ojluni/src/main/java/sun/awt/X11/XDropTargetProtocol.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package sun.awt.X11;

 import java.io.IOException;

 import java.util.HashMap;

 import sun.util.logging.PlatformLogger;

 /**
  * An abstract class for drop protocols on X11 systems.
  * Contains protocol-independent drop target code.
  *
  * @since 1.5
  */
 abstract class XDropTargetProtocol {
     private static final PlatformLogger logger =
         PlatformLogger.getLogger("sun.awt.X11.xembed.xdnd.XDropTargetProtocol");

     private final XDropTargetProtocolListener listener;

     public static final int EMBEDDER_ALREADY_REGISTERED = 0;

     public static final int UNKNOWN_MESSAGE = 0;
     public static final int ENTER_MESSAGE   = 1;
     public static final int MOTION_MESSAGE  = 2;
     public static final int LEAVE_MESSAGE   = 3;
     public static final int DROP_MESSAGE    = 4;

     protected XDropTargetProtocol(XDropTargetProtocolListener listener) {
         if (listener == null) {
             throw new NullPointerException("Null XDropTargetProtocolListener");
         }
         this.listener = listener;
     }

     protected final XDropTargetProtocolListener getProtocolListener() {
         return listener;
     }

     /**
      * Returns the protocol name. The protocol name cannot be null.
      */
     public abstract String getProtocolName();

     /* The caller must hold AWT_LOCK. */
     public abstract void registerDropTarget(long window);

     /* The caller must hold AWT_LOCK. */
     public abstract void unregisterDropTarget(long window);

     /* The caller must hold AWT_LOCK. */
     public abstract void registerEmbedderDropSite(long window);

     /* The caller must hold AWT_LOCK. */
     public abstract void unregisterEmbedderDropSite(long window);

     /* The caller must hold AWT_LOCK. */
     public abstract void registerEmbeddedDropSite(long embedded);

     /* The caller must hold AWT_LOCK. */
     public final void unregisterEmbeddedDropSite(long embedded) {
         removeEmbedderRegistryEntry(embedded);
     }


     /* The caller must hold AWT_LOCK. */
     public abstract boolean isProtocolSupported(long window);

     public abstract int getMessageType(XClientMessageEvent xclient);

     /* The caller must hold AWT_LOCK. */
     public final boolean processClientMessage(XClientMessageEvent xclient) {
         int type = getMessageType(xclient);
         boolean processed = processClientMessageImpl(xclient);

         postProcessClientMessage(xclient, processed, type);

         return processed;
     }

     /* The caller must hold AWT_LOCK. */
     protected abstract boolean processClientMessageImpl(XClientMessageEvent xclient);

     /*
      * Forwards a drag notification to the embedding toplevel modifying the event
      * to match the protocol version supported by the toplevel.
      * The caller must hold AWT_LOCK.
      * Returns True if the event is sent, False otherwise.
      */
     protected final boolean forwardClientMessageToToplevel(long toplevel,
                                                            XClientMessageEvent xclient) {
         EmbedderRegistryEntry entry = getEmbedderRegistryEntry(toplevel);

         if (logger.isLoggable(PlatformLogger.FINEST)) {
             logger.finest("        entry={0}", entry);
         }
         // Window not registered as an embedder for this protocol.
         if (entry == null) {
             return false;
         }

         if (logger.isLoggable(PlatformLogger.FINEST)) {
             logger.finest("        entry.isOverriden()={0}", entry.isOverriden());
         }
         // Window didn't have an associated drop site, so there is no need
         // to forward the message.
         if (!entry.isOverriden()) {
             return false;
         }

         adjustEventForForwarding(xclient, entry);

         long proxy = entry.getProxy();

         if (logger.isLoggable(PlatformLogger.FINEST)) {
             logger.finest("        proxy={0} toplevel={1}", proxy, toplevel);
         }
         if (proxy == 0) {
             proxy = toplevel;
         }

         xclient.set_window(toplevel);

         XToolkit.awtLock();
         try {
             XlibWrapper.XSendEvent(XToolkit.getDisplay(), proxy, false,
                                    XConstants.NoEventMask, xclient.pData);
         } finally {
             XToolkit.awtUnlock();
         }

         return true;
     }


     /* True iff the previous notification was MotionEvent and it was
        forwarded to the browser. */
     private boolean motionPassedAlong = false;

     protected abstract void sendEnterMessageToToplevel(long toplevel,
                                                        XClientMessageEvent xclient);

     protected abstract void sendLeaveMessageToToplevel(long toplevel,
                                                        XClientMessageEvent xclient);

     private void postProcessClientMessage(XClientMessageEvent xclient,
                                           boolean processed,
                                           int type) {
         long toplevel = xclient.get_window();

         if (getEmbedderRegistryEntry(toplevel) != null) {
             /*
              * This code forwards drag notifications to the browser according to the
              * following rules:
              *  - the messages that we failed to process are always forwarded to the
              *    browser;
              *  - MotionEvents and DropEvents are forwarded if and only if the drag
              *    is not over a plugin window;
              *  - XDnD: EnterEvents and LeaveEvents are never forwarded, instead, we
              *    send synthesized EnterEvents or LeaveEvents when the drag
              *    respectively exits or enters plugin windows;
              *  - Motif DnD: EnterEvents and LeaveEvents are always forwarded.
              * Synthetic EnterEvents and LeaveEvents are needed, because the XDnD drop
              * site implemented Netscape 6.2 has a nice feature: when it receives
              * the first XdndPosition it continuously sends XdndStatus messages to
              * the source (every 100ms) until the drag terminates or leaves the drop
              * site. When the mouse is dragged over plugin window embedded in the
              * browser frame, these XdndStatus messages are mixed with the XdndStatus
              * messages sent from the plugin.
              * For Motif DnD, synthetic events cause Motif warnings being displayed,
              * so these events are always forwarded. However, Motif DnD drop site in
              * Netscape 6.2 is implemented in the same way, so there could be similar
              * problems if the drag source choose Motif DnD for communication.
              */
             if (!processed) {
                 forwardClientMessageToToplevel(toplevel, xclient);
             } else {
                 boolean motifProtocol =
                     xclient.get_message_type() ==
                     MotifDnDConstants.XA_MOTIF_DRAG_AND_DROP_MESSAGE.getAtom();

                 switch (type) {
                 case XDropTargetProtocol.MOTION_MESSAGE:
                     if (!isDragOverComponent()) {
                         if (!motionPassedAlong && !motifProtocol) {
                             sendEnterMessageToToplevel(toplevel, xclient);
                         }
                         forwardClientMessageToToplevel(toplevel, xclient);
                         motionPassedAlong = true;
                     } else {
                         if (motionPassedAlong && !motifProtocol) {
                             sendLeaveMessageToToplevel(toplevel, xclient);
                         }
                         motionPassedAlong = false;
                     }
                     break;
                 case XDropTargetProtocol.DROP_MESSAGE:
                     if (!isDragOverComponent()) {
                         forwardClientMessageToToplevel(toplevel, xclient);
                     }
                     motionPassedAlong = false;
                     break;
                 case XDropTargetProtocol.ENTER_MESSAGE:
                 case XDropTargetProtocol.LEAVE_MESSAGE:
                     if (motifProtocol) {
                         forwardClientMessageToToplevel(toplevel, xclient);
                     }
                     motionPassedAlong = false;
                     break;
                 }
             }
         }
     }

     public abstract boolean sendResponse(long ctxt, int eventID, int action);

     /*
      * Retrieves the data from the drag source in the specified format.
      *
      * @param ctxt a pointer to the XClientMessageEvent structure for this
      *             protocol's drop message.
      * @param format the format in which the data should be retrieved.
      *
      * @throws IllegalArgumentException if ctxt doesn't point to the
      *         XClientMessageEvent structure for this protocol's drop message.
      * @throws IOException if data retrieval failed.
      */
     public abstract Object getData(long ctxt, long format)
       throws IllegalArgumentException, IOException;

     public abstract boolean sendDropDone(long ctxt, boolean success,
                                          int dropAction);

     public abstract long getSourceWindow();

     public abstract void cleanup();

     public abstract boolean isDragOverComponent();

     public void adjustEventForForwarding(XClientMessageEvent xclient,
         EmbedderRegistryEntry entry) {}

     public abstract boolean forwardEventToEmbedded(long embedded, long ctxt,
                                                    int eventID);

     /*
      * Returns true if the XEmbed protocol prescribes that an XEmbed server must
      * support this DnD protocol for drop sites associated with XEmbed clients.
      */
     public abstract boolean isXEmbedSupported();

     protected static final class EmbedderRegistryEntry {
         private final boolean overriden;
         private final int version;
         private final long proxy;
         EmbedderRegistryEntry(boolean overriden, int version, long proxy) {
             this.overriden = overriden;
             this.version = version;
             this.proxy = proxy;
         }
         public boolean isOverriden() {
             return overriden;
         }
         public int getVersion() {
             return version;
         }
         public long getProxy() {
             return proxy;
         }
     }

     /* Access to HashMap is synchronized on this XDropTargetProtocol instance. */
     private final HashMap embedderRegistry = new HashMap();

     protected final void putEmbedderRegistryEntry(long embedder,
                                                   boolean overriden,
                                                   int version,
                                                   long proxy) {
         synchronized (this) {
             embedderRegistry.put(Long.valueOf(embedder),
                                  new EmbedderRegistryEntry(overriden, version,
                                                            proxy));
         }
     }

     protected final EmbedderRegistryEntry getEmbedderRegistryEntry(long embedder) {
         synchronized (this) {
             return
                 (EmbedderRegistryEntry)embedderRegistry.get(Long.valueOf(embedder));
         }
     }

     protected final void removeEmbedderRegistryEntry(long embedder) {
         synchronized (this) {
             embedderRegistry.remove(Long.valueOf(embedder));
         }
     }
 }
	/*
	* Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.awt.X11;

	import java.io.IOException;

	import java.util.HashMap;

	import sun.util.logging.PlatformLogger;

	/**
	* An abstract class for drop protocols on X11 systems.
	* Contains protocol-independent drop target code.
	*
	* @since 1.5
	*/
	abstract class XDropTargetProtocol {
	private static final PlatformLogger logger =
	PlatformLogger.getLogger("sun.awt.X11.xembed.xdnd.XDropTargetProtocol");

	private final XDropTargetProtocolListener listener;

	public static final int EMBEDDER_ALREADY_REGISTERED = 0;

	public static final int UNKNOWN_MESSAGE = 0;
	public static final int ENTER_MESSAGE = 1;
	public static final int MOTION_MESSAGE = 2;
	public static final int LEAVE_MESSAGE = 3;
	public static final int DROP_MESSAGE = 4;

	protected XDropTargetProtocol(XDropTargetProtocolListener listener) {
	if (listener == null) {
	throw new NullPointerException("Null XDropTargetProtocolListener");
	}
	this.listener = listener;
	}

	protected final XDropTargetProtocolListener getProtocolListener() {
	return listener;
	}

	/**
	* Returns the protocol name. The protocol name cannot be null.
	*/
	public abstract String getProtocolName();

	/* The caller must hold AWT_LOCK. */
	public abstract void registerDropTarget(long window);

	/* The caller must hold AWT_LOCK. */
	public abstract void unregisterDropTarget(long window);

	/* The caller must hold AWT_LOCK. */
	public abstract void registerEmbedderDropSite(long window);

	/* The caller must hold AWT_LOCK. */
	public abstract void unregisterEmbedderDropSite(long window);

	/* The caller must hold AWT_LOCK. */
	public abstract void registerEmbeddedDropSite(long embedded);

	/* The caller must hold AWT_LOCK. */
	public final void unregisterEmbeddedDropSite(long embedded) {
	removeEmbedderRegistryEntry(embedded);
	}


	/* The caller must hold AWT_LOCK. */
	public abstract boolean isProtocolSupported(long window);

	public abstract int getMessageType(XClientMessageEvent xclient);

	/* The caller must hold AWT_LOCK. */
	public final boolean processClientMessage(XClientMessageEvent xclient) {
	int type = getMessageType(xclient);
	boolean processed = processClientMessageImpl(xclient);

	postProcessClientMessage(xclient, processed, type);

	return processed;
	}

	/* The caller must hold AWT_LOCK. */
	protected abstract boolean processClientMessageImpl(XClientMessageEvent xclient);

	/*
	* Forwards a drag notification to the embedding toplevel modifying the event
	* to match the protocol version supported by the toplevel.
	* The caller must hold AWT_LOCK.
	* Returns True if the event is sent, False otherwise.
	*/
	protected final boolean forwardClientMessageToToplevel(long toplevel,
	XClientMessageEvent xclient) {
	EmbedderRegistryEntry entry = getEmbedderRegistryEntry(toplevel);

	if (logger.isLoggable(PlatformLogger.FINEST)) {
	logger.finest(" entry={0}", entry);
	}
	// Window not registered as an embedder for this protocol.
	if (entry == null) {
	return false;
	}

	if (logger.isLoggable(PlatformLogger.FINEST)) {
	logger.finest(" entry.isOverriden()={0}", entry.isOverriden());
	}
	// Window didn't have an associated drop site, so there is no need
	// to forward the message.
	if (!entry.isOverriden()) {
	return false;
	}

	adjustEventForForwarding(xclient, entry);

	long proxy = entry.getProxy();

	if (logger.isLoggable(PlatformLogger.FINEST)) {
	logger.finest(" proxy={0} toplevel={1}", proxy, toplevel);
	}
	if (proxy == 0) {
	proxy = toplevel;
	}

	xclient.set_window(toplevel);

	XToolkit.awtLock();
	try {
	XlibWrapper.XSendEvent(XToolkit.getDisplay(), proxy, false,
	XConstants.NoEventMask, xclient.pData);
	} finally {
	XToolkit.awtUnlock();
	}

	return true;
	}


	/* True iff the previous notification was MotionEvent and it was
	forwarded to the browser. */
	private boolean motionPassedAlong = false;

	protected abstract void sendEnterMessageToToplevel(long toplevel,
	XClientMessageEvent xclient);

	protected abstract void sendLeaveMessageToToplevel(long toplevel,
	XClientMessageEvent xclient);

	private void postProcessClientMessage(XClientMessageEvent xclient,
	boolean processed,
	int type) {
	long toplevel = xclient.get_window();

	if (getEmbedderRegistryEntry(toplevel) != null) {
	/*
	* This code forwards drag notifications to the browser according to the
	* following rules:
	* - the messages that we failed to process are always forwarded to the
	* browser;
	* - MotionEvents and DropEvents are forwarded if and only if the drag
	* is not over a plugin window;
	* - XDnD: EnterEvents and LeaveEvents are never forwarded, instead, we
	* send synthesized EnterEvents or LeaveEvents when the drag
	* respectively exits or enters plugin windows;
	* - Motif DnD: EnterEvents and LeaveEvents are always forwarded.
	* Synthetic EnterEvents and LeaveEvents are needed, because the XDnD drop
	* site implemented Netscape 6.2 has a nice feature: when it receives
	* the first XdndPosition it continuously sends XdndStatus messages to
	* the source (every 100ms) until the drag terminates or leaves the drop
	* site. When the mouse is dragged over plugin window embedded in the
	* browser frame, these XdndStatus messages are mixed with the XdndStatus
	* messages sent from the plugin.
	* For Motif DnD, synthetic events cause Motif warnings being displayed,
	* so these events are always forwarded. However, Motif DnD drop site in
	* Netscape 6.2 is implemented in the same way, so there could be similar
	* problems if the drag source choose Motif DnD for communication.
	*/
	if (!processed) {
	forwardClientMessageToToplevel(toplevel, xclient);
	} else {
	boolean motifProtocol =
	xclient.get_message_type() ==
	MotifDnDConstants.XA_MOTIF_DRAG_AND_DROP_MESSAGE.getAtom();

	switch (type) {
	case XDropTargetProtocol.MOTION_MESSAGE:
	if (!isDragOverComponent()) {
	if (!motionPassedAlong && !motifProtocol) {
	sendEnterMessageToToplevel(toplevel, xclient);
	}
	forwardClientMessageToToplevel(toplevel, xclient);
	motionPassedAlong = true;
	} else {
	if (motionPassedAlong && !motifProtocol) {
	sendLeaveMessageToToplevel(toplevel, xclient);
	}
	motionPassedAlong = false;
	}
	break;
	case XDropTargetProtocol.DROP_MESSAGE:
	if (!isDragOverComponent()) {
	forwardClientMessageToToplevel(toplevel, xclient);
	}
	motionPassedAlong = false;
	break;
	case XDropTargetProtocol.ENTER_MESSAGE:
	case XDropTargetProtocol.LEAVE_MESSAGE:
	if (motifProtocol) {
	forwardClientMessageToToplevel(toplevel, xclient);
	}
	motionPassedAlong = false;
	break;
	}
	}
	}
	}

	public abstract boolean sendResponse(long ctxt, int eventID, int action);

	/*
	* Retrieves the data from the drag source in the specified format.
	*
	* @param ctxt a pointer to the XClientMessageEvent structure for this
	* protocol's drop message.
	* @param format the format in which the data should be retrieved.
	*
	* @throws IllegalArgumentException if ctxt doesn't point to the
	* XClientMessageEvent structure for this protocol's drop message.
	* @throws IOException if data retrieval failed.
	*/
	public abstract Object getData(long ctxt, long format)
	throws IllegalArgumentException, IOException;

	public abstract boolean sendDropDone(long ctxt, boolean success,
	int dropAction);

	public abstract long getSourceWindow();

	public abstract void cleanup();

	public abstract boolean isDragOverComponent();

	public void adjustEventForForwarding(XClientMessageEvent xclient,
	EmbedderRegistryEntry entry) {}

	public abstract boolean forwardEventToEmbedded(long embedded, long ctxt,
	int eventID);

	/*
	* Returns true if the XEmbed protocol prescribes that an XEmbed server must
	* support this DnD protocol for drop sites associated with XEmbed clients.
	*/
	public abstract boolean isXEmbedSupported();

	protected static final class EmbedderRegistryEntry {
	private final boolean overriden;
	private final int version;
	private final long proxy;
	EmbedderRegistryEntry(boolean overriden, int version, long proxy) {
	this.overriden = overriden;
	this.version = version;
	this.proxy = proxy;
	}
	public boolean isOverriden() {
	return overriden;
	}
	public int getVersion() {
	return version;
	}
	public long getProxy() {
	return proxy;
	}
	}

	/* Access to HashMap is synchronized on this XDropTargetProtocol instance. */
	private final HashMap embedderRegistry = new HashMap();

	protected final void putEmbedderRegistryEntry(long embedder,
	boolean overriden,
	int version,
	long proxy) {
	synchronized (this) {
	embedderRegistry.put(Long.valueOf(embedder),
	new EmbedderRegistryEntry(overriden, version,
	proxy));
	}
	}

	protected final EmbedderRegistryEntry getEmbedderRegistryEntry(long embedder) {
	synchronized (this) {
	return
	(EmbedderRegistryEntry)embedderRegistry.get(Long.valueOf(embedder));
	}
	}

	protected final void removeEmbedderRegistryEntry(long embedder) {
	synchronized (this) {
	embedderRegistry.remove(Long.valueOf(embedder));
	}
	}
	}