/* * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.plaf; import javax.swing.JList;import java.awt.Point;import java.awt.Rectangle;  /** * The {@code JList} pluggable look and feel delegate. * * @author Hans Muller */ public abstract class ListUI extends ComponentUI{    /**     * Returns the cell index in the specified {@code JList} closest to the     * given location in the list's coordinate system. To determine if the     * cell actually contains the specified location, compare the point against     * the cell's bounds, as provided by {@code getCellBounds}.     * This method returns {@code -1} if the list's model is empty.     *     * @param list the list     * @param location the coordinates of the point     * @return the cell index closest to the given location, or {@code -1}     * @throws NullPointerException if {@code location} is null     */    public abstract int locationToIndex(JList list, Point location);      /**     * Returns the origin in the given {@code JList}, of the specified item,     * in the list's coordinate system.     * Returns {@code null} if the index isn't valid.     *     * @param list the list     * @param index the cell index     * @return the origin of the cell, or {@code null}     */    public abstract Point indexToLocation(JList list, int index);      /**     * Returns the bounding rectangle, in the given list's coordinate system,     * for the range of cells specified by the two indices.     * The indices can be supplied in any order.     * <p>     * If the smaller index is outside the list's range of cells, this method     * returns {@code null}. If the smaller index is valid, but the larger     * index is outside the list's range, the bounds of just the first index     * is returned. Otherwise, the bounds of the valid range is returned.     *     * @param list the list     * @param index1 the first index in the range     * @param index2 the second index in the range     * @return the bounding rectangle for the range of cells, or {@code null}     */    public abstract Rectangle getCellBounds(JList list, int index1, int index2);}