content: /*
   * $Id: LuaInvocationHandler.java,v 1.4 2006/12/22 14:06:40 thiago Exp $
   * Copyright (C) 2003-2007 Kepler Project.
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
   * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  package org.keplerproject.luajava;
  
  import java.lang.reflect.InvocationHandler;
  import java.lang.reflect.Method;
  
  /**
   * Class that implements the InvocationHandler interface.
   * This class is used in the LuaJava's proxy system.
   * When a proxy object is accessed, the method invoked is
   * called from Lua
   * @author Rizzato
   * @author Thiago Ponte
   */
  public class LuaInvocationHandler implements InvocationHandler
  {
  	private LuaObject obj;
  
  	
  	public LuaInvocationHandler(LuaObject obj)
  	{
  		this.obj = obj;
  	}
  	
  	/**
  	 * Function called when a proxy object function is invoked.
  	 */
    public Object invoke(Object proxy, Method method, Object[] args) throws LuaException
    {
      synchronized(obj.L)
      {
  	  	String methodName = method.getName();
  	  	LuaObject func    = obj.getField(methodName);
  	  	
  	  	if ( func.isNil() )
  	  	{
  	  		return null;
  	  	}
  	  	
  	  	Class retType = method.getReturnType();
  	  	Object ret;
  
  	  	// Checks if returned type is void. if it is returns null.
  	  	if ( retType.equals( Void.class ) || retType.equals( void.class ) )
  	  	{
  	  		func.call( args , 0 );
  	  		ret = null;
  	  	}
  	  	else
  	  	{
  	  		ret = func.call(args, 1)[0];
  	  		if( ret != null && ret instanceof Double )
  	  		{
  	  		  ret = LuaState.convertLuaNumber((Double) ret, retType);
  	  		}
  	  	}
  	  	
  	  	return ret;
  	  }
    }
  }
  