/*

 * Copyright 2003-2008 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.util.*;

class XProtocol {

    private Map<XAtom, XAtomList> atomToList = new HashMap<XAtom, XAtomList>();

    private Map<XAtom, Long> atomToAnchor = new HashMap<XAtom, Long>();

    volatile boolean firstCheck = true;

    /*

     * Check that that the list of protocols specified by WM in property

     * named LIST_NAME on the root window contains protocol PROTO.

     */

    boolean checkProtocol(XAtom listName, XAtom protocol) {

        XAtomList protocols = atomToList.get(listName);

        if (protocols != null) {

            return protocols.contains(protocol);

        }

        protocols = listName.getAtomListPropertyList(XToolkit.getDefaultRootWindow());

        atomToList.put(listName, protocols);

        try {

            return protocols.contains(protocol);

        } finally {

            if (firstCheck) {

                firstCheck = false;

            }

        }

    }

    /*

     * Check for anchor_prop(anchor_type) on root, take the value as the

     * window id and check if that window exists and has anchor_prop(anchor_type)

     * with the same value (i.e. pointing back to self).

     *

     * Returns the anchor window, as some WM may put interesting stuff in

     * its properties (e.g. sawfish).

     */

    long checkAnchorImpl(XAtom anchorProp, long anchorType) {

        long root_xref, self_xref;

        XToolkit.awtLock();

        try {

            root_xref = anchorProp.get32Property(XToolkit.getDefaultRootWindow(),

                                                 anchorType);

        } finally {

            XToolkit.awtUnlock();

        }

        if (root_xref == 0) {

            return 0;

        }

        self_xref = anchorProp.get32Property(root_xref, anchorType);

        if (self_xref != root_xref) {

            return 0;

        }

        return self_xref;

    }

    public long checkAnchor(XAtom anchorProp, long anchorType) {

        Long val = atomToAnchor.get(anchorProp);

        if (val != null) {

            return val.longValue();

        }

        long res = checkAnchorImpl(anchorProp, anchorType);

        atomToAnchor.put(anchorProp, res);

        return res;

    }

    public long checkAnchor(XAtom anchorProp, XAtom anchorType) {

        return checkAnchor(anchorProp, anchorType.getAtom());

    }

}