intro.html

jsf、swing的官方指南

<p>
<li>Clipboard transfer via cut/copy and paste.
    The following diagrams illustrate the Java portion of the
    cut/copy and paste operations:

<p>
<p><center><IMG SRC="../../figures/uiswing/dnd/dndprocess2.gif" WIDTH="485" HEIGHT="103" ALIGN="BOTTOM" ALT="Cut/Copy Illustration"></center></p>
<p>
<p><center><IMG SRC="../../figures/uiswing/dnd/dndprocess3.gif" WIDTH="486" HEIGHT="104" ALIGN="BOTTOM" ALT="Paste Illustration"></center></p></ul>
<p>The arrows in the preceding diagrams show the path of the data.

<p>
In a nutshell, a data transfer begins by bundling the data
into a package, called a <code>Transferable</code>.
Then the component provides an object, called a
<code>TransferHandler</code> that extracts the data from
the <code>Transferable</code>.

<p>Many Swing components provide out-of-the-box support for transferring
data, as shown in the following table:

<p>
<table summary="Data Transfer Support" border=1>
<caption><a name=defaultSupport>Data Transfer Support</a></caption>
<tr><th>Component</th>
    <th>Drag*<br>Copy</th>
    <th>Drag*<br>Move</th>
    <th>Drop</th>
    <th>Cut</th>
    <th>Copy</th>
    <th>Paste</th>
</tr>

<tr><th align=left><code>JColorChooser**</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>

<tr><th align=left><code>JEditorPane</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
</tr>

<tr><th align=left><code>JFileChooser***</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
</tr>

<tr><th align=left><code>JFormattedTextField</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
</tr>

<tr><th align=left><code>JList</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
</tr>

<tr><th align=left><code>JPasswordField</code>
<td align=center><i>n/a</i></td>
<td align=center><i>n/a</i></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center><i>n/a</i></td>
<td align=center><i>n/a</i></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
</tr>

<tr><th align=left><code>JTable</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
</tr>

<tr><th align=left><code>JTextArea</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
</tr>

<tr><th align=left><code>JTextField</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p><td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p><td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></tr>

<tr><th align=left><code>JTextPane</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
</tr>

<tr><th align=left><code>JTree</code>
<td align=center>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>
<p><center><IMG SRC="../../figures/uiswing/../../images/check.gif" WIDTH="12" HEIGHT="12" ALIGN="BOTTOM" ALT="checked"></center></p></td>
<td>&nbsp;</td>
</table>
&nbsp;&nbsp;*Enabled by invoking <code>component.setDragEnabled(true)</code>
on the component.
<br>
&nbsp;**Imports and exports data of type <code>java.awt.Color</code>.
<br>
***Exports both a list of filenames as <code>java.io.File</code>
objects (preferred) and as strings for those components
that do not accept <code>File</code> objects.  The <em>File
Name</em> text field in the file chooser accepts strings;
the browser in the file chooser does not accept data.
Note that as of release 1.4, clipboard copy from a <code>JFileChooser</code>
is broken and actually causes the file to be moved when it
is pasted.  You may want to watch bug
<a class="OutsideLink" target="_blank" href="http://developer.java.sun.com/developer/bugParade/bugs/4915992.html">#4915992</a>.

<p>The data transfer mechanism is built in to every 
<code>JComponent</code>. For all the components
with an empty space in the preceding table only a small
amount of code is needed to customize the support.
Support can easily be added to 
<code>JComponent</code>s not listed in the table so they
can fully participate in data transfer.

<p>
The rest of this section covers the following topics:

<ul>
<li><a href=#cursorIcons>A Visual Guide to Drag and Drop Cursor Icons</a>
<li><a href=#intro>Introduction to Data Transfer Support</a>
<li><a href=#label>A Simple Example: Adding DnD to JLabel</a>
<li><a href=#complex>Extending Default DnD Support</a>
<li><a href=#dataFormat>Specifying the Data Format</a>
<li><a href=#customImport>Importing a New Flavor: Color</a>
<li><a href=#replacingSupport>Replacing Default Support: Color and Text</a>
<li><a href=#importFiles>Importing a New Flavor: Files</a>
<li><a href=#customComp>Data Transfer with a Custom Component</a>
<li><a href=#customFlavor>Data Transfer with a Custom DataFlavor</a>
<li><a href=#cut>Adding Cut/Copy/Paste Support</a>
<li><a href=#api>The Data Transfer API</a>
<li><a href=#eg>Examples that Use Data Transfer</a>
</ul>

</blockquote>
<a name=cursorIcons>
<h2>A Visual Guide to Drag and Drop Cursor Icons</h2></a>
<blockquote>
<p>
Before delving into drag and drop further, it's useful
to take a look at the various cursor icons you may
encounter when initiating a drag operation.
We expect the Solaris and Linux cursor icons
to change for release 1.5, but here is a guide
as of release 1.4:

<a name=cursorIconTable>
<h4 align=center>Cursor Icons for Drag and Drop</h4>
</a>
<table align=center border=1>
<tr>
<th align=left>Microsoft<br>Windows</th>
<th align=left>Solaris/<br>Linux</th>
<th align=left>Description</th>
</tr>
<tr valign=center>
<td align=center>
<IMG SRC="../../figures/uiswing/dnd/win32_CopyDrop.gif" WIDTH="23" HEIGHT="32" ALT="Copy cursor icon for Windows, the component below accepts the drop."></td>
<td align=center>
<IMG SRC="../../figures/uiswing/dnd/motif_CopyDrop.gif" WIDTH="32" HEIGHT="32" ALT="Copy cursor icon for Linux/Solaris, the component below accepts the drop."></td>
<td>
Copy.
The component underneath accepts this type of data.
</td>
</tr>

<tr valign=center>
<td align=center>
<IMG SRC="../../figures/uiswing/dnd/no.gif" WIDTH="20" HEIGHT="20" ALT="Copy cursor icon for Windows, the component below won't accept."></td>
<td align=center>
<IMG SRC="../../figures/uiswing/dnd/motif_CopyNoDrop.gif" WIDTH="32" HEIGHT="32" ALT="Copy cursor icon for Linux/Solaris, the component below won't accept."></td>
<td>
Copy.  The area underneath will not accept this data.
</td>
</tr>

<tr>
<td align=center valign=center>
<IMG SRC="../../figures/uiswing/dnd/win32_MoveDrop.gif" WIDTH="16" HEIGHT="27" ALT="Move cursor icon for Windows, the component accepts the drop."></td>
<td align=center valign=center>
<IMG SRC="../../figures/uiswing/dnd/motif_MoveDrop.gif" WIDTH="32" HEIGHT="32" ALT="Move cursor icon for Linux/Solaris, the component accepts the drop."></td>
<td>
Move.
The component underneath accepts this type of data.
</td>
</tr>

<tr>
<td align=center valign=center>
<IMG SRC="../../figures/uiswing/dnd/no.gif" WIDTH="20" HEIGHT="20" ALT="Move cursor icon for Windows, the component won't accept."></td>
<td align=center valign=center>
<IMG SRC="../../figures/uiswing/dnd/motif_MoveNoDrop.gif" WIDTH="32" HEIGHT="32" ALT="Move cursor icon for Linux/Solaris, the component won't accept."></td>
<td>
Move.  The area underneath will not accept this data.
</td>
</tr>

</table>

<p>On a <code>Component</code> supporting both Copy and Move,
a normal drag from the component performs a move and a Control-drag
performs a copy.  The drag behavior from a native application to
a Java application is platform dependent.  If only one of the operations
is supported, a normal drag performs that operation. For more
information on the behavior of the drop action, see the class spec for
<a class="APILink" target="_blank" href="http://java.sun.com/javase/6/docs/api/java/awt/dnd/DragSourceDragEvent.html">DragSourceDragEvent</a>.

</blockquote>
<a name=intro>
<h2>Introduction to Data Transfer Support</h2></a>
<blockquote>
<p>
The simple demo <code>BasicDnD</code> illustrates default
drag and drop behavior for several Swing components.
At startup the components do not have drag turned on,
but a check box allows you to enable dragging on the fly.
Note that at startup, even though drag is not yet enabled,
many of the components do support the cut/copy/paste of text
using key bindings.

<p><center><a href="../../figures/uiswing/../../figures/uiswing/dnd/BasicDND.png" target="_top"><IMG SRC="../../figures/uiswing/../../figures/uiswing/dnd/BasicDND.png" WIDTH="500" HEIGHT="341" ALIGN="BOTTOM" ALT=""></a><br><em>This figure has been reduced to fit on the page. <br> Click the image to view it at its natural size.</em></center></p>
<blockquote><hr><strong>Try this:</strong>&nbsp;<ol>
<li> <a href="http://java.sun.com/docs/books/tutorialJWS/uiswing/misc/examples/BasicDnD.jnlp">Run
     BasicDnD</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#BasicDnD">example index</a>.
<li> Select an item in the list, and then release the mouse button
     so it is now highlighted.
<li> Press the item again, this time holding down the mouse
     button and begin to drag. Nothing happens because
     <nobr><code>setDragEnabled(true)</code></nobr> has not yet been 
     called on the list.
<li> Type Control-C.  This puts the text of the selected
     list item onto the system clipboard.
<li> Click in the text area.  The caret cursor blinks
     showing that this component now has the focus.
<li> Type Control-V.  The contents of the previously copied
     text are pasted at the caret location.
<li> Click the "Turn on Drag and Drop" check box.
<li> Once again, press the selected item in the list