/*

 * Copyright 2000-2007 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.dnd;

import java.awt.Component;

import java.awt.Point;

import java.awt.datatransfer.DataFlavor;

import java.awt.datatransfer.Transferable;

import java.awt.datatransfer.UnsupportedFlavorException;

import java.awt.dnd.DnDConstants;

import java.awt.dnd.DropTarget;

import java.awt.dnd.DropTargetContext;

import java.awt.dnd.DropTargetListener;

import java.awt.dnd.DropTargetEvent;

import java.awt.dnd.DropTargetDragEvent;

import java.awt.dnd.DropTargetDropEvent;

import java.awt.dnd.InvalidDnDOperationException;

import java.awt.dnd.peer.DropTargetContextPeer;

import java.util.HashSet;

import java.util.Map;

import java.util.Arrays;

import java.io.IOException;

import java.io.InputStream;

import sun.awt.AppContext;

import sun.awt.SunToolkit;

import sun.awt.datatransfer.DataTransferer;

import sun.awt.datatransfer.ToolkitThreadBlockedHandler;

/**

 * <p>

 * The SunDropTargetContextPeer class is the generic class responsible for handling

 * the interaction between a windowing systems DnD system and Java.

 * </p>

 *

 * @since JDK1.3.1

 *

 */

public abstract class SunDropTargetContextPeer implements DropTargetContextPeer, Transferable {

    /*

     * A boolean constant that requires the peer to wait until the

     * SunDropTargetEvent is processed and return the status back

     * to the native code.

     */

    public static final boolean DISPATCH_SYNC = true;

    private   DropTarget              currentDT;

    private   DropTargetContext       currentDTC;

    private   long[]                  currentT;

    private   int                     currentA;   // target actions

    private   int                     currentSA;  // source actions

    private   int                     currentDA;  // current drop action

    private   int                     previousDA;

    private   long                    nativeDragContext;

    private   Transferable            local;

    private boolean                   dragRejected = false;

    protected int                     dropStatus   = STATUS_NONE;

    protected boolean                 dropComplete = false;

    /*

     * global lock

     */

    protected static final Object _globalLock = new Object();

    /*

     * a primitive mechanism for advertising intra-JVM Transferables

     */

    protected static Transferable         currentJVMLocalSourceTransferable = null;

    public static void setCurrentJVMLocalSourceTransferable(Transferable t) throws InvalidDnDOperationException {

        synchronized(_globalLock) {

            if (t != null && currentJVMLocalSourceTransferable != null) {

                    throw new InvalidDnDOperationException();

            } else {

                currentJVMLocalSourceTransferable = t;

            }

        }

    }

    /**

     * obtain the transferable iff the operation is in the same VM

     */

    private static Transferable getJVMLocalSourceTransferable() {

        return currentJVMLocalSourceTransferable;

    }

    /*

     * constants used by dropAccept() or dropReject()

     */

    protected final static int STATUS_NONE   =  0; // none pending

    protected final static int STATUS_WAIT   =  1; // drop pending

    protected final static int STATUS_ACCEPT =  2;

    protected final static int STATUS_REJECT = -1;

    /**

     * create the peer

     */

    public SunDropTargetContextPeer() {

        super();

    }

    /**

     * @return the DropTarget associated with this peer

     */

    public DropTarget getDropTarget() { return currentDT; }

    /**

     * @param actions set the current actions

     */

    public synchronized void setTargetActions(int actions) {

        currentA = actions &

            (DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK);

    }

    /**

     * @return the current target actions

     */

    public int getTargetActions() {

        return currentA;

    }

    /**

     * get the Transferable associated with the drop

     */

    public Transferable getTransferable() {

        return this;

    }

    /**

     * @return current DataFlavors available

     */

    // NOTE: This method may be called by privileged threads.

    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!

    public DataFlavor[] getTransferDataFlavors() {

        final Transferable    localTransferable = local;

        if (localTransferable != null) {

            return localTransferable.getTransferDataFlavors();

        } else {

            return DataTransferer.getInstance().getFlavorsForFormatsAsArray

                (currentT, DataTransferer.adaptFlavorMap

                    (currentDT.getFlavorMap()));

        }

    }

    /**

     * @return if the flavor is supported

     */

    public boolean isDataFlavorSupported(DataFlavor df) {

        Transferable localTransferable = local;

        if (localTransferable != null) {

            return localTransferable.isDataFlavorSupported(df);

        } else {

            return DataTransferer.getInstance().getFlavorsForFormats

                (currentT, DataTransferer.adaptFlavorMap

                    (currentDT.getFlavorMap())).

                containsKey(df);

        }

    }

    /**

     * @return the data

     */

    public Object getTransferData(DataFlavor df)

      throws UnsupportedFlavorException, IOException,

        InvalidDnDOperationException

    {

        Long lFormat = null;

        Transferable localTransferable = local;

        if (localTransferable != null) {

            return localTransferable.getTransferData(df);

        }

        if (dropStatus != STATUS_ACCEPT || dropComplete) {

            throw new InvalidDnDOperationException("No drop current");

        }

        Map flavorMap = DataTransferer.getInstance().getFlavorsForFormats

            (currentT, DataTransferer.adaptFlavorMap

                (currentDT.getFlavorMap()));

        lFormat = (Long)flavorMap.get(df);

        if (lFormat == null) {

            throw new UnsupportedFlavorException(df);

        }

        if (df.isRepresentationClassRemote() &&

            currentDA != DnDConstants.ACTION_LINK) {

            throw new InvalidDnDOperationException("only ACTION_LINK is permissable for transfer of java.rmi.Remote objects");

        }

        final long format = lFormat.longValue();

        Object ret = getNativeData(format);

        if (ret instanceof byte[]) {

            try {

                return DataTransferer.getInstance().

                    translateBytes((byte[])ret, df, format, this);

            } catch (IOException e) {

                throw new InvalidDnDOperationException(e.getMessage());

            }

        } else if (ret instanceof InputStream) {

            try {

                return DataTransferer.getInstance().

                    translateStream((InputStream)ret, df, format, this);

            } catch (IOException e) {

                throw new InvalidDnDOperationException(e.getMessage());

            }

        } else {

            throw new IOException("no native data was transfered");

        }

    }

    protected abstract Object getNativeData(long format)

      throws IOException;

    /**

     * @return if the transfer is a local one

     */

    public boolean isTransferableJVMLocal() {

        return local != null || getJVMLocalSourceTransferable() != null;

    }

    private int handleEnterMessage(final Component component,

                                   final int x, final int y,

                                   final int dropAction,

                                   final int actions, final long[] formats,

                                   final long nativeCtxt) {

        return postDropTargetEvent(component, x, y, dropAction, actions,

                                   formats, nativeCtxt,

                                   SunDropTargetEvent.MOUSE_ENTERED,

                                   SunDropTargetContextPeer.DISPATCH_SYNC);

    }

    /**

     * actual processing on EventQueue Thread

     */

    protected void processEnterMessage(SunDropTargetEvent event) {

        Component  c    = (Component)event.getSource();

        DropTarget dt   = c.getDropTarget();

        Point      hots = event.getPoint();

        local = getJVMLocalSourceTransferable();

        if (currentDTC != null) { // some wreckage from last time

            currentDTC.removeNotify();

            currentDTC = null;

        }

        if (c.isShowing() && dt != null && dt.isActive()) {

            currentDT  = dt;

            currentDTC = currentDT.getDropTargetContext();

            currentDTC.addNotify(this);

            currentA   = dt.getDefaultActions();

            try {

                ((DropTargetListener)dt).dragEnter(new DropTargetDragEvent(currentDTC,

                                                                           hots,

                                                                           currentDA,

                                                                           currentSA));

            } catch (Exception e) {

                e.printStackTrace();

                currentDA = DnDConstants.ACTION_NONE;

            }

        } else {

            currentDT  = null;

            currentDTC = null;

            currentDA   = DnDConstants.ACTION_NONE;

            currentSA   = DnDConstants.ACTION_NONE;

            currentA   = DnDConstants.ACTION_NONE;

        }

    }

    /**

     * upcall to handle exit messages

     */

    private void handleExitMessage(final Component component,

                                   final long nativeCtxt) {

        /*

         * Even though the return value is irrelevant for this event, it is

         * dispatched synchronously to fix 4393148 properly.

         */

        postDropTargetEvent(component, 0, 0, DnDConstants.ACTION_NONE,

                            DnDConstants.ACTION_NONE, null, nativeCtxt,

                            SunDropTargetEvent.MOUSE_EXITED,

                            SunDropTargetContextPeer.DISPATCH_SYNC);

    }

    /**

     *

     */

    protected void processExitMessage(SunDropTargetEvent event) {

        Component         c   = (Component)event.getSource();

        DropTarget        dt  = c.getDropTarget();

        DropTargetContext dtc = null;

        if (dt == null) {

            currentDT = null;

            currentT  = null;

            if (currentDTC != null) {

                currentDTC.removeNotify();

            }

            currentDTC = null;

            return;

        }

        if (dt != currentDT) {

            if (currentDTC != null) {

                currentDTC.removeNotify();

            }

            currentDT  = dt;

            currentDTC = dt.getDropTargetContext();

            currentDTC.addNotify(this);

        }

        dtc = currentDTC;

        if (dt.isActive()) try {

            ((DropTargetListener)dt).dragExit(new DropTargetEvent(dtc));

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            currentA  = DnDConstants.ACTION_NONE;

            currentSA = DnDConstants.ACTION_NONE;

            currentDA = DnDConstants.ACTION_NONE;

            currentDT = null;

            currentT  = null;

            currentDTC.removeNotify();

            currentDTC = null;

            local = null;

            dragRejected = false;

        }

    }

    private int handleMotionMessage(final Component component,

                                    final int x, final int y,

                                    final int dropAction,

                                    final int actions, final long[] formats,

                                    final long nativeCtxt) {

        return postDropTargetEvent(component, x, y, dropAction, actions,

                                   formats, nativeCtxt,

                                   SunDropTargetEvent.MOUSE_DRAGGED,

                                   SunDropTargetContextPeer.DISPATCH_SYNC);

    }

    /**

     *

     */

    protected void processMotionMessage(SunDropTargetEvent event,

                                      boolean operationChanged) {

        Component         c    = (Component)event.getSource();

        Point             hots = event.getPoint();

        int               id   = event.getID();

        DropTarget        dt   = c.getDropTarget();

        DropTargetContext dtc  = null;

        if (c.isShowing() && (dt != null) && dt.isActive()) {

            if (currentDT != dt) {

                if (currentDTC != null) {

                    currentDTC.removeNotify();

                }

                currentDT  = dt;

                currentDTC = null;

            }

            dtc = currentDT.getDropTargetContext();

            if (dtc != currentDTC) {

                if (currentDTC != null) {

                    currentDTC.removeNotify();

                }

                currentDTC = dtc;

                currentDTC.addNotify(this);

            }

            currentA = currentDT.getDefaultActions();

            try {

                DropTargetDragEvent dtde = new DropTargetDragEvent(dtc,

                                                                   hots,

                                                                   currentDA,

                                                                   currentSA);

                DropTargetListener dtl = (DropTargetListener)dt;

                if (operationChanged) {

                    dtl.dropActionChanged(dtde);

                } else {

                    dtl.dragOver(dtde);

                }

                if (dragRejected) {

                    currentDA = DnDConstants.ACTION_NONE;

                }

            } catch (Exception e) {

                e.printStackTrace();

                currentDA = DnDConstants.ACTION_NONE;

            }

        } else {

            currentDA = DnDConstants.ACTION_NONE;

        }

    }

    /**

     * upcall to handle the Drop message

     */

    private void handleDropMessage(final Component component,

                                   final int x, final int y,

                                   final int dropAction, final int actions,

                                   final long[] formats,

                                   final long nativeCtxt) {

        postDropTargetEvent(component, x, y, dropAction, actions,

                            formats, nativeCtxt,

                            SunDropTargetEvent.MOUSE_DROPPED,

                            !SunDropTargetContextPeer.DISPATCH_SYNC);

    }

    /**

     *

     */

    protected void processDropMessage(SunDropTargetEvent event) {

        Component  c    = (Component)event.getSource();

        Point      hots = event.getPoint();

        DropTarget dt   = c.getDropTarget();

        dropStatus   = STATUS_WAIT; // drop pending ACK

        dropComplete = false;

        if (c.isShowing() && dt != null && dt.isActive()) {

            DropTargetContext dtc = dt.getDropTargetContext();

            currentDT = dt;

            if (currentDTC != null) {

                currentDTC.removeNotify();

            }

            currentDTC = dtc;

            currentDTC.addNotify(this);

            currentA = dt.getDefaultActions();

            synchronized(_globalLock) {

                if ((local = getJVMLocalSourceTransferable()) != null)

                    setCurrentJVMLocalSourceTransferable(null);

            }

            try {

                ((DropTargetListener)dt).drop(new DropTargetDropEvent(dtc,

                                                                      hots,

                                                                      currentDA,

                                                                      currentSA,

                                                                      local != null));

            } finally {

                if (dropStatus == STATUS_WAIT) {

                    rejectDrop();

                } else if (dropComplete == false) {

                    dropComplete(false);

                }

            }