/*

 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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 */

package java.awt.event;

import java.util.EventListener;

/**

 * The listener interface for receiving keyboard focus events on

 * a component.

 * The class that is interested in processing a focus event

 * either implements this interface (and all the methods it

 * contains) or extends the abstract <code>FocusAdapter</code> class

 * (overriding only the methods of interest).

 * The listener object created from that class is then registered with a

 * component using the component's <code>addFocusListener</code>

 * method. When the component gains or loses the keyboard focus,

 * the relevant method in the listener object

 * is invoked, and the <code>FocusEvent</code> is passed to it.

 *

 * @see FocusAdapter

 * @see FocusEvent

 * @see <a href="https://docs.oracle.com/javase/tutorial/uiswing/events/focuslistener.html">Tutorial: Writing a Focus Listener</a>

 *

 * @author Carl Quinn

 * @since 1.1

 */

public interface FocusListener extends EventListener {

    /**

     * Invoked when a component gains the keyboard focus.

     */

    public void focusGained(FocusEvent e);

    /**

     * Invoked when a component loses the keyboard focus.

     */

    public void focusLost(FocusEvent e);

}