1 /*
   2  * Copyright (c) 2000, 2005, 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 
  26 package sun.awt.datatransfer;
  27 
  28 import java.awt.datatransfer.DataFlavor;
  29 import java.awt.datatransfer.Transferable;
  30 import java.awt.datatransfer.UnsupportedFlavorException;
  31 
  32 import java.io.IOException;
  33 
  34 import java.util.HashMap;
  35 import java.util.Iterator;
  36 import java.util.Map;
  37 
  38 
  39 /**
  40  * Reads all of the data from the system Clipboard which the data transfer
  41  * subsystem knows how to translate. This includes all text data, File Lists,
  42  * Serializable objects, Remote objects, and properly registered, arbitrary
  43  * data as InputStreams. The data is stored in byte format until requested
  44  * by client code. At that point, the data is converted, if necessary, into
  45  * the proper format to deliver to the application.
  46  *
  47  * This hybrid pre-fetch/delayed-rendering approach allows us to circumvent
  48  * the API restriction that client code cannot lock the Clipboard to discover
  49  * its formats before requesting data in a particular format, while avoiding
  50  * the overhead of fully rendering all data ahead of time.
  51  *
  52  * @author David Mendenhall
  53  * @author Danila Sinopalnikov
  54  *
  55  * @since 1.4 (appeared in modified form as FullyRenderedTransferable in 1.3.1)
  56  */
  57 public class ClipboardTransferable implements Transferable {
  58     private final HashMap flavorsToData = new HashMap();
  59     private DataFlavor[] flavors = new DataFlavor[0];
  60 
  61     private final class DataFactory {
  62         final long format;
  63         final byte[] data;
  64         DataFactory(long format, byte[] data) {
  65             this.format = format;
  66             this.data   = data;
  67         }
  68 
  69         public Object getTransferData(DataFlavor flavor) throws IOException {
  70             return DataTransferer.getInstance().
  71                 translateBytes(data, flavor, format,
  72                                ClipboardTransferable.this);
  73         }
  74     }
  75 
  76     public ClipboardTransferable(SunClipboard clipboard) {
  77 
  78         clipboard.openClipboard(null);
  79 
  80         try {
  81             long[] formats = clipboard.getClipboardFormats();
  82 
  83             if (formats != null && formats.length > 0) {
  84                 // Since the SystemFlavorMap will specify many DataFlavors
  85                 // which map to the same format, we should cache data as we
  86                 // read it.
  87                 HashMap cached_data = new HashMap(formats.length, 1.0f);
  88 
  89                 Map flavorsForFormats = DataTransferer.getInstance().
  90                     getFlavorsForFormats(formats, SunClipboard.flavorMap);
  91                 for (Iterator iter = flavorsForFormats.keySet().iterator();
  92                      iter.hasNext(); )
  93                 {
  94                     DataFlavor flavor = (DataFlavor)iter.next();
  95                     Long lFormat = (Long)flavorsForFormats.get(flavor);
  96 
  97                     fetchOneFlavor(clipboard, flavor, lFormat, cached_data);
  98                 }
  99 
 100                 flavors = DataTransferer.getInstance().
 101                     setToSortedDataFlavorArray(flavorsToData.keySet(),
 102                                                flavorsForFormats);
 103             }
 104         } finally {
 105             clipboard.closeClipboard();
 106         }
 107     }
 108 
 109     private boolean fetchOneFlavor(SunClipboard clipboard, DataFlavor flavor,
 110                                    Long lFormat, HashMap cached_data)
 111     {
 112         if (!flavorsToData.containsKey(flavor)) {
 113             long format = lFormat.longValue();
 114             Object data = null;
 115 
 116             if (!cached_data.containsKey(lFormat)) {
 117                 try {
 118                     data = clipboard.getClipboardData(format);
 119                 } catch (IOException e) {
 120                     data = e;
 121                 } catch (Throwable e) {
 122                     e.printStackTrace();
 123                 }
 124 
 125                 // Cache this data, even if it's null, so we don't have to go
 126                 // to native code again for this format.
 127                 cached_data.put(lFormat, data);
 128             } else {
 129                 data = cached_data.get(lFormat);
 130             }
 131 
 132             // Casting IOException to byte array causes ClassCastException.
 133             // We should handle IOException separately - do not wrap them into
 134             // DataFactory and report failure.
 135             if (data instanceof IOException) {
 136                 flavorsToData.put(flavor, data);
 137                 return false;
 138             } else if (data != null) {
 139                 flavorsToData.put(flavor, new DataFactory(format,
 140                                                           (byte[])data));
 141                 return true;
 142             }
 143         }
 144 
 145         return false;
 146     }
 147 
 148     public DataFlavor[] getTransferDataFlavors() {
 149         return (DataFlavor[])flavors.clone();
 150     }
 151 
 152     public boolean isDataFlavorSupported(DataFlavor flavor) {
 153         return flavorsToData.containsKey(flavor);
 154     }
 155 
 156     public Object getTransferData(DataFlavor flavor)
 157         throws UnsupportedFlavorException, IOException
 158     {
 159         if (!isDataFlavorSupported(flavor)) {
 160             throw new UnsupportedFlavorException(flavor);
 161         }
 162         Object ret = flavorsToData.get(flavor);
 163         if (ret instanceof IOException) {
 164             // rethrow IOExceptions generated while fetching data
 165             throw (IOException)ret;
 166         } else if (ret instanceof DataFactory) {
 167             // Now we can render the data
 168             DataFactory factory = (DataFactory)ret;
 169             ret = factory.getTransferData(flavor);
 170         }
 171         return ret;
 172     }
 173 
 174 }
--- EOF ---