PluginCreator.h

/*
Hyperspace Explorer - visualizing higher-dimensional geometry
Copyright (C) 2010  Lene Preuss <lene.preuss@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 2 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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#ifndef PLUGIN_CREATOR_H
#define PLUGIN_CREATOR_H

namespace UI {
    namespace Dialogs {

        class PluginCreator {

            template <class F> class LoadFunctionHelper {
                public:
                    static bool functionPresent(const QString &, QDialog *);
            };

            public:

                virtual ~PluginCreator() { }    


                QString libraryName () { return LibraryName; }

            protected:
                bool loadFunction(const QString &, QDialog *);
                bool checkValidity(const QString &, const QString &, QDialog *);

                bool compile (QString);
                bool link (QString);

            private:
                virtual bool loadFunction() = 0;
                virtual bool functionPresent(const QString &) = 0;
                virtual void writeSource() = 0;

                QString LibraryName;    
        };
    }
}

#include <dlfcn.h>
#include <iostream>
#include <QFile>
#include <QMessageBox>

namespace UI {
    namespace Dialogs {

        template <class F>
                bool PluginCreator::LoadFunctionHelper<F>::functionPresent(
                    const QString &libName, QDialog *parent) {
            void *handle;
            F *f;
            const char *error;

            if (!QFile::exists (libName)) {
                QMessageBox::warning (parent, "Error opening library",
                                    "Library does not exist: "+libName);
                std::cerr << "Library does not exist: "+libName.toStdString()
                        << std::endl;
                return false;
            }

            handle = dlopen (libName.toStdString().c_str(), RTLD_LAZY);
            if (!handle) {
                QMessageBox::warning (parent, "Error opening library", dlerror());
                return false;
            }

            f = (F *)dlsym(handle, "f");

            if (f == NULL) {
                if ((error = dlerror()) != NULL)  {
                    QMessageBox::warning (parent, "Error finding function", error);
                    abort ();
                    return false;
                }
            }

            dlclose(handle);

            return true;
        }
    }
}
#endif