/* * 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);}