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}