Add cairo interface.

src/visual_elements/TextElement.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "DiscretePoint.h"
+
+#include <memory>
+#include <string>
+
+class Color;
+
+class TextElement
+{
+    std::string mContent;
+    DiscretePoint mLocation;
+    std::string mFontLabel;
+    std::unique_ptr<Color> mFillColor;
+    std::unique_ptr<Color> mStrokeColor;
+
+public:
+
+    TextElement(const std::string& content, const DiscretePoint& loc);
+
+    ~TextElement();
+
+    static std::unique_ptr<TextElement> Create(const std::string& content, const DiscretePoint& loc);
+
+    Color* GetFillColor() const;
+    Color* GetStrokeColor() const;
+
+    DiscretePoint GetLocation() const;
+    std::string GetContent() const;
+    std::string GetFontLabel() const;
+    void SetContent(const std::string& content);
+    void SetFillColor(std::unique_ptr<Color> color);
+    void SetStrokeColor(std::unique_ptr<Color> color);
+};
+
+using TextElementUPtr = std::unique_ptr<TextElement>;