/*
* @(#)DefaultListCellRenderer.java 1.27 05/05/27
*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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;
/**
* 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}.
*
* @version 1.27 05/27/05
* @author Philip Milne
* @author Hans Muller
*/
public class DefaultListCellRenderer extends JLabel
implements ListCellRenderer, Serializable
{
protected static Border noFocusBorder;
/**
* Constructs a default renderer object for an item
* in a list.
*/
public DefaultListCellRenderer() {
super();
if (noFocusBorder == null) {
noFocusBorder = new EmptyBorder(1, 1, 1, 1);
}
setOpaque(true);
setBorder(noFocusBorder);
}
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus)
{
setComponentOrientation(list.getComponentOrientation());
if (isSelected) {
setBackground(list.getSelectionBackground());
setForeground(list.getSelectionForeground());
}
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 = UIManager.getBorder("List.focusSelectedCellHighlightBorder");
}
if (border == null) {
border = UIManager.getBorder("List.focusCellHighlightBorder");
}
} else {
border = noFocusBorder;
}
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
*/
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.
*/
public void validate() {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*
* @since 1.5
*/
public void invalidate() {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*
* @since 1.5
*/
public void repaint() {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void revalidate() {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
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.
*/
public void repaint(Rectangle r) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {
// Strings get interned...
if (propertyName=="text")
super.firePropertyChange(propertyName, oldValue, newValue);
}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, byte oldValue, byte newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, char oldValue, char newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, short oldValue, short newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, int oldValue, int newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, long oldValue, long newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, float oldValue, float newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
public void firePropertyChange(String propertyName, double oldValue, double newValue) {}
/**
* Overridden for performance reasons.
* See the <a href="#override">Implementation Note</a>
* for more information.
*/
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
{
}
}
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