game_cursor.h

#pragma once
 
#include "scid/core/game.h"
#include "scid/core/movetext_location.h"
#include "scid/core/position.h"
 
#include <cstddef>
#include <optional>
#include <vector>
 
namespace scid::core {
 
class GameCursor {
private:
    struct ParentFrame {
        const MoveSequence* line = nullptr;
        std::size_t nextIndex = 0;
        std::size_t variationIndex = 0;
    };
 
public:
    explicit GameCursor(const Game& game);
 
    const Move* previousMove() const;
    const Move* nextMove() const;
    const Variation* currentVariation() const;
    std::vector<const Move*> movesToCursor() const;
    std::optional<scid::core::Position> currentPosition() const;
    std::size_t ply() const;
    std::size_t variationCount() const;
    std::size_t variationDepth() const;
    std::size_t variationIndex() const;
 
    bool isAtLineStart() const;
    bool isAtLineEnd() const;
    bool isAtVariationStart() const;
    bool isAtVariationEnd() const;
    bool isAtGameStart() const;
    bool isAtGameEnd() const;
    bool isAtEmptyVariation() const;
 
    bool next();
    bool previous();
    bool enterVariation(std::size_t index);
    bool exitVariation();
    void toStart();
    void toEnd();
    bool toPly(std::size_t ply);
 
    MovetextLocation location() const;
    bool restore(MovetextLocation location);
 
private:
    const MoveSequence& currentLine() const;
 
    const Game& game_;
    const MoveSequence* currentLine_ = nullptr;
    std::size_t nextIndex_ = 0;
    std::vector<ParentFrame> parents_;
};
 
} // namespace scid::core