001 /* BasicComboBoxRenderer.java --
002 Copyright (C) 2004, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing.plaf.basic;
040
041 import java.awt.Component;
042 import java.awt.Dimension;
043 import java.io.Serializable;
044
045 import javax.swing.Icon;
046 import javax.swing.JComboBox;
047 import javax.swing.JLabel;
048 import javax.swing.JList;
049 import javax.swing.ListCellRenderer;
050 import javax.swing.border.Border;
051 import javax.swing.border.EmptyBorder;
052
053 /**
054 * A renderer for a {@link JComboBox}.
055 *
056 * @author Olga Rodimina
057 */
058 public class BasicComboBoxRenderer
059 extends JLabel
060 implements ListCellRenderer, Serializable
061 {
062 /**
063 * A shared border instance for all renderers.
064 */
065 protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);
066
067 /**
068 * Creates a new <code>BasicComboBoxRenderer</code> object.
069 */
070 public BasicComboBoxRenderer()
071 {
072 setOpaque(true);
073 setBorder(noFocusBorder);
074 }
075
076 /**
077 * Returns preferredSize of the renderer
078 *
079 * @return preferredSize of the renderer
080 */
081 public Dimension getPreferredSize()
082 {
083 if (this.getText() != null && ! this.getText().equals(""))
084 return super.getPreferredSize();
085 else
086 {
087 // If the combo box option's text is empty or null, it won't size
088 // properly (ie, it'll be way too short)... so we throw in a dummy
089 // space to trick the superclass's sizing methods.
090 String oldText = this.getText();
091 this.setText(" ");
092 Dimension d = super.getPreferredSize();
093 this.setText(oldText);
094 return d;
095 }
096 }
097
098 /**
099 * Returns a component that has been configured to display the given
100 * <code>value</code>.
101 *
102 * @param list List of items for which to the background and foreground
103 * colors
104 * @param value object that should be rendered in the cell
105 * @param index index of the cell in the list of items.
106 * @param isSelected draw cell highlighted if isSelected is true
107 * @param cellHasFocus draw focus rectangle around cell if the cell has
108 * focus
109 *
110 * @return Component that will be used to draw the desired cell.
111 */
112 public Component getListCellRendererComponent(JList list, Object value,
113 int index, boolean isSelected,
114 boolean cellHasFocus)
115 {
116 if (isSelected)
117 {
118 setBackground(list.getSelectionBackground());
119 setForeground(list.getSelectionForeground());
120 }
121 else
122 {
123 setBackground(list.getBackground());
124 setForeground(list.getForeground());
125 }
126 setFont(list.getFont());
127
128 if (value instanceof Icon)
129 setIcon((Icon) value);
130 else
131 setText(value == null ? "" : value.toString());
132
133 return this;
134 }
135
136 /**
137 * A subclass of {@link BasicComboBoxRenderer} that implements the
138 * {@link javax.swing.plaf.UIResource} interface.
139 */
140 public static class UIResource extends BasicComboBoxRenderer
141 implements javax.swing.plaf.UIResource
142 {
143 /**
144 * Creates a new <code>UIResource</code> object.
145 */
146 public UIResource()
147 {
148 // Nothing to do here.
149 }
150 }
151 }