dispatchproxy.java

jacob is a connection between java and windows

/*
 * Copyright (c) 1999 Dan Adler, 315 E72 St. NY, NY, 10021, USA.
 * mailto:[e-mail]. 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. Redistributions in any form must be accompanied by information on
 *    how to obtain complete source code for the JACOB software.
 *
 * Redistribution of the JACOB software is not permitted as part of any
 * commercial product that is targeted primarily at Java developers.
 * Such products include, but are not limited to: Java virtual machines,
 * integrated development environments, code libraries, and application
 * server products. Licensing terms for such distribution may be
 * obtained from the copyright holder.
 *
 * THIS SOFTWARE IS PROVIDED ``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 HOLDER 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.
 */
package com.jacob.com;

/**
 * If you need to pass a COM Dispatch object between STA threads, you
 * have to marshall the interface.
 * This class is used as follows: the STA that creates the Dispatch
 * object must construct an instance of this class. Another thread
 * can then call toDispatch() on that instance and get a Dispatch
 * pointer which has been marshalled.
 * WARNING: You can only call toDispatch() once! If you need to call
 * it multiple times (or from multiple threads) you need to construct
 * a separate DispatchProxy instance for each such case!
 */
public class DispatchProxy extends JacobObject
{
  public int m_pStream;

  public DispatchProxy(Dispatch localDispatch)
  {
    MarshalIntoStream(localDispatch);
  }

  public Dispatch toDispatch()
  {
    return MarshalFromStream();
  }

  private native void MarshalIntoStream(Dispatch d);
  private native Dispatch MarshalFromStream();
  public native void release();

  public void finalize()
  {
    if (m_pStream != 0) release();
  }
}