1 /*
2 * Copyright (c) 1997, 2014, 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 java.awt.*;
28 import java.awt.event.*;
29 import java.applet.Applet;
30 import java.beans.PropertyChangeListener;
31 import java.util.Locale;
32 import java.util.Vector;
33 import java.io.Serializable;
34 import javax.accessibility.*;
35
36 /**
37 * An extended version of <code>java.applet.Applet</code> that adds support for
38 * the JFC/Swing component architecture.
39 * You can find task-oriented documentation about using <code>JApplet</code>
40 * in <em>The Java Tutorial</em>,
41 * in the section
42 * <a
43 href="http://docs.oracle.com/javase/tutorial/uiswing/components/applet.html">How to Make Applets</a>.
44 * <p>
45 * The <code>JApplet</code> class is slightly incompatible with
46 * <code>java.applet.Applet</code>. <code>JApplet</code> contains a
47 * <code>JRootPane</code> as its only child. The <code>contentPane</code>
48 * should be the parent of any children of the <code>JApplet</code>.
49 * As a convenience, the {@code add}, {@code remove}, and {@code setLayout}
50 * methods of this class are overridden, so that they delegate calls
51 * to the corresponding methods of the {@code ContentPane}.
52 * For example, you can add a child component to an applet as follows:
53 * <pre>
54 * applet.add(child);
55 * </pre>
56 *
57 * And the child will be added to the <code>contentPane</code>.
58 * The <code>contentPane</code> will always be non-<code>null</code>.
59 * Attempting to set it to <code>null</code> will cause the
60 * <code>JApplet</code> to throw an exception. The default
61 * <code>contentPane</code> will have a <code>BorderLayout</code>
62 * manager set on it.
63 * Refer to {@link javax.swing.RootPaneContainer}
64 * for details on adding, removing and setting the <code>LayoutManager</code>
65 * of a <code>JApplet</code>.
66 * <p>
67 * Please see the <code>JRootPane</code> documentation for a
68 * complete description of the <code>contentPane</code>, <code>glassPane</code>,
69 * and <code>layeredPane</code> properties.
70 * <p>
71 * <strong>Warning:</strong> Swing is not thread safe. For more
72 * information see <a
73 * href="package-summary.html#threading">Swing's Threading
74 * Policy</a>.
75 * <p>
76 * <strong>Warning:</strong>
77 * Serialized objects of this class will not be compatible with
78 * future Swing releases. The current serialization support is
79 * appropriate for short term storage or RMI between applications running
80 * the same version of Swing. As of 1.4, support for long term storage
81 * of all JavaBeans™
82 * has been added to the <code>java.beans</code> package.
83 * Please see {@link java.beans.XMLEncoder}.
84 *
85 * @see javax.swing.RootPaneContainer
86 * @beaninfo
87 * attribute: isContainer true
88 * attribute: containerDelegate getContentPane
89 * description: Swing's Applet subclass.
90 *
91 * @author Arnaud Weber
92 * @since 1.2
93 */
94 @SuppressWarnings("serial") // Same-version serialization only
95 public class JApplet extends Applet implements Accessible,
96 RootPaneContainer,
97 TransferHandler.HasGetTransferHandler
98 {
99 /**
100 * @see #getRootPane
101 * @see #setRootPane
102 */
103 protected JRootPane rootPane;
104
105 /**
106 * If true then calls to <code>add</code> and <code>setLayout</code>
107 * will be forwarded to the <code>contentPane</code>. This is initially
108 * false, but is set to true when the <code>JApplet</code> is constructed.
109 *
110 * @see #isRootPaneCheckingEnabled
111 * @see #setRootPaneCheckingEnabled
112 * @see javax.swing.RootPaneContainer
113 */
114 protected boolean rootPaneCheckingEnabled = false;
115
116 /**
117 * The <code>TransferHandler</code> for this applet.
118 */
119 private TransferHandler transferHandler;
120
121 /**
122 * Creates a swing applet instance.
123 * <p>
124 * This constructor sets the component's locale property to the value
125 * returned by <code>JComponent.getDefaultLocale</code>.
126 *
127 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
128 * returns true.
129 * @see java.awt.GraphicsEnvironment#isHeadless
130 * @see JComponent#getDefaultLocale
131 */
132 public JApplet() throws HeadlessException {
133 super();
134 // Check the timerQ and restart if necessary.
135 TimerQueue q = TimerQueue.sharedInstance();
136 if(q != null) {
137 q.startIfNeeded();
138 }
139
140 /* Workaround for bug 4155072. The shared double buffer image
141 * may hang on to a reference to this applet; unfortunately
142 * Image.getGraphics() will continue to call JApplet.getForeground()
143 * and getBackground() even after this applet has been destroyed.
144 * So we ensure that these properties are non-null here.
145 */
146 setForeground(Color.black);
147 setBackground(Color.white);
148
149 setLocale( JComponent.getDefaultLocale() );
150 setLayout(new BorderLayout());
151 setRootPane(createRootPane());
152 setRootPaneCheckingEnabled(true);
153
154 setFocusTraversalPolicyProvider(true);
155 sun.awt.SunToolkit.checkAndSetPolicy(this);
156
157 enableEvents(AWTEvent.KEY_EVENT_MASK);
158 }
159
160 /**
161 * Called by the constructor methods to create the default rootPane.
162 *
163 * @return a new {@code JRootPane}
164 */
165 protected JRootPane createRootPane() {
166 JRootPane rp = new JRootPane();
167 // NOTE: this uses setOpaque vs LookAndFeel.installProperty as there
168 // is NO reason for the RootPane not to be opaque. For painting to
169 // work the contentPane must be opaque, therefor the RootPane can
170 // also be opaque.
171 rp.setOpaque(true);
172 return rp;
173 }
174
175 /**
176 * Sets the {@code transferHandler} property, which is a mechanism to
177 * support transfer of data into this component. Use {@code null}
178 * if the component does not support data transfer operations.
179 * <p>
180 * If the system property {@code suppressSwingDropSupport} is {@code false}
181 * (the default) and the current drop target on this component is either
182 * {@code null} or not a user-set drop target, this method will change the
183 * drop target as follows: If {@code newHandler} is {@code null} it will
184 * clear the drop target. If not {@code null} it will install a new
185 * {@code DropTarget}.
186 * <p>
187 * Note: When used with {@code JApplet}, {@code TransferHandler} only
188 * provides data import capability, as the data export related methods
189 * are currently typed to {@code JComponent}.
190 * <p>
191 * Please see
192 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html">
193 * How to Use Drag and Drop and Data Transfer</a>, a section in
194 * <em>The Java Tutorial</em>, for more information.
195 *
196 * @param newHandler the new {@code TransferHandler}
197 *
198 * @see TransferHandler
199 * @see #getTransferHandler
200 * @see java.awt.Component#setDropTarget
201 * @since 1.6
202 *
203 * @beaninfo
204 * bound: true
205 * hidden: true
206 * description: Mechanism for transfer of data into the component
207 */
208 public void setTransferHandler(TransferHandler newHandler) {
209 TransferHandler oldHandler = transferHandler;
210 transferHandler = newHandler;
211 SwingUtilities.installSwingDropTargetAsNecessary(this, transferHandler);
212 firePropertyChange("transferHandler", oldHandler, newHandler);
213 }
214
215 /**
216 * Gets the <code>transferHandler</code> property.
217 *
218 * @return the value of the <code>transferHandler</code> property
219 *
220 * @see TransferHandler
221 * @see #setTransferHandler
222 * @since 1.6
223 */
224 public TransferHandler getTransferHandler() {
225 return transferHandler;
226 }
227
228 /**
229 * Just calls <code>paint(g)</code>. This method was overridden to
230 * prevent an unnecessary call to clear the background.
231 */
232 public void update(Graphics g) {
233 paint(g);
234 }
235
236 /**
237 * Sets the menubar for this applet.
238 * @param menuBar the menubar being placed in the applet
239 *
240 * @see #getJMenuBar
241 *
242 * @beaninfo
243 * hidden: true
244 * description: The menubar for accessing pulldown menus from this applet.
245 */
246 @SuppressWarnings("deprecation")
247 public void setJMenuBar(JMenuBar menuBar) {
248 getRootPane().setMenuBar(menuBar);
249 }
250
251 /**
252 * Returns the menubar set on this applet.
253 *
254 * @return the menubar set on this applet
255 * @see #setJMenuBar
256 */
257 @SuppressWarnings("deprecation")
258 public JMenuBar getJMenuBar() {
259 return getRootPane().getMenuBar();
260 }
261
262
263 /**
264 * Returns whether calls to <code>add</code> and
265 * <code>setLayout</code> are forwarded to the <code>contentPane</code>.
266 *
267 * @return true if <code>add</code> and <code>setLayout</code>
268 * are forwarded; false otherwise
269 *
270 * @see #addImpl
271 * @see #setLayout
272 * @see #setRootPaneCheckingEnabled
273 * @see javax.swing.RootPaneContainer
274 */
275 protected boolean isRootPaneCheckingEnabled() {
276 return rootPaneCheckingEnabled;
277 }
278
279
280 /**
281 * Sets whether calls to <code>add</code> and
282 * <code>setLayout</code> are forwarded to the <code>contentPane</code>.
283 *
284 * @param enabled true if <code>add</code> and <code>setLayout</code>
285 * are forwarded, false if they should operate directly on the
286 * <code>JApplet</code>.
287 *
288 * @see #addImpl
289 * @see #setLayout
290 * @see #isRootPaneCheckingEnabled
291 * @see javax.swing.RootPaneContainer
292 * @beaninfo
293 * hidden: true
294 * description: Whether the add and setLayout methods are forwarded
295 */
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 public JRootPane getRootPane() {
379 return rootPane;
380 }
381
382
383 /**
384 * Sets the rootPane property. This method is called by the constructor.
385 * @param root the rootPane object for this applet
386 *
387 * @see #getRootPane
388 *
389 * @beaninfo
390 * hidden: true
391 * description: the RootPane object for this applet.
392 */
393 protected void setRootPane(JRootPane root) {
394 if(rootPane != null) {
395 remove(rootPane);
396 }
397 rootPane = root;
398 if(rootPane != null) {
399 boolean checkingEnabled = isRootPaneCheckingEnabled();
400 try {
401 setRootPaneCheckingEnabled(false);
402 add(rootPane, BorderLayout.CENTER);
403 }
404 finally {
405 setRootPaneCheckingEnabled(checkingEnabled);
406 }
407 }
408 }
409
410
411 /**
412 * Returns the contentPane object for this applet.
413 *
414 * @see #setContentPane
415 * @see RootPaneContainer#getContentPane
416 */
417 public Container getContentPane() {
418 return getRootPane().getContentPane();
419 }
420
421 /**
422 * Sets the contentPane property. This method is called by the constructor.
423 * @param contentPane the contentPane object for this applet
424 *
425 * @exception java.awt.IllegalComponentStateException (a runtime
426 * exception) if the content pane parameter is null
427 * @see #getContentPane
428 * @see RootPaneContainer#setContentPane
429 *
430 * @beaninfo
431 * hidden: true
432 * description: The client area of the applet where child
433 * components are normally inserted.
434 */
435 public void setContentPane(Container contentPane) {
436 getRootPane().setContentPane(contentPane);
437 }
438
439 /**
440 * Returns the layeredPane object for this applet.
441 *
442 * @exception java.awt.IllegalComponentStateException (a runtime
443 * exception) if the layered pane parameter is null
444 * @see #setLayeredPane
445 * @see RootPaneContainer#getLayeredPane
446 */
447 public JLayeredPane getLayeredPane() {
448 return getRootPane().getLayeredPane();
449 }
450
451 /**
452 * Sets the layeredPane property. This method is called by the constructor.
453 * @param layeredPane the layeredPane object for this applet
454 *
455 * @see #getLayeredPane
456 * @see RootPaneContainer#setLayeredPane
457 *
458 * @beaninfo
459 * hidden: true
460 * description: The pane which holds the various applet layers.
461 */
462 public void setLayeredPane(JLayeredPane layeredPane) {
463 getRootPane().setLayeredPane(layeredPane);
464 }
465
466 /**
467 * Returns the glassPane object for this applet.
468 *
469 * @see #setGlassPane
470 * @see RootPaneContainer#getGlassPane
471 */
472 public Component getGlassPane() {
473 return getRootPane().getGlassPane();
474 }
475
476 /**
477 * Sets the glassPane property.
478 * This method is called by the constructor.
479 * @param glassPane the glassPane object for this applet
480 *
481 * @see #getGlassPane
482 * @see RootPaneContainer#setGlassPane
483 *
484 * @beaninfo
485 * hidden: true
486 * description: A transparent pane used for menu rendering.
487 */
488 public void setGlassPane(Component glassPane) {
489 getRootPane().setGlassPane(glassPane);
490 }
491
492 /**
493 * {@inheritDoc}
494 *
495 * @since 1.6
496 */
497 public Graphics getGraphics() {
498 JComponent.getGraphicsInvoked(this);
499 return super.getGraphics();
500 }
501
502 /**
503 * Repaints the specified rectangle of this component within
504 * <code>time</code> milliseconds. Refer to <code>RepaintManager</code>
505 * for details on how the repaint is handled.
506 *
507 * @param time maximum time in milliseconds before update
508 * @param x the <i>x</i> coordinate
509 * @param y the <i>y</i> coordinate
510 * @param width the width
511 * @param height the height
512 * @see RepaintManager
513 * @since 1.6
514 */
515 public void repaint(long time, int x, int y, int width, int height) {
516 if (RepaintManager.HANDLE_TOP_LEVEL_PAINT) {
517 RepaintManager.currentManager(this).addDirtyRegion(
518 this, x, y, width, height);
519 }
520 else {
521 super.repaint(time, x, y, width, height);
522 }
523 }
524
525 /**
526 * Returns a string representation of this JApplet. This method
527 * is intended to be used only for debugging purposes, and the
528 * content and format of the returned string may vary between
529 * implementations. The returned string may be empty but may not
530 * be <code>null</code>.
531 *
532 * @return a string representation of this JApplet.
533 */
534 protected String paramString() {
535 String rootPaneString = (rootPane != null ?
536 rootPane.toString() : "");
537 String rootPaneCheckingEnabledString = (rootPaneCheckingEnabled ?
538 "true" : "false");
539
540 return super.paramString() +
541 ",rootPane=" + rootPaneString +
542 ",rootPaneCheckingEnabled=" + rootPaneCheckingEnabledString;
543 }
544
545
546
547 /////////////////
548 // Accessibility support
549 ////////////////
550
551 /**
552 * {@code AccessibleContext} associated with this {@code JApplet}
553 */
554 protected AccessibleContext accessibleContext = null;
555
556 /**
557 * Gets the AccessibleContext associated with this JApplet.
558 * For JApplets, the AccessibleContext takes the form of an
559 * AccessibleJApplet.
560 * A new AccessibleJApplet instance is created if necessary.
561 *
562 * @return an AccessibleJApplet that serves as the
563 * AccessibleContext of this JApplet
564 */
565 public AccessibleContext getAccessibleContext() {
566 if (accessibleContext == null) {
567 accessibleContext = new AccessibleJApplet();
568 }
569 return accessibleContext;
570 }
571
572 /**
573 * This class implements accessibility support for the
574 * <code>JApplet</code> class.
575 */
576 protected class AccessibleJApplet extends AccessibleApplet {
577 // everything moved to new parent, AccessibleApplet
578 }
579 }