void PluginManager::CalculateDependencies ()
{
    for (PluginsContainer_t::const_iterator i = Plugins_.begin (); i != Plugins_.end (); ++i)
    {
        QObject *pEntity = (*i)->instance ();
        IInfo *info = qobject_cast<IInfo*> (pEntity);
        QStringList needs = info->Needs (),
                    uses = info->Uses ();
        DependenciesMet_ [i] = true;
 
        if (!needs.isEmpty ())
        {
            for (PluginsContainer_t::const_iterator j = Plugins_.begin (); j != Plugins_.end (); ++j)
            {
                if (j == i)
                    continue;
 
                QObject *qpEntity = (*j)->instance ();
                IInfo *qinfo = qobject_cast<IInfo*> (qpEntity);
                QStringList qprovides = qinfo->Provides ();
                for (int k = 0; k < needs.size (); ++k)
                    if (qprovides.contains (needs [i]))
                    {
                        info->SetProvider (qpEntity, needs [k]);
                        needs.removeAt (k--);
                    }
            }
            if (!needs.isEmpty ())
            {
                DependenciesMet_ [i] = false;
                FailedDependencies_ [i] = needs;
                qWarning () << Q_FUNC_INFO << "not all plugins providing needs of" << info->GetName () << "are found. The remaining ones are:" << needs;
            }
        }
        if (!uses.isEmpty ())
        {
            QMap<QString, bool> usesMet;
            for (int j = 0; j < uses.size (); ++j)
                usesMet [uses.at (j)] = false;
 
            for (PluginsContainer_t::const_iterator j = Plugins_.begin (); j != Plugins_.end (); ++j)
            {
                if (j == i)
                    continue;
 
                QObject *qpEntity = (*j)->instance ();
                IInfo *qinfo = qobject_cast<IInfo*> (qpEntity);
                QStringList qprovides = qinfo->Provides ();
                for (int k = 0; k < uses.size (); ++k)
                    if (qprovides.contains (uses [i]))
                    {
                        info->SetProvider (qpEntity, uses [k]);
                        usesMet [uses [i]] = true;
                    }
            }
        }
    }
}