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 
  31 import java.awt.dnd.DnDConstants;
  32 import java.awt.dnd.InvalidDnDOperationException;
  33 
  34 import java.util.Map;
  35 
  36 /**
  37  * An abstract class for drag protocols on X11 systems.
  38  * Contains protocol-independent drag source code.
  39  *
  40  * @since 1.5
  41  */
  42 abstract class XDragSourceProtocol {
  43     private final XDragSourceProtocolListener listener;
  44 
  45     private boolean initialized = false;
  46 
  47     private long targetWindow = 0;
  48     private long targetProxyWindow = 0;
  49     private int targetProtocolVersion = 0;
  50     private long targetWindowMask = 0;
  51 
  52     // Always use the XAWT root window as the drag source window.
  53     static long getDragSourceWindow() {
  54         return XWindow.getXAWTRootWindow().getWindow();
  55     }
  56 
  57     protected XDragSourceProtocol(XDragSourceProtocolListener listener) {
  58         if (listener == null) {
  59             throw new NullPointerException("Null XDragSourceProtocolListener");
  60         }
  61         this.listener = listener;
  62     }
  63 
  64     protected final XDragSourceProtocolListener getProtocolListener() {
  65         return listener;
  66     }
  67 
  68     /**
  69      * Returns the protocol name. The protocol name cannot be null.
  70      */
  71     public abstract String getProtocolName();
  72 
  73     /**
  74      * Initializes a drag operation with the specified supported drop actions,
  75      * contents and data formats.
  76      *
  77      * @param actions a bitwise mask of <code>DnDConstants</code> that represent
  78      *                the supported drop actions.
  79      * @param contents the contents for the drag operation.
  80      * @param formats an array of Atoms that represent the supported data formats.
  81      * @param formats an array of Atoms that represent the supported data formats.
  82      * @throws InvalidDnDOperationException if a drag operation is already
  83      * initialized.
  84      * @throws IllegalArgumentException if some argument has invalid value.
  85      * @throws XException if some X call failed.
  86      */
  87     public final void initializeDrag(int actions, Transferable contents,
  88                                      Map<Long, DataFlavor> formatMap, long[] formats)
  89       throws InvalidDnDOperationException,
  90              IllegalArgumentException, XException {
  91         XToolkit.awtLock();
  92         try {
  93             try {
  94                 if (initialized) {
  95                     throw new InvalidDnDOperationException("Already initialized");
  96                 }
  97 
  98                 initializeDragImpl(actions, contents, formatMap, formats);
  99 
 100                 initialized = true;
 101             } finally {
 102                 if (!initialized) {
 103                     cleanup();
 104                 }
 105             }
 106         } finally {
 107             XToolkit.awtUnlock();
 108         }
 109     }
 110 
 111     /* The caller must hold AWT_LOCK. */
 112     protected abstract void initializeDragImpl(int actions,
 113                                                Transferable contents,
 114                                                Map<Long, DataFlavor> formatMap,
 115                                                long[] formats)
 116       throws InvalidDnDOperationException, IllegalArgumentException, XException;
 117 
 118     /**
 119      * Terminates the current drag operation (if any) and resets the internal
 120      * state of this object.
 121      *
 122      * @throws XException if some X call failed.
 123      */
 124     public void cleanup() {
 125         initialized = false;
 126         cleanupTargetInfo();
 127     }
 128 
 129     /**
 130      * Clears the information on the current drop target.
 131      *
 132      * @throws XException if some X call failed.
 133      */
 134     public void cleanupTargetInfo() {
 135         targetWindow = 0;
 136         targetProxyWindow = 0;
 137         targetProtocolVersion = 0;
 138     }
 139 
 140     /**
 141      * Processes the specified client message event.
 142      *
 143      * @returns true if the event was successfully processed.
 144      */
 145     public abstract boolean processClientMessage(XClientMessageEvent xclient)
 146       throws XException;
 147 
 148     /* The caller must hold AWT_LOCK. */
 149     public final boolean attachTargetWindow(long window, long time) {
 150         assert XToolkit.isAWTLockHeldByCurrentThread();
 151 
 152         TargetWindowInfo info = getTargetWindowInfo(window);
 153         if (info == null) {
 154             return false;
 155         } else {
 156             targetWindow = window;
 157             targetProxyWindow = info.getProxyWindow();
 158             targetProtocolVersion = info.getProtocolVersion();
 159             return true;
 160         }
 161     }
 162 
 163     /* The caller must hold AWT_LOCK. */
 164     public abstract TargetWindowInfo getTargetWindowInfo(long window);
 165 
 166     /* The caller must hold AWT_LOCK. */
 167     public abstract void sendEnterMessage(long[] formats, int sourceAction,
 168                                           int sourceActions, long time);
 169     /* The caller must hold AWT_LOCK. */
 170     public abstract void sendMoveMessage(int xRoot, int yRoot,
 171                                          int sourceAction, int sourceActions,
 172                                          long time);
 173     /* The caller must hold AWT_LOCK. */
 174     public abstract void sendLeaveMessage(long time);
 175 
 176     /* The caller must hold AWT_LOCK. */
 177     protected abstract void sendDropMessage(int xRoot, int yRoot,
 178                                             int sourceAction, int sourceActions,
 179                                             long time);
 180 
 181     public final void initiateDrop(int xRoot, int yRoot,
 182                                    int sourceAction, int sourceActions,
 183                                    long time) {
 184         XWindowAttributes wattr = new XWindowAttributes();
 185         try {
 186             XErrorHandlerUtil.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 187             int status = XlibWrapper.XGetWindowAttributes(XToolkit.getDisplay(),
 188                                                           targetWindow, wattr.pData);
 189 
 190             XErrorHandlerUtil.RESTORE_XERROR_HANDLER();
 191 
 192             if ((status == 0) ||
 193                 ((XErrorHandlerUtil.saved_error != null) &&
 194                 (XErrorHandlerUtil.saved_error.get_error_code() != XConstants.Success))) {
 195                 throw new XException("XGetWindowAttributes failed");
 196             }
 197 
 198             targetWindowMask = wattr.get_your_event_mask();
 199         } finally {
 200             wattr.dispose();
 201         }
 202 
 203         XErrorHandlerUtil.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 204         XlibWrapper.XSelectInput(XToolkit.getDisplay(), targetWindow,
 205                                  targetWindowMask |
 206                                  XConstants.StructureNotifyMask);
 207 
 208         XErrorHandlerUtil.RESTORE_XERROR_HANDLER();
 209 
 210         if ((XErrorHandlerUtil.saved_error != null) &&
 211             (XErrorHandlerUtil.saved_error.get_error_code() != XConstants.Success)) {
 212             throw new XException("XSelectInput failed");
 213         }
 214 
 215         sendDropMessage(xRoot, yRoot, sourceAction, sourceActions, time);
 216     }
 217 
 218     protected final void finalizeDrop() {
 219         XErrorHandlerUtil.WITH_XERROR_HANDLER(XErrorHandler.IgnoreBadWindowHandler.getInstance());
 220         XlibWrapper.XSelectInput(XToolkit.getDisplay(), targetWindow,
 221                                  targetWindowMask);
 222         XErrorHandlerUtil.RESTORE_XERROR_HANDLER();
 223     }
 224 
 225     public abstract boolean processProxyModeEvent(XClientMessageEvent xclient,
 226                                                   long sourceWindow);
 227 
 228     protected final long getTargetWindow() {
 229         return targetWindow;
 230     }
 231 
 232     protected final long getTargetProxyWindow() {
 233         if (targetProxyWindow != 0) {
 234             return targetProxyWindow;
 235         } else {
 236             return targetWindow;
 237         }
 238     }
 239 
 240     protected final int getTargetProtocolVersion() {
 241         return targetProtocolVersion;
 242     }
 243 
 244     public static class TargetWindowInfo {
 245         private final long proxyWindow;
 246         private final int protocolVersion;
 247         public TargetWindowInfo(long proxy, int version) {
 248             proxyWindow = proxy;
 249             protocolVersion = version;
 250         }
 251         public long getProxyWindow() {
 252             return proxyWindow;
 253         }
 254         public int getProtocolVersion() {
 255             return protocolVersion;
 256         }
 257     }
 258 }