/*

 * Copyright 2003-2004 Sun Microsystems, Inc.  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.  Sun designates this

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

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

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

 * have any questions.

 */

package sun.awt.X11;

import java.awt.Component;

import java.awt.peer.ComponentPeer;

import java.io.IOException;

import java.util.Iterator;

import sun.awt.AppContext;

import sun.awt.SunToolkit;

import sun.awt.dnd.SunDropTargetContextPeer;

import sun.awt.dnd.SunDropTargetEvent;

import sun.misc.Unsafe;

/**

 * The XDropTargetContextPeer is the class responsible for handling

 * the interaction between the XDnD/Motif DnD subsystem and Java drop targets.

 *

 * @since 1.5

 */

final class XDropTargetContextPeer extends SunDropTargetContextPeer {

    private static final Unsafe unsafe = XlibWrapper.unsafe;

    /*

     * A key to store a peer instance for an AppContext.

     */

    private static final Object DTCP_KEY = "DropTargetContextPeer";

    private XDropTargetContextPeer() {}

    static XDropTargetContextPeer getPeer(AppContext appContext) {

        synchronized (_globalLock) {

            XDropTargetContextPeer peer =

                (XDropTargetContextPeer)appContext.get(DTCP_KEY);

            if (peer == null) {

                peer = new XDropTargetContextPeer();

                appContext.put(DTCP_KEY, peer);

            }

            return peer;

        }

    }

    static XDropTargetProtocolListener getXDropTargetProtocolListener() {

        return XDropTargetProtocolListenerImpl.getInstance();

    }

    /*

     * @param returnValue the drop action selected by the Java drop target.

     */

    protected void eventProcessed(SunDropTargetEvent e, int returnValue,

                                  boolean dispatcherDone) {

        /* The native context is the pointer to the XClientMessageEvent

           structure. */

        long ctxt = getNativeDragContext();

        /* If the event was not consumed, send a response to the source. */

        try {

            if (ctxt != 0 && !e.isConsumed()) {

                Iterator dropTargetProtocols =

                    XDragAndDropProtocols.getDropTargetProtocols();

                while (dropTargetProtocols.hasNext()) {

                    XDropTargetProtocol dropTargetProtocol =

                        (XDropTargetProtocol)dropTargetProtocols.next();

                    if (dropTargetProtocol.sendResponse(ctxt, e.getID(),

                                                        returnValue)) {

                        break;

                    }

                }

            }

        } finally {

            if (dispatcherDone && ctxt != 0) {

                unsafe.freeMemory(ctxt);

            }

        }

    }

    protected void doDropDone(boolean success, int dropAction,

                              boolean isLocal) {

        /* The native context is the pointer to the XClientMessageEvent

           structure. */

        long ctxt = getNativeDragContext();

        if (ctxt != 0) {

            try {

                Iterator dropTargetProtocols =

                    XDragAndDropProtocols.getDropTargetProtocols();

                while (dropTargetProtocols.hasNext()) {

                    XDropTargetProtocol dropTargetProtocol =

                        (XDropTargetProtocol)dropTargetProtocols.next();

                    if (dropTargetProtocol.sendDropDone(ctxt, success,

                                                        dropAction)) {

                        break;

                    }

                }

            } finally {

                unsafe.freeMemory(ctxt);

            }

        }

    }

    protected Object getNativeData(long format)

      throws IOException {

        /* The native context is the pointer to the XClientMessageEvent

           structure. */

        long ctxt = getNativeDragContext();

        if (ctxt != 0) {

            Iterator dropTargetProtocols =

                XDragAndDropProtocols.getDropTargetProtocols();

            while (dropTargetProtocols.hasNext()) {

                XDropTargetProtocol dropTargetProtocol =

                    (XDropTargetProtocol)dropTargetProtocols.next();

                // getData throws IAE if ctxt is not for this protocol.

                try {

                    return dropTargetProtocol.getData(ctxt, format);

                } catch (IllegalArgumentException iae) {

                }

            }

        }

        return null;

    }

    private void cleanup() {

    }

    protected void processEnterMessage(SunDropTargetEvent event) {

        if (!processSunDropTargetEvent(event)) {

            super.processEnterMessage(event);

        }

    }

    protected void processExitMessage(SunDropTargetEvent event) {

        if (!processSunDropTargetEvent(event)) {

            super.processExitMessage(event);

        }

    }

    protected void processMotionMessage(SunDropTargetEvent event,

                                        boolean operationChanged) {

        if (!processSunDropTargetEvent(event)) {

            super.processMotionMessage(event, operationChanged);

        }

    }

    protected void processDropMessage(SunDropTargetEvent event) {

        if (!processSunDropTargetEvent(event)) {

            super.processDropMessage(event);

        }

    }

    // If source is an XEmbedCanvasPeer, passes the event to it for processing and

    // return true if the event is forwarded to the XEmbed child.

    // Otherwise, does nothing and return false.

    private boolean processSunDropTargetEvent(SunDropTargetEvent event) {

        Object source = event.getSource();

        if (source instanceof Component) {

            ComponentPeer peer = ((Component)source).getPeer();

            if (peer instanceof XEmbedCanvasPeer) {

                XEmbedCanvasPeer xEmbedCanvasPeer = (XEmbedCanvasPeer)peer;

                /* The native context is the pointer to the XClientMessageEvent

                   structure. */

                long ctxt = getNativeDragContext();

                    logger.finer("        processing " + event + " ctxt=" + ctxt +

                                 " consumed=" + event.isConsumed());

                }

                /* If the event is not consumed, pass it to the

                   XEmbedCanvasPeer for processing. */

                if (!event.isConsumed()) {

                    // NOTE: ctxt can be zero at this point.

                    if (xEmbedCanvasPeer.processXEmbedDnDEvent(ctxt,

                                                               event.getID())) {

                        event.consume();

                        return true;

                    }

                }

            }

        }

        return false;

    }

    public void forwardEventToEmbedded(long embedded, long ctxt,

                                       int eventID) {

        Iterator dropTargetProtocols =

            XDragAndDropProtocols.getDropTargetProtocols();

        while (dropTargetProtocols.hasNext()) {

            XDropTargetProtocol dropTargetProtocol =

                (XDropTargetProtocol)dropTargetProtocols.next();

            if (dropTargetProtocol.forwardEventToEmbedded(embedded, ctxt,

                                                          eventID)) {

                break;

            }

        }

    }

    static final class XDropTargetProtocolListenerImpl

        implements XDropTargetProtocolListener {

        private final static XDropTargetProtocolListener theInstance =

            new XDropTargetProtocolListenerImpl();

        private XDropTargetProtocolListenerImpl() {}

        static XDropTargetProtocolListener getInstance() {

            return theInstance;

        }

        public void handleDropTargetNotification(XWindow xwindow, int x, int y,

                                                 int dropAction, int actions,

                                                 long[] formats, long nativeCtxt,

                                                 int eventID) {

            Object target = xwindow.getTarget();

            // The Every component is associated with some AppContext.

            assert target instanceof Component;

            Component component = (Component)target;

            AppContext appContext = SunToolkit.targetToAppContext(target);

            // Every component is associated with some AppContext.

            assert appContext != null;

            XDropTargetContextPeer peer = XDropTargetContextPeer.getPeer(appContext);

            peer.postDropTargetEvent(component, x, y, dropAction, actions, formats,

                                     nativeCtxt, eventID,

                                     !SunDropTargetContextPeer.DISPATCH_SYNC);

        }

    }

}