libreoffice/odk/examples/DevelopersGuide/OfficeDev/DesktopEnvironment/OnewayExecutor.java

/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*************************************************************************
 *
 *  The Contents of this file are made available subject to the terms of
 *  the BSD license.
 *
 *  Copyright 2000, 2010 Oracle and/or its affiliates.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of Sun Microsystems, Inc. nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *************************************************************************/

import java.util.ArrayList;

// __________ Implementation __________

/**
 * It's not allowed to call synchronous back inside a oneway interface call.
 * (see IOnewayLink too). So we start a thread (implemented by this class), which
 * gets all necessary parameters from the original called object and
 * call it back later inside his run() method. So the execution of such oneway call
 * will be asynchronous. It works in a generic way and can be used or any type
 * of oneway request. Because the source and the target of this call-link knows,
 * which method was used and which parameters must be handled.
 *
 */
class OnewayExecutor extends Thread
{


    /**
     * const
     * We define some request for some well known oneway interface
     * calls here too. So they mustn't be declared more than ones.
     * Of course it's not necessary to use it ... but why not :-)
     */

    public static final int     REQUEST_FRAMEACTION             = 1     ;



    public static final int     REQUEST_DISPATCH                = 5     ;






    /**
     * @member  m_rLink     the object, which wishes to be called back by this thread
     * @member  m_nRequest  describes the type of the original request (means the
     *                      called oneway method)
     * @member  m_lParams   list of parameters of the original request
     */
    private final IOnewayLink m_rLink     ;
    private final int         m_nRequest  ;
    private final ArrayList<Object>      m_lParams   ;



    /**
     * ctor
     * It's initialize this thread with all necessary parameters.
     * It gets the object, which wishes to be called back and the type
     * and parameters of the original request.
     *
     * @param nRequest
     *          The two user of this callback can define a unique number,
     *          which identify the type of original interface method.
     *          So the called interface object can decide, which action will be
     *          necessary.
     *
     * @param lParams
     *          If the original method used parameters, they will be coded here in
     *          a generic way. Only the called interface object know (it depends
     *          from the original request - see nRequest too), how this list must
     *          be interpreted.
     *          Note: Atomic types (e.g. int, long) will be transported as objects
     *          too (Integer, Long)!
     */
    public OnewayExecutor( IOnewayLink rLink    ,
                           int         nRequest ,
                           ArrayList<Object>      lParams  )
    {
        m_rLink    = rLink   ;
        m_nRequest = nRequest;
        m_lParams  = lParams ;

        if (m_rLink==null)
            System.out.println("ctor ... m_rLink == null");
        if (m_lParams==null)
            System.out.println("ctor ... m_lParams == null");
    }



    /**
     * implements the thread function
     * Here we call the internal set link object back and
     * give him all necessary parameters.
     * After that we die by ourselves ...
     */
    @Override
    public void run()
    {
        if (m_rLink==null)
            System.out.println("run ... m_rLink == null");
        if (m_lParams==null)
            System.out.println("run ... m_lParams == null");

        if (m_rLink!=null)
            m_rLink.execOneway( m_nRequest, m_lParams );
    }



    /**
     * static helper!
     * To make conversion of the generic parameter list to the original
     * one easier - you can use this helper methods. They know how such list
     * must be coded. It's not a must to use it - but you can ...
     */



    public static ArrayList<Object> encodeDispatch(
        com.sun.star.util.URL[] aURL,
        com.sun.star.beans.PropertyValue[][] lArgs)
    {
        int nLength = lArgs.length+1;
        int nPos    = 0;
        ArrayList<Object> lParams = new ArrayList<Object>(nLength);

        lParams.add( aURL[0] );
        --nLength;

        while (nLength>0)
        {
            lParams.add( lArgs[0][nPos] );
            --nLength;
            ++nPos   ;
        }
        return lParams;
    }

    public static void decodeDispatch(
            ArrayList<Object> lParams,
            com.sun.star.util.URL[] aURL,
            com.sun.star.beans.PropertyValue[][] lArgs)
    {
            int nLength = lParams.size()-1;
            int nPos    = 0;

            lArgs[0] = new com.sun.star.beans.PropertyValue[nLength];
            aURL[0]  = (com.sun.star.util.URL) lParams.get(0);

            while (nPos<nLength)
            {
                lArgs[0][nPos] = (com.sun.star.beans.PropertyValue)
                    (lParams.get(nPos+1));
                ++nPos;
            }
    }
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */