/*

 * Copyright (c) 1998, 2007, 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 javax.swing.*;

import javax.swing.event.*;

import javax.swing.border.*;

import java.awt.Component;

import java.awt.Color;

import java.awt.Rectangle;

import java.io.Serializable;

import sun.swing.DefaultLookup;

/**

 * Renders an item in a list.

 * <p>

 * <strong><a name="override">Implementation Note:</a></strong>

 * This class overrides

 * <code>invalidate</code>,

 * <code>validate</code>,

 * <code>revalidate</code>,

 * <code>repaint</code>,

 * <code>isOpaque</code>,

 * and

 * <code>firePropertyChange</code>

 * solely to improve performance.

 * If not overridden, these frequently called methods would execute code paths

 * that are unnecessary for the default list cell renderer.

 * If you write your own renderer,

 * take care to weigh the benefits and

 * drawbacks of overriding these methods.

 *

 * <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 Philip Milne

 * @author Hans Muller

 */

public class DefaultListCellRenderer extends JLabel

    implements ListCellRenderer<Object>, Serializable

{

   /**

    * An empty <code>Border</code>. This field might not be used. To change the

    * <code>Border</code> used by this renderer override the

    * <code>getListCellRendererComponent</code> method and set the border

    * of the returned component directly.

    */

    private static final Border SAFE_NO_FOCUS_BORDER = new EmptyBorder(1, 1, 1, 1);

    private static final Border DEFAULT_NO_FOCUS_BORDER = new EmptyBorder(1, 1, 1, 1);

    protected static Border noFocusBorder = DEFAULT_NO_FOCUS_BORDER;

    /**

     * Constructs a default renderer object for an item

     * in a list.

     */

    public DefaultListCellRenderer() {

        super();

        setOpaque(true);

        setBorder(getNoFocusBorder());

        setName("List.cellRenderer");

    }

    private Border getNoFocusBorder() {

        Border border = DefaultLookup.getBorder(this, ui, "List.cellNoFocusBorder");

        if (System.getSecurityManager() != null) {

            if (border != null) return border;

            return SAFE_NO_FOCUS_BORDER;

        } else {

            if (border != null &&

                    (noFocusBorder == null ||

                    noFocusBorder == DEFAULT_NO_FOCUS_BORDER)) {

                return border;

            }

            return noFocusBorder;

        }

    }

    public Component getListCellRendererComponent(

        JList<?> list,

        Object value,

        int index,

        boolean isSelected,

        boolean cellHasFocus)

    {

        setComponentOrientation(list.getComponentOrientation());

        Color bg = null;

        Color fg = null;

        JList.DropLocation dropLocation = list.getDropLocation();

        if (dropLocation != null

                && !dropLocation.isInsert()

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

            bg = DefaultLookup.getColor(this, ui, "List.dropCellBackground");

            fg = DefaultLookup.getColor(this, ui, "List.dropCellForeground");

            isSelected = true;

        }

        if (isSelected) {

            setBackground(bg == null ? list.getSelectionBackground() : bg);

            setForeground(fg == null ? list.getSelectionForeground() : fg);

        }

        else {

            setBackground(list.getBackground());

            setForeground(list.getForeground());

        }

        if (value instanceof Icon) {

            setIcon((Icon)value);

            setText("");

        }

        else {

            setIcon(null);

            setText((value == null) ? "" : value.toString());

        }

        setEnabled(list.isEnabled());

        setFont(list.getFont());

        Border border = null;

        if (cellHasFocus) {

            if (isSelected) {

                border = DefaultLookup.getBorder(this, ui, "List.focusSelectedCellHighlightBorder");

            }

            if (border == null) {

                border = DefaultLookup.getBorder(this, ui, "List.focusCellHighlightBorder");

            }

        } else {

            border = getNoFocusBorder();

        }

        setBorder(border);

        return this;

    }

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     *

     * @since 1.5

     * @return <code>true</code> if the background is completely opaque

     *         and differs from the JList's background;

     *         <code>false</code> otherwise

     */

    @Override

    public boolean isOpaque() {

        Color back = getBackground();

        Component p = getParent();

        if (p != null) {

            p = p.getParent();

        }

        // p should now be the JList.

        boolean colorMatch = (back != null) && (p != null) &&

            back.equals(p.getBackground()) &&

                        p.isOpaque();

        return !colorMatch && super.isOpaque();

    }

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void validate() {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    *

    * @since 1.5

    */

    @Override

    public void invalidate() {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    *

    * @since 1.5

    */

    @Override

    public void repaint() {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void revalidate() {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void repaint(long tm, int x, int y, int width, int height) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void repaint(Rectangle r) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {

        // Strings get interned...

        if (propertyName == "text"

                || ((propertyName == "font" || propertyName == "foreground")

                    && oldValue != newValue

                    && getClientProperty(javax.swing.plaf.basic.BasicHTML.propertyKey) != null)) {

            super.firePropertyChange(propertyName, oldValue, newValue);

        }

    }

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, byte oldValue, byte newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, char oldValue, char newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, short oldValue, short newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, int oldValue, int newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, long oldValue, long newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, float oldValue, float newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, double oldValue, double newValue) {}

   /**

    * Overridden for performance reasons.

    * See the <a href="#override">Implementation Note</a>

    * for more information.

    */

    @Override

    public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) {}

    /**

     * A subclass of DefaultListCellRenderer that implements UIResource.

     * DefaultListCellRenderer doesn't implement UIResource

     * directly so that applications can safely override the

     * cellRenderer property with DefaultListCellRenderer subclasses.

     * <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}.

     */

    public static class UIResource extends DefaultListCellRenderer

        implements javax.swing.plaf.UIResource

    {

    }

}