001/* BasicComboBoxRenderer.java --
002   Copyright (C) 2004, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.swing.plaf.basic;
040
041import java.awt.Component;
042import java.awt.Dimension;
043import java.io.Serializable;
044
045import javax.swing.Icon;
046import javax.swing.JComboBox;
047import javax.swing.JLabel;
048import javax.swing.JList;
049import javax.swing.ListCellRenderer;
050import javax.swing.border.Border;
051import javax.swing.border.EmptyBorder;
052
053/**
054 * A renderer for a {@link JComboBox}.
055 *
056 * @author Olga Rodimina
057 */
058public 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}