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public class

ClipboardTransferable

extends Object
implements Transferable
/*
 * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */


package sun.awt.datatransfer;

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;

import java.io.IOException;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;


/**
 * Reads all of the data from the system Clipboard which the data transfer
 * subsystem knows how to translate. This includes all text data, File Lists,
 * Serializable objects, Remote objects, and properly registered, arbitrary
 * data as InputStreams. The data is stored in byte format until requested
 * by client code. At that point, the data is converted, if necessary, into
 * the proper format to deliver to the application.
 *
 * This hybrid pre-fetch/delayed-rendering approach allows us to circumvent
 * the API restriction that client code cannot lock the Clipboard to discover
 * its formats before requesting data in a particular format, while avoiding
 * the overhead of fully rendering all data ahead of time.
 *
 * @author David Mendenhall
 * @author Danila Sinopalnikov
 *
 * @since 1.4 (appeared in modified form as FullyRenderedTransferable in 1.3.1)
 */

public class ClipboardTransferable implements Transferable {
   
private final HashMap flavorsToData = new HashMap();
   
private DataFlavor[] flavors = new DataFlavor[0];

   
private final class DataFactory {
       
final long format;
       
final byte[] data;
       
DataFactory(long format, byte[] data) {
           
this.format = format;
           
this.data   = data;
       
}

       
public Object getTransferData(DataFlavor flavor) throws IOException {
           
return DataTransferer.getInstance().
                translateBytes
(data, flavor, format,
                               
ClipboardTransferable.this);
       
}
   
}

   
public ClipboardTransferable(SunClipboard clipboard) {

        clipboard
.openClipboard(null);

       
try {
           
long[] formats = clipboard.getClipboardFormats();

           
if (formats != null && formats.length > 0) {
               
// Since the SystemFlavorMap will specify many DataFlavors
               
// which map to the same format, we should cache data as we
               
// read it.
               
HashMap cached_data = new HashMap(formats.length, 1.0f);

               
Map flavorsForFormats = DataTransferer.getInstance().
                    getFlavorsForFormats
(formats, SunClipboard.flavorMap);
               
for (Iterator iter = flavorsForFormats.keySet().iterator();
                     iter
.hasNext(); )
               
{
                   
DataFlavor flavor = (DataFlavor)iter.next();
                   
Long lFormat = (Long)flavorsForFormats.get(flavor);

                    fetchOneFlavor
(clipboard, flavor, lFormat, cached_data);
               
}

                flavors
= DataTransferer.getInstance().
                    setToSortedDataFlavorArray
(flavorsToData.keySet(),
                                               flavorsForFormats
);
           
}
       
} finally {
            clipboard
.closeClipboard();
       
}
   
}

   
private boolean fetchOneFlavor(SunClipboard clipboard, DataFlavor flavor,
                                   
Long lFormat, HashMap cached_data)
   
{
       
if (!flavorsToData.containsKey(flavor)) {
           
long format = lFormat.longValue();
           
Object data = null;

           
if (!cached_data.containsKey(lFormat)) {
               
try {
                    data
= clipboard.getClipboardData(format);
               
} catch (IOException e) {
                    data
= e;
               
} catch (Throwable e) {
                    e
.printStackTrace();
               
}

               
// Cache this data, even if it's null, so we don't have to go
               
// to native code again for this format.
                cached_data
.put(lFormat, data);
           
} else {
                data
= cached_data.get(lFormat);
           
}

           
// Casting IOException to byte array causes ClassCastException.
           
// We should handle IOException separately - do not wrap them into
           
// DataFactory and report failure.
           
if (data instanceof IOException) {
                flavorsToData
.put(flavor, data);
               
return false;
           
} else if (data != null) {
                flavorsToData
.put(flavor, new DataFactory(format,
                                                         
(byte[])data));
               
return true;
           
}
       
}

       
return false;
   
}

   
public DataFlavor[] getTransferDataFlavors() {
       
return (DataFlavor[])flavors.clone();
   
}

   
public boolean isDataFlavorSupported(DataFlavor flavor) {
       
return flavorsToData.containsKey(flavor);
   
}

   
public Object getTransferData(DataFlavor flavor)
       
throws UnsupportedFlavorException, IOException
   
{
       
if (!isDataFlavorSupported(flavor)) {
           
throw new UnsupportedFlavorException(flavor);
       
}
       
Object ret = flavorsToData.get(flavor);
       
if (ret instanceof IOException) {
           
// rethrow IOExceptions generated while fetching data
           
throw (IOException)ret;
       
} else if (ret instanceof DataFactory) {
           
// Now we can render the data
           
DataFactory factory = (DataFactory)ret;
            ret
= factory.getTransferData(flavor);
       
}
       
return ret;
   
}

}