//C++ header - Open Scene Graph - Copyright (C) 1998-2001 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSGUTIL_GUIACTIONADAPTER
#define OSGUTIL_GUIACTIONADAPTER 1 

#include <osgUtil/Export>

namespace osgUtil{


/** Pure virtual base class for adapting the GUI actions requested by CameraManipulators
  * into actions which are handled by the GUI toolkit of the users application.
  *
  * There are several was of using the ActionAdapter either inheriting it as 
  * done with osgGLUT::Viewer class or passing a simple struct to the camera 
  * manipulator then unpacking the results and working out what to do to respond
  * to the requests.
  * 
  * Also there are several ways to run your app and handle the updating of
  * the window.  osgGLUT::Viewer always has a idle callback registered which does a
  * redraw all the time.  osgGLUT::Viewer can safely ignore both requestRedraw() and
  * requestContinousUpdate() as these are happening all the time anyway.
  * 
  * Other apps will probably want to respond to the requestRedraw() and
  * requestContinousUpdate(bool) and again there is more than one way to handle it.
  * You can override requestRedraw() and implement to call your own window
  * redraw straight away. Or you can implement so that a flag is set and
  * then you then respond the flag being set in your own leisure.
  * 
  * requestContinousUpdate(bool) is for enabling a throw or idle 
  * callback to be requested by the camera manipulator.  Again you can respond 
  * to this immediately by registering a idle callback or a timed callback, or
  * you can delay setting the callback and do at you own leisure.
  * 
  * requestWarpPointer(int,int) is requesting a respositioning of a mouse pointer
  * to a specified x,y location on the window.  Used by some camera manipulators
  * to initialize the mouse pointer when mouse position relative to a controls
  * neutral mouse position is required, i.e when mimicking a aircrafts joystick.
  */
class GUIActionAdapter
{
    public:
        
        virtual void requestRedraw() = 0;
        virtual void requestContinuousUpdate(bool needed=true) = 0;
        virtual void requestWarpPointer(int x,int y) = 0;

};

}

#endif