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1   /*
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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
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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
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20   *
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24   */
25  package javax.swing;
26  
27  import java.applet.Applet;
28  import java.awt.*;
29  import java.awt.event.*;
30  import java.beans.*;
31  import java.security.AccessController;
32  import javax.accessibility.*;
33  import javax.swing.plaf.RootPaneUI;
34  import java.util.Vector;
35  import java.io.Serializable;
36  import javax.swing.border.*;
37  import sun.awt.AWTAccessor;
38  import sun.security.action.GetBooleanAction;
39  
40  
41  /**
42   * A lightweight container used behind the scenes by
43   * <code>JFrame</code>, <code>JDialog</code>, <code>JWindow</code>,
44   * <code>JApplet</code>, and <code>JInternalFrame</code>.
45   * For task-oriented information on functionality provided by root panes
46   * see <a href="http://docs.oracle.com/javase/tutorial/uiswing/components/rootpane.html">How to Use Root Panes</a>,
47   * a section in <em>The Java Tutorial</em>.
48   *
49   * <p>
50   * The following image shows the relationships between
51   * the classes that use root panes.
52   * <p style="text-align:center"><img src="doc-files/JRootPane-1.gif"
53   * alt="The following text describes this graphic."
54   * HEIGHT=484 WIDTH=629></p>
55   * The &quot;heavyweight&quot; components (those that delegate to a peer, or native
56   * component on the host system) are shown with a darker, heavier box. The four
57   * heavyweight JFC/Swing containers (<code>JFrame</code>, <code>JDialog</code>,
58   * <code>JWindow</code>, and <code>JApplet</code>) are
59   * shown in relation to the AWT classes they extend.
60   * These four components are the
61   * only heavyweight containers in the Swing library. The lightweight container
62   * <code>JInternalFrame</code> is also shown.
63   * All five of these JFC/Swing containers implement the
64   * <code>RootPaneContainer</code> interface,
65   * and they all delegate their operations to a
66   * <code>JRootPane</code> (shown with a little "handle" on top).
67   * <blockquote>
68   * <b>Note:</b> The <code>JComponent</code> method <code>getRootPane</code>
69   * can be used to obtain the <code>JRootPane</code> that contains
70   * a given component.
71   * </blockquote>
72   * <table style="float:right" border="0" summary="layout">
73   * <tr>
74   * <td align="center">
75   * <img src="doc-files/JRootPane-2.gif"
76   * alt="The following text describes this graphic." HEIGHT=386 WIDTH=349>
77   * </td>
78   * </tr>
79   * </table>
80   * The diagram at right shows the structure of a <code>JRootPane</code>.
81   * A <code>JRootpane</code> is made up of a <code>glassPane</code>,
82   * an optional <code>menuBar</code>, and a <code>contentPane</code>.
83   * (The <code>JLayeredPane</code> manages the <code>menuBar</code>
84   * and the <code>contentPane</code>.)
85   * The <code>glassPane</code> sits over the top of everything,
86   * where it is in a position to intercept mouse movements.
87   * Since the <code>glassPane</code> (like the <code>contentPane</code>)
88   * can be an arbitrary component, it is also possible to set up the
89   * <code>glassPane</code> for drawing. Lines and images on the
90   * <code>glassPane</code> can then range
91   * over the frames underneath without being limited by their boundaries.
92   * <p>
93   * Although the <code>menuBar</code> component is optional,
94   * the <code>layeredPane</code>, <code>contentPane</code>,
95   * and <code>glassPane</code> always exist.
96   * Attempting to set them to <code>null</code> generates an exception.
97   * <p>
98   * To add components to the <code>JRootPane</code> (other than the
99   * optional menu bar), you add the object to the <code>contentPane</code>
100  * of the <code>JRootPane</code>, like this:
101  * <pre>
102  *       rootPane.getContentPane().add(child);
103  * </pre>
104  * The same principle holds true for setting layout managers, removing
105  * components, listing children, etc. All these methods are invoked on
106  * the <code>contentPane</code> instead of on the <code>JRootPane</code>.
107  * <blockquote>
108  * <b>Note:</b> The default layout manager for the <code>contentPane</code> is
109  *  a <code>BorderLayout</code> manager. However, the <code>JRootPane</code>
110  *  uses a custom <code>LayoutManager</code>.
111  *  So, when you want to change the layout manager for the components you added
112  *  to a <code>JRootPane</code>, be sure to use code like this:
113  * <pre>
114  *    rootPane.getContentPane().setLayout(new BoxLayout());
115  * </pre></blockquote>
116  * If a <code>JMenuBar</code> component is set on the <code>JRootPane</code>,
117  * it is positioned along the upper edge of the frame.
118  * The <code>contentPane</code> is adjusted in location and size to
119  * fill the remaining area.
120  * (The <code>JMenuBar</code> and the <code>contentPane</code> are added to the
121  * <code>layeredPane</code> component at the
122  * <code>JLayeredPane.FRAME_CONTENT_LAYER</code> layer.)
123  * <p>
124  * The <code>layeredPane</code> is the parent of all children in the
125  * <code>JRootPane</code> -- both as the direct parent of the menu and
126  * the grandparent of all components added to the <code>contentPane</code>.
127  * It is an instance of <code>JLayeredPane</code>,
128  * which provides the ability to add components at several layers.
129  * This capability is very useful when working with menu popups,
130  * dialog boxes, and dragging -- situations in which you need to place
131  * a component on top of all other components in the pane.
132  * <p>
133  * The <code>glassPane</code> sits on top of all other components in the
134  * <code>JRootPane</code>.
135  * That provides a convenient place to draw above all other components,
136  * and makes it possible to intercept mouse events,
137  * which is useful both for dragging and for drawing.
138  * Developers can use <code>setVisible</code> on the <code>glassPane</code>
139  * to control when the <code>glassPane</code> displays over the other children.
140  * By default the <code>glassPane</code> is not visible.
141  * <p>
142  * The custom <code>LayoutManager</code> used by <code>JRootPane</code>
143  * ensures that:
144  * <OL>
145  * <LI>The <code>glassPane</code> fills the entire viewable
146  *     area of the <code>JRootPane</code> (bounds - insets).
147  * <LI>The <code>layeredPane</code> fills the entire viewable area of the
148  *     <code>JRootPane</code>. (bounds - insets)
149  * <LI>The <code>menuBar</code> is positioned at the upper edge of the
150  *     <code>layeredPane</code>.
151  * <LI>The <code>contentPane</code> fills the entire viewable area,
152  *     minus the <code>menuBar</code>, if present.
153  * </OL>
154  * Any other views in the <code>JRootPane</code> view hierarchy are ignored.
155  * <p>
156  * If you replace the <code>LayoutManager</code> of the <code>JRootPane</code>,
157  * you are responsible for managing all of these views.
158  * So ordinarily you will want to be sure that you
159  * change the layout manager for the <code>contentPane</code> rather than
160  * for the <code>JRootPane</code> itself!
161  * <p>
162  * The painting architecture of Swing requires an opaque
163  * <code>JComponent</code>
164  * to exist in the containment hierarchy above all other components. This is
165  * typically provided by way of the content pane. If you replace the content
166  * pane, it is recommended that you make the content pane opaque
167  * by way of <code>setOpaque(true)</code>. Additionally, if the content pane
168  * overrides <code>paintComponent</code>, it
169  * will need to completely fill in the background in an opaque color in
170  * <code>paintComponent</code>.
171  * <p>
172  * <strong>Warning:</strong> Swing is not thread safe. For more
173  * information see <a
174  * href="package-summary.html#threading">Swing's Threading
175  * Policy</a>.
176  * <p>
177  * <strong>Warning:</strong>
178  * Serialized objects of this class will not be compatible with
179  * future Swing releases. The current serialization support is
180  * appropriate for short term storage or RMI between applications running
181  * the same version of Swing.  As of 1.4, support for long term storage
182  * of all JavaBeans&trade;
183  * has been added to the <code>java.beans</code> package.
184  * Please see {@link java.beans.XMLEncoder}.
185  *
186  * @see JLayeredPane
187  * @see JMenuBar
188  * @see JWindow
189  * @see JFrame
190  * @see JDialog
191  * @see JApplet
192  * @see JInternalFrame
193  * @see JComponent
194  * @see BoxLayout
195  *
196  * @see <a href="http://java.sun.com/products/jfc/tsc/articles/mixing/">
197  * Mixing Heavy and Light Components</a>
198  *
199  * @author David Kloba
200  */
201 /// PENDING(klobad) Who should be opaque in this component?
202 @SuppressWarnings("serial")
203 public class JRootPane extends JComponent implements Accessible {
204 
205     private static final String uiClassID = "RootPaneUI";
206 
207     /**
208      * Whether or not we should dump the stack when true double buffering
209      * is disabled. Default is false.
210      */
211     private static final boolean LOG_DISABLE_TRUE_DOUBLE_BUFFERING;
212 
213     /**
214      * Whether or not we should ignore requests to disable true double
215      * buffering. Default is false.
216      */
217     private static final boolean IGNORE_DISABLE_TRUE_DOUBLE_BUFFERING;
218 
219     /**
220      * Constant used for the windowDecorationStyle property. Indicates that
221      * the <code>JRootPane</code> should not provide any sort of
222      * Window decorations.
223      *
224      * @since 1.4
225      */
226     public static final int NONE = 0;
227 
228     /**
229      * Constant used for the windowDecorationStyle property. Indicates that
230      * the <code>JRootPane</code> should provide decorations appropriate for
231      * a Frame.
232      *
233      * @since 1.4
234      */
235     public static final int FRAME = 1;
236 
237     /**
238      * Constant used for the windowDecorationStyle property. Indicates that
239      * the <code>JRootPane</code> should provide decorations appropriate for
240      * a Dialog.
241      *
242      * @since 1.4
243      */
244     public static final int PLAIN_DIALOG = 2;
245 
246     /**
247      * Constant used for the windowDecorationStyle property. Indicates that
248      * the <code>JRootPane</code> should provide decorations appropriate for
249      * a Dialog used to display an informational message.
250      *
251      * @since 1.4
252      */
253     public static final int INFORMATION_DIALOG = 3;
254 
255     /**
256      * Constant used for the windowDecorationStyle property. Indicates that
257      * the <code>JRootPane</code> should provide decorations appropriate for
258      * a Dialog used to display an error message.
259      *
260      * @since 1.4
261      */
262     public static final int ERROR_DIALOG = 4;
263 
264     /**
265      * Constant used for the windowDecorationStyle property. Indicates that
266      * the <code>JRootPane</code> should provide decorations appropriate for
267      * a Dialog used to display a <code>JColorChooser</code>.
268      *
269      * @since 1.4
270      */
271     public static final int COLOR_CHOOSER_DIALOG = 5;
272 
273     /**
274      * Constant used for the windowDecorationStyle property. Indicates that
275      * the <code>JRootPane</code> should provide decorations appropriate for
276      * a Dialog used to display a <code>JFileChooser</code>.
277      *
278      * @since 1.4
279      */
280     public static final int FILE_CHOOSER_DIALOG = 6;
281 
282     /**
283      * Constant used for the windowDecorationStyle property. Indicates that
284      * the <code>JRootPane</code> should provide decorations appropriate for
285      * a Dialog used to present a question to the user.
286      *
287      * @since 1.4
288      */
289     public static final int QUESTION_DIALOG = 7;
290 
291     /**
292      * Constant used for the windowDecorationStyle property. Indicates that
293      * the <code>JRootPane</code> should provide decorations appropriate for
294      * a Dialog used to display a warning message.
295      *
296      * @since 1.4
297      */
298     public static final int WARNING_DIALOG = 8;
299 
300     private int windowDecorationStyle;
301 
302     /** The menu bar. */
303     protected JMenuBar menuBar;
304 
305     /** The content pane. */
306     protected Container contentPane;
307 
308     /** The layered pane that manages the menu bar and content pane. */
309     protected JLayeredPane layeredPane;
310 
311     /**
312      * The glass pane that overlays the menu bar and content pane,
313      *  so it can intercept mouse movements and such.
314      */
315     protected Component glassPane;
316     /**
317      * The button that gets activated when the pane has the focus and
318      * a UI-specific action like pressing the <b>Enter</b> key occurs.
319      */
320     protected JButton defaultButton;
321     /**
322      * As of Java 2 platform v1.3 this unusable field is no longer used.
323      * To override the default button you should replace the <code>Action</code>
324      * in the <code>JRootPane</code>'s <code>ActionMap</code>. Please refer to
325      * the key bindings specification for further details.
326      *
327      * @deprecated As of Java 2 platform v1.3.
328      *  @see #defaultButton
329      */
330     @Deprecated
331     protected DefaultAction defaultPressAction;
332     /**
333      * As of Java 2 platform v1.3 this unusable field is no longer used.
334      * To override the default button you should replace the <code>Action</code>
335      * in the <code>JRootPane</code>'s <code>ActionMap</code>. Please refer to
336      * the key bindings specification for further details.
337      *
338      * @deprecated As of Java 2 platform v1.3.
339      *  @see #defaultButton
340      */
341     @Deprecated
342     protected DefaultAction defaultReleaseAction;
343 
344     /**
345      * Whether or not true double buffering should be used.  This is typically
346      * true, but may be set to false in special situations.  For example,
347      * heavy weight popups (backed by a window) set this to false.
348      */
349     boolean useTrueDoubleBuffering = true;
350 
351     static {
352         LOG_DISABLE_TRUE_DOUBLE_BUFFERING =
353             AccessController.doPrivileged(new GetBooleanAction(
354                                    "swing.logDoubleBufferingDisable"));
355         IGNORE_DISABLE_TRUE_DOUBLE_BUFFERING =
356             AccessController.doPrivileged(new GetBooleanAction(
357                                    "swing.ignoreDoubleBufferingDisable"));
358     }
359 
360     /**
361      * Creates a <code>JRootPane</code>, setting up its
362      * <code>glassPane</code>, <code>layeredPane</code>,
363      * and <code>contentPane</code>.
364      */
365     public JRootPane() {
366         setGlassPane(createGlassPane());
367         setLayeredPane(createLayeredPane());
368         setContentPane(createContentPane());
369         setLayout(createRootLayout());
370         setDoubleBuffered(true);
371         updateUI();
372     }
373 
374     /**
375      * {@inheritDoc}
376      * @since 1.6
377      */
378     public void setDoubleBuffered(boolean aFlag) {
379         if (isDoubleBuffered() != aFlag) {
380             super.setDoubleBuffered(aFlag);
381             RepaintManager.currentManager(this).doubleBufferingChanged(this);
382         }
383     }
384 
385     /**
386      * Returns a constant identifying the type of Window decorations the
387      * <code>JRootPane</code> is providing.
388      *
389      * @return One of <code>NONE</code>, <code>FRAME</code>,
390      *        <code>PLAIN_DIALOG</code>, <code>INFORMATION_DIALOG</code>,
391      *        <code>ERROR_DIALOG</code>, <code>COLOR_CHOOSER_DIALOG</code>,
392      *        <code>FILE_CHOOSER_DIALOG</code>, <code>QUESTION_DIALOG</code> or
393      *        <code>WARNING_DIALOG</code>.
394      * @see #setWindowDecorationStyle
395      * @since 1.4
396      */
397     public int getWindowDecorationStyle() {
398         return windowDecorationStyle;
399     }
400 
401     /**
402      * Sets the type of Window decorations (such as borders, widgets for
403      * closing a Window, title ...) the <code>JRootPane</code> should
404      * provide. The default is to provide no Window decorations
405      * (<code>NONE</code>).
406      * <p>
407      * This is only a hint, and some look and feels may not support
408      * this.
409      * This is a bound property.
410      *
411      * @param windowDecorationStyle Constant identifying Window decorations
412      *        to provide.
413      * @see JDialog#setDefaultLookAndFeelDecorated
414      * @see JFrame#setDefaultLookAndFeelDecorated
415      * @see LookAndFeel#getSupportsWindowDecorations
416      * @throws IllegalArgumentException if <code>style</code> is
417      *        not one of: <code>NONE</code>, <code>FRAME</code>,
418      *        <code>PLAIN_DIALOG</code>, <code>INFORMATION_DIALOG</code>,
419      *        <code>ERROR_DIALOG</code>, <code>COLOR_CHOOSER_DIALOG</code>,
420      *        <code>FILE_CHOOSER_DIALOG</code>, <code>QUESTION_DIALOG</code>, or
421      *        <code>WARNING_DIALOG</code>.
422      * @since 1.4
423      * @beaninfo
424      *        bound: true
425      *         enum: NONE                   JRootPane.NONE
426      *               FRAME                  JRootPane.FRAME
427      *               PLAIN_DIALOG           JRootPane.PLAIN_DIALOG
428      *               INFORMATION_DIALOG     JRootPane.INFORMATION_DIALOG
429      *               ERROR_DIALOG           JRootPane.ERROR_DIALOG
430      *               COLOR_CHOOSER_DIALOG   JRootPane.COLOR_CHOOSER_DIALOG
431      *               FILE_CHOOSER_DIALOG    JRootPane.FILE_CHOOSER_DIALOG
432      *               QUESTION_DIALOG        JRootPane.QUESTION_DIALOG
433      *               WARNING_DIALOG         JRootPane.WARNING_DIALOG
434      *       expert: true
435      *    attribute: visualUpdate true
436      *  description: Identifies the type of Window decorations to provide
437      */
438     public void setWindowDecorationStyle(int windowDecorationStyle) {
439         if (windowDecorationStyle < 0 ||
440                   windowDecorationStyle > WARNING_DIALOG) {
441             throw new IllegalArgumentException("Invalid decoration style");
442         }
443         int oldWindowDecorationStyle = getWindowDecorationStyle();
444         this.windowDecorationStyle = windowDecorationStyle;
445         firePropertyChange("windowDecorationStyle",
446                             oldWindowDecorationStyle,
447                             windowDecorationStyle);
448     }
449 
450     /**
451      * Returns the L&amp;F object that renders this component.
452      *
453      * @return <code>LabelUI</code> object
454      * @since 1.3
455      */
456     public RootPaneUI getUI() {
457         return (RootPaneUI)ui;
458     }
459 
460     /**
461      * Sets the L&amp;F object that renders this component.
462      *
463      * @param ui  the <code>LabelUI</code> L&amp;F object
464      * @see UIDefaults#getUI
465      * @beaninfo
466      *        bound: true
467      *       hidden: true
468      *      expert: true
469      *    attribute: visualUpdate true
470      *  description: The UI object that implements the Component's LookAndFeel.
471      * @since 1.3
472      */
473     public void setUI(RootPaneUI ui) {
474         super.setUI(ui);
475     }
476 
477 
478     /**
479      * Resets the UI property to a value from the current look and feel.
480      *
481      * @see JComponent#updateUI
482      */
483     public void updateUI() {
484         setUI((RootPaneUI)UIManager.getUI(this));
485     }
486 
487 
488     /**
489      * Returns a string that specifies the name of the L&amp;F class
490      * that renders this component.
491      *
492      * @return the string "RootPaneUI"
493      *
494      * @see JComponent#getUIClassID
495      * @see UIDefaults#getUI
496      */
497     public String getUIClassID() {
498         return uiClassID;
499     }
500 
501     /**
502       * Called by the constructor methods to create the default
503       * <code>layeredPane</code>.
504       * Bt default it creates a new <code>JLayeredPane</code>.
505       * @return the default <code>layeredPane</code>
506       */
507     protected JLayeredPane createLayeredPane() {
508         JLayeredPane p = new JLayeredPane();
509         p.setName(this.getName()+".layeredPane");
510         return p;
511     }
512 
513     /**
514      * Called by the constructor methods to create the default
515      * <code>contentPane</code>.
516      * By default this method creates a new <code>JComponent</code> add sets a
517      * <code>BorderLayout</code> as its <code>LayoutManager</code>.
518      * @return the default <code>contentPane</code>
519      */
520     protected Container createContentPane() {
521         JComponent c = new JPanel();
522         c.setName(this.getName()+".contentPane");
523         c.setLayout(new BorderLayout() {
524             /* This BorderLayout subclass maps a null constraint to CENTER.
525              * Although the reference BorderLayout also does this, some VMs
526              * throw an IllegalArgumentException.
527              */
528             public void addLayoutComponent(Component comp, Object constraints) {
529                 if (constraints == null) {
530                     constraints = BorderLayout.CENTER;
531                 }
532                 super.addLayoutComponent(comp, constraints);
533             }
534         });
535         return c;
536     }
537 
538     /**
539       * Called by the constructor methods to create the default
540       * <code>glassPane</code>.
541       * By default this method creates a new <code>JComponent</code>
542       * with visibility set to false.
543       * @return the default <code>glassPane</code>
544       */
545     protected Component createGlassPane() {
546         JComponent c = new JPanel();
547         c.setName(this.getName()+".glassPane");
548         c.setVisible(false);
549         ((JPanel)c).setOpaque(false);
550         return c;
551     }
552 
553     /**
554      * Called by the constructor methods to create the default
555      * <code>layoutManager</code>.
556      * @return the default <code>layoutManager</code>.
557      */
558     protected LayoutManager createRootLayout() {
559         return new RootLayout();
560     }
561 
562     /**
563      * Adds or changes the menu bar used in the layered pane.
564      * @param menu the <code>JMenuBar</code> to add
565      */
566     public void setJMenuBar(JMenuBar menu) {
567         if(menuBar != null && menuBar.getParent() == layeredPane)
568             layeredPane.remove(menuBar);
569         menuBar = menu;
570 
571         if(menuBar != null)
572             layeredPane.add(menuBar, JLayeredPane.FRAME_CONTENT_LAYER);
573     }
574 
575     /**
576      * Specifies the menu bar value.
577      * @deprecated As of Swing version 1.0.3
578      *  replaced by <code>setJMenuBar(JMenuBar menu)</code>.
579      * @param menu the <code>JMenuBar</code> to add.
580      */
581     @Deprecated
582     public void setMenuBar(JMenuBar menu){
583         if(menuBar != null && menuBar.getParent() == layeredPane)
584             layeredPane.remove(menuBar);
585         menuBar = menu;
586 
587         if(menuBar != null)
588             layeredPane.add(menuBar, JLayeredPane.FRAME_CONTENT_LAYER);
589     }
590 
591     /**
592      * Returns the menu bar from the layered pane.
593      * @return the <code>JMenuBar</code> used in the pane
594      */
595     public JMenuBar getJMenuBar() { return menuBar; }
596 
597     /**
598      * Returns the menu bar value.
599      * @deprecated As of Swing version 1.0.3
600      *  replaced by <code>getJMenuBar()</code>.
601      * @return the <code>JMenuBar</code> used in the pane
602      */
603     @Deprecated
604     public JMenuBar getMenuBar() { return menuBar; }
605 
606     /**
607      * Sets the content pane -- the container that holds the components
608      * parented by the root pane.
609      * <p>
610      * Swing's painting architecture requires an opaque <code>JComponent</code>
611      * in the containment hierarchy. This is typically provided by the
612      * content pane. If you replace the content pane it is recommended you
613      * replace it with an opaque <code>JComponent</code>.
614      *
615      * @param content the <code>Container</code> to use for component-contents
616      * @exception java.awt.IllegalComponentStateException (a runtime
617      *            exception) if the content pane parameter is <code>null</code>
618      */
619     public void setContentPane(Container content) {
620         if(content == null)
621             throw new IllegalComponentStateException("contentPane cannot be set to null.");
622         if(contentPane != null && contentPane.getParent() == layeredPane)
623             layeredPane.remove(contentPane);
624         contentPane = content;
625 
626         layeredPane.add(contentPane, JLayeredPane.FRAME_CONTENT_LAYER);
627     }
628 
629     /**
630      * Returns the content pane -- the container that holds the components
631      * parented by the root pane.
632      *
633      * @return the <code>Container</code> that holds the component-contents
634      */
635     public Container getContentPane() { return contentPane; }
636 
637 // PENDING(klobad) Should this reparent the contentPane and MenuBar?
638     /**
639      * Sets the layered pane for the root pane. The layered pane
640      * typically holds a content pane and an optional <code>JMenuBar</code>.
641      *
642      * @param layered  the <code>JLayeredPane</code> to use
643      * @exception java.awt.IllegalComponentStateException (a runtime
644      *            exception) if the layered pane parameter is <code>null</code>
645      */
646     public void setLayeredPane(JLayeredPane layered) {
647         if(layered == null)
648             throw new IllegalComponentStateException("layeredPane cannot be set to null.");
649         if(layeredPane != null && layeredPane.getParent() == this)
650             this.remove(layeredPane);
651         layeredPane = layered;
652 
653         this.add(layeredPane, -1);
654     }
655     /**
656      * Gets the layered pane used by the root pane. The layered pane
657      * typically holds a content pane and an optional <code>JMenuBar</code>.
658      *
659      * @return the <code>JLayeredPane</code> currently in use
660      */
661     public JLayeredPane getLayeredPane() { return layeredPane; }
662 
663     /**
664      * Sets a specified <code>Component</code> to be the glass pane for this
665      * root pane.  The glass pane should normally be a lightweight,
666      * transparent component, because it will be made visible when
667      * ever the root pane needs to grab input events.
668      * <p>
669      * The new glass pane's visibility is changed to match that of
670      * the current glass pane.  An implication of this is that care
671      * must be taken when you want to replace the glass pane and
672      * make it visible.  Either of the following will work:
673      * <pre>
674      *   root.setGlassPane(newGlassPane);
675      *   newGlassPane.setVisible(true);
676      * </pre>
677      * or:
678      * <pre>
679      *   root.getGlassPane().setVisible(true);
680      *   root.setGlassPane(newGlassPane);
681      * </pre>
682      *
683      * @param glass the <code>Component</code> to use as the glass pane
684      *              for this <code>JRootPane</code>
685      * @exception NullPointerException if the <code>glass</code> parameter is
686      *          <code>null</code>
687      */
688     public void setGlassPane(Component glass) {
689         if (glass == null) {
690             throw new NullPointerException("glassPane cannot be set to null.");
691         }
692 
693         AWTAccessor.getComponentAccessor().setMixingCutoutShape(glass,
694                 new Rectangle());
695 
696         boolean visible = false;
697         if (glassPane != null && glassPane.getParent() == this) {
698             this.remove(glassPane);
699             visible = glassPane.isVisible();
700         }
701 
702         glass.setVisible(visible);
703         glassPane = glass;
704         this.add(glassPane, 0);
705         if (visible) {
706             repaint();
707         }
708     }
709 
710     /**
711      * Returns the current glass pane for this <code>JRootPane</code>.
712      * @return the current glass pane
713      * @see #setGlassPane
714      */
715     public Component getGlassPane() {
716         return glassPane;
717     }
718 
719     /**
720      * If a descendant of this <code>JRootPane</code> calls
721      * <code>revalidate</code>, validate from here on down.
722      *<p>
723      * Deferred requests to layout a component and its descendents again.
724      * For example, calls to <code>revalidate</code>, are pushed upwards to
725      * either a <code>JRootPane</code> or a <code>JScrollPane</code>
726      * because both classes override <code>isValidateRoot</code> to return true.
727      *
728      * @see JComponent#isValidateRoot
729      * @see java.awt.Container#isValidateRoot
730      * @return true
731      */
732     @Override
733     public boolean isValidateRoot() {
734         return true;
735     }
736 
737     /**
738      * The <code>glassPane</code> and <code>contentPane</code>
739      * have the same bounds, which means <code>JRootPane</code>
740      * does not tiles its children and this should return false.
741      * On the other hand, the <code>glassPane</code>
742      * is normally not visible, and so this can return true if the
743      * <code>glassPane</code> isn't visible. Therefore, the
744      * return value here depends upon the visibility of the
745      * <code>glassPane</code>.
746      *
747      * @return true if this component's children don't overlap
748      */
749     public boolean isOptimizedDrawingEnabled() {
750         return !glassPane.isVisible();
751     }
752 
753     /**
754      * {@inheritDoc}
755      */
756     public void addNotify() {
757         super.addNotify();
758         enableEvents(AWTEvent.KEY_EVENT_MASK);
759     }
760 
761     /**
762      * {@inheritDoc}
763      */
764     public void removeNotify() {
765         super.removeNotify();
766     }
767 
768 
769     /**
770      * Sets the <code>defaultButton</code> property,
771      * which determines the current default button for this <code>JRootPane</code>.
772      * The default button is the button which will be activated
773      * when a UI-defined activation event (typically the <b>Enter</b> key)
774      * occurs in the root pane regardless of whether or not the button
775      * has keyboard focus (unless there is another component within
776      * the root pane which consumes the activation event,
777      * such as a <code>JTextPane</code>).
778      * For default activation to work, the button must be an enabled
779      * descendent of the root pane when activation occurs.
780      * To remove a default button from this root pane, set this
781      * property to <code>null</code>.
782      *
783      * @see JButton#isDefaultButton
784      * @param defaultButton the <code>JButton</code> which is to be the default button
785      *
786      * @beaninfo
787      *  description: The button activated by default in this root pane
788      */
789     public void setDefaultButton(JButton defaultButton) {
790         JButton oldDefault = this.defaultButton;
791 
792         if (oldDefault != defaultButton) {
793             this.defaultButton = defaultButton;
794 
795             if (oldDefault != null) {
796                 oldDefault.repaint();
797             }
798             if (defaultButton != null) {
799                 defaultButton.repaint();
800             }
801         }
802 
803         firePropertyChange("defaultButton", oldDefault, defaultButton);
804     }
805 
806     /**
807      * Returns the value of the <code>defaultButton</code> property.
808      * @return the <code>JButton</code> which is currently the default button
809      * @see #setDefaultButton
810      */
811     public JButton getDefaultButton() {
812         return defaultButton;
813     }
814 
815     final void setUseTrueDoubleBuffering(boolean useTrueDoubleBuffering) {
816         this.useTrueDoubleBuffering = useTrueDoubleBuffering;
817     }
818 
819     final boolean getUseTrueDoubleBuffering() {
820         return useTrueDoubleBuffering;
821     }
822 
823     final void disableTrueDoubleBuffering() {
824         if (useTrueDoubleBuffering) {
825             if (!IGNORE_DISABLE_TRUE_DOUBLE_BUFFERING) {
826                 if (LOG_DISABLE_TRUE_DOUBLE_BUFFERING) {
827                     System.out.println("Disabling true double buffering for " +
828                                        this);
829                     Thread.dumpStack();
830                 }
831                 useTrueDoubleBuffering = false;
832                 RepaintManager.currentManager(this).
833                         doubleBufferingChanged(this);
834             }
835         }
836     }
837 
838     @SuppressWarnings("serial")
839     static class DefaultAction extends AbstractAction {
840         JButton owner;
841         JRootPane root;
842         boolean press;
843         DefaultAction(JRootPane root, boolean press) {
844             this.root = root;
845             this.press = press;
846         }
847         public void setOwner(JButton owner) {
848             this.owner = owner;
849         }
850         public void actionPerformed(ActionEvent e) {
851             if (owner != null && SwingUtilities.getRootPane(owner) == root) {
852                 ButtonModel model = owner.getModel();
853                 if (press) {
854                     model.setArmed(true);
855                     model.setPressed(true);
856                 } else {
857                     model.setPressed(false);
858                 }
859             }
860         }
861         public boolean isEnabled() {
862             return owner.getModel().isEnabled();
863         }
864     }
865 
866 
867     /**
868      * Overridden to enforce the position of the glass component as
869      * the zero child.
870      *
871      * @param comp the component to be enhanced
872      * @param constraints the constraints to be respected
873      * @param index the index
874      */
875     protected void addImpl(Component comp, Object constraints, int index) {
876         super.addImpl(comp, constraints, index);
877 
878         /// We are making sure the glassPane is on top.
879         if(glassPane != null
880             && glassPane.getParent() == this
881             && getComponent(0) != glassPane) {
882             add(glassPane, 0);
883         }
884     }
885 
886 
887 ///////////////////////////////////////////////////////////////////////////////
888 //// Begin Inner Classes
889 ///////////////////////////////////////////////////////////////////////////////
890 
891 
892     /**
893      * A custom layout manager that is responsible for the layout of
894      * layeredPane, glassPane, and menuBar.
895      * <p>
896      * <strong>Warning:</strong>
897      * Serialized objects of this class will not be compatible with
898      * future Swing releases. The current serialization support is
899      * appropriate for short term storage or RMI between applications running
900      * the same version of Swing.  As of 1.4, support for long term storage
901      * of all JavaBeans&trade;
902      * has been added to the <code>java.beans</code> package.
903      * Please see {@link java.beans.XMLEncoder}.
904      */
905     @SuppressWarnings("serial")
906     protected class RootLayout implements LayoutManager2, Serializable
907     {
908         /**
909          * Returns the amount of space the layout would like to have.
910          *
911          * @param parent the Container for which this layout manager
912          * is being used
913          * @return a Dimension object containing the layout's preferred size
914          */
915         public Dimension preferredLayoutSize(Container parent) {
916             Dimension rd, mbd;
917             Insets i = getInsets();
918 
919             if(contentPane != null) {
920                 rd = contentPane.getPreferredSize();
921             } else {
922                 rd = parent.getSize();
923             }
924             if(menuBar != null && menuBar.isVisible()) {
925                 mbd = menuBar.getPreferredSize();
926             } else {
927                 mbd = new Dimension(0, 0);
928             }
929             return new Dimension(Math.max(rd.width, mbd.width) + i.left + i.right,
930                                         rd.height + mbd.height + i.top + i.bottom);
931         }
932 
933         /**
934          * Returns the minimum amount of space the layout needs.
935          *
936          * @param parent the Container for which this layout manager
937          * is being used
938          * @return a Dimension object containing the layout's minimum size
939          */
940         public Dimension minimumLayoutSize(Container parent) {
941             Dimension rd, mbd;
942             Insets i = getInsets();
943             if(contentPane != null) {
944                 rd = contentPane.getMinimumSize();
945             } else {
946                 rd = parent.getSize();
947             }
948             if(menuBar != null && menuBar.isVisible()) {
949                 mbd = menuBar.getMinimumSize();
950             } else {
951                 mbd = new Dimension(0, 0);
952             }
953             return new Dimension(Math.max(rd.width, mbd.width) + i.left + i.right,
954                         rd.height + mbd.height + i.top + i.bottom);
955         }
956 
957         /**
958          * Returns the maximum amount of space the layout can use.
959          *
960          * @param target the Container for which this layout manager
961          * is being used
962          * @return a Dimension object containing the layout's maximum size
963          */
964         public Dimension maximumLayoutSize(Container target) {
965             Dimension rd, mbd;
966             Insets i = getInsets();
967             if(menuBar != null && menuBar.isVisible()) {
968                 mbd = menuBar.getMaximumSize();
969             } else {
970                 mbd = new Dimension(0, 0);
971             }
972             if(contentPane != null) {
973                 rd = contentPane.getMaximumSize();
974             } else {
975                 // This is silly, but should stop an overflow error
976                 rd = new Dimension(Integer.MAX_VALUE,
977                         Integer.MAX_VALUE - i.top - i.bottom - mbd.height - 1);
978             }
979             return new Dimension(Math.min(rd.width, mbd.width) + i.left + i.right,
980                                          rd.height + mbd.height + i.top + i.bottom);
981         }
982 
983         /**
984          * Instructs the layout manager to perform the layout for the specified
985          * container.
986          *
987          * @param parent the Container for which this layout manager
988          * is being used
989          */
990         public void layoutContainer(Container parent) {
991             Rectangle b = parent.getBounds();
992             Insets i = getInsets();
993             int contentY = 0;
994             int w = b.width - i.right - i.left;
995             int h = b.height - i.top - i.bottom;
996 
997             if(layeredPane != null) {
998                 layeredPane.setBounds(i.left, i.top, w, h);
999             }
1000             if(glassPane != null) {
1001                 glassPane.setBounds(i.left, i.top, w, h);
1002             }
1003             // Note: This is laying out the children in the layeredPane,
1004             // technically, these are not our children.
1005             if(menuBar != null && menuBar.isVisible()) {
1006                 Dimension mbd = menuBar.getPreferredSize();
1007                 menuBar.setBounds(0, 0, w, mbd.height);
1008                 contentY += mbd.height;
1009             }
1010             if(contentPane != null) {
1011                 contentPane.setBounds(0, contentY, w, h - contentY);
1012             }
1013         }
1014 
1015         public void addLayoutComponent(String name, Component comp) {}
1016         public void removeLayoutComponent(Component comp) {}
1017         public void addLayoutComponent(Component comp, Object constraints) {}
1018         public float getLayoutAlignmentX(Container target) { return 0.0f; }
1019         public float getLayoutAlignmentY(Container target) { return 0.0f; }
1020         public void invalidateLayout(Container target) {}
1021     }
1022 
1023     /**
1024      * Returns a string representation of this <code>JRootPane</code>.
1025      * This method is intended to be used only for debugging purposes,
1026      * and the content and format of the returned string may vary between
1027      * implementations. The returned string may be empty but may not
1028      * be <code>null</code>.
1029      *
1030      * @return  a string representation of this <code>JRootPane</code>.
1031      */
1032     protected String paramString() {
1033         return super.paramString();
1034     }
1035 
1036 /////////////////
1037 // Accessibility support
1038 ////////////////
1039 
1040     /**
1041      * Gets the <code>AccessibleContext</code> associated with this
1042      * <code>JRootPane</code>. For root panes, the
1043      * <code>AccessibleContext</code> takes the form of an
1044      * <code>AccessibleJRootPane</code>.
1045      * A new <code>AccessibleJRootPane</code> instance is created if necessary.
1046      *
1047      * @return an <code>AccessibleJRootPane</code> that serves as the
1048      *         <code>AccessibleContext</code> of this <code>JRootPane</code>
1049      */
1050     public AccessibleContext getAccessibleContext() {
1051         if (accessibleContext == null) {
1052             accessibleContext = new AccessibleJRootPane();
1053         }
1054         return accessibleContext;
1055     }
1056 
1057     /**
1058      * This class implements accessibility support for the
1059      * <code>JRootPane</code> class.  It provides an implementation of the
1060      * Java Accessibility API appropriate to root pane user-interface elements.
1061      * <p>
1062      * <strong>Warning:</strong>
1063      * Serialized objects of this class will not be compatible with
1064      * future Swing releases. The current serialization support is
1065      * appropriate for short term storage or RMI between applications running
1066      * the same version of Swing.  As of 1.4, support for long term storage
1067      * of all JavaBeans&trade;
1068      * has been added to the <code>java.beans</code> package.
1069      * Please see {@link java.beans.XMLEncoder}.
1070      */
1071     @SuppressWarnings("serial")
1072     protected class AccessibleJRootPane extends AccessibleJComponent {
1073         /**
1074          * Get the role of this object.
1075          *
1076          * @return an instance of AccessibleRole describing the role of
1077          * the object
1078          */
1079         public AccessibleRole getAccessibleRole() {
1080             return AccessibleRole.ROOT_PANE;
1081         }
1082 
1083         /**
1084          * Returns the number of accessible children of the object.
1085          *
1086          * @return the number of accessible children of the object.
1087          */
1088         public int getAccessibleChildrenCount() {
1089             return super.getAccessibleChildrenCount();
1090         }
1091 
1092         /**
1093          * Returns the specified Accessible child of the object.  The Accessible
1094          * children of an Accessible object are zero-based, so the first child
1095          * of an Accessible child is at index 0, the second child is at index 1,
1096          * and so on.
1097          *
1098          * @param i zero-based index of child
1099          * @return the Accessible child of the object
1100          * @see #getAccessibleChildrenCount
1101          */
1102         public Accessible getAccessibleChild(int i) {
1103             return super.getAccessibleChild(i);
1104         }
1105     } // inner class AccessibleJRootPane
1106 }