S.F. Tracker (121)

Undo Redoの実装を再検討中。

Undo RedoをUndo/Redoをコンテナ(stack) + ファンクタ(boost.function) + 引数束縛(boost.bind)で実装したのであるが、問題が発生。

実装の前提として、「操作および値」のみをUndo・Redoの対象と考えていた。
だが、「操作を行う前の状態」もUndo・Redoの対象としなくてはいけないことが発覚した。
<!-- </p> <p>#pragma once /** @file</p> <ul> <li>@brief undo redo command class</li> <li>@author S.F. (Satoshi Fujiwara) <em>/ #include <stack> namespace sf { namespace model { struct command_manager; struct command { typedef boost::function<void () > func_type; friend struct command_manager; command(const func_type& exec_func,const func_type& undo_func,const bool term = true) { m_undo_func = undo_func; m_exec_func = exec_func; m_terminate = term; }; command(const func_type& exec_func,const bool term = true) { m_exec_func = exec_func; m_terminate = term; }; ~command(){}; private: const bool can_undo() const throw() { return !m_undo_func.empty(); }; const bool can_redo() const throw() { return !m_exec_func.empty(); }; const bool is_terminate() const throw() { return m_terminate;}; void undo(){m_undo_func();}; void redo(){m_exec_func();}; void execute(){m_exec_func();}; func_type m_undo_func; func_type m_exec_func; bool m_terminate; static void null_func(){}; }; struct command_manager { command_manager(){}; ~command_manager(){}; void execute(command& exec_command) { if(exec_command.can_undo()) { m_redo.c.clear(); m_undo.push(boost::addressof(exec_command)); } exec<em>command.execute(); }; void undo() { bool term</em> = false; while(!term_ && !m_undo.empty()) { m<em>undo.top()->undo(); term</em> = m_undo.top()->is_terminate(); m_redo.push(m_undo.top()); m<em>undo.pop(); } }; void redo() { bool term</em> = false; while(!term_ && !m_redo.empty()) { m<em>redo.top()->redo(); term</em> = m_redo.top()->is_terminate(); m_undo.push(m_redo.top()); m_redo.pop(); } }; private: std::stack<sf::model::command</em>,boost::ptr_deque<sf::model::command> > m_undo; std::stack<sf::model::command*,boost::ptr_deque<sf::model::command> > m_redo; }; }; -->