/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
* Copyright 2008-2014 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/
#pragma once

#include <osgEarth/Export>
#include <osgEarth/RefinePolicy>

namespace osgEarth
{
    /**
     * Pure interface for an object that can load or unload data.
     */
    class /*interface*/ LoadableNode
    {
    public:
        //! Instruct the object to load its payload
        virtual void load() = 0;

        //! Instruct the object to discard its payload
        virtual void unload() = 0;

        //! How to behave when higher resolution data is loaded
        virtual RefinePolicy getRefinePolicy() const = 0;

        //! Whether a call to load() completed (successfully or not)
        virtual bool isLoadComplete() const = 0;

        //! Whether the node is the highest resolution node in the scene graph
        virtual bool isHighestResolution() const = 0;

        //! Whether to automatically discard the payload when the
        //! system determines that this node is not currently in use
        virtual bool getAutoUnload() const = 0;

        //! Whether to automatically discard the payload when the
        //! system determines that this node is not currently in use
        virtual void setAutoUnload(bool value) = 0;
    };
}