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.event;
  26 
  27 import java.awt.event.*;
  28 import java.awt.*;
  29 import javax.swing.*;
  30 
  31 /**
  32  * An event reported to a child component that originated from an
  33  * ancestor in the component hierarchy.
  34  * <p>
  35  * <strong>Warning:</strong>
  36  * Serialized objects of this class will not be compatible with
  37  * future Swing releases. The current serialization support is
  38  * appropriate for short term storage or RMI between applications running
  39  * the same version of Swing.  As of 1.4, support for long term storage
  40  * of all JavaBeans&trade;
  41  * has been added to the <code>java.beans</code> package.
  42  * Please see {@link java.beans.XMLEncoder}.
  43  *
  44  * @author Dave Moore
  45  */
  46 @SuppressWarnings("serial")
  47 public class AncestorEvent extends AWTEvent {
  48     /**
  49      * An ancestor-component was added to the hierarchy of
  50      * visible objects (made visible), and is currently being displayed.
  51      */
  52     public static final int ANCESTOR_ADDED = 1;
  53     /**
  54      * An ancestor-component was removed from the hierarchy
  55      * of visible objects (hidden) and is no longer being displayed.
  56      */
  57     public static final int ANCESTOR_REMOVED = 2;
  58     /** An ancestor-component changed its position on the screen. */
  59     public static final int ANCESTOR_MOVED = 3;
  60 
  61     Container ancestor;
  62     Container ancestorParent;
  63 
  64     /**
  65      * Constructs an AncestorEvent object to identify a change
  66      * in an ancestor-component's display-status.
  67      *
  68      * @param source          the JComponent that originated the event
  69      *                        (typically <code>this</code>)
  70      * @param id              an int specifying {@link #ANCESTOR_ADDED},
  71      *                        {@link #ANCESTOR_REMOVED} or {@link #ANCESTOR_MOVED}
  72      * @param ancestor        a Container object specifying the ancestor-component
  73      *                        whose display-status changed
  74      * @param ancestorParent  a Container object specifying the ancestor's parent
  75      */
  76     public AncestorEvent(JComponent source, int id, Container ancestor, Container ancestorParent) {
  77         super(source, id);
  78         this.ancestor = ancestor;
  79         this.ancestorParent = ancestorParent;
  80     }
  81 
  82     /**
  83      * Returns the ancestor that the event actually occurred on.
  84      *
  85      * @return the {@code Container} object specifying the ancestor component
  86      */
  87     public Container getAncestor() {
  88         return ancestor;
  89     }
  90 
  91     /**
  92      * Returns the parent of the ancestor the event actually occurred on.
  93      * This is most interesting in an ANCESTOR_REMOVED event, as
  94      * the ancestor may no longer be in the component hierarchy.
  95      *
  96      * @return the {@code Container} object specifying the ancestor's parent
  97      */
  98     public Container getAncestorParent() {
  99         return ancestorParent;
 100     }
 101 
 102     /**
 103      * Returns the component that the listener was added to.
 104      *
 105      * @return the {@code JComponent} on which the event occurred
 106      */
 107     public JComponent getComponent() {
 108         return (JComponent)getSource();
 109     }
 110 }