swing/event/ListSelectionEvent.java

/*
 * Copyright (c) 1997, 2006, 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.swing.event;

import java.util.EventObject;
import javax.swing.*;


/**
 * An event that characterizes a change in selection. The change is limited to a
 * a single inclusive interval. The selection of at least one index within the
 * range will have changed. A decent {@code ListSelectionModel} implementation
 * will keep the range as small as possible. {@code ListSelectionListeners} will
 * generally query the source of the event for the new selected status of each
 * potentially changed row.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans<sup><font size="-2">TM</font></sup>
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Hans Muller
 * @author Ray Ryan
 * @see ListSelectionModel
 */
public class ListSelectionEvent extends EventObject
{
    private int firstIndex;
    private int lastIndex;
    private boolean isAdjusting;

    /**
     * Represents a change in selection status between {@code firstIndex} and
     * {@code lastIndex}, inclusive. {@code firstIndex} is less than or equal to
     * {@code lastIndex}. The selection of at least one index within the range will
     * have changed.
     *
     * @param firstIndex the first index in the range, &lt;= lastIndex
     * @param lastIndex the last index in the range, &gt;= firstIndex
     * @param isAdjusting whether or not this is one in a series of
     *        multiple events, where changes are still being made
     */
    public ListSelectionEvent(Object source, int firstIndex, int lastIndex,
                              boolean isAdjusting)
    {
        super(source);
        this.firstIndex = firstIndex;
        this.lastIndex = lastIndex;
        this.isAdjusting = isAdjusting;
    }

    /**
     * Returns the index of the first row whose selection may have changed.
     * {@code getFirstIndex() &lt;= getLastIndex()}
     *
     * @return the first row whose selection value may have changed,
     *         where zero is the first row
     */
    public int getFirstIndex() { return firstIndex; }

    /**
     * Returns the index of the last row whose selection may have changed.
     * {@code getLastIndex() &gt;= getFirstIndex()}
     *
     * @return the last row whose selection value may have changed,
     *         where zero is the first row
     */
    public int getLastIndex() { return lastIndex; }

    /**
     * Returns whether or not this is one in a series of multiple events,
     * where changes are still being made. See the documentation for
     * {@link javax.swing.ListSelectionModel#setValueIsAdjusting} for
     * more details on how this is used.
     *
     * @return {@code true} if this is one in a series of multiple events,
     *         where changes are still being made
     */
    public boolean getValueIsAdjusting() { return isAdjusting; }

    /**
     * Returns a {@code String} that displays and identifies this
     * object's properties.
     *
     * @return a String representation of this object
     */
    public String toString() {
        String properties =
            " source=" + getSource() +
            " firstIndex= " + firstIndex +
            " lastIndex= " + lastIndex +
            " isAdjusting= " + isAdjusting +
            " ";
        return getClass().getName() + "[" + properties + "]";
    }
}