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 * 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

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package sun.awt.datatransfer;

import java.awt.EventQueue;

import java.awt.datatransfer.Clipboard;

import java.awt.datatransfer.FlavorTable;

import java.awt.datatransfer.SystemFlavorMap;

import java.awt.datatransfer.Transferable;

import java.awt.datatransfer.ClipboardOwner;

import java.awt.datatransfer.DataFlavor;

import java.awt.datatransfer.FlavorListener;

import java.awt.datatransfer.FlavorEvent;

import java.awt.datatransfer.UnsupportedFlavorException;

import java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeListener;

import java.util.Set;

import java.util.HashSet;

import java.io.IOException;

import sun.awt.AppContext;

import sun.awt.PeerEvent;

import sun.awt.SunToolkit;

/**

 * Serves as a common, helper superclass for the Win32 and X11 system

 * Clipboards.

 *

 * @author Danila Sinopalnikov

 * @author Alexander Gerasimov

 *

 * @since 1.3

 */

public abstract class SunClipboard extends Clipboard

    implements PropertyChangeListener {

    private AppContext contentsContext = null;

    private final Object CLIPBOARD_FLAVOR_LISTENER_KEY;

    /**

     * A number of <code>FlavorListener</code>s currently registered

     * on this clipboard across all <code>AppContext</code>s.

     */

    private volatile int numberOfFlavorListeners = 0;

    /**

     */

    public SunClipboard(String name) {

        super(name);

        CLIPBOARD_FLAVOR_LISTENER_KEY = new StringBuffer(name + "_CLIPBOARD_FLAVOR_LISTENER_KEY");

    }

    public synchronized void setContents(Transferable contents,

                                         ClipboardOwner owner) {

        // 4378007 : Toolkit.getSystemClipboard().setContents(null, null)

        // should throw NPE

        if (contents == null) {

            throw new NullPointerException("contents");

        }

        initContext();

        final ClipboardOwner oldOwner = this.owner;

        final Transferable oldContents = this.contents;

        try {

            this.owner = owner;

            this.contents = new TransferableProxy(contents, true);

            setContentsNative(contents);

        } finally {

            if (oldOwner != null && oldOwner != owner) {

                EventQueue.invokeLater(() -> oldOwner.lostOwnership(SunClipboard.this, oldContents));

            }

        }

    }

    private synchronized void initContext() {

        final AppContext context = AppContext.getAppContext();

        if (contentsContext != context) {

            // Need to synchronize on the AppContext to guarantee that it cannot

            // be disposed after the check, but before the listener is added.

            synchronized (context) {

                if (context.isDisposed()) {

                    throw new IllegalStateException("Can't set contents from disposed AppContext");

                }

                context.addPropertyChangeListener

                    (AppContext.DISPOSED_PROPERTY_NAME, this);

            }

            if (contentsContext != null) {

                contentsContext.removePropertyChangeListener

                    (AppContext.DISPOSED_PROPERTY_NAME, this);

            }

            contentsContext = context;

        }

    }

    public synchronized Transferable getContents(Object requestor) {

        if (contents != null) {

            return contents;

        }

        return new ClipboardTransferable(this);

    }

    /**

     * @return the contents of this clipboard if it has been set from the same

     *         AppContext as it is currently retrieved or null otherwise

     * @since 1.5

     */

    private synchronized Transferable getContextContents() {

        AppContext context = AppContext.getAppContext();

        return (context == contentsContext) ? contents : null;

    }

    /**

     * @see java.awt.Clipboard#getAvailableDataFlavors

     * @since 1.5

     */

    public DataFlavor[] getAvailableDataFlavors() {

        Transferable cntnts = getContextContents();

        if (cntnts != null) {

            return cntnts.getTransferDataFlavors();

        }

        long[] formats = getClipboardFormatsOpenClose();

        return DataTransferer.getInstance().

            getFlavorsForFormatsAsArray(formats, getDefaultFlavorTable());

    }

    /**

     * @see java.awt.Clipboard#isDataFlavorAvailable

     * @since 1.5

     */

    public boolean isDataFlavorAvailable(DataFlavor flavor) {

        if (flavor == null) {

            throw new NullPointerException("flavor");

        }

        Transferable cntnts = getContextContents();

        if (cntnts != null) {

            return cntnts.isDataFlavorSupported(flavor);

        }

        long[] formats = getClipboardFormatsOpenClose();

        return formatArrayAsDataFlavorSet(formats).contains(flavor);

    }

    /**

     * @see java.awt.Clipboard#getData

     * @since 1.5

     */

    public Object getData(DataFlavor flavor)

        throws UnsupportedFlavorException, IOException {

        if (flavor == null) {

            throw new NullPointerException("flavor");

        }

        Transferable cntnts = getContextContents();

        if (cntnts != null) {

            return cntnts.getTransferData(flavor);

        }

        long format = 0;

        byte[] data = null;

        Transferable localeTransferable = null;

        try {

            openClipboard(null);

            long[] formats = getClipboardFormats();

            Long lFormat = DataTransferer.getInstance().

                    getFlavorsForFormats(formats, getDefaultFlavorTable()).get(flavor);

            if (lFormat == null) {

                throw new UnsupportedFlavorException(flavor);

            }

            format = lFormat.longValue();

            data = getClipboardData(format);

            if (DataTransferer.getInstance().isLocaleDependentTextFormat(format)) {

                localeTransferable = createLocaleTransferable(formats);

            }

        } finally {

            closeClipboard();

        }

        return DataTransferer.getInstance().

                translateBytes(data, flavor, format, localeTransferable);

    }

    /**

     * The clipboard must be opened.

     *

     * @since 1.5

     */

    protected Transferable createLocaleTransferable(long[] formats) throws IOException {

        return null;

    }

    /**

     * @throws IllegalStateException if the clipboard has not been opened

     */

    public void openClipboard(SunClipboard newOwner) {}

    public void closeClipboard() {}

    public abstract long getID();

    public void propertyChange(PropertyChangeEvent evt) {

        if (AppContext.DISPOSED_PROPERTY_NAME.equals(evt.getPropertyName()) &&

            Boolean.TRUE.equals(evt.getNewValue())) {

            final AppContext disposedContext = (AppContext)evt.getSource();

            lostOwnershipLater(disposedContext);

        }

    }

    protected void lostOwnershipImpl() {

        lostOwnershipLater(null);

    }

    /**

     * Clears the clipboard state (contents, owner and contents context) and

     * notifies the current owner that ownership is lost. Does nothing if the

     * argument is not <code>null</code> and is not equal to the current

     * contents context.

     *

     * @param disposedContext the AppContext that is disposed or

     *        <code>null</code> if the ownership is lost because another

     *        application acquired ownership.

     */

    protected void lostOwnershipLater(final AppContext disposedContext) {

        final AppContext context = this.contentsContext;

        if (context == null) {

            return;

        }

        final Runnable runnable = new Runnable() {

                public void run() {

                    final SunClipboard sunClipboard = SunClipboard.this;

                    ClipboardOwner owner = null;

                    Transferable contents = null;

                    synchronized (sunClipboard) {

                        final AppContext context = sunClipboard.contentsContext;

                        if (context == null) {

                            return;

                        }

                        if (disposedContext == null || context == disposedContext) {

                            owner = sunClipboard.owner;

                            contents = sunClipboard.contents;

                            sunClipboard.contentsContext = null;

                            sunClipboard.owner = null;

                            sunClipboard.contents = null;

                            sunClipboard.clearNativeContext();

                            context.removePropertyChangeListener

                                (AppContext.DISPOSED_PROPERTY_NAME, sunClipboard);

                        } else {

                            return;

                        }

                    }

                    if (owner != null) {

                        owner.lostOwnership(sunClipboard, contents);

                    }

                }

            };

        SunToolkit.postEvent(context, new PeerEvent(this, runnable,

                                                    PeerEvent.PRIORITY_EVENT));

    }

    protected abstract void clearNativeContext();

    protected abstract void setContentsNative(Transferable contents);

    /**

     * @since 1.5

     */

    protected long[] getClipboardFormatsOpenClose() {

        try {

            openClipboard(null);

            return getClipboardFormats();

        } finally {

            closeClipboard();

        }

    }

    /**

     * Returns zero-length array (not null) if the number of available formats is zero.

     *

     * @throws IllegalStateException if formats could not be retrieved

     */

    protected abstract long[] getClipboardFormats();

    protected abstract byte[] getClipboardData(long format) throws IOException;

    private static Set<DataFlavor> formatArrayAsDataFlavorSet(long[] formats) {

        return (formats == null) ? null :

                DataTransferer.getInstance().

                getFlavorsForFormatsAsSet(formats, getDefaultFlavorTable());

    }

    public synchronized void addFlavorListener(FlavorListener listener) {

        if (listener == null) {

            return;

        }

        AppContext appContext = AppContext.getAppContext();

        Set<FlavorListener> flavorListeners = getFlavorListeners(appContext);

        if (flavorListeners == null) {

            flavorListeners = new HashSet<>();

            appContext.put(CLIPBOARD_FLAVOR_LISTENER_KEY, flavorListeners);

        }

        flavorListeners.add(listener);

        if (numberOfFlavorListeners++ == 0) {

            long[] currentFormats = null;

            try {

                openClipboard(null);

                currentFormats = getClipboardFormats();

            } finally {

                closeClipboard();

            }

            registerClipboardViewerChecked();

        }

    }

    public synchronized void removeFlavorListener(FlavorListener listener) {

        if (listener == null) {

            return;

        }

        Set<FlavorListener> flavorListeners = getFlavorListeners(AppContext.getAppContext());

        if (flavorListeners == null){

            //else we throw NullPointerException, but it is forbidden

            return;

        }

        if (flavorListeners.remove(listener) && --numberOfFlavorListeners == 0) {

            unregisterClipboardViewerChecked();

        }

    }

    @SuppressWarnings("unchecked")

    private Set<FlavorListener> getFlavorListeners(AppContext appContext) {

        return (Set<FlavorListener>)appContext.get(CLIPBOARD_FLAVOR_LISTENER_KEY);

    }

    public synchronized FlavorListener[] getFlavorListeners() {

        Set<FlavorListener> flavorListeners = getFlavorListeners(AppContext.getAppContext());

        return flavorListeners == null ? new FlavorListener[0]

                : flavorListeners.toArray(new FlavorListener[flavorListeners.size()]);

    }

    public boolean areFlavorListenersRegistered() {

        return (numberOfFlavorListeners > 0);

    }

    protected abstract void registerClipboardViewerChecked();

    protected abstract void unregisterClipboardViewerChecked();

    /**

     * Checks change of the <code>DataFlavor</code>s and, if necessary,

     * posts notifications on <code>FlavorEvent</code>s to the

     * AppContexts' EDTs.

     * The parameter <code>formats</code> is null iff we have just

     * failed to get formats available on the clipboard.

     *

     * @param formats data formats that have just been retrieved from

     *        this clipboard

     */

            // we've been able to successfully get available on the clipboard

            // DataFlavors this and previous time and they are coincident;

            // don't notify

            return;

        }

            if (appContext == null || appContext.isDisposed()) {

                continue;

            }

            Set<FlavorListener> flavorListeners = getFlavorListeners(appContext);

            if (flavorListeners != null) {

                for (FlavorListener listener : flavorListeners) {

                    if (listener != null) {

                        PeerEvent peerEvent = new PeerEvent(this,

                                () -> listener.flavorsChanged(new FlavorEvent(SunClipboard.this)),

                                PeerEvent.PRIORITY_EVENT);

                        SunToolkit.postEvent(appContext, peerEvent);

                    }

                }

            }

        }

    }

    public static FlavorTable getDefaultFlavorTable() {

        return (FlavorTable) SystemFlavorMap.getDefaultFlavorMap();

    }

}