http://www.eclipse.org/platform: Commands (Eclipse Foundation) 
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 changes in some state.




Clients may implement, but must not extend this interface.



Since:3.2
/**
 * <p>
 * A listener to changes in some state.
 * </p>
 * <p>
 * Clients may implement, but must not extend this interface.
 * </p>
 *
 * @since 3.2
 */
public interface IStateListener {

	
Handles a change to the value in some state.

Params:
  • state – 
           The state that has changed; never null. The
           value for this state has been updated to the new value.
  • oldValue – 
           The old value; may be anything.
/**
	 * Handles a change to the value in some state.
	 *
	 * @param state
	 *            The state that has changed; never <code>null</code>. The
	 *            value for this state has been updated to the new value.
	 * @param oldValue
	 *            The old value; may be anything.
	 */
	public void handleStateChange(State state, Object oldValue);
}