
-    }
+  if (v1 == WAT) {
+    int v2 = getchar();
+    return Event{v1, v2};
+  }
 
-    if (v1 == WAT2) {
-      int v2 = getchar();
-      return Event{v1, v2};
-    }
+  if (v1 == WAT2) {
+    int v2 = getchar();
+    return Event{v1, v2};
+  }
 
-    return Event{v1};
-  };
+  return Event{v1};
 };
+};  // namespace
 
 class ScreenInteractive::Delegate : public component::Delegate {
  public:
@@ -67,7 +67,6 @@ class ScreenInteractive::Delegate : public component::Delegate {
 
   void OnEvent(Event event) { component_->OnEvent(event); }
 
-
   std::vector<component::Delegate*> children() override {
     std::vector<component::Delegate*> ret;
     for (auto& it : child_)
@@ -129,12 +128,14 @@ void ScreenInteractive::Loop() {
   tcsetattr(STDIN_FILENO, TCSANOW, &terminal_configuration_new);
 
   Draw();
-  while(!quit_) {
+  while (!quit_) {
     delegate_->OnEvent(GetEvent());
     Clear();
     Draw();
-  } while(!quit_);
-  //std::cout << std::endl;
+  }
+  while (!quit_)
+    ;
+  // std::cout << std::endl;
 
   // Restore the old terminal configuration.
   tcsetattr(STDIN_FILENO, TCSANOW, &terminal_configuration_old);
@@ -144,7 +145,7 @@ void ScreenInteractive::Draw() {
   auto document = delegate_->component()->Render();
   size_t dimx;
   size_t dimy;
-  switch(dimension_) {
+  switch (dimension_) {
     case Dimension::Fixed:
       break;
     case Dimension::TerminalOutput:
@@ -162,7 +163,8 @@ void ScreenInteractive::Draw() {
   if (dimx != dimx_ || dimy != dimy_) {
     dimx_ = dimx;
     dimy_ = dimy;
-    pixels_ = std::vector<std::vector<Pixel>>(dimy, std::vector<Pixel>(dimx));
+    pixels_ = std::vector<std::vector<screen::Pixel>>(
+        dimy, std::vector<screen::Pixel>(dimx));
   }
 
   Render(*this, document.get());
@@ -182,4 +184,4 @@ std::function<void()> ScreenInteractive::ExitLoopClosure() {
   return [this]() { quit_ = true; };
 }
 
-}  // namespace ftxui
+}  // namespace ftxui::component.

ftxui/src/ftxui/component/toggle.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/component/toggle.hpp"
 
-namespace ftxui {
-namespace component {
+namespace ftxui::component {
 
 Toggle::Toggle(Delegate* delegate) : Component(delegate) {}
 
@@ -41,5 +40,4 @@ bool Toggle::OnEvent(Event event) {
   return false;
 }
 
-}  // namespace component
-}  // namespace ftxui
+}  // namespace ftxui::component

ftxui/src/ftxui/dom/blink.cpp

@@ -1,15 +1,14 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class Blink : public NodeDecorator {
  public:
   Blink(Children children) : NodeDecorator(std::move(children)) {}
   ~Blink() override {}
 
-  void Render(Screen& screen) override {
+  void Render(screen::Screen& screen) override {
     Node::Render(screen);
     for (int y = box_.top; y <= box_.bottom; ++y) {
       for (int x = box_.left; x <= box_.right; ++x) {
@@ -23,5 +22,4 @@ std::unique_ptr<Node> blink(Child child) {
   return std::make_unique<Blink>(unpack(std::move(child)));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/bold.cpp

@@ -1,15 +1,14 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class Bold : public NodeDecorator {
  public:
   Bold(Children children) : NodeDecorator(std::move(children)) {}
   ~Bold() override {}
 
-  void Render(Screen& screen) override {
+  void Render(screen::Screen& screen) override {
     for (int y = box_.top; y <= box_.bottom; ++y) {
       for (int x = box_.left; x <= box_.right; ++x) {
         screen.PixelAt(x,y).bold = true; 
@@ -23,5 +22,4 @@ std::unique_ptr<Node> bold(Child child) {
   return std::make_unique<Bold>(unpack(std::move(child)));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/color.cpp

@@ -1,15 +1,14 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class BgColor : public NodeDecorator {
  public:
   BgColor(Children children, Color color)
       : NodeDecorator(std::move(children)), color_(color) {}
 
-  void Render(Screen& screen) override {
+  void Render(screen::Screen& screen) override {
     for (int y = box_.top; y <= box_.bottom; ++y) {
       for (int x = box_.left; x <= box_.right; ++x) {
         screen.PixelAt(x, y).background_color = color_;
@@ -27,7 +26,7 @@ class FgColor : public NodeDecorator {
       : NodeDecorator(std::move(children)), color_(color) {}
   ~FgColor() override {}
 
-  void Render(Screen& screen) override {
+  void Render(screen::Screen& screen) override {
     for (int y = box_.top; y <= box_.bottom; ++y) {
       for (int x = box_.left; x <= box_.right; ++x) {
         screen.PixelAt(x, y).foreground_color = color_;
@@ -59,5 +58,4 @@ Decorator bgcolor(Color c) {
   };
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/composite_decorator.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 std::unique_ptr<Node> hcenter(Element child) {
   return hbox(filler(), std::move(child), filler());
@@ -16,5 +15,4 @@ std::unique_ptr<Node> center(Element child) {
   return hcenter(vcenter(std::move(child)));
 }
 
-} // namespace dom
-} // namespace ftxui
+} // namespace ftxui::dom

ftxui/src/ftxui/dom/dbox.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class DBox : public Node {
  public:
@@ -33,5 +32,4 @@ std::unique_ptr<Node> dbox(Children children) {
   return std::make_unique<DBox>(std::move(children));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/dim.cpp

@@ -1,8 +1,9 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 class Dim : public NodeDecorator {
  public:
@@ -23,5 +24,4 @@ std::unique_ptr<Node> dim(Child child) {
   return std::make_unique<Dim>(unpack(std::move(child)));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/flex.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class Flex : public Node {
  public:
@@ -35,5 +34,4 @@ std::unique_ptr<Node> flex(Element child) {
   return std::make_unique<Flex>(std::move(child));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/frame.cpp

@@ -1,8 +1,9 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using namespace ftxui::screen;
 
 static wchar_t charset[] = L"┌┐└┘─│┬┴┤├";
 
@@ -94,5 +95,4 @@ Decorator boxed() {
   };
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/gauge.cpp

@@ -1,8 +1,9 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using namespace ftxui::screen;
 
 static wchar_t charset[] = L"  ▏▎▍▌▋▊▉█";
 
@@ -35,5 +36,4 @@ std::unique_ptr<Node> gauge(float progress) {
   return std::make_unique<Gauge>(progress);
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/gauge_test.cpp

@@ -1,9 +1,9 @@
 #include "ftxui/dom/elements.hpp"
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include "gtest/gtest.h"
 
-namespace ftxui {
-namespace dom {
+using namespace ftxui::screen;
+using namespace ftxui::dom;
 
 TEST(GaugeTest, zero) {
   auto root = gauge(0);
@@ -29,6 +29,3 @@ TEST(GaugeTest, one) {
 
   EXPECT_EQ("███████████", screen.ToString());
 }
-
-} // namespace dom
-} // namespace ftxui

ftxui/src/ftxui/dom/hbox.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class HBox : public Node {
  public:
@@ -64,5 +63,4 @@ std::unique_ptr<Node> hbox(Children children) {
   return std::make_unique<HBox>(std::move(children));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/hbox_test.cpp

@@ -1,9 +1,9 @@
 #include "ftxui/dom/elements.hpp"
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include "gtest/gtest.h"
 
-namespace ftxui {
-namespace dom {
+using namespace ftxui::screen;
+using namespace ftxui::dom;
 
 TEST(HBoxTest, ScreenSmaller1) {
   auto root = hbox(
@@ -118,6 +118,3 @@ TEST(HBoxTest, ScreenBigger2Flex) {
 
   EXPECT_EQ("text_1  text_2", screen.ToString());
 }
-
-};  // namespace dom
-};  // namespace ftxui

ftxui/src/ftxui/dom/inverted.cpp

@@ -1,8 +1,9 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 class Inverted : public NodeDecorator {
  public:
@@ -23,5 +24,4 @@ std::unique_ptr<Node> inverted(Child child) {
   return std::make_unique<Inverted>(unpack(std::move(child)));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/node.cpp

@@ -1,7 +1,8 @@
 #include "ftxui/dom/node.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 Node::Node() {}
 Node::Node(std::vector<std::unique_ptr<Node>> children)
@@ -39,5 +40,4 @@ void Render(Screen& screen, Node* node) {
   node->Render(screen);
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/node_decorator.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/dom/node_decorator.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 void NodeDecorator::ComputeRequirement() {
   Node::ComputeRequirement();
@@ -13,5 +12,4 @@ void NodeDecorator::SetBox(Box box) {
   children[0]->SetBox(box);
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/node_decorator.hpp

@@ -4,8 +4,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 // Helper class.
 class NodeDecorator : public Node {
@@ -16,7 +15,6 @@ class NodeDecorator : public Node {
   void SetBox(Box box) override;
 };
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom
 
 #endif /* end of include guard: FTXUI_DOM_NODE_DECORATOR_H_ */

ftxui/src/ftxui/dom/separator.cpp

@@ -1,7 +1,8 @@
 #include "ftxui/dom/node.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 class Separator : public Node {
  public:
@@ -34,5 +35,4 @@ std::unique_ptr<Node> separator() {
   return std::make_unique<Separator>();
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/text.cpp

@@ -1,7 +1,8 @@
 #include "ftxui/dom/node.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 class Text : public Node {
  public:
@@ -33,5 +34,4 @@ std::unique_ptr<Node> text(std::wstring text) {
   return std::make_unique<Text>(text);
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/text_test.cpp

@@ -1,9 +1,9 @@
 #include "ftxui/dom/elements.hpp"
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include "gtest/gtest.h"
 
-namespace ftxui {
-namespace dom {
+using namespace ftxui::screen;
+using namespace ftxui::dom;
 
 TEST(TextTest, ScreenHeightSmaller) {
   auto element = text(L"test");
@@ -44,6 +44,3 @@ TEST(TextTest, ScreenBigger2) {
 
   EXPECT_EQ("test  \n      ", screen.ToString());
 }
-
-};  // namespace dom
-};  // namespace ftxui

ftxui/src/ftxui/dom/underlined.cpp

@@ -1,8 +1,9 @@
 #include "ftxui/dom/node_decorator.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
+
+using ftxui::screen::Screen;
 
 class Underlined : public NodeDecorator {
  public:
@@ -23,5 +24,4 @@ std::unique_ptr<Node> underlined(Child child) {
   return std::make_unique<Underlined>(unpack(std::move(child)));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/util.cpp

@@ -1,7 +1,6 @@
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 Element nothing(Element element) {
   return std::move(element);
@@ -24,5 +23,4 @@ Element operator|(Element e, Decorator d) {
   return d(std::move(e));
 }
 
-}  // namespace dom
-}  // namespace ftxui
+}  // namespace ftxui::dom

ftxui/src/ftxui/dom/vbox.cpp

@@ -1,8 +1,7 @@
 #include "ftxui/dom/node.hpp"
 #include "ftxui/dom/elements.hpp"
 
-namespace ftxui {
-namespace dom {
+namespace ftxui::dom {
 
 class VBox : public Node {
  public:
@@ -64,5 +63,4 @@ std::unique_ptr<Node> vbox(Children children) {
   return std::make_unique<VBox>(std::move(children));
 }
 
-};  // namespace dom
-};  // namespace ftxui
+};  // namespace ftxui::dom

ftxui/src/ftxui/dom/vbox_test.cpp

@@ -1,9 +1,9 @@
 #include "ftxui/dom/elements.hpp"
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include "gtest/gtest.h"
 
-namespace ftxui {
-namespace dom {
+using namespace ftxui::screen;
+using namespace ftxui::dom;
 
 TEST(VBoxTest, ScreenSmaller1) {
   auto root = vbox(text(L"text_1"), text(L"text_2"));
@@ -66,6 +66,3 @@ TEST(VBoxTest, ScreenBigger2Flex) {
 
   EXPECT_EQ("text_1\n      \n      \ntext_2", screen.ToString());
 }
-
-};  // namespace dom
-};  // namespace ftxui

ftxui/src/ftxui/screen/screen.cpp

@@ -1,26 +1,46 @@
-#include "ftxui/screen.hpp"
+#include "ftxui/screen/screen.hpp"
 #include "ftxui/dom/node.hpp"
 #include "ftxui/terminal.hpp"
 #include "ftxui/util/string.hpp"
 
 #include <sstream>
 
-namespace ftxui {
+namespace ftxui::screen {
+
+static const wchar_t* BOLD_SET = L"\e[1m";
+static const wchar_t* BOLD_RESET = L"\e[22m"; // Can't use 21 here.
+
+static const wchar_t* DIM_SET = L"\e[2m";
+static const wchar_t* DIM_RESET = L"\e[22m";
+
+static const wchar_t* UNDERLINED_SET = L"\e[4m";
+static const wchar_t* UNDERLINED_RESET = L"\e[24m";
+
+static const wchar_t* BLINK_SET = L"\e[5m";
+static const wchar_t* BLINK_RESET = L"\e[25m";
+
+static const wchar_t* INVERTED_SET = L"\e[7m";
+static const wchar_t* INVERTED_RESET = L"\e[27m";
 
 Screen::Screen(size_t dimx, size_t dimy)
     : dimx_(dimx), dimy_(dimy), pixels_(dimy, std::vector<Pixel>(dimx)) {}
 
 void UpdatePixelStyle(std::wstringstream& ss, Pixel& previous, Pixel& next) {
   if (next.bold != previous.bold)
-    ss << (next.bold ? L"\e[1m" : L"\e[22m"); // Can't use 21 here.
+    ss << (next.bold ? BOLD_SET : BOLD_RESET);
+
   if (next.dim != previous.dim)
-    ss << (next.dim ? L"\e[2m" : L"\e[22m");
+    ss << (next.dim ? DIM_SET : DIM_RESET);
+
   if (next.underlined != previous.underlined)
-    ss << (next.underlined ? L"\e[4m" : L"\e[24m");
+    ss << (next.underlined ? UNDERLINED_SET : UNDERLINED_RESET);
+
   if (next.blink != previous.blink)
-    ss << (next.blink ? L"\e[5m" : L"\e[25m");
+    ss << (next.blink ? BLINK_SET : BLINK_RESET);
+
   if (next.inverted != previous.inverted)
-    ss << (next.inverted ? L"\e[7m" : L"\e[27m");
+    ss << (next.inverted ? INVERTED_SET : INVERTED_RESET);
+
   if (next.foreground_color != previous.foreground_color ||
       next.background_color != previous.background_color) {
     ss << L"\e[" + to_wstring(std::to_string((uint8_t)next.foreground_color)) + L"m";
@@ -84,4 +104,4 @@ void Screen::Clear() {
                                             std::vector<Pixel>(dimx_, Pixel()));
 }
 
-};  // namespace ftxui
+};  // namespace ftxui::screen