log.hpp

/*
    log.hpp - Support file for writing LV2 plugins in C++

    Copyright (C) 2012 Michael Fisher <mfisher31@gmail.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program 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, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307  USA
*/

#ifndef LVTK_LOG_HPP
#define LVTK_LOG_HPP

#include <stdio.h>
#include <lv2/lv2plug.in/ns/ext/log/log.h>

namespace lvtk
{

    template<bool Required = true>
    struct Log
    {
        template<class Derived>
        struct I : Extension<Required>
        {
            I() : p_log(NULL) { }

            static void
            map_feature_handlers(FeatureHandlerMap& hmap)
            {
                hmap[LV2_LOG__log] = &I<Derived>::handle_feature;
            }

            static void
            handle_feature(void* instance, FeatureData data)
            {
                Derived* d = reinterpret_cast<Derived*>(instance);
                I<Derived>* mixin = static_cast<I<Derived>*>(d);

                mixin->p_log = reinterpret_cast<LV2_Log_Log*>(data);
                mixin->m_ok = true;
            }

            bool
            check_ok()
            {
                if (LVTK_DEBUG)
                {
                    std::clog << "    [Log] Validation "
                            << (this->m_ok ? "succeeded" : "failed")
                            << "." << std::endl;
                }
                return this->m_ok;
            }

        protected:

            int
            vprintf (LV2_URID type, const char* fmt, va_list ap)
            {
                if (p_log != NULL)
                    return p_log->vprintf(p_log->handle, type, fmt, ap);
                return ::vprintf (fmt, ap);
            }

            int
            printf (LV2_URID type, const char* fmt, ...)
            {
                va_list argptr;
                va_start(argptr, fmt);

                int res (this->vprintf(type, fmt, argptr));
                va_end(argptr);

                return res;
            }

            LV2_Log_Log * p_log;

        };
    };
}

#endif /* LVTK_LOG_HPP */