undo_stack.hpp

#pragma once
#include "coord.hpp"
#include <vector>

class BaseUndoCommand
{
public:
  virtual ~BaseUndoCommand();
  virtual void undo(Coord &cursor) = 0;
  virtual void redo(Coord &cursor) = 0;
};

template <typename RedoFunc, typename UndoFunc>
class UndoCommand: public BaseUndoCommand
{
public:
  UndoCommand(Coord cursor, const RedoFunc &redoFunc, const UndoFunc &undoFunc):
    redoFunc_(redoFunc),
    undoFunc_(undoFunc),
    cursor_(cursor)
  {}
  virtual void undo(Coord &cursor)
  {
    Coord tmp = cursor_;
    undoFunc_(tmp, data_);
    cursor = tmp;
  }
  virtual void redo(Coord &cursor)
  {
    Coord tmp = cursor_;
    data_ = redoFunc_(tmp);
    cursor = tmp;
  }
private:
  RedoFunc redoFunc_;
  UndoFunc undoFunc_;
  typedef decltype(redoFunc_(*(new Coord))) Data;
  Data data_;
  Coord cursor_;
};

class UndoStack
{
public:
  UndoStack();
  ~UndoStack();
  template <typename RedoFunc, typename UndoFunc>
  void push(Coord &cursor, const RedoFunc &redoFunc, const UndoFunc &undoFunc)
  {
    auto command = new UndoCommand<RedoFunc, UndoFunc>{cursor, redoFunc, undoFunc};
    undoStack_.push_back(command);
    command->redo(cursor);
    for (auto c: redoStack_)
      delete c;
    redoStack_.clear();
  }   
  void undo(Coord &cursor);
  void redo(Coord &cursor);
  bool canUndo() const;
  bool canRedo() const;
  void clean();
  bool isModified() const;
  void clearModified();
public:
  std::vector<BaseUndoCommand *> undoStack_;
  std::vector<BaseUndoCommand *> redoStack_;
  std::vector<BaseUndoCommand *>::size_type originalState_;
};