1 /* JPanel.java --
2    Copyright (C) 2002, 2004 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;
40 
41 import java.awt.FlowLayout;
42 import java.awt.LayoutManager;
43 
44 import javax.accessibility.Accessible;
45 import javax.accessibility.AccessibleContext;
46 import javax.accessibility.AccessibleRole;
47 import javax.swing.plaf.PanelUI;
48 
49 /**
50  * An instance of JPanel can be added to a panel, frame etc
51  *
52  * @author Ronald Veldema (rveldema@cs.vu.nl)
53  */
54 public class JPanel extends JComponent implements Accessible
55 {
56   /**
57    * Provides accessibility support for <code>JPanel</code>.
58    *
59    * @author Roman Kennke (roman@kennke.org)
60    */
61   protected class AccessibleJPanel extends AccessibleJComponent
62   {
63     /**
64      * Creates a new instance of <code>AccessibleJPanel</code>.
65      */
AccessibleJPanel()66     public AccessibleJPanel()
67     {
68       // Nothing to do here.
69     }
70 
71     /**
72      * Returns the accessible role for <code>JPanel</code>, which is
73      * {@link AccessibleRole#PANEL}.
74      *
75      * @return the accessible role for <code>JPanel</code>
76      */
getAccessibleRole()77     public AccessibleRole getAccessibleRole()
78     {
79       return AccessibleRole.PANEL;
80     }
81   }
82 
JPanel()83   public JPanel()
84   {
85     this(new FlowLayout(), true);
86   }
87 
JPanel(boolean double_buffered)88   public JPanel(boolean double_buffered)
89   {
90     this(new FlowLayout(), double_buffered);
91   }
92 
JPanel(LayoutManager layout)93   public JPanel(LayoutManager layout)
94   {
95     this(layout, true);
96   }
97 
JPanel(LayoutManager layout, boolean isDoubleBuffered)98   public JPanel(LayoutManager layout, boolean isDoubleBuffered)
99   {
100     if (layout == null)
101       {
102         // TODO: Is this correct? Or should we throw a NPE?
103         layout = new FlowLayout();
104       }
105     setLayout(layout);
106     setOpaque(true);
107 
108     updateUI();
109   }
110 
getUIClassID()111   public String getUIClassID()
112   {
113     return "PanelUI";
114   }
115 
setUI(PanelUI ui)116   public void setUI(PanelUI ui)
117   {
118     super.setUI(ui);
119   }
120 
getUI()121   public PanelUI getUI()
122   {
123     return (PanelUI) ui;
124   }
125 
updateUI()126   public void updateUI()
127   {
128     setUI((PanelUI) UIManager.getUI(this));
129   }
130 
getAccessibleContext()131   public AccessibleContext getAccessibleContext()
132   {
133     if (accessibleContext == null)
134       accessibleContext = new AccessibleJPanel();
135     return accessibleContext;
136   }
137 
paramString()138   protected  String paramString()
139   {
140 	return "JPanel";
141   }
142 }
143