1 /*
2 * Copyright (c) 1997, 2015, 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 package javax.swing;
26
27 import javax.swing.plaf.*;
28 import javax.accessibility.*;
29
30 import java.beans.JavaBean;
31 import java.beans.BeanProperty;
32 import java.io.ObjectOutputStream;
33 import java.io.IOException;
34
35 /**
36 * <code>JSeparator</code> provides a general purpose component for
37 * implementing divider lines - most commonly used as a divider
38 * between menu items that breaks them up into logical groupings.
39 * Instead of using <code>JSeparator</code> directly,
40 * you can use the <code>JMenu</code> or <code>JPopupMenu</code>
41 * <code>addSeparator</code> method to create and add a separator.
42 * <code>JSeparator</code>s may also be used elsewhere in a GUI
43 * wherever a visual divider is useful.
44 *
45 * <p>
46 *
47 * For more information and examples see
48 * <a
49 href="https://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
50 * a section in <em>The Java Tutorial.</em>
51 * <p>
52 * <strong>Warning:</strong> Swing is not thread safe. For more
53 * information see <a
54 * href="package-summary.html#threading">Swing's Threading
55 * Policy</a>.
56 * <p>
57 * <strong>Warning:</strong>
58 * Serialized objects of this class will not be compatible with
59 * future Swing releases. The current serialization support is
60 * appropriate for short term storage or RMI between applications running
61 * the same version of Swing. As of 1.4, support for long term storage
62 * of all JavaBeans™
63 * has been added to the <code>java.beans</code> package.
64 * Please see {@link java.beans.XMLEncoder}.
65 *
66 * @author Georges Saab
67 * @author Jeff Shapiro
68 * @since 1.2
69 */
70 @JavaBean(defaultProperty = "UI", description = "A divider between menu items.")
71 @SwingContainer(false)
72 @SuppressWarnings("serial")
73 public class JSeparator extends JComponent implements SwingConstants, Accessible
74 {
75 /**
76 * @see #getUIClassID
77 * @see #readObject
78 */
79 private static final String uiClassID = "SeparatorUI";
80
81 private int orientation = HORIZONTAL;
82
83 /** Creates a new horizontal separator. */
84 public JSeparator()
85 {
86 this( HORIZONTAL );
87 }
88
89 /**
90 * Creates a new separator with the specified horizontal or
91 * vertical orientation.
92 *
93 * @param orientation an integer specifying
94 * <code>SwingConstants.HORIZONTAL</code> or
95 * <code>SwingConstants.VERTICAL</code>
96 * @exception IllegalArgumentException if <code>orientation</code>
97 * is neither <code>SwingConstants.HORIZONTAL</code> nor
98 * <code>SwingConstants.VERTICAL</code>
99 */
100 public JSeparator( int orientation )
101 {
102 checkOrientation( orientation );
103 this.orientation = orientation;
104 setFocusable(false);
105 updateUI();
106 }
107
108 /**
109 * Returns the L&F object that renders this component.
110 *
111 * @return the SeparatorUI object that renders this component
112 */
113 public SeparatorUI getUI() {
114 return (SeparatorUI)ui;
115 }
116
117 /**
118 * Sets the L&F object that renders this component.
119 *
120 * @param ui the SeparatorUI L&F object
121 * @see UIDefaults#getUI
122 */
123 @BeanProperty(hidden = true, visualUpdate = true, description
124 = "The UI object that implements the Component's LookAndFeel.")
125 public void setUI(SeparatorUI ui) {
126 super.setUI(ui);
127 }
128
129 /**
130 * Resets the UI property to a value from the current look and feel.
131 *
132 * @see JComponent#updateUI
133 */
134 public void updateUI() {
135 setUI((SeparatorUI)UIManager.getUI(this));
136 }
137
138
139 /**
140 * Returns the name of the L&F class that renders this component.
141 *
142 * @return the string "SeparatorUI"
143 * @see JComponent#getUIClassID
144 * @see UIDefaults#getUI
145 */
146 @BeanProperty(bound = false)
147 public String getUIClassID() {
148 return uiClassID;
149 }
150
151
152 /**
153 * See <code>readObject</code> and <code>writeObject</code> in
154 * <code>JComponent</code> for more
155 * information about serialization in Swing.
156 */
157 private void writeObject(ObjectOutputStream s) throws IOException {
158 s.defaultWriteObject();
159 if (getUIClassID().equals(uiClassID)) {
160 byte count = JComponent.getWriteObjCounter(this);
161 JComponent.setWriteObjCounter(this, --count);
162 if (count == 0 && ui != null) {
163 ui.installUI(this);
164 }
165 }
166 }
167
168 /**
169 * Returns the orientation of this separator.
170 *
171 * @return The value of the orientation property, one of the
172 * following constants defined in <code>SwingConstants</code>:
173 * <code>VERTICAL</code>, or
174 * <code>HORIZONTAL</code>.
175 *
176 * @see SwingConstants
177 * @see #setOrientation
178 */
179 public int getOrientation() {
180 return this.orientation;
181 }
182
183 /**
184 * Sets the orientation of the separator.
185 * The default value of this property is HORIZONTAL.
186 * @param orientation either <code>SwingConstants.HORIZONTAL</code>
187 * or <code>SwingConstants.VERTICAL</code>
188 * @exception IllegalArgumentException if <code>orientation</code>
189 * is neither <code>SwingConstants.HORIZONTAL</code>
190 * nor <code>SwingConstants.VERTICAL</code>
191 *
192 * @see SwingConstants
193 * @see #getOrientation
194 */
195 @BeanProperty(preferred = true, visualUpdate = true, enumerationValues = {
196 "SwingConstants.HORIZONTAL",
197 "SwingConstants.VERTICAL"}, description
198 = "The orientation of the separator.")
199 public void setOrientation( int orientation ) {
200 if (this.orientation == orientation) {
201 return;
202 }
203 int oldValue = this.orientation;
204 checkOrientation( orientation );
205 this.orientation = orientation;
206 firePropertyChange("orientation", oldValue, orientation);
207 revalidate();
208 repaint();
209 }
210
211 private void checkOrientation( int orientation )
212 {
213 switch ( orientation )
214 {
215 case VERTICAL:
216 case HORIZONTAL:
217 break;
218 default:
219 throw new IllegalArgumentException( "orientation must be one of: VERTICAL, HORIZONTAL" );
220 }
221 }
222
223
224 /**
225 * Returns a string representation of this <code>JSeparator</code>.
226 * This method
227 * is intended to be used only for debugging purposes, and the
228 * content and format of the returned string may vary between
229 * implementations. The returned string may be empty but may not
230 * be <code>null</code>.
231 *
232 * @return a string representation of this <code>JSeparator</code>
233 */
234 protected String paramString() {
235 String orientationString = (orientation == HORIZONTAL ?
236 "HORIZONTAL" : "VERTICAL");
237
238 return super.paramString() +
239 ",orientation=" + orientationString;
240 }
241
242 /////////////////
243 // Accessibility support
244 ////////////////
245
246 /**
247 * Gets the AccessibleContext associated with this JSeparator.
248 * For separators, the AccessibleContext takes the form of an
249 * AccessibleJSeparator.
250 * A new AccessibleJSeparator instance is created if necessary.
251 *
252 * @return an AccessibleJSeparator that serves as the
253 * AccessibleContext of this JSeparator
254 */
255 @BeanProperty(bound = false)
256 public AccessibleContext getAccessibleContext() {
257 if (accessibleContext == null) {
258 accessibleContext = new AccessibleJSeparator();
259 }
260 return accessibleContext;
261 }
262
263 /**
264 * This class implements accessibility support for the
265 * <code>JSeparator</code> class. It provides an implementation of the
266 * Java Accessibility API appropriate to separator user-interface elements.
267 * <p>
268 * <strong>Warning:</strong>
269 * Serialized objects of this class will not be compatible with
270 * future Swing releases. The current serialization support is
271 * appropriate for short term storage or RMI between applications running
272 * the same version of Swing. As of 1.4, support for long term storage
273 * of all JavaBeans™
274 * has been added to the <code>java.beans</code> package.
275 * Please see {@link java.beans.XMLEncoder}.
276 */
277 @SuppressWarnings("serial")
278 protected class AccessibleJSeparator extends AccessibleJComponent {
279
280 /**
281 * Get the role of this object.
282 *
283 * @return an instance of AccessibleRole describing the role of the
284 * object
285 */
286 public AccessibleRole getAccessibleRole() {
287 return AccessibleRole.SEPARATOR;
288 }
289 }
290 }