/*

 * Copyright 1995-2003 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.image;

import java.util.Hashtable;

import java.io.InputStream;

import java.io.IOException;

import java.awt.image.*;

public abstract class ImageDecoder {

    InputStreamImageSource source;

    InputStream input;

    Thread feeder;

    protected boolean aborted;

    protected boolean finished;

    ImageConsumerQueue queue;

    ImageDecoder next;

    public ImageDecoder(InputStreamImageSource src, InputStream is) {

        source = src;

        input = is;

        feeder = Thread.currentThread();

    }

    public boolean isConsumer(ImageConsumer ic) {

        return ImageConsumerQueue.isConsumer(queue, ic);

    }

    public void removeConsumer(ImageConsumer ic) {

        queue = ImageConsumerQueue.removeConsumer(queue, ic, false);

        if (!finished && queue == null) {

            abort();

        }

    }

    protected ImageConsumerQueue nextConsumer(ImageConsumerQueue cq) {

        synchronized (source) {

            if (aborted) {

                return null;

            }

            cq = ((cq == null) ? queue : cq.next);

            while (cq != null) {

                if (cq.interested) {

                    return cq;

                }

                cq = cq.next;

            }

        }

        return null;

    }

    protected int setDimensions(int w, int h) {

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setDimensions(w, h);

            count++;

        }

        return count;

    }

    protected int setProperties(Hashtable props) {

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setProperties(props);

            count++;

        }

        return count;

    }

    protected int setColorModel(ColorModel model) {

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setColorModel(model);

            count++;

        }

        return count;

    }

    protected int setHints(int hints) {

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setHints(hints);

            count++;

        }

        return count;

    }

    protected void headerComplete() {

        feeder.setPriority(ImageFetcher.LOW_PRIORITY);

    }

    protected int setPixels(int x, int y, int w, int h, ColorModel model,

                            byte pix[], int off, int scansize) {

        source.latchConsumers(this);

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setPixels(x, y, w, h, model, pix, off, scansize);

            count++;

        }

        return count;

    }

    protected int setPixels(int x, int y, int w, int h, ColorModel model,

                            int pix[], int off, int scansize) {

        source.latchConsumers(this);

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.setPixels(x, y, w, h, model, pix, off, scansize);

            count++;

        }

        return count;

    }

    protected int imageComplete(int status, boolean done) {

        source.latchConsumers(this);

        if (done) {

            finished = true;

            source.doneDecoding(this);

        }

        ImageConsumerQueue cq = null;

        int count = 0;

        while ((cq = nextConsumer(cq)) != null) {

            cq.consumer.imageComplete(status);

            count++;

        }

        return count;

    }

    public abstract void produceImage() throws IOException,

                                               ImageFormatException;

    public void abort() {

        aborted = true;

        source.doneDecoding(this);

        close();

        java.security.AccessController.doPrivileged(

            new java.security.PrivilegedAction() {

            public Object run() {

                feeder.interrupt();

                return null;

            }

        });

    }

    public synchronized void close() {

        if (input != null) {

            try {

                input.close();

            } catch (IOException e) {

            }

        }

    }

}