/home/pete/Work/TSE3.svn/tse3/src/tse3/cmd/Command.h

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/*
 * @(#)cmd/Command.h 3.00 10 June 1999
 *
 * Copyright (c) 2000 Pete Goodliffe (pete@cthree.org)
 *
 * This file is part of TSE3 - the Trax Sequencer Engine version 3.00.
 *
 * This library is modifiable/redistributable under the terms of the GNU
 * General Public License.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING. If not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 */

#ifndef TSE3_CMD_COMMAND_H
#define TSE3_CMD_COMMAND_H

#include <string>

namespace TSE3
{
    namespace Cmd
    {
        class Command
        {
            public:

                virtual ~Command() {}

                void execute()
                {
                    if (!_done)
                    {
                        executeImpl();
                        _done = true;
                    }
                }

                void undo()
                {
                    if (_done && _undoable)
                    {
                        undoImpl();
                        _done = false;
                    }
                }

                const std::string &title() const { return _title; }

                bool undoable() const { return _undoable; }

                bool done() const { return _done; }

            protected:

                Command(const std::string &title, bool undoable = true)
                : _title(title), _undoable(undoable), _done(false)
                {}

                virtual void executeImpl() = 0;

                virtual void undoImpl() = 0;

                void setTitle(const std::string &title) { _title = title; }

            private:

                std::string _title;
                bool        _undoable;
                bool        _done;
        };

        template <class cls_type, class arg_type, class param_type,
                  param_type (cls_type::*getmfn)() const,
                  void (cls_type::*setmfn)(param_type)>
        class VariableSetCommand : public Command
        {
            public:
                VariableSetCommand(cls_type *cls, param_type arg,
                                   const std::string &title)
                : Command(title), cls(cls), arg(arg) {}
                virtual ~VariableSetCommand() {}
            protected:
                virtual void executeImpl()
                {
                    old = (cls->*getmfn)();
                    (cls->*setmfn)(arg);
                }
                virtual void undoImpl()
                {
                    (cls->*setmfn)(old);
                }
            private:
                cls_type *cls;
                arg_type  arg;
                arg_type  old;
        };
    }
}

#endif

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