/*
 * Copyright (c) 2009, 2013, 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;

public abstract class XErrorHandler {

    /*
     * Called under AWT lock
     */
    public abstract int handleError(long display, XErrorEvent err);

    /*
     * Forwards all the errors to saved error handler (which was
     * set before XToolkit had been initialized).
     */
    public static class XBaseErrorHandler extends XErrorHandler {
        @Override
        public int handleError(long display, XErrorEvent err) {
            return XErrorHandlerUtil.SAVED_XERROR_HANDLER(display, err);
        }
    }

    /**
     * This is a base synthetic error handler containing a boolean flag which allows
     * to show that an error is handled or not.
     */
    public static class XErrorHandlerWithFlag extends XBaseErrorHandler {
        private volatile boolean errorOccurred = false;

        public boolean getErrorOccurredFlag() {
            return errorOccurred;
        }

        /**
         * Sets an internal boolean flag to a particular value. Should be always called with
         * <code>false</code> value of the parameter <code>errorOccurred</code> before this
         * error handler is set as current.
         * @param errorOccurred <code>true</code> to indicate that an error was handled,
         *     <code>false</code> to reset the internal boolean flag
         */
        public void setErrorOccurredFlag(boolean errorOccurred) {
            this.errorOccurred = errorOccurred;
        }
    }

    /*
     * Instead of validating window id, we simply call XGetWindowProperty,
     * but temporary install this function as the error handler to ignore
     * BadWindow error.
     */
    public static class IgnoreBadWindowHandler extends XBaseErrorHandler {
        @Override
        public int handleError(long display, XErrorEvent err) {
            if (err.get_error_code() == XConstants.BadWindow) {
                return 0;
            }
            return super.handleError(display, err);
        }
        // Shared instance
        private static IgnoreBadWindowHandler theInstance = new IgnoreBadWindowHandler();
        public static IgnoreBadWindowHandler getInstance() {
            return theInstance;
        }
    }

    public static class VerifyChangePropertyHandler extends XBaseErrorHandler {
        @Override
        public int handleError(long display, XErrorEvent err) {
            if (err.get_request_code() == XProtocolConstants.X_ChangeProperty) {
                return 0;
            }
            return super.handleError(display, err);
        }
        // Shared instance
        private static VerifyChangePropertyHandler theInstance = new VerifyChangePropertyHandler();
        public static VerifyChangePropertyHandler getInstance() {
            return theInstance;
        }
    }

    /**
     * This is a synthetic error handler for errors generated by the native function
     * <code>XShmAttach</code>. If an error is handled, an internal boolean flag of the
     * handler is set to <code>true</code>.
     */
    public static final class XShmAttachHandler extends XErrorHandlerWithFlag {
        private XShmAttachHandler() {}

        @Override
        public int handleError(long display, XErrorEvent err) {
            if (err.get_minor_code() == XConstants.X_ShmAttach) {
                setErrorOccurredFlag(true);
                return 0;
            }
            return super.handleError(display, err);
        }

        // Shared instance
        private static XShmAttachHandler theInstance = new XShmAttachHandler();
        public static XShmAttachHandler getInstance() {
            return theInstance;
        }
    }

    /**
     * This is a synthetic error handler for <code>BadAlloc</code> errors generated by the
     * native <code>glX*</code> functions. Its internal boolean flag is set to <code>true</code>,
     * if an error is handled.
     */
    public static final class GLXBadAllocHandler extends XErrorHandlerWithFlag {
        private GLXBadAllocHandler() {}
        
        @Override
        public int handleError(long display, XErrorEvent err) {
            if (err.get_error_code() == XConstants.BadAlloc) {
                setErrorOccurredFlag(true);
                return 0;
            }
            return super.handleError(display, err);
        }

        private static GLXBadAllocHandler theInstance = new GLXBadAllocHandler();
        public static GLXBadAllocHandler getInstance() {
            return theInstance;
        }
    }
}