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

/*************************************************************************
 *
 *  $RCSfile: OnewayExecutor.java,v $
 *
 *  $Revision: 1.4 $
 *
 *  last change: $Author: rt $ $Date: 2005-01-31 16:39:52 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  the BSD license.
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 *  Copyright (c) 2003 by Sun Microsystems, Inc.
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import java.util.Vector;

// __________ Implementation __________

/**
 * It's not allowed to call synchronoues back inside an oneway interface call.
 * (see IOnewayLink too). So we start a thread (implemented by this class), which
 * gets all neccessary 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.
 *
 * @author     Andreas Schlüns
 * @created    17.07.2002 08:18
 */
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 then 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_STATUSCHANGED           = 2     ;
    public static final int     REQUEST_ADDSTATUSLISTENER       = 3     ;
    public static final int     REQUEST_REMOVESTATUSLISTENER    = 4     ;
    public static final int     REQUEST_DISPATCH                = 5     ;

    public static final boolean ENCODE_PARAMS                   = true  ;
    public static final boolean DECODE_PARAMS                   = false ;

    // _______________________________

    /**
     * @member  m_rLink     the object, which wish to be called back by this thread
     * @member  m_nRequest  describes the type of the original request (means the
     *                      called oneyway method)
     * @member  m_lParams   list of parameters of the original request
     */
    private IOnewayLink m_rLink     ;
    private int         m_nRequest  ;
    private Vector      m_lParams   ;

    // _______________________________

    /**
     * ctor
     * It's initialize this thread with all neccessary parameters.
     * It gets the object, which wish to be called back and the type
     * and parameters of the original request.
     *
     * @param nRequest
     *          The two user of this callback can define an unique number,
     *          which identify the type of original interface method.
     *          So the called interface object can decide, which action will be
     *          neccessary.
     *
     * @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 ,
                           Vector      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 neccessary parameters.
     * After that we die by ouerself ...
     */
    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 convertion of the generic parameter list to the original
     * one easier - you can use this helper methods. They know how suchlist
     * must be coded. It's not a must to use it - but you can ...
     */
    public static void codeFrameAction(
        boolean bEncode, Vector[] lParams,
        com.sun.star.frame.FrameActionEvent[] aAction)
    {
        if (bEncode)
        {
            lParams[0] = new Vector(1);
            lParams[0].add( (Object)(aAction[0]) );
        }
        else
        {
            aAction[0] = (com.sun.star.frame.FrameActionEvent)
                (lParams[0].elementAt(0));
        }
    }

    // _______________________________

    public static void codeStatusChanged(
        boolean bEncode, Vector[] lParams,
        com.sun.star.frame.FeatureStateEvent[] aStatus)
    {
        if (bEncode)
        {
            lParams[0] = new Vector(1);
            lParams[0].add( (Object)aStatus[0] );
        }
        else
        {
            aStatus[0] = (com.sun.star.frame.FeatureStateEvent)
                (lParams[0].elementAt(0));
        }
    }

    // _______________________________

    public static void codeAddOrRemoveStatusListener(
        boolean bEncode, Vector[] lParams,
        com.sun.star.frame.XStatusListener[] xListener,
        com.sun.star.util.URL[] aURL)
    {
        if (bEncode)
        {
            lParams[0] = new Vector(2);
            lParams[0].add( (Object)xListener[0] );
            lParams[0].add( (Object)aURL[0]      );
        }
        else
        {
            xListener[0] = (com.sun.star.frame.XStatusListener)
                (lParams[0].elementAt(0));
            aURL[0] = (com.sun.star.util.URL)(lParams[0].elementAt(1));
        }
    }

    // _______________________________

    public static void codeDispatch(
        boolean bEncode, Vector[] lParams,
        com.sun.star.util.URL[] aURL,
        com.sun.star.beans.PropertyValue[][] lArgs)
    {
        if (bEncode)
        {
            int nLength = lArgs.length+1;
            int nPos    = 0;
            lParams[0] = new Vector(nLength);

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

            while (nLength>0)
            {
                lParams[0].add( (Object)lArgs[0][nPos] );
                --nLength;
                ++nPos   ;
            }
        }
        else
        {
            int nLength = lParams[0].size()-1;
            int nPos    = 0;

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

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