jdk

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/*
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 * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.  Oracle designates this
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 * particular file as subject to the "Classpath" exception as provided
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 * by Oracle in the LICENSE file that accompanied this code.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 */
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package java.awt.desktop;
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import java.awt.Desktop;
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import java.awt.GraphicsEnvironment;
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import java.awt.HeadlessException;
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import java.io.Serial;
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/**
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 * Event sent when the user session has been changed. Some systems may provide a
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 * reason of a user session change.
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 *
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 * @see UserSessionListener#userSessionActivated(UserSessionEvent)
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 * @see UserSessionListener#userSessionDeactivated(UserSessionEvent)
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 * @since 9
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 */
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public final class UserSessionEvent extends AppEvent {
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    /**
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     * Use serialVersionUID from JDK 9 for interoperability.
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     */
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    @Serial
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    private static final long serialVersionUID = 6747138462796569055L;
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    /**
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     * The reason of the user session change.
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     */
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    private final Reason reason;
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    /**
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     * Kinds of available reasons of user session change.
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     */
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    public static enum Reason {
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        /**
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         * The system does not provide a reason for a session change.
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         */
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        UNSPECIFIED,
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        /**
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         * The session was connected/disconnected to the console terminal.
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         */
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        CONSOLE,
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        /**
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         * The session was connected/disconnected to the remote terminal.
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         */
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        REMOTE,
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        /**
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         * The session has been locked/unlocked.
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         */
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        LOCK
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    }
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    /**
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     * Constructs a {@code UserSessionEvent}.
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     *
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     * @param  reason the reason of the user session change
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     * @throws HeadlessException if {@link GraphicsEnvironment#isHeadless()}
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     *         returns {@code true}
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     * @throws UnsupportedOperationException if Desktop API is not supported on
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     *         the current platform
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     * @see Desktop#isDesktopSupported()
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     * @see java.awt.GraphicsEnvironment#isHeadless
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     */
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    public UserSessionEvent(Reason reason) {
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        this.reason = reason;
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    }
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    /**
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     * Gets a reason of the user session change.
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     *
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     * @return reason a reason
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     * @see Reason#UNSPECIFIED
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     * @see Reason#CONSOLE
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     * @see Reason#REMOTE
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     * @see Reason#LOCK
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     */
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    public Reason getReason() {
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        return reason;
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    }
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}
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