gomp-20050608-branch/libjava/classpath/javax/swing/plaf/basic/BasicComboBoxRenderer.java

   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    */
  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    */
  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    */
 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      */
 157     public UIResource()
 158     {
 159       // Nothing to do here.
 160     }
 161   }
 162 }