listdatalistener.html

来自「jsf、swing的官方指南」· HTML 代码 · 共 549 行 · 第 1/2 页

                            <a href="../../search.html" target="_blank">Search the
                                Tutorials</a>
                            <br>
                            <a href="javascript:toggleLeft()"
                                id="ToggleLeft">Hide the TOC</a>
                        </div>
                    </div> </div> </div> </div> </div>
    <div class=PrintHeaders>
        <b>Trail:</b> Creating a GUI with JFC/Swing
        <br><b>Lesson:</b> Writing Event Listeners
        <br><b>Section:</b> Implementing Listeners for Commonly Handled Events
    </div>

    <div id=LeftBar class=LeftBar_shown>
        <div id=Contents>
            <div class="linkLESSON"><a href="index.html">Writing Event Listeners</a></div>
<div class="linkAHEAD"><a href="intro.html">Introduction to Event Listeners</a></div>
<div class="linkAHEAD"><a href="generalrules.html">General Information about Writing Event Listeners</a></div>
<div class="linkAHEAD"><a href="eventsandcomponents.html">Listeners Supported by Swing Components</a></div>
<div class="linkAHEAD"><a href="handling.html">Implementing Listeners for Commonly Handled Events</a></div>
<div class="linkBHEAD"><a href="actionlistener.html">How to Write an Action Listener</a></div>
<div class="linkBHEAD"><a href="caretlistener.html">How to Write a Caret Listener</a></div>
<div class="linkBHEAD"><a href="changelistener.html">How to Write a Change Listener</a></div>
<div class="linkBHEAD"><a href="componentlistener.html">How to Write a Component Listener</a></div>
<div class="linkBHEAD"><a href="containerlistener.html">How to Write a Container Listener</a></div>
<div class="linkBHEAD"><a href="documentlistener.html">How to Write a Document Listener</a></div>
<div class="linkBHEAD"><a href="focuslistener.html">How to Write a Focus Listener</a></div>
<div class="linkBHEAD"><a href="internalframelistener.html">How to Write an Internal Frame Listener</a></div>
<div class="linkBHEAD"><a href="itemlistener.html">How to Write an Item Listener</a></div>
<div class="linkBHEAD"><a href="keylistener.html">How to Write a Key Listener</a></div>
<div class="nolinkBHEAD">How to Write a List Data Listener</div>
<div class="linkBHEAD"><a href="listselectionlistener.html">How to Write a List Selection Listener</a></div>
<div class="linkBHEAD"><a href="mouselistener.html">How to Write a Mouse Listener</a></div>
<div class="linkBHEAD"><a href="mousemotionlistener.html">How to Write a Mouse-Motion Listener</a></div>
<div class="linkBHEAD"><a href="mousewheellistener.html">How to Write a Mouse-Wheel Listener</a></div>
<div class="linkBHEAD"><a href="propertychangelistener.html">How to Write a Property Change Listener</a></div>
<div class="linkBHEAD"><a href="tablemodellistener.html">How to Write a Table Model Listener</a></div>
<div class="linkBHEAD"><a href="treeexpansionlistener.html">How to Write a Tree Expansion Listener</a></div>
<div class="linkBHEAD"><a href="treemodellistener.html">How to Write a Tree Model Listener</a></div>
<div class="linkBHEAD"><a href="treeselectionlistener.html">How to Write a Tree Selection Listener</a></div>
<div class="linkBHEAD"><a href="treewillexpandlistener.html">How to Write a Tree-Will-Expand Listener</a></div>
<div class="linkBHEAD"><a href="undoableeditlistener.html">How to Write an Undoable Edit Listener</a></div>
<div class="linkBHEAD"><a href="windowlistener.html">How to Write Window Listeners</a></div>
<div class="linkAHEAD"><a href="api.html">Listener API Table</a></div>
<div class="linkAHEAD"><a href="problems.html">Solving Common Event-Handling Problems</a></div>
</div>
    </div>
    <div id=MainFlow class=MainFlow_indented>
            <span id=BreadCrumbs>
                <a href=../../index.html target=_top>Home Page</a>
                &gt;
                <a href=../index.html target=_top>Creating a GUI with JFC/Swing</a>
                &gt;
                <a href=index.html target=_top>Writing Event Listeners</a>
            </span>
            <div class=NavBit>
                <a target=_top href=keylistener.html>&laquo;&nbsp;Previous</a>&nbsp;&bull;&nbsp;<a target=_top href=../TOC.html>Trail</a>&nbsp;&bull;&nbsp;<a target=_top href=listselectionlistener.html>Next&nbsp;&raquo;</a>
            </div>
            <div id=PageTitle>How to Write a List Data Listener</div>
            <blockquote>

List data events occur when the contents of a mutable
<a class="TutorialLink" target="_top" href="../components/list.html">list</a> change.
Since the model &#151; not the component &#151; fires these events,
you have to register a list data listener with the list model.
If you haven't explicitly created a list with a mutable list model,
then your list is immutable, and its model will not fire these events.

<blockquote><hr><strong>Note:</strong>&nbsp;<a class="TutorialLink" target="_top" href="../components/combobox.html">Combo box</a> models also fire list data events.
However, you normally don't need to know about them
unless you're 
<a class="TutorialLink" target="_top" href="../components/combobox.html#datsun">creating a custom combo box model</a>.
<hr></blockquote>

<p>
The following example demonstrates list data events on a mutable list:

<p><center><IMG SRC="../../figures/uiswing/events/ListDataEventDemo.png" WIDTH="417" HEIGHT="324" ALIGN="BOTTOM" ALT=""></center></p>


<blockquote><hr><strong>Try this:</strong>&nbsp;
<ol>
<li> <a href="http://java.sun.com/docs/books/tutorialJWS/uiswing/events/examples/ListDataEventDemo.jnlp">Run
     ListDataEventDemo</a> using
     <a href=http://java.sun.com/products/javawebstart>
     Java<sup><font size=-2>TM</font></sup> Web Start</a>.
     Or, to compile and run the example yourself,
     consult the
     <a href="examples/index.html#ListDataEventDemo">example index</a>.
<li> Type in the name of your favorite ski resort and click the
     <strong>Add</strong> button.  An <code>intervalAdded</code>
     event was fired.
<li> Select a few continguous items in the list and click the
     <strong>Delete</strong> button. An <code>intervalRemoved</code>
     event was fired.
<li> Select one item and move it up or down in the list with the arrow buttons.
     Two <code>contentsChanged</code> events are fired &#151; one for
     the item that moved and one for the item that was displaced.
</ol>
<hr></blockquote>

You can find the demo's code in

<a class="SourceLink" target="_blank" href="examples/ListDataEventDemo.java"><code>ListDataEventDemo.java</code></a>.
Here's the code that registers
a list data listener on the list model
and implements the listener:
<blockquote><pre>
//<em>...where member variables are declared...</em>
private DefaultListModel listModel;
...
//Create and populate the list model
listModel = new DefaultListModel();
...
listModel.addListDataListener(new MyListDataListener());

class MyListDataListener implements ListDataListener {
    public void contentsChanged(ListDataEvent e) {
        log.append("contentsChanged: " + e.getIndex0() +
	           ", " + e.getIndex1() + newline);
    }
    public void intervalAdded(ListDataEvent e) {
        log.append("intervalAdded: " + e.getIndex0() +
	           ", " + e.getIndex1() + newline);
    }
    public void intervalRemoved(ListDataEvent e) {
        log.append("intervalRemoved: " + e.getIndex0() +
	           ", " + e.getIndex1() + newline);
    }
} 
</pre></blockquote>

</blockquote>
<h3>
<a name="api">The List Data Listener API</a>
</h3>
<blockquote>

<p align=center><a name="listdatalistener">The ListDataListener
   Interface</a>
<p><em><code>ListDataListener</code> has no corresponding
   adapter class.</em>
<table border=1>
<tr>
<th align=left>Method</th>
<th align=left>Purpose</th>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataListener.html#intervalAdded(javax.swing.event.ListDataEvent)">intervalAdded(ListDataEvent)</a></td>
<td> Called when one or more items have been added to the list.
</td>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataListener.html#intervalRemoved(javax.swing.event.ListDataEvent)">intervalRemoved(ListDataEvent)</a></td>
<td> Called when one or more items have been removed from the list.
</td>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataListener.html#contentsChanged(javax.swing.event.ListDataEvent)">contentsChanged(ListDataEvent)</a></td>
<td> Called when the contents of one or more items in the list have changed.
</td>
</tr>
</table>

<p align=center><a name="listdataevent">The ListDataEvent API</a>
<p>
<table border=1>
<tr>
<th align=left>Method</th>
<th align=left>Purpose</th>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/java/util/EventObject.html#getSource()">Object getSource()</a><br>(<em>in <code>java.util.EventObject</code></em>)
</td>
<td> Return the object that fired the event.
</td>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataEvent.html#getIndex0()">int getIndex0()</a></td>
<td> Return the index of the first item
     whose value has changed.
</td>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataEvent.html#getIndex1()">int getIndex1()</a></td>
<td> Return the index of the last item
     whose value has changed.
</td>
</tr>

<tr>
<td>
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/javax/swing/event/ListDataEvent.html#getType()">int getType()</a></td>
<td>Return the event type.  The possible values are:
    <code>CONTENTS_CHANGED</code>, <code>INTERVAL_ADDED</code>,
    or <code>INTERVAL_REMOVED</code>.
</td>
</tr>
</table>
</blockquote>

<a name="eg">
<h3>Examples that Use List Data Listeners</h3>
</a>
<blockquote>
The following table lists the
examples that use list data listeners.
 
<p>
 
<table>
<tr>
<th align=left> Example
</th>
<th align=left> Where Described
</th>
<th align=left> Notes

</th>
</tr>
<tr valign=top>
<td> <a href="examples/index.html#ListDataEventDemo"><code>ListDataEventDemo</code></a>
</td>
<td> This section
</td>
<td> Reports all list data events that occur on a list.

</td>
</tr>
</table>
        </blockquote>
        <div class=NavBit>
            <a target=_top href=keylistener.html>&laquo; Previous</a>
            &bull;
            <a target=_top href=../TOC.html>Trail</a>
            &bull;
            <a target=_top href=listselectionlistener.html>Next &raquo;</a>
        </div>
    </div>
    <div id=Footer>
<div id=TagNotes>
    Problems with the examples? Try <a target="_blank"
        href=../../information/run-examples.html>Compiling and Running
        the Examples: FAQs</a>.
    <br>
    Complaints? Compliments? Suggestions? <a target="_blank"
        href="http://developer.sun.com/contact/tutorial_feedback.jsp">Give
    us your feedback</a>.
<br><br>
    <a target="_blank" href="../../information/copyright.html">Copyright</a>
    1995-2006 Sun Microsystems, Inc.  All rights reserved.
    <span id=Download>
</span></div> 

    </div>
    <div class=PrintHeaders>
        <b>Previous page:</b> How to Write a Key Listener
        <br><b>Next page:</b> How to Write a List Selection Listener
    </div>
    </body>
</html>