1 /*
   2  * Copyright (c) 2003, 2013, 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.X11;
  27 
  28 import java.awt.datatransfer.Transferable;
  29 import java.awt.datatransfer.DataFlavor;
  30 import java.util.SortedMap;
  31 import java.io.IOException;
  32 import java.security.AccessController;
  33 import java.util.HashMap;
  34 import java.util.Map;
  35 import sun.awt.UNIXToolkit;
  36 import sun.awt.datatransfer.desktop.DataTransferer;
  37 import sun.awt.datatransfer.desktop.SunClipboard;
  38 import sun.awt.datatransfer.desktop.ClipboardTransferable;
  39 import sun.security.action.GetIntegerAction;
  40 
  41 /**
  42  * A class which interfaces with the X11 selection service in order to support
  43  * data transfer via Clipboard operations.
  44  */
  45 public final class XClipboard extends SunClipboard implements OwnershipListener
  46 {
  47     private final XSelection selection;
  48     // Time of calling XConvertSelection().
  49     private long convertSelectionTime;
  50     // The flag used not to call XConvertSelection() if the previous SelectionNotify
  51     // has not been processed by checkChange().
  52     private volatile boolean isSelectionNotifyProcessed;
  53     // The property in which the owner should place requested targets
  54     // when tracking changes of available data flavors (practically targets).
  55     private volatile XAtom targetsPropertyAtom;
  56 
  57     private static final Object classLock = new Object();
  58 
  59     private static final int defaultPollInterval = 200;
  60 
  61     private static int pollInterval;
  62 
  63     private static Map<Long, XClipboard> targetsAtom2Clipboard;
  64 
  65     /**
  66      * Creates a system clipboard object.
  67      */
  68     public XClipboard(String name, String selectionName) {
  69         super(name);
  70         selection = new XSelection(XAtom.get(selectionName));
  71         selection.registerOwershipListener(this);
  72     }
  73 
  74     /*
  75      * NOTE: This method may be called by privileged threads.
  76      *       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
  77      */
  78     public void ownershipChanged(final boolean isOwner) {
  79         if (isOwner) {
  80             checkChangeHere(contents);
  81         } else {
  82             lostOwnershipImpl();
  83         }
  84     }
  85 
  86     protected synchronized void setContentsNative(Transferable contents) {
  87         SortedMap<Long,DataFlavor> formatMap =
  88             DataTransferer.getInstance().getFormatsForTransferable
  89                 (contents, DataTransferer.adaptFlavorMap(getDefaultFlavorTable()));
  90         long[] formats = DataTransferer.keysToLongArray(formatMap);
  91 
  92         if (!selection.setOwner(contents, formatMap, formats,
  93                                 XToolkit.getCurrentServerTime())) {
  94             this.owner = null;
  95             this.contents = null;
  96         }
  97     }
  98 
  99     public long getID() {
 100         return selection.getSelectionAtom().getAtom();
 101     }
 102 
 103     @Override
 104     public synchronized Transferable getContents(Object requestor) {
 105         if (contents != null) {
 106             return contents;
 107         }
 108         return new ClipboardTransferable(this);
 109     }
 110 
 111     /* Caller is synchronized on this. */
 112     protected void clearNativeContext() {
 113         selection.reset();
 114     }
 115 
 116 
 117     protected long[] getClipboardFormats() {
 118         return selection.getTargets(XToolkit.getCurrentServerTime());
 119     }
 120 
 121     protected byte[] getClipboardData(long format) throws IOException {
 122         return selection.getData(format, XToolkit.getCurrentServerTime());
 123     }
 124 
 125     private void checkChangeHere(Transferable contents) {
 126         if (areFlavorListenersRegistered()) {
 127             checkChange(DataTransferer.getInstance().
 128                         getFormatsForTransferableAsArray(contents, getDefaultFlavorTable()));
 129         }
 130     }
 131 
 132     private static int getPollInterval() {
 133         synchronized (XClipboard.classLock) {
 134             if (pollInterval <= 0) {
 135                 pollInterval = AccessController.doPrivileged(
 136                         new GetIntegerAction("awt.datatransfer.clipboard.poll.interval",
 137                                              defaultPollInterval));
 138                 if (pollInterval <= 0) {
 139                     pollInterval = defaultPollInterval;
 140                 }
 141             }
 142             return pollInterval;
 143         }
 144     }
 145 
 146     private XAtom getTargetsPropertyAtom() {
 147         if (null == targetsPropertyAtom) {
 148             targetsPropertyAtom =
 149                     XAtom.get("XAWT_TARGETS_OF_SELECTION:" + selection.getSelectionAtom().getName());
 150         }
 151         return targetsPropertyAtom;
 152     }
 153 
 154     protected void registerClipboardViewerChecked() {
 155         // for XConvertSelection() to be called for the first time in getTargetsDelayed()
 156         isSelectionNotifyProcessed = true;
 157 
 158         boolean mustSchedule = false;
 159         synchronized (XClipboard.classLock) {
 160             if (targetsAtom2Clipboard == null) {
 161                 targetsAtom2Clipboard = new HashMap<Long, XClipboard>(2);
 162             }
 163             mustSchedule = targetsAtom2Clipboard.isEmpty();
 164             targetsAtom2Clipboard.put(getTargetsPropertyAtom().getAtom(), this);
 165             if (mustSchedule) {
 166                 XToolkit.addEventDispatcher(XWindow.getXAWTRootWindow().getWindow(),
 167                                             new SelectionNotifyHandler());
 168             }
 169         }
 170         if (mustSchedule) {
 171             XToolkit.schedule(new CheckChangeTimerTask(), XClipboard.getPollInterval());
 172         }
 173     }
 174 
 175     private static class CheckChangeTimerTask implements Runnable {
 176         public void run() {
 177             for (XClipboard clpbrd : targetsAtom2Clipboard.values()) {
 178                 clpbrd.getTargetsDelayed();
 179             }
 180             synchronized (XClipboard.classLock) {
 181                 if (targetsAtom2Clipboard != null && !targetsAtom2Clipboard.isEmpty()) {
 182                     // The viewer is still registered, schedule next poll.
 183                     XToolkit.schedule(this, XClipboard.getPollInterval());
 184                 }
 185             }
 186         }
 187     }
 188 
 189     private static class SelectionNotifyHandler implements XEventDispatcher {
 190         public void dispatchEvent(XEvent ev) {
 191             if (ev.get_type() == XConstants.SelectionNotify) {
 192                 final XSelectionEvent xse = ev.get_xselection();
 193                 XClipboard clipboard = null;
 194                 synchronized (XClipboard.classLock) {
 195                     if (targetsAtom2Clipboard != null && targetsAtom2Clipboard.isEmpty()) {
 196                         // The viewer was unregistered, remove the dispatcher.
 197                         XToolkit.removeEventDispatcher(XWindow.getXAWTRootWindow().getWindow(), this);
 198                         return;
 199                     }
 200                     final long propertyAtom = xse.get_property();
 201                     clipboard = targetsAtom2Clipboard.get(propertyAtom);
 202                 }
 203                 if (null != clipboard) {
 204                     clipboard.checkChange(xse);
 205                 }
 206             }
 207         }
 208     }
 209 
 210     protected void unregisterClipboardViewerChecked() {
 211         isSelectionNotifyProcessed = false;
 212         synchronized (XClipboard.classLock) {
 213             targetsAtom2Clipboard.remove(getTargetsPropertyAtom().getAtom());
 214         }
 215     }
 216 
 217     // checkChange() will be called on SelectionNotify
 218     private void getTargetsDelayed() {
 219         XToolkit.awtLock();
 220         try {
 221             long curTime = System.currentTimeMillis();
 222             if (isSelectionNotifyProcessed || curTime >= (convertSelectionTime + UNIXToolkit.getDatatransferTimeout()))
 223             {
 224                 convertSelectionTime = curTime;
 225                 XlibWrapper.XConvertSelection(XToolkit.getDisplay(),
 226                                               selection.getSelectionAtom().getAtom(),
 227                                               XDataTransferer.TARGETS_ATOM.getAtom(),
 228                                               getTargetsPropertyAtom().getAtom(),
 229                                               XWindow.getXAWTRootWindow().getWindow(),
 230                                               XConstants.CurrentTime);
 231                 isSelectionNotifyProcessed = false;
 232             }
 233         } finally {
 234             XToolkit.awtUnlock();
 235         }
 236     }
 237 
 238     /*
 239      * Tracks changes of available formats.
 240      * NOTE: This method may be called by privileged threads.
 241      *       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
 242      */
 243     private void checkChange(XSelectionEvent xse) {
 244         final long propertyAtom = xse.get_property();
 245         if (propertyAtom != getTargetsPropertyAtom().getAtom()) {
 246             // wrong atom
 247             return;
 248         }
 249 
 250         final XAtom selectionAtom = XAtom.get(xse.get_selection());
 251         final XSelection changedSelection = XSelection.getSelection(selectionAtom);
 252 
 253         if (null == changedSelection || changedSelection != selection) {
 254             // unknown selection - do nothing
 255             return;
 256         }
 257 
 258         isSelectionNotifyProcessed = true;
 259 
 260         if (selection.isOwner()) {
 261             // selection is owner - do not need formats
 262             return;
 263         }
 264 
 265         long[] formats = null;
 266 
 267         if (propertyAtom == XConstants.None) {
 268             // We treat None property atom as "empty selection".
 269             formats = new long[0];
 270         } else {
 271             WindowPropertyGetter targetsGetter =
 272                 new WindowPropertyGetter(XWindow.getXAWTRootWindow().getWindow(),
 273                                          XAtom.get(propertyAtom), 0,
 274                                          XSelection.MAX_LENGTH, true,
 275                                          XConstants.AnyPropertyType);
 276             try {
 277                 targetsGetter.execute();
 278                 formats = XSelection.getFormats(targetsGetter);
 279             } finally {
 280                 targetsGetter.dispose();
 281             }
 282         }
 283 
 284         checkChange(formats);
 285     }
 286 }