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include/ftxui/dom/canvas.hpp

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+// 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.
+#ifndef FTXUI_DOM_CANVAS_HPP
+#define FTXUI_DOM_CANVAS_HPP
+
+#include <cstddef>        // for size_t
+#include <functional>     // for function
+#include <string>         // for string
+#include <unordered_map>  // for unordered_map
+
+#include "ftxui/screen/color.hpp"   // for Color
+#include "ftxui/screen/screen.hpp"  // for Pixel
+
+#ifdef DrawText
+// Workaround for WinUsr.h (via Windows.h) defining macros that break things.
+// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-drawtext
+#undef DrawText
+#endif
+
+namespace ftxui {
+
+struct Canvas {
+ public:
+  Canvas() = default;
+  Canvas(int width, int height);
+
+  // Getters:
+  int width() const { return width_; }
+  int height() const { return height_; }
+  Pixel GetPixel(int x, int y) const;
+
+  using Stylizer = std::function<void(Pixel&)>;
+
+  // Draws using braille characters --------------------------------------------
+  void DrawPointOn(int x, int y);
+  void DrawPointOff(int x, int y);
+  void DrawPointToggle(int x, int y);
+  void DrawPoint(int x, int y, bool value);
+  void DrawPoint(int x, int y, bool value, const Stylizer& s);
+  void DrawPoint(int x, int y, bool value, const Color& color);
+  void DrawPointLine(int x1, int y1, int x2, int y2);
+  void DrawPointLine(int x1, int y1, int x2, int y2, const Stylizer& s);
+  void DrawPointLine(int x1, int y1, int x2, int y2, const Color& color);
+  void DrawPointCircle(int x, int y, int radius);
+  void DrawPointCircle(int x, int y, int radius, const Stylizer& s);
+  void DrawPointCircle(int x, int y, int radius, const Color& color);
+  void DrawPointCircleFilled(int x, int y, int radius);
+  void DrawPointCircleFilled(int x, int y, int radius, const Stylizer& s);
+  void DrawPointCircleFilled(int x, int y, int radius, const Color& color);
+  void DrawPointEllipse(int x, int y, int r1, int r2);
+  void DrawPointEllipse(int x, int y, int r1, int r2, const Color& color);
+  void DrawPointEllipse(int x, int y, int r1, int r2, const Stylizer& s);
+  void DrawPointEllipseFilled(int x, int y, int r1, int r2);
+  void DrawPointEllipseFilled(int x, int y, int r1, int r2, const Color& color);
+  void DrawPointEllipseFilled(int x, int y, int r1, int r2, const Stylizer& s);
+
+  // Draw using box characters -------------------------------------------------
+  // Block are of size 1x2. y is considered to be a multiple of 2.
+  void DrawBlockOn(int x, int y);
+  void DrawBlockOff(int x, int y);
+  void DrawBlockToggle(int x, int y);
+  void DrawBlock(int x, int y, bool value);
+  void DrawBlock(int x, int y, bool value, const Stylizer& s);
+  void DrawBlock(int x, int y, bool value, const Color& color);
+  void DrawBlockLine(int x1, int y1, int x2, int y2);
+  void DrawBlockLine(int x1, int y1, int x2, int y2, const Stylizer& s);
+  void DrawBlockLine(int x1, int y1, int x2, int y2, const Color& color);
+  void DrawBlockCircle(int x1, int y1, int radius);
+  void DrawBlockCircle(int x1, int y1, int radius, const Stylizer& s);
+  void DrawBlockCircle(int x1, int y1, int radius, const Color& color);
+  void DrawBlockCircleFilled(int x1, int y1, int radius);
+  void DrawBlockCircleFilled(int x1, int y1, int radius, const Stylizer& s);
+  void DrawBlockCircleFilled(int x1, int y1, int radius, const Color& color);
+  void DrawBlockEllipse(int x1, int y1, int r1, int r2);
+  void DrawBlockEllipse(int x1, int y1, int r1, int r2, const Stylizer& s);
+  void DrawBlockEllipse(int x1, int y1, int r1, int r2, const Color& color);
+  void DrawBlockEllipseFilled(int x1, int y1, int r1, int r2);
+  void DrawBlockEllipseFilled(int x1,
+                              int y1,
+                              int r1,
+                              int r2,
+                              const Stylizer& s);
+  void DrawBlockEllipseFilled(int x1,
+                              int y1,
+                              int r1,
+                              int r2,
+                              const Color& color);
+
+  // Draw using normal characters ----------------------------------------------
+  // Draw using character of size 2x4 at position (x,y)
+  // x is considered to be a multiple of 2.
+  // y is considered to be a multiple of 4.
+  void DrawText(int x, int y, const std::string& value);
+  void DrawText(int x, int y, const std::string& value, const Color& color);
+  void DrawText(int x, int y, const std::string& value, const Stylizer& style);
+
+  // Decorator:
+  // x is considered to be a multiple of 2.
+  // y is considered to be a multiple of 4.
+  void Style(int x, int y, const Stylizer& style);
+
+ private:
+  bool IsIn(int x, int y) const {
+    return x >= 0 && x < width_ && y >= 0 && y < height_;
+  }
+  enum CellType {
+    kBraille,
+    kBlock,
+    kText,
+  };
+  struct Cell {
+    CellType type = kText;
+    Pixel content;
+  };
+  struct XY {
+    int x;
+    int y;
+    bool operator==(const XY& other) const {
+      return x == other.x && y == other.y;
+    }
+  };
+
+  struct XYHash {
+    size_t operator()(const XY& xy) const {
+      constexpr size_t shift = 1024;
+      return size_t(xy.x) * shift + size_t(xy.y);
+    }
+  };
+
+  int width_ = 0;
+  int height_ = 0;
+  std::unordered_map<XY, Cell, XYHash> storage_;
+};
+
+}  // namespace ftxui
+
+#endif  // FTXUI_DOM_CANVAS_HPP