1 /* BasicComboBoxRenderer.java --
2    Copyright (C) 2004, 2005  Free Software Foundation, Inc.
3 
4 This file is part of GNU Classpath.
5 
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10 
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING.  If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20 
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library.  Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25 
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module.  An independent module is a module which is not derived from
33 or based on this library.  If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so.  If you do not wish to do so, delete this
36 exception statement from your version. */
37 
38 
39 package javax.swing.plaf.basic;
40 
41 import java.awt.Component;
42 import java.awt.Dimension;
43 import java.awt.FontMetrics;
44 import java.io.Serializable;
45 
46 import javax.swing.JComboBox;
47 import javax.swing.JLabel;
48 import javax.swing.JList;
49 import javax.swing.ListCellRenderer;
50 import javax.swing.SwingConstants;
51 import javax.swing.SwingUtilities;
52 import javax.swing.border.Border;
53 import javax.swing.border.EmptyBorder;
54 
55 /**
56  * A renderer for a {@link JComboBox}.
57  *
58  * @author Olga Rodimina
59  */
60 public class BasicComboBoxRenderer
61   extends JLabel
62   implements ListCellRenderer, Serializable
63 {
64   /**
65    * A shared border instance for all renderers.
66    */
67   protected static Border noFocusBorder = new EmptyBorder(0, 0, 0, 0);
68 
69   /**
70    * Creates a new <code>BasicComboBoxRenderer</code> object.
71    */
BasicComboBoxRenderer()72   public BasicComboBoxRenderer()
73   {
74     setHorizontalAlignment(SwingConstants.LEFT);
75     setBorder(noFocusBorder);
76   }
77 
78   /**
79    * Returns preferredSize of the renderer
80    *
81    * @return preferredSize of the renderer
82    */
getPreferredSize()83   public Dimension getPreferredSize()
84   {
85     return super.getPreferredSize();
86   }
87 
88   /**
89    * Returns a component that has been configured to display the given
90    * <code>value</code>.
91    *
92    * @param list List of items for which to the background and foreground
93    *        colors
94    * @param value object that should be rendered in the cell
95    * @param index index of the cell in the list of items.
96    * @param isSelected draw cell highlighted if isSelected is true
97    * @param cellHasFocus draw focus rectangle around cell if the cell has
98    *        focus
99    *
100    * @return Component that will be used to draw the desired cell.
101    */
getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)102   public Component getListCellRendererComponent(JList list, Object value,
103                                                 int index, boolean isSelected,
104                                                 boolean cellHasFocus)
105   {
106     String s = value.toString();
107 
108     // String maybe larger than comboBox.
109     FontMetrics fm = getToolkit().getFontMetrics(list.getFont());
110     int strWidth = SwingUtilities.computeStringWidth(fm, s);
111     int cbWidth = getSize().width;
112     if (cbWidth != 0 && strWidth > cbWidth)
113       {
114         char[] str = s.toCharArray();
115         int currWidth = 0;
116         int i = 0;
117         String postStr = "... ";
118         cbWidth -= SwingUtilities.computeStringWidth(fm, postStr);
119         while (i < str.length && currWidth < cbWidth)
120           {
121             ++i;
122             currWidth = SwingUtilities.computeStringWidth(fm, new String(str, 0, i));
123           }
124         setText(new String(str, 0, i)  + postStr);
125       }
126     else
127       setText(s);
128 
129     setOpaque(true);
130 
131     if (isSelected || cellHasFocus)
132       {
133         setBackground(list.getSelectionBackground());
134         setForeground(list.getSelectionForeground());
135       }
136     else
137       {
138         setBackground(list.getBackground());
139         setForeground(list.getForeground());
140       }
141 
142     setEnabled(list.isEnabled());
143     setFont(list.getFont());
144     return this;
145   }
146 
147   /**
148    * A subclass of {@link BasicComboBoxRenderer} that implements the
149    * {@link javax.swing.plaf.UIResource} interface.
150    */
151   public static class UIResource extends BasicComboBoxRenderer
152     implements javax.swing.plaf.UIResource
153   {
154     /**
155      * Creates a new <code>UIResource</code> object.
156      */
UIResource()157     public UIResource()
158     {
159       // Nothing to do here.
160     }
161   }
162 }
163