/*

 * 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.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);

}