1 /*
2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.swing;
27
28 import javax.swing.plaf.*;
29 import javax.accessibility.*;
30
31 import java.io.ObjectOutputStream;
32 import java.io.ObjectInputStream;
33 import java.io.IOException;
34
35
36 /**
37 * <code>JSeparator</code> provides a general purpose component for
38 * implementing divider lines - most commonly used as a divider
39 * between menu items that breaks them up into logical groupings.
40 * Instead of using <code>JSeparator</code> directly,
41 * you can use the <code>JMenu</code> or <code>JPopupMenu</code>
42 * <code>addSeparator</code> method to create and add a separator.
43 * <code>JSeparator</code>s may also be used elsewhere in a GUI
44 * wherever a visual divider is useful.
45 *
46 * <p>
47 *
48 * For more information and examples see
49 * <a
50 href="http://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
51 * a section in <em>The Java Tutorial.</em>
52 * <p>
53 * <strong>Warning:</strong> Swing is not thread safe. For more
54 * information see <a
55 * href="package-summary.html#threading">Swing's Threading
56 * Policy</a>.
57 * <p>
58 * <strong>Warning:</strong>
59 * Serialized objects of this class will not be compatible with
60 * future Swing releases. The current serialization support is
61 * appropriate for short term storage or RMI between applications running
62 * the same version of Swing. As of 1.4, support for long term storage
63 * of all JavaBeans<sup><font size="-2">TM</font></sup>
64 * has been added to the <code>java.beans</code> package.
65 * Please see {@link java.beans.XMLEncoder}.
66 *
67 * @beaninfo
68 * attribute: isContainer false
69 * description: A divider between menu items.
70 *
71 * @author Georges Saab
72 * @author Jeff Shapiro
73 */
74 @SuppressWarnings("serial")
75 public class JSeparator extends JComponent implements SwingConstants, Accessible
76 {
77 /**
78 * @see #getUIClassID
79 * @see #readObject
80 */
81 private static final String uiClassID = "SeparatorUI";
82
83 private int orientation = HORIZONTAL;
84
85 /** Creates a new horizontal separator. */
86 public JSeparator()
87 {
88 this( HORIZONTAL );
89 }
90
91 /**
92 * Creates a new separator with the specified horizontal or
93 * vertical orientation.
94 *
95 * @param orientation an integer specifying
96 * <code>SwingConstants.HORIZONTAL</code> or
97 * <code>SwingConstants.VERTICAL</code>
98 * @exception IllegalArgumentException if <code>orientation</code>
99 * is neither <code>SwingConstants.HORIZONTAL</code> nor
100 * <code>SwingConstants.VERTICAL</code>
101 */
102 public JSeparator( int orientation )
103 {
104 checkOrientation( orientation );
105 this.orientation = orientation;
106 setFocusable(false);
107 updateUI();
108 }
109
110 /**
111 * Returns the L&F object that renders this component.
112 *
113 * @return the SeparatorUI object that renders this component
114 */
115 public SeparatorUI getUI() {
116 return (SeparatorUI)ui;
117 }
118
119 /**
120 * Sets the L&F object that renders this component.
121 *
122 * @param ui the SeparatorUI L&F object
123 * @see UIDefaults#getUI
124 * @beaninfo
125 * bound: true
126 * hidden: true
127 * attribute: visualUpdate true
128 * description: The UI object that implements the Component's LookAndFeel.
129 */
130 public void setUI(SeparatorUI ui) {
131 super.setUI(ui);
132 }
133
134 /**
135 * Resets the UI property to a value from the current look and feel.
136 *
137 * @see JComponent#updateUI
138 */
139 public void updateUI() {
140 setUI((SeparatorUI)UIManager.getUI(this));
141 }
142
143
144 /**
145 * Returns the name of the L&F class that renders this component.
146 *
147 * @return the string "SeparatorUI"
148 * @see JComponent#getUIClassID
149 * @see UIDefaults#getUI
150 */
151 public String getUIClassID() {
152 return uiClassID;
153 }
154
155
156 /**
157 * See <code>readObject</code> and <code>writeObject</code> in
158 * <code>JComponent</code> for more
159 * information about serialization in Swing.
160 */
161 private void writeObject(ObjectOutputStream s) throws IOException {
162 s.defaultWriteObject();
163 if (getUIClassID().equals(uiClassID)) {
164 byte count = JComponent.getWriteObjCounter(this);
165 JComponent.setWriteObjCounter(this, --count);
166 if (count == 0 && ui != null) {
167 ui.installUI(this);
168 }
169 }
170 }
171
172 /**
173 * Returns the orientation of this separator.
174 *
175 * @return The value of the orientation property, one of the
176 * following constants defined in <code>SwingConstants</code>:
177 * <code>VERTICAL</code>, or
178 * <code>HORIZONTAL</code>.
179 *
180 * @see SwingConstants
181 * @see #setOrientation
182 */
183 public int getOrientation() {
184 return this.orientation;
185 }
186
187 /**
188 * Sets the orientation of the separator.
189 * The default value of this property is HORIZONTAL.
190 * @param orientation either <code>SwingConstants.HORIZONTAL</code>
191 * or <code>SwingConstants.VERTICAL</code>
192 * @exception IllegalArgumentException if <code>orientation</code>
193 * is neither <code>SwingConstants.HORIZONTAL</code>
194 * nor <code>SwingConstants.VERTICAL</code>
195 *
196 * @see SwingConstants
197 * @see #getOrientation
198 * @beaninfo
199 * bound: true
200 * preferred: true
201 * enum: HORIZONTAL SwingConstants.HORIZONTAL
202 * VERTICAL SwingConstants.VERTICAL
203 * attribute: visualUpdate true
204 * description: The orientation of the separator.
205 */
206 public void setOrientation( int orientation ) {
207 if (this.orientation == orientation) {
208 return;
209 }
210 int oldValue = this.orientation;
211 checkOrientation( orientation );
212 this.orientation = orientation;
213 firePropertyChange("orientation", oldValue, orientation);
214 revalidate();
215 repaint();
216 }
217
218 private void checkOrientation( int orientation )
219 {
220 switch ( orientation )
221 {
222 case VERTICAL:
223 case HORIZONTAL:
224 break;
225 default:
226 throw new IllegalArgumentException( "orientation must be one of: VERTICAL, HORIZONTAL" );
227 }
228 }
229
230
231 /**
232 * Returns a string representation of this <code>JSeparator</code>.
233 * This method
234 * is intended to be used only for debugging purposes, and the
235 * content and format of the returned string may vary between
236 * implementations. The returned string may be empty but may not
237 * be <code>null</code>.
238 *
239 * @return a string representation of this <code>JSeparator</code>
240 */
241 protected String paramString() {
242 String orientationString = (orientation == HORIZONTAL ?
243 "HORIZONTAL" : "VERTICAL");
244
245 return super.paramString() +
246 ",orientation=" + orientationString;
247 }
248
249 /////////////////
250 // Accessibility support
251 ////////////////
252
253 /**
254 * Gets the AccessibleContext associated with this JSeparator.
255 * For separators, the AccessibleContext takes the form of an
256 * AccessibleJSeparator.
257 * A new AccessibleJSeparator instance is created if necessary.
258 *
259 * @return an AccessibleJSeparator that serves as the
260 * AccessibleContext of this JSeparator
261 */
262 public AccessibleContext getAccessibleContext() {
263 if (accessibleContext == null) {
264 accessibleContext = new AccessibleJSeparator();
265 }
266 return accessibleContext;
267 }
268
269 /**
270 * This class implements accessibility support for the
271 * <code>JSeparator</code> class. It provides an implementation of the
272 * Java Accessibility API appropriate to separator user-interface elements.
273 * <p>
274 * <strong>Warning:</strong>
275 * Serialized objects of this class will not be compatible with
276 * future Swing releases. The current serialization support is
277 * appropriate for short term storage or RMI between applications running
278 * the same version of Swing. As of 1.4, support for long term storage
279 * of all JavaBeans<sup><font size="-2">TM</font></sup>
280 * has been added to the <code>java.beans</code> package.
281 * Please see {@link java.beans.XMLEncoder}.
282 */
283 @SuppressWarnings("serial")
284 protected class AccessibleJSeparator extends AccessibleJComponent {
285
286 /**
287 * Get the role of this object.
288 *
289 * @return an instance of AccessibleRole describing the role of the
290 * object
291 */
292 public AccessibleRole getAccessibleRole() {
293 return AccessibleRole.SEPARATOR;
294 }
295 }
296 }