GoF.h

#pragma once

namespace FlyweightPattern::GoF
{
	class Window;
	class GlyphContext;
	class Font;

	class Glyph {
	public:
		virtual ~Glyph() {}

		virtual void Draw(Window*, GlyphContext&) {}

		virtual void SetFont(Font*, GlyphContext&) {}
		virtual Font* GetFont(GlyphContext&) { return nullptr; }

		virtual void First(GlyphContext&) {}
		virtual void Next(GlyphContext&) {}
		virtual bool IsDone(GlyphContext&) { return true; }
		virtual Glyph* Current(GlyphContext&) { return nullptr; }

		virtual void Insert(Glyph*, GlyphContext&) {}
		virtual void Remove(GlyphContext&) {}
	protected:
		Glyph() {}
	};

	class Character : public Glyph {
	public:
		Character(char) {}

		virtual void Draw(Window*, GlyphContext&) {}
	private:
		char _charcode;
	};

	class BTree;

	class GlyphContext {
	public:
		GlyphContext() {}
		virtual ~GlyphContext() {}

		virtual void Next(int step = 1) {}
		virtual void Insert(int quantity = 1) {}

		virtual Font* GetFont() {}
		virtual void SetFont(Font*, int span = 1) {}
	private:
		int _index;
		BTree* _fonts;
	};

	class Row {};
	class Column {};

	const int NCHARCODES = 128;

	class GlyphFactory {
	public:
		GlyphFactory();
		virtual ~GlyphFactory() {}

		virtual Character* CreateCharacter(char);
		virtual Row* CreateRow();
		virtual Column* CreateColumn();
		// ... 
	private:
		Character* _character[NCHARCODES];
	};

	GlyphFactory::GlyphFactory() {
		for (int i = 0; i < NCHARCODES; ++i) {
			_character[i] = 0;
		}
	}

	Character* GlyphFactory::CreateCharacter(char c) {
		if (!_character[c]) {
			_character[c] = new Character(c);
		}

		return _character[c];
	}

	Row* GlyphFactory::CreateRow() {
		return new Row;
	}

	Column* GlyphFactory::CreateColumn() {
		return new Column;
	}
}