1 /*
2 * Copyright (c) 1997, 2018, 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 java.applet.Applet;
29 import java.awt.AWTEvent;
30 import java.awt.BorderLayout;
31 import java.awt.Color;
32 import java.awt.Component;
33 import java.awt.Container;
34 import java.awt.Graphics;
35 import java.awt.HeadlessException;
36 import java.awt.LayoutManager;
37 import java.beans.BeanProperty;
38 import java.beans.JavaBean;
39
40 import javax.accessibility.Accessible;
41 import javax.accessibility.AccessibleContext;
42
43 /**
44 * An extended version of <code>java.applet.Applet</code> that adds support for
45 * the JFC/Swing component architecture.
46 * You can find task-oriented documentation about using <code>JApplet</code>
47 * in <em>The Java Tutorial</em>,
48 * in the section
49 * <a
50 href="https://docs.oracle.com/javase/tutorial/uiswing/components/applet.html">How to Make Applets</a>.
51 * <p>
52 * The <code>JApplet</code> class is slightly incompatible with
53 * <code>java.applet.Applet</code>. <code>JApplet</code> contains a
54 * <code>JRootPane</code> as its only child. The <code>contentPane</code>
55 * should be the parent of any children of the <code>JApplet</code>.
56 * As a convenience, the {@code add}, {@code remove}, and {@code setLayout}
57 * methods of this class are overridden, so that they delegate calls
58 * to the corresponding methods of the {@code ContentPane}.
59 * For example, you can add a child component to an applet as follows:
60 * <pre>
61 * applet.add(child);
62 * </pre>
63 *
64 * And the child will be added to the <code>contentPane</code>.
65 * The <code>contentPane</code> will always be non-<code>null</code>.
66 * Attempting to set it to <code>null</code> will cause the
67 * <code>JApplet</code> to throw an exception. The default
68 * <code>contentPane</code> will have a <code>BorderLayout</code>
69 * manager set on it.
70 * Refer to {@link javax.swing.RootPaneContainer}
71 * for details on adding, removing and setting the <code>LayoutManager</code>
72 * of a <code>JApplet</code>.
73 * <p>
74 * Please see the <code>JRootPane</code> documentation for a
75 * complete description of the <code>contentPane</code>, <code>glassPane</code>,
76 * and <code>layeredPane</code> properties.
77 * <p>
78 * <strong>Warning:</strong> Swing is not thread safe. For more
79 * information see <a
80 * href="package-summary.html#threading">Swing's Threading
81 * Policy</a>.
82 * <p>
83 * <strong>Warning:</strong>
84 * Serialized objects of this class will not be compatible with
85 * future Swing releases. The current serialization support is
86 * appropriate for short term storage or RMI between applications running
87 * the same version of Swing. As of 1.4, support for long term storage
88 * of all JavaBeans™
89 * has been added to the <code>java.beans</code> package.
90 * Please see {@link java.beans.XMLEncoder}.
91 *
92 * @see javax.swing.RootPaneContainer
93 *
94 * @author Arnaud Weber
95 * @since 1.2
96 *
97 * @deprecated The Applet API is deprecated, no replacement.
98 */
99 @Deprecated(since = "9")
100 @JavaBean(defaultProperty = "JMenuBar", description = "Swing's Applet subclass.")
101 @SwingContainer(delegate = "getContentPane")
102 @SuppressWarnings("serial") // Same-version serialization only
103 public class JApplet extends Applet implements Accessible,
104 RootPaneContainer,
105 TransferHandler.HasGetTransferHandler
106 {
107 /**
108 * @see #getRootPane
109 * @see #setRootPane
110 */
111 protected JRootPane rootPane;
112
113 /**
114 * If true then calls to <code>add</code> and <code>setLayout</code>
115 * will be forwarded to the <code>contentPane</code>. This is initially
116 * false, but is set to true when the <code>JApplet</code> is constructed.
117 *
118 * @see #isRootPaneCheckingEnabled
119 * @see #setRootPaneCheckingEnabled
120 * @see javax.swing.RootPaneContainer
121 */
122 protected boolean rootPaneCheckingEnabled = false;
123
124 /**
125 * The <code>TransferHandler</code> for this applet.
126 */
127 private TransferHandler transferHandler;
128
129 /**
130 * Creates a swing applet instance.
131 * <p>
132 * This constructor sets the component's locale property to the value
133 * returned by <code>JComponent.getDefaultLocale</code>.
134 *
135 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
136 * returns true.
137 * @see java.awt.GraphicsEnvironment#isHeadless
138 * @see JComponent#getDefaultLocale
139 */
140 public JApplet() throws HeadlessException {
141 super();
142 // Check the timerQ and restart if necessary.
143 TimerQueue q = TimerQueue.sharedInstance();
144 if(q != null) {
145 q.startIfNeeded();
146 }
147
148 /* Workaround for bug 4155072. The shared double buffer image
149 * may hang on to a reference to this applet; unfortunately
150 * Image.getGraphics() will continue to call JApplet.getForeground()
151 * and getBackground() even after this applet has been destroyed.
152 * So we ensure that these properties are non-null here.
153 */
154 setForeground(Color.black);
155 setBackground(Color.white);
156
157 setLocale( JComponent.getDefaultLocale() );
158 setLayout(new BorderLayout());
159 setRootPane(createRootPane());
160 setRootPaneCheckingEnabled(true);
161
162 setFocusTraversalPolicyProvider(true);
163 sun.awt.SunToolkit.checkAndSetPolicy(this);
164
165 enableEvents(AWTEvent.KEY_EVENT_MASK);
166 }
167
168 /**
169 * Called by the constructor methods to create the default rootPane.
170 *
171 * @return a new {@code JRootPane}
172 */
173 protected JRootPane createRootPane() {
174 JRootPane rp = new JRootPane();
175 // NOTE: this uses setOpaque vs LookAndFeel.installProperty as there
176 // is NO reason for the RootPane not to be opaque. For painting to
177 // work the contentPane must be opaque, therefor the RootPane can
178 // also be opaque.
179 rp.setOpaque(true);
180 return rp;
181 }
182
183 /**
184 * Sets the {@code transferHandler} property, which is a mechanism to
185 * support transfer of data into this component. Use {@code null}
186 * if the component does not support data transfer operations.
187 * <p>
188 * If the system property {@code suppressSwingDropSupport} is {@code false}
189 * (the default) and the current drop target on this component is either
190 * {@code null} or not a user-set drop target, this method will change the
191 * drop target as follows: If {@code newHandler} is {@code null} it will
192 * clear the drop target. If not {@code null} it will install a new
193 * {@code DropTarget}.
194 * <p>
195 * Note: When used with {@code JApplet}, {@code TransferHandler} only
196 * provides data import capability, as the data export related methods
197 * are currently typed to {@code JComponent}.
198 * <p>
199 * Please see
200 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html">
201 * How to Use Drag and Drop and Data Transfer</a>, a section in
202 * <em>The Java Tutorial</em>, for more information.
203 *
204 * @param newHandler the new {@code TransferHandler}
205 *
206 * @see TransferHandler
207 * @see #getTransferHandler
208 * @see java.awt.Component#setDropTarget
209 * @since 1.6
210 */
211 @BeanProperty(hidden = true, description
212 = "Mechanism for transfer of data into the component")
213 public void setTransferHandler(TransferHandler newHandler) {
214 TransferHandler oldHandler = transferHandler;
215 transferHandler = newHandler;
216 SwingUtilities.installSwingDropTargetAsNecessary(this, transferHandler);
217 firePropertyChange("transferHandler", oldHandler, newHandler);
218 }
219
220 /**
221 * Gets the <code>transferHandler</code> property.
222 *
223 * @return the value of the <code>transferHandler</code> property
224 *
225 * @see TransferHandler
226 * @see #setTransferHandler
227 * @since 1.6
228 */
229 public TransferHandler getTransferHandler() {
230 return transferHandler;
231 }
232
233 /**
234 * Just calls <code>paint(g)</code>. This method was overridden to
235 * prevent an unnecessary call to clear the background.
236 */
237 public void update(Graphics g) {
238 paint(g);
239 }
240
241 /**
242 * Sets the menubar for this applet.
243 * @param menuBar the menubar being placed in the applet
244 *
245 * @see #getJMenuBar
246 */
247 @BeanProperty(bound = false, hidden = true, description
248 = "The menubar for accessing pulldown menus from this applet.")
249 public void setJMenuBar(final JMenuBar menuBar) {
250 getRootPane().setJMenuBar(menuBar);
251 }
252
253 /**
254 * Returns the menubar set on this applet.
255 *
256 * @return the menubar set on this applet
257 * @see #setJMenuBar
258 */
259 public JMenuBar getJMenuBar() {
260 return getRootPane().getJMenuBar();
261 }
262
263
264 /**
265 * Returns whether calls to <code>add</code> and
266 * <code>setLayout</code> are forwarded to the <code>contentPane</code>.
267 *
268 * @return true if <code>add</code> and <code>setLayout</code>
269 * are forwarded; false otherwise
270 *
271 * @see #addImpl
272 * @see #setLayout
273 * @see #setRootPaneCheckingEnabled
274 * @see javax.swing.RootPaneContainer
275 */
276 protected boolean isRootPaneCheckingEnabled() {
277 return rootPaneCheckingEnabled;
278 }
279
280
281 /**
282 * Sets whether calls to <code>add</code> and
283 * <code>setLayout</code> are forwarded to the <code>contentPane</code>.
284 *
285 * @param enabled true if <code>add</code> and <code>setLayout</code>
286 * are forwarded, false if they should operate directly on the
287 * <code>JApplet</code>.
288 *
289 * @see #addImpl
290 * @see #setLayout
291 * @see #isRootPaneCheckingEnabled
292 * @see javax.swing.RootPaneContainer
293 */
294 @BeanProperty(hidden = true, description
295 = "Whether the add and setLayout methods are forwarded")
296 protected void setRootPaneCheckingEnabled(boolean enabled) {
297 rootPaneCheckingEnabled = enabled;
298 }
299
300
301 /**
302 * Adds the specified child <code>Component</code>.
303 * This method is overridden to conditionally forward calls to the
304 * <code>contentPane</code>.
305 * By default, children are added to the <code>contentPane</code> instead
306 * of the frame, refer to {@link javax.swing.RootPaneContainer} for
307 * details.
308 *
309 * @param comp the component to be enhanced
310 * @param constraints the constraints to be respected
311 * @param index the index
312 * @exception IllegalArgumentException if <code>index</code> is invalid
313 * @exception IllegalArgumentException if adding the container's parent
314 * to itself
315 * @exception IllegalArgumentException if adding a window to a container
316 *
317 * @see #setRootPaneCheckingEnabled
318 * @see javax.swing.RootPaneContainer
319 */
320 protected void addImpl(Component comp, Object constraints, int index)
321 {
322 if(isRootPaneCheckingEnabled()) {
323 getContentPane().add(comp, constraints, index);
324 }
325 else {
326 super.addImpl(comp, constraints, index);
327 }
328 }
329
330 /**
331 * Removes the specified component from the container. If
332 * <code>comp</code> is not the <code>rootPane</code>, this will forward
333 * the call to the <code>contentPane</code>. This will do nothing if
334 * <code>comp</code> is not a child of the <code>JFrame</code> or
335 * <code>contentPane</code>.
336 *
337 * @param comp the component to be removed
338 * @throws NullPointerException if <code>comp</code> is null
339 * @see #add
340 * @see javax.swing.RootPaneContainer
341 */
342 public void remove(Component comp) {
343 if (comp == rootPane) {
344 super.remove(comp);
345 } else {
346 getContentPane().remove(comp);
347 }
348 }
349
350
351 /**
352 * Sets the <code>LayoutManager</code>.
353 * Overridden to conditionally forward the call to the
354 * <code>contentPane</code>.
355 * Refer to {@link javax.swing.RootPaneContainer} for
356 * more information.
357 *
358 * @param manager the <code>LayoutManager</code>
359 * @see #setRootPaneCheckingEnabled
360 * @see javax.swing.RootPaneContainer
361 */
362 public void setLayout(LayoutManager manager) {
363 if(isRootPaneCheckingEnabled()) {
364 getContentPane().setLayout(manager);
365 }
366 else {
367 super.setLayout(manager);
368 }
369 }
370
371
372 /**
373 * Returns the rootPane object for this applet.
374 *
375 * @see #setRootPane
376 * @see RootPaneContainer#getRootPane
377 */
378 @BeanProperty(bound = false, hidden = true, description
379 = "the RootPane object for this applet.")
380 public JRootPane getRootPane() {
381 return rootPane;
382 }
383
384
385 /**
386 * Sets the rootPane property. This method is called by the constructor.
387 * @param root the rootPane object for this applet
388 *
389 * @see #getRootPane
390 */
391 protected void setRootPane(JRootPane root) {
392 if(rootPane != null) {
393 remove(rootPane);
394 }
395 rootPane = root;
396 if(rootPane != null) {
397 boolean checkingEnabled = isRootPaneCheckingEnabled();
398 try {
399 setRootPaneCheckingEnabled(false);
400 add(rootPane, BorderLayout.CENTER);
401 }
402 finally {
403 setRootPaneCheckingEnabled(checkingEnabled);
404 }
405 }
406 }
407
408
409 /**
410 * Returns the contentPane object for this applet.
411 *
412 * @see #setContentPane
413 * @see RootPaneContainer#getContentPane
414 */
415 public Container getContentPane() {
416 return getRootPane().getContentPane();
417 }
418
419 /**
420 * Sets the contentPane property. This method is called by the constructor.
421 * @param contentPane the contentPane object for this applet
422 *
423 * @exception java.awt.IllegalComponentStateException (a runtime
424 * exception) if the content pane parameter is null
425 * @see #getContentPane
426 * @see RootPaneContainer#setContentPane
427 */
428 @BeanProperty(bound = false, hidden = true, description
429 = "The client area of the applet where child components are normally inserted.")
430 public void setContentPane(Container contentPane) {
431 getRootPane().setContentPane(contentPane);
432 }
433
434 /**
435 * Returns the layeredPane object for this applet.
436 *
437 * @exception java.awt.IllegalComponentStateException (a runtime
438 * exception) if the layered pane parameter is null
439 * @see #setLayeredPane
440 * @see RootPaneContainer#getLayeredPane
441 */
442 public JLayeredPane getLayeredPane() {
443 return getRootPane().getLayeredPane();
444 }
445
446 /**
447 * Sets the layeredPane property. This method is called by the constructor.
448 * @param layeredPane the layeredPane object for this applet
449 *
450 * @see #getLayeredPane
451 * @see RootPaneContainer#setLayeredPane
452 */
453 @BeanProperty(bound = false, hidden = true, description
454 = "The pane which holds the various applet layers.")
455 public void setLayeredPane(JLayeredPane layeredPane) {
456 getRootPane().setLayeredPane(layeredPane);
457 }
458
459 /**
460 * Returns the glassPane object for this applet.
461 *
462 * @see #setGlassPane
463 * @see RootPaneContainer#getGlassPane
464 */
465 public Component getGlassPane() {
466 return getRootPane().getGlassPane();
467 }
468
469 /**
470 * Sets the glassPane property.
471 * This method is called by the constructor.
472 * @param glassPane the glassPane object for this applet
473 *
474 * @see #getGlassPane
475 * @see RootPaneContainer#setGlassPane
476 */
477 @BeanProperty(bound = false, hidden = true, description
478 = "A transparent pane used for menu rendering.")
479 public void setGlassPane(Component glassPane) {
480 getRootPane().setGlassPane(glassPane);
481 }
482
483 /**
484 * {@inheritDoc}
485 *
486 * @since 1.6
487 */
488 @BeanProperty(bound = false)
489 public Graphics getGraphics() {
490 JComponent.getGraphicsInvoked(this);
491 return super.getGraphics();
492 }
493
494 /**
495 * Repaints the specified rectangle of this component within
496 * <code>time</code> milliseconds. Refer to <code>RepaintManager</code>
497 * for details on how the repaint is handled.
498 *
499 * @param time maximum time in milliseconds before update
500 * @param x the <i>x</i> coordinate
501 * @param y the <i>y</i> coordinate
502 * @param width the width
503 * @param height the height
504 * @see RepaintManager
505 * @since 1.6
506 */
507 public void repaint(long time, int x, int y, int width, int height) {
508 if (RepaintManager.HANDLE_TOP_LEVEL_PAINT) {
509 RepaintManager.currentManager(this).addDirtyRegion(
510 this, x, y, width, height);
511 }
512 else {
513 super.repaint(time, x, y, width, height);
514 }
515 }
516
517 /**
518 * Returns a string representation of this JApplet. This method
519 * is intended to be used only for debugging purposes, and the
520 * content and format of the returned string may vary between
521 * implementations. The returned string may be empty but may not
522 * be <code>null</code>.
523 *
524 * @return a string representation of this JApplet.
525 */
526 protected String paramString() {
527 String rootPaneString = (rootPane != null ?
528 rootPane.toString() : "");
529 String rootPaneCheckingEnabledString = (rootPaneCheckingEnabled ?
530 "true" : "false");
531
532 return super.paramString() +
533 ",rootPane=" + rootPaneString +
534 ",rootPaneCheckingEnabled=" + rootPaneCheckingEnabledString;
535 }
536
537
538
539 /////////////////
540 // Accessibility support
541 ////////////////
542
543 /**
544 * {@code AccessibleContext} associated with this {@code JApplet}
545 */
546 protected AccessibleContext accessibleContext = null;
547
548 /**
549 * Gets the AccessibleContext associated with this JApplet.
550 * For JApplets, the AccessibleContext takes the form of an
551 * AccessibleJApplet.
552 * A new AccessibleJApplet instance is created if necessary.
553 *
554 * @return an AccessibleJApplet that serves as the
555 * AccessibleContext of this JApplet
556 */
557 public AccessibleContext getAccessibleContext() {
558 if (accessibleContext == null) {
559 accessibleContext = new AccessibleJApplet();
560 }
561 return accessibleContext;
562 }
563
564 /**
565 * This class implements accessibility support for the
566 * <code>JApplet</code> class.
567 */
568 protected class AccessibleJApplet extends AccessibleApplet {
569 // everything moved to new parent, AccessibleApplet
570 }
571 }