1 /*
2 * Copyright (c) 1997, 2013, 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™
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 * @since 1.2
74 */
75 @SuppressWarnings("serial")
76 public class JSeparator extends JComponent implements SwingConstants, Accessible
77 {
78 /**
79 * @see #getUIClassID
80 * @see #readObject
81 */
82 private static final String uiClassID = "SeparatorUI";
83
84 private int orientation = HORIZONTAL;
85
86 /** Creates a new horizontal separator. */
87 public JSeparator()
88 {
89 this( HORIZONTAL );
90 }
91
92 /**
93 * Creates a new separator with the specified horizontal or
94 * vertical orientation.
95 *
96 * @param orientation an integer specifying
97 * <code>SwingConstants.HORIZONTAL</code> or
98 * <code>SwingConstants.VERTICAL</code>
99 * @exception IllegalArgumentException if <code>orientation</code>
100 * is neither <code>SwingConstants.HORIZONTAL</code> nor
101 * <code>SwingConstants.VERTICAL</code>
102 */
103 public JSeparator( int orientation )
104 {
105 checkOrientation( orientation );
106 this.orientation = orientation;
107 setFocusable(false);
108 updateUI();
109 }
110
111 /**
112 * Returns the L&F object that renders this component.
113 *
114 * @return the SeparatorUI object that renders this component
115 */
116 public SeparatorUI getUI() {
117 return (SeparatorUI)ui;
118 }
119
120 /**
121 * Sets the L&F object that renders this component.
122 *
123 * @param ui the SeparatorUI L&F object
124 * @see UIDefaults#getUI
125 * @beaninfo
126 * bound: true
127 * hidden: true
128 * attribute: visualUpdate true
129 * description: The UI object that implements the Component's LookAndFeel.
130 */
131 public void setUI(SeparatorUI ui) {
132 super.setUI(ui);
133 }
134
135 /**
136 * Resets the UI property to a value from the current look and feel.
137 *
138 * @see JComponent#updateUI
139 */
140 public void updateUI() {
141 setUI((SeparatorUI)UIManager.getUI(this));
142 }
143
144
145 /**
146 * Returns the name of the L&F class that renders this component.
147 *
148 * @return the string "SeparatorUI"
149 * @see JComponent#getUIClassID
150 * @see UIDefaults#getUI
151 */
152 public String getUIClassID() {
153 return uiClassID;
154 }
155
156
157 /**
158 * See <code>readObject</code> and <code>writeObject</code> in
159 * <code>JComponent</code> for more
160 * information about serialization in Swing.
161 */
162 private void writeObject(ObjectOutputStream s) throws IOException {
163 s.defaultWriteObject();
164 if (getUIClassID().equals(uiClassID)) {
165 byte count = JComponent.getWriteObjCounter(this);
166 JComponent.setWriteObjCounter(this, --count);
167 if (count == 0 && ui != null) {
168 ui.installUI(this);
169 }
170 }
171 }
172
173 /**
174 * Returns the orientation of this separator.
175 *
176 * @return The value of the orientation property, one of the
177 * following constants defined in <code>SwingConstants</code>:
178 * <code>VERTICAL</code>, or
179 * <code>HORIZONTAL</code>.
180 *
181 * @see SwingConstants
182 * @see #setOrientation
183 */
184 public int getOrientation() {
185 return this.orientation;
186 }
187
188 /**
189 * Sets the orientation of the separator.
190 * The default value of this property is HORIZONTAL.
191 * @param orientation either <code>SwingConstants.HORIZONTAL</code>
192 * or <code>SwingConstants.VERTICAL</code>
193 * @exception IllegalArgumentException if <code>orientation</code>
194 * is neither <code>SwingConstants.HORIZONTAL</code>
195 * nor <code>SwingConstants.VERTICAL</code>
196 *
197 * @see SwingConstants
198 * @see #getOrientation
199 * @beaninfo
200 * bound: true
201 * preferred: true
202 * enum: HORIZONTAL SwingConstants.HORIZONTAL
203 * VERTICAL SwingConstants.VERTICAL
204 * attribute: visualUpdate true
205 * description: The orientation of the separator.
206 */
207 public void setOrientation( int orientation ) {
208 if (this.orientation == orientation) {
209 return;
210 }
211 int oldValue = this.orientation;
212 checkOrientation( orientation );
213 this.orientation = orientation;
214 firePropertyChange("orientation", oldValue, orientation);
215 revalidate();
216 repaint();
217 }
218
219 private void checkOrientation( int orientation )
220 {
221 switch ( orientation )
222 {
223 case VERTICAL:
224 case HORIZONTAL:
225 break;
226 default:
227 throw new IllegalArgumentException( "orientation must be one of: VERTICAL, HORIZONTAL" );
228 }
229 }
230
231
232 /**
233 * Returns a string representation of this <code>JSeparator</code>.
234 * This method
235 * is intended to be used only for debugging purposes, and the
236 * content and format of the returned string may vary between
237 * implementations. The returned string may be empty but may not
238 * be <code>null</code>.
239 *
240 * @return a string representation of this <code>JSeparator</code>
241 */
242 protected String paramString() {
243 String orientationString = (orientation == HORIZONTAL ?
244 "HORIZONTAL" : "VERTICAL");
245
246 return super.paramString() +
247 ",orientation=" + orientationString;
248 }
249
250 /////////////////
251 // Accessibility support
252 ////////////////
253
254 /**
255 * Gets the AccessibleContext associated with this JSeparator.
256 * For separators, the AccessibleContext takes the form of an
257 * AccessibleJSeparator.
258 * A new AccessibleJSeparator instance is created if necessary.
259 *
260 * @return an AccessibleJSeparator that serves as the
261 * AccessibleContext of this JSeparator
262 */
263 public AccessibleContext getAccessibleContext() {
264 if (accessibleContext == null) {
265 accessibleContext = new AccessibleJSeparator();
266 }
267 return accessibleContext;
268 }
269
270 /**
271 * This class implements accessibility support for the
272 * <code>JSeparator</code> class. It provides an implementation of the
273 * Java Accessibility API appropriate to separator user-interface elements.
274 * <p>
275 * <strong>Warning:</strong>
276 * Serialized objects of this class will not be compatible with
277 * future Swing releases. The current serialization support is
278 * appropriate for short term storage or RMI between applications running
279 * the same version of Swing. As of 1.4, support for long term storage
280 * of all JavaBeans™
281 * has been added to the <code>java.beans</code> package.
282 * Please see {@link java.beans.XMLEncoder}.
283 */
284 @SuppressWarnings("serial")
285 protected class AccessibleJSeparator extends AccessibleJComponent {
286
287 /**
288 * Get the role of this object.
289 *
290 * @return an instance of AccessibleRole describing the role of the
291 * object
292 */
293 public AccessibleRole getAccessibleRole() {
294 return AccessibleRole.SEPARATOR;
295 }
296 }
297 }