XBase.h

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012 Bolton Software Ltd.
 * Copyright (C) 2002 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef XBASE_H
#define XBASE_H

#include "CString.h"


class XBase {
public:
    XBase();
    XBase(const CString& msg);
    virtual ~XBase();

    virtual const char* what() const;

protected:
    virtual CString     getWhat() const throw() = 0;


    virtual CString     format(const char* id,
                            const char* defaultFormat, ...) const throw();

private:
    mutable CString     m_what;
};

#define XBASE_SUBCLASS(name_, super_)                                   \
class name_ : public super_ {                                           \
public:                                                                 \
    name_() : super_() { }                                              \
    name_(const CString& msg) : super_(msg) { }                         \
}

#define XBASE_SUBCLASS_WHAT(name_, super_)                              \
class name_ : public super_ {                                           \
public:                                                                 \
    name_() : super_() { }                                              \
    name_(const CString& msg) : super_(msg) { }                         \
                                                                        \
protected:                                                              \
    virtual CString     getWhat() const throw();                        \
}

#define XBASE_SUBCLASS_FORMAT(name_, super_)                            \
class name_ : public super_ {                                           \
private:                                                                \
    enum EState { kFirst, kFormat, kDone };                             \
                                                                        \
public:                                                                 \
    name_() : super_(), m_state(kDone) { }                              \
    name_(const CString& msg) : super_(msg), m_state(kFirst) { }        \
                                                                        \
    virtual const char* what() const                                    \
    {                                                                   \
        if (m_state == kFirst) {                                        \
            m_state = kFormat;                                          \
            m_formatted = getWhat();                                    \
            m_state = kDone;                                            \
        }                                                               \
        if (m_state == kDone) {                                         \
            return m_formatted.c_str();                                 \
        }                                                               \
        else {                                                          \
            return super_::what();                                      \
        }                                                               \
    }                                                                   \
                                                                        \
protected:                                                              \
    virtual CString     getWhat() const throw();                        \
                                                                        \
private:                                                                \
    mutable EState              m_state;                                \
    mutable std::string         m_formatted;                            \
}

#endif