/*

 * Copyright (c) 1997, 2005, 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;

import java.awt.Component;

/**

 * Identifies components that can be used as "rubber stamps" to paint

 * the cells in a JList.  For example, to use a JLabel as a

 * ListCellRenderer, you would write something like this:

 * <pre>

 * {@code

 * class MyCellRenderer extends JLabel implements ListCellRenderer<Object> {

 *     public MyCellRenderer() {

 *         setOpaque(true);

 *     }

 *

 *     public Component getListCellRendererComponent(JList<?> list,

 *                                                   Object value,

 *                                                   int index,

 *                                                   boolean isSelected,

 *                                                   boolean cellHasFocus) {

 *

 *         setText(value.toString());

 *

 *         Color background;

 *         Color foreground;

 *

 *         // check if this cell represents the current DnD drop location

 *         JList.DropLocation dropLocation = list.getDropLocation();

 *         if (dropLocation != null

 *                 && !dropLocation.isInsert()

 *                 && dropLocation.getIndex() == index) {

 *

 *             background = Color.BLUE;

 *             foreground = Color.WHITE;

 *

 *         // check if this cell is selected

 *         } else if (isSelected) {

 *             background = Color.RED;

 *             foreground = Color.WHITE;

 *

 *         // unselected, and not the DnD drop location

 *         } else {

 *             background = Color.WHITE;

 *             foreground = Color.BLACK;

 *         };

 *

 *         setBackground(background);

 *         setForeground(foreground);

 *

 *         return this;

 *     }

 * }

 * }

 * </pre>

 *

 * @param <E> the type of values this renderer can be used for

 *

 * @see JList

 * @see DefaultListCellRenderer

 *

 * @author Hans Muller

 */

public interface ListCellRenderer<E>

{

    /**

     * Return a component that has been configured to display the specified

     * value. That component's <code>paint</code> method is then called to

     * "render" the cell.  If it is necessary to compute the dimensions

     * of a list because the list cells do not have a fixed size, this method

     * is called to generate a component on which <code>getPreferredSize</code>

     * can be invoked.

     *

     * @param list The JList we're painting.

     * @param value The value returned by list.getModel().getElementAt(index).

     * @param index The cells index.

     * @param isSelected True if the specified cell was selected.

     * @param cellHasFocus True if the specified cell has the focus.

     * @return A component whose paint() method will render the specified value.

     *

     * @see JList

     * @see ListSelectionModel

     * @see ListModel

     */

    Component getListCellRendererComponent(

        JList<? extends E> list,

        E value,

        int index,

        boolean isSelected,

        boolean cellHasFocus);

}