/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library 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 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGVIEWER_HELPHANDLER
#define OSGVIEWER_HELPHANDLER 1

#include <osgViewer/Viewer>

#include <osg/ApplicationUsage>

namespace osgViewer {

class OSGVIEWER_EXPORT HelpHandler : public osgGA::GUIEventHandler 
{
    public: 

        HelpHandler(osg::ApplicationUsage* au=0);
        
        void setApplicationUsage(osg::ApplicationUsage* au) { _applicationUsage = au; }
        osg::ApplicationUsage* getApplicationUsage() { return _applicationUsage.get(); }
        const osg::ApplicationUsage* getApplicationUsage() const { return _applicationUsage.get(); }

        void setKeyEventTogglesOnScreenHelp(int key) { _keyEventTogglesOnScreenHelp = key; }
        int getKeyEventTogglesOnScreenHelp() const { return _keyEventTogglesOnScreenHelp; }
        
        void reset();

        osg::Camera* getCamera() { return _camera.get(); }
        const osg::Camera* getCamera() const { return _camera.get(); }

        bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage& usage) const;

    protected:

        void setUpHUDCamera(osgViewer::Viewer* viewer);

        void setUpScene(osgViewer::Viewer* viewer);
        
        osg::ref_ptr<osg::ApplicationUsage> _applicationUsage;

        int                                 _keyEventTogglesOnScreenHelp;

        bool                                _helpEnabled;

        bool                                _initialized;
        osg::ref_ptr<osg::Camera>           _camera;
        osg::ref_ptr<osg::Switch>           _switch;
        
};

}

#endif