1 /*

     2  * Copyright 2003-2007 Sun Microsystems, Inc.  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.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package sun.awt.X11;

    27 

    28 import java.util.Iterator;

    29 

    30 /**

    31  * This class is a registry for the supported drag and drop protocols.

    32  *

    33  * @since 1.5

    34  */

    35 final class XDropTargetEventProcessor {

    36     private static final XDropTargetEventProcessor theInstance =

    37         new XDropTargetEventProcessor();

    38     private static boolean active = false;

    39 

    40     // The current drop protocol.

    41     private XDropTargetProtocol protocol = null;

    42 

    43     private XDropTargetEventProcessor() {}

    44 

    45     private boolean doProcessEvent(XEvent ev) {

    46         if (ev.get_type() == (int)XlibWrapper.DestroyNotify &&

    47             protocol != null &&

    48             ev.get_xany().get_window() == protocol.getSourceWindow()) {

    49             protocol.cleanup();

    50             protocol = null;

    51             return false;

    52         }

    53 

    54         if (ev.get_type() == (int)XlibWrapper.PropertyNotify) {

    55             XPropertyEvent xproperty = ev.get_xproperty();

    56             if (xproperty.get_atom() ==

    57                 MotifDnDConstants.XA_MOTIF_DRAG_RECEIVER_INFO.getAtom()) {

    58 

    59                 XDropTargetRegistry.getRegistry().updateEmbedderDropSite(xproperty.get_window());

    60             }

    61         }

    62 

    63         if (ev.get_type() != (int)XlibWrapper.ClientMessage) {

    64             return false;

    65         }

    66 

    67         boolean processed = false;

    68         XClientMessageEvent xclient = ev.get_xclient();

    69 

    70         XDropTargetProtocol curProtocol = protocol;

    71 

    72         if (protocol != null) {

    73             if (protocol.getMessageType(xclient) !=

    74                 XDropTargetProtocol.UNKNOWN_MESSAGE) {

    75                 processed = protocol.processClientMessage(xclient);

    76             } else {

    77                 protocol = null;

    78             }

    79         }

    80 

    81         if (protocol == null) {

    82             Iterator dropTargetProtocols =

    83                 XDragAndDropProtocols.getDropTargetProtocols();

    84 

    85             while (dropTargetProtocols.hasNext()) {

    86                 XDropTargetProtocol dropTargetProtocol =

    87                     (XDropTargetProtocol)dropTargetProtocols.next();

    88                 // Don't try to process it again with the current protocol.

    89                 if (dropTargetProtocol == curProtocol) {

    90                     continue;

    91                 }

    92 

    93                 if (dropTargetProtocol.getMessageType(xclient) ==

    94                     XDropTargetProtocol.UNKNOWN_MESSAGE) {

    95                     continue;

    96                 }

    97 

    98                 protocol = dropTargetProtocol;

    99                 processed = protocol.processClientMessage(xclient);

   100                 break;

   101             }

   102         }

   103 

   104         return processed;

   105     }

   106 

   107     static void reset() {

   108         theInstance.protocol = null;

   109     }

   110 

   111     static void activate() {

   112         active = true;

   113     }

   114 

   115     // Fix for 4915454 - do not call doProcessEvent() until the first drop

   116     // target is registered to avoid premature loading of DnD protocol

   117     // classes.

   118     static boolean processEvent(XEvent ev) {

   119         return active ? theInstance.doProcessEvent(ev) : false;

   120     }

   121 }