/*
* org.openmicroscopy.shoola.util.concur.tasks.ExecHandle
*
*------------------------------------------------------------------------------
* Copyright (C) 2006 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.util.concur.tasks;
//Java imports
//Third-party libraries
//Application-internal dependencies
/**
* Allows to cancel the execution of a service.
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author <br>Andrea Falconi
* <a href="mailto:a.falconi@dundee.ac.uk">
* a.falconi@dundee.ac.uk</a>
* @version 2.2
* <small>
* (<b>Internal version:</b> $Revision$ $Date$)
* </small>
* @since OME2.2
*/
public class ExecHandle
{
/** Points to the command that encapsulates the service work-flow. */
private ExecCommand command;
/**
* Creates a new handle.
* This handle is temporary invalid because it points to no command.
*
* @see #setCommand(ExecCommand)
*/
ExecHandle() {}
/**
* Links this handle to the specified service.
*
* @param cmd The command that encapsulates the service work-flow.
* Must be a valid reference.
*/
void setCommand(ExecCommand cmd)
{
if (cmd == null)
throw new NullPointerException("No command.");
command = cmd;
}
/**
* Interrupts the service execution.
* Whether execution is actually cancelled depends on the state of the
* computation at the point when the cancellation signal is received.
*/
public void cancelExecution()
{
command.cancel();
}
/*
* ==============================================================
* Follows code to enable testing.
* ==============================================================
*/
ExecCommand getCommand() { return command; }
}