/*
* org.openmicroscopy.shoola.env.data.views.ProcessCallback
*
*------------------------------------------------------------------------------
* Copyright (C) 2006-2010 University of Dundee. All rights reserved.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*------------------------------------------------------------------------------
*/
package org.openmicroscopy.shoola.env.data.views;
//Java imports
//Third-party libraries
//Application-internal dependencies
import org.openmicroscopy.shoola.env.data.RequestCallback;
import org.openmicroscopy.shoola.env.data.ScriptCallback;
import org.openmicroscopy.shoola.env.data.ProcessException;
import org.openmicroscopy.shoola.env.data.events.DSCallAdapter;
/**
* Wraps the various call handle.
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author Donald MacDonald
* <a href="mailto:donald@lifesci.dundee.ac.uk">donald@lifesci.dundee.ac.uk</a>
* @version 3.0
* <small>
* (<b>Internal version:</b> $Revision: $Date: $)
* </small>
* @since 3.0-Beta4
*/
public class ProcessCallback
{
/** The length of the unit of work. */
static final long UNIT_OF_WORK = 500;
/** The actual call-back to handle. */
private Object callback;
/**
* Checks if the passed handle is supported.
*
* @param callback The call-back to check.
*/
private void checkHandle(Object callback)
{
if (callback instanceof ScriptCallback) return;
if (callback instanceof RequestCallback) return;
throw new omero.IllegalArgumentException("Call back not supported.");
}
/**
* Creates a new instance.
*
* @param callback The call-back to check.
*/
public ProcessCallback(Object callback)
{
if (callback == null)
throw new IllegalArgumentException("Handle cannot be null.");
checkHandle(callback);
this.callback = callback;
}
/**
* Sets the adapter.
*
* @param adapter The value to set.
*/
public void setAdapter(DSCallAdapter adapter)
{
if (callback instanceof ScriptCallback)
((ScriptCallback) callback).setAdapter(adapter);
else if (callback instanceof RequestCallback)
((RequestCallback) callback).setAdapter(adapter);
}
/** Cancels the on-going process. */
public void cancel()
throws ProcessException
{
if (callback instanceof ScriptCallback)
((ScriptCallback) callback).cancel();
}
/**
* Blocks to do a unit of work and returns the corresponding action.
*
* @param value The length of the block.
* @return See above.
* @throws Exception If an error occurs.
*/
Object block(long value)
throws Exception
{
if (callback instanceof ScriptCallback)
return ((ScriptCallback) callback).block(value);
if (callback instanceof RequestCallback)
return ((RequestCallback) callback).block(value);
return null;
}
/**
* Closes the handle.
* @throws Exception If an error occurs.
*/
void close()
throws Exception
{
if (callback instanceof ScriptCallback) {
((ScriptCallback) callback).close();
} else if (callback instanceof RequestCallback) {
((RequestCallback) callback).close(true);
}
}
}