/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id$ */

package org.apache.xmlgraphics.image.codec.util;

import java.awt.image.ColorModel;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.io.IOException;
import java.io.OutputStream;

/**
 * A partial implementation of the ImageEncoder interface useful for
 * subclassing.
 *
 * <p><b> This class is not a committed part of the JAI API.  It may
 * be removed or changed in future releases of JAI.</b>
 */
public abstract class ImageEncoderImpl implements ImageEncoder {
    
    /** The OutputStream associcted with this ImageEncoder. */
    protected OutputStream output;

    /** The ImageEncodeParam object associcted with this ImageEncoder. */
    protected ImageEncodeParam param;

    /**
     * Constructs an ImageEncoderImpl with a given OutputStream
     * and ImageEncoderParam instance.
     */
    public ImageEncoderImpl(OutputStream output,
                            ImageEncodeParam param) {
        this.output = output;
        this.param = param;
    }

    /**
     * Returns the current parameters as an instance of the
     * ImageEncodeParam interface.  Concrete implementations of this
     * interface will return corresponding concrete implementations of
     * the ImageEncodeParam interface.  For example, a JPEGImageEncoder
     * will return an instance of JPEGEncodeParam.
     */
    public ImageEncodeParam getParam() {
        return param;
    }

    /**
     * Sets the current parameters to an instance of the 
     * ImageEncodeParam interface.  Concrete implementations
     * of ImageEncoder may throw a RuntimeException if the
     * params argument is not an instance of the appropriate
     * subclass or subinterface.  For example, a JPEGImageEncoder
     * will expect param to be an instance of JPEGEncodeParam.
     */
    public void setParam(ImageEncodeParam param) {
        this.param = param;
    }

    /** Returns the OutputStream associated with this ImageEncoder. */
    public OutputStream getOutputStream() {
        return output;
    }
    
    /**
     * Encodes a Raster with a given ColorModel and writes the output
     * to the OutputStream associated with this ImageEncoder.
     */
    public void encode(Raster ras, ColorModel cm) throws IOException {
        RenderedImage im = new SingleTileRenderedImage(ras, cm);
        encode(im);
    }

    /**
     * Encodes a RenderedImage and writes the output to the
     * OutputStream associated with this ImageEncoder.
     */
    public abstract void encode(RenderedImage im) throws IOException;
}