Add Graph.

ftxui/include/ftxui/component/checkbox.hpp

@@ -17,7 +17,7 @@ class CheckBox : public Component {
 
   //std::wstring checked = L"[X] ";
   //std::wstring unchecked = L"[ ] ";
-  std::wstring checked = L"☑ ";
+  std::wstring checked = L"▣ ";
   std::wstring unchecked = L"☐ ";
 
   Decorator focused_style = inverted;

ftxui/include/ftxui/component/screen_interactive.hpp

@@ -10,7 +10,7 @@ class Component;
 
 class ScreenInteractive : public Screen {
   public:
-    static ScreenInteractive FixedSize(size_t dimx, size_t dimy);
+    static ScreenInteractive FixedSize(int dimx, int dimy);
     static ScreenInteractive Fullscreen();
     static ScreenInteractive FitComponent();
     static ScreenInteractive TerminalOutput();
@@ -30,7 +30,7 @@ class ScreenInteractive : public Screen {
      TerminalOutput,
    };
    Dimension dimension_ = Dimension::Fixed;
-   ScreenInteractive(size_t dimx, size_t dimy, Dimension dimension);
+   ScreenInteractive(int dimx, int dimy, Dimension dimension);
 };
 
 }  // namespace ftxui

ftxui/include/ftxui/dom/elements.hpp

@@ -3,6 +3,7 @@
 
 #include <functional>
 
+#include "ftxui/dom/graph.hpp"
 #include "ftxui/dom/node.hpp"
 #include "ftxui/screen/color.hpp"
 
@@ -20,6 +21,7 @@ Element border(Element);
 Element window(Element title, Element content);
 Element spinner(int charset_index, size_t image_index);
 Elements paragraph(std::wstring text); // Use inside hflow(). Split by space.
+Element graph(GraphFunction&); // See graph.hpp
 
 // -- Decorator ---
 Element bold(Element);
@@ -68,6 +70,7 @@ Element nothing(Element element);
 // Pipe elements into decorator togethers.
 // Examples: text("ftxui") | bold | underlined;
 Element operator|(Element, Decorator);
+Elements operator|(Elements, Decorator);
 Decorator operator|(Decorator, Decorator);
 
 // Make container able to take any number of children as input.

ftxui/include/ftxui/dom/graph.hpp

@@ -0,0 +1,15 @@
+#ifndef FTXUI_DOM_GRAPH_HPP
+#define FTXUI_DOM_GRAPH_HPP
+
+#include "ftxui/dom/elements.hpp"
+
+namespace ftxui {
+
+class GraphFunction {
+ public:
+  virtual std::vector<int> operator()(int width, int height) = 0;
+};
+
+} // namespace ftxui
+
+#endif /* end of include guard: FTXUI_DOM_GRAPH_HPP */

ftxui/include/ftxui/screen/screen.hpp

@@ -25,26 +25,32 @@ struct Pixel {
   Color foreground_color = Color::Default;
 };
 
+struct Dimension {
+  static Dimension Fixed(int);
+  static Dimension Fit(std::unique_ptr<Node>&);
+  static Dimension Full();
+
+  int dimx;
+  int dimy;
+};
+
 class Screen {
  public:
   // Constructor.
-  Screen(size_t dimx, size_t dimy);
-
-  // Constructor using the terminal.
-  static Screen TerminalFullscreen();
-  static Screen TerminalOutput(std::unique_ptr<Node>& element);
-  static Screen FitDocument(std::unique_ptr<Node>& element);
+  Screen(int dimx, int dimy);
+  static Screen Create(Dimension dimension);
+  static Screen Create(Dimension width, Dimension height);
 
   // Node write into the screen using Screen::at.
-  wchar_t& at(size_t x, size_t y);
-  Pixel& PixelAt(size_t x, size_t y);
+  wchar_t& at(int x, int y);
+  Pixel& PixelAt(int x, int y);
 
   // Convert the screen into a printable string in the terminal.
   std::string ToString();
 
   // Get screen dimensions.
-  size_t dimx() { return dimx_;}
-  size_t dimy() { return dimy_;}
+  int dimx() { return dimx_;}
+  int dimy() { return dimy_;}
 
   // Move the terminal cursor n-lines up with n = dimy().
   std::string ResetPosition();
@@ -56,8 +62,8 @@ class Screen {
   Box stencil;
 
  protected:
-  size_t dimx_;
-  size_t dimy_;
+  int dimx_;
+  int dimy_;
   std::vector<std::vector<Pixel>> pixels_;
 };