Copyright (c) 2005, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2005, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/

package org.eclipse.core.commands;


A listener to the execution of commands. This listener will be notified if a
command is about to execute, and when that execution completes. It is not
possible for the listener to prevent the execution, only to respond to it in
some way.

Since:
3.1/**
 * <p>
 * A listener to the execution of commands. This listener will be notified if a
 * command is about to execute, and when that execution completes. It is not
 * possible for the listener to prevent the execution, only to respond to it in
 * some way.
 * </p>
 *
 * @since 3.1
 */
public interface IExecutionListener {

	
Notifies the listener that an attempt was made to execute a command with
no handler.
Params:
commandId – 
           The identifier of command that is not handled; never
           null
exception – 
           The exception that occurred; never null./**
	 * Notifies the listener that an attempt was made to execute a command with
	 * no handler.
	 *
	 * @param commandId
	 *            The identifier of command that is not handled; never
	 *            <code>null</code>
	 * @param exception
	 *            The exception that occurred; never <code>null</code>.
	 */
	public void notHandled(String commandId, NotHandledException exception);

	
Notifies the listener that a command has failed to complete execution.
Params:
commandId – 
           The identifier of the command that has executed; never
           null.
exception – 
           The exception that occurred; never null./**
	 * Notifies the listener that a command has failed to complete execution.
	 *
	 * @param commandId
	 *            The identifier of the command that has executed; never
	 *            <code>null</code>.
	 * @param exception
	 *            The exception that occurred; never <code>null</code>.
	 */
	public void postExecuteFailure(String commandId,
			ExecutionException exception);

	
Notifies the listener that a command has completed execution
successfully.
Params:
commandId – 
           The identifier of the command that has executed; never
           null.
returnValue – 
           The return value from the command; may be null./**
	 * Notifies the listener that a command has completed execution
	 * successfully.
	 *
	 * @param commandId
	 *            The identifier of the command that has executed; never
	 *            <code>null</code>.
	 * @param returnValue
	 *            The return value from the command; may be <code>null</code>.
	 */
	public void postExecuteSuccess(String commandId, Object returnValue);

	
Notifies the listener that a command is about to execute.
Params:
commandId – 
           The identifier of the command that is about to execute, never
           null.
event – 
           The event that will be passed to the execute
           method; never null./**
	 * Notifies the listener that a command is about to execute.
	 *
	 * @param commandId
	 *            The identifier of the command that is about to execute, never
	 *            <code>null</code>.
	 * @param event
	 *            The event that will be passed to the <code>execute</code>
	 *            method; never <code>null</code>.
	 */
	public void preExecute(String commandId, ExecutionEvent event);
}