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 }