1 /*
   2  * Copyright (c) 2003, 2008, 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 
  30 import java.awt.dnd.DnDConstants;
  31 import java.awt.dnd.InvalidDnDOperationException;
  32 
  33 import java.util.Map;
  34 
  35 /**
  36  * An abstract class for drag protocols on X11 systems.
  37  * Contains protocol-independent drag source code.
  38  *
  39  * @since 1.5
  40  */
  41 abstract class XDragSourceProtocol {
  42     private final XDragSourceProtocolListener listener;
  43 
  44     private boolean initialized = false;
  45 
  46     private long targetWindow = 0;
  47     private long targetProxyWindow = 0;
  48     private int targetProtocolVersion = 0;
  49     private long targetWindowMask = 0;
  50 
  51     // Always use the XAWT root window as the drag source window.
  52     static long getDragSourceWindow() {
  53         return XWindow.getXAWTRootWindow().getWindow();
  54     }
  55 
  56     protected XDragSourceProtocol(XDragSourceProtocolListener listener) {
  57         if (listener == null) {
  58             throw new NullPointerException("Null XDragSourceProtocolListener");
  59         }
  60         this.listener = listener;
  61     }
  62 
  63     protected final XDragSourceProtocolListener getProtocolListener() {
  64         return listener;
  65     }
  66 
  67     /**
  68      * Returns the protocol name. The protocol name cannot be null.
  69      */
  70     public abstract String getProtocolName();
  71 
  72     /**
  73      * Initalizes a drag operation with the specified supported drop actions,
  74      * contents and data formats.
  75      *
  76      * @param actions a bitwise mask of <code>DnDConstants</code> that represent
  77      *                the supported drop actions.
  78      * @param contents the contents for the drag operation.
  79      * @param formats an array of Atoms that represent the supported data formats.
  80      * @param formats an array of Atoms that represent the supported data formats.
  81      * @throws InvalidDnDOperationException if a drag operation is already
  82      * initialized.
  83      * @throws IllegalArgumentException if some argument has invalid value.
  84      * @throws XException if some X call failed.
  85      */
  86     public final void initializeDrag(int actions, Transferable contents,
  87                                      Map formatMap, long[] formats)
  88       throws InvalidDnDOperationException,
  89              IllegalArgumentException, XException {
  90         XToolkit.awtLock();
  91         try {
  92             try {
  93                 if (initialized) {
  94                     throw new InvalidDnDOperationException("Already initialized");
  95                 }
  96 
  97                 initializeDragImpl(actions, contents, formatMap, formats);
  98 
  99                 initialized = true;
 100             } finally {
 101                 if (!initialized) {
 102                     cleanup();
 103                 }
 104             }
 105         } finally {
 106             XToolkit.awtUnlock();
 107         }
 108     }
 109 
 110     /* The caller must hold AWT_LOCK. */
 111     protected abstract void initializeDragImpl(int actions,
 112                                                Transferable contents,
 113                                                Map formatMap, long[] formats)
 114       throws InvalidDnDOperationException, IllegalArgumentException, XException;
 115 
 116     /**
 117      * Terminates the current drag operation (if any) and resets the internal
 118      * state of this object.
 119      *
 120      * @throws XException if some X call failed.
 121      */
 122     public void cleanup() {
 123         initialized = false;
 124         cleanupTargetInfo();
 125     }
 126 
 127     /**
 128      * Clears the information on the current drop target.
 129      *
 130      * @throws XException if some X call failed.
 131      */
 132     public void cleanupTargetInfo() {
 133         targetWindow = 0;
 134         targetProxyWindow = 0;
 135         targetProtocolVersion = 0;
 136     }
 137 
 138     /**
 139      * Processes the specified client message event.
 140      *
 141      * @returns true if the event was successfully processed.
 142      */
 143     public abstract boolean processClientMessage(XClientMessageEvent xclient)
 144       throws XException;
 145 
 146     /* The caller must hold AWT_LOCK. */
 147     public final boolean attachTargetWindow(long window, long time) {
 148         assert XToolkit.isAWTLockHeldByCurrentThread();
 149 
 150         TargetWindowInfo info = getTargetWindowInfo(window);
 151         if (info == null) {
 152             return false;
 153         } else {
 154             targetWindow = window;
 155             targetProxyWindow = info.getProxyWindow();
 156             targetProtocolVersion = info.getProtocolVersion();
 157             return true;
 158         }
 159     }
 160 
 161     /* The caller must hold AWT_LOCK. */
 162     public abstract TargetWindowInfo getTargetWindowInfo(long window);
 163 
 164     /* The caller must hold AWT_LOCK. */
 165     public abstract void sendEnterMessage(long[] formats, int sourceAction,
 166                                           int sourceActions, long time);
 167     /* The caller must hold AWT_LOCK. */
 168     public abstract void sendMoveMessage(int xRoot, int yRoot,
 169                                          int sourceAction, int sourceActions,
 170                                          long time);
 171     /* The caller must hold AWT_LOCK. */
 172     public abstract void sendLeaveMessage(long time);
 173 
 174     /* The caller must hold AWT_LOCK. */
 175     protected abstract void sendDropMessage(int xRoot, int yRoot,
 176                                             int sourceAction, int sourceActions,
 177                                             long time);
 178 
 179     public final void initiateDrop(int xRoot, int yRoot,
 180                                    int sourceAction, int sourceActions,
 181                                    long time) {
 182         XWindowAttributes wattr = new XWindowAttributes();
 183         try {
 184             XToolkit.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 185             int status = XlibWrapper.XGetWindowAttributes(XToolkit.getDisplay(),
 186                                                           targetWindow, wattr.pData);
 187 
 188             XToolkit.RESTORE_XERROR_HANDLER();
 189 
 190             if (status == 0 ||
 191                 (XToolkit.saved_error != null &&
 192                  XToolkit.saved_error.get_error_code() != XConstants.Success)) {
 193                 throw new XException("XGetWindowAttributes failed");
 194             }
 195 
 196             targetWindowMask = wattr.get_your_event_mask();
 197         } finally {
 198             wattr.dispose();
 199         }
 200 
 201         XToolkit.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 202         XlibWrapper.XSelectInput(XToolkit.getDisplay(), targetWindow,
 203                                  targetWindowMask |
 204                                  XConstants.StructureNotifyMask);
 205 
 206         XToolkit.RESTORE_XERROR_HANDLER();
 207 
 208         if (XToolkit.saved_error != null &&
 209             XToolkit.saved_error.get_error_code() != XConstants.Success) {
 210             throw new XException("XSelectInput failed");
 211         }
 212 
 213         sendDropMessage(xRoot, yRoot, sourceAction, sourceActions, time);
 214     }
 215 
 216     protected final void finalizeDrop() {
 217         XToolkit.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 218         XlibWrapper.XSelectInput(XToolkit.getDisplay(), targetWindow,
 219                                  targetWindowMask);
 220         XToolkit.RESTORE_XERROR_HANDLER();
 221     }
 222 
 223     public abstract boolean processProxyModeEvent(XClientMessageEvent xclient,
 224                                                   long sourceWindow);
 225 
 226     protected final long getTargetWindow() {
 227         return targetWindow;
 228     }
 229 
 230     protected final long getTargetProxyWindow() {
 231         if (targetProxyWindow != 0) {
 232             return targetProxyWindow;
 233         } else {
 234             return targetWindow;
 235         }
 236     }
 237 
 238     protected final int getTargetProtocolVersion() {
 239         return targetProtocolVersion;
 240     }
 241 
 242     public static class TargetWindowInfo {
 243         private final long proxyWindow;
 244         private final int protocolVersion;
 245         public TargetWindowInfo(long proxy, int version) {
 246             proxyWindow = proxy;
 247             protocolVersion = version;
 248         }
 249         public long getProxyWindow() {
 250             return proxyWindow;
 251         }
 252         public int getProtocolVersion() {
 253             return protocolVersion;
 254         }
 255     }
 256 }
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