/* ImageConsumer.java -- Java interface for image consumption
   Copyright (C) 1999, 2003 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
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permission to link this library with independent modules to produce an
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package java.awt.image;

import java.util.Hashtable;

/**
 * An object implementing the <code>ImageProducer</code> interface can
 * use objects implementing this interface to deliver the image data.
 * 
 * @author C. Brian Jones (cbj@gnu.org)
 */
public interface ImageConsumer
{
    /**
     * The pixel order may be random.  This should be
     * the default assumption of the <code>ImageConsumer</code>.
     *
     * @see #setHints 
     */
    int RANDOMPIXELORDER = 1;

    /**
     * The pixel order is top-down, left-right.
     *
     * @see #setHints
     */
    int TOPDOWNLEFTRIGHT = 2;

    /**
     * The pixel order is in multiples of complete scanlines.
     *
     * @see #setHints
     */
    int COMPLETESCANLINES = 4;

    /**
     * The pixels will be delivered in a single pass.  There is at
     * most one call to <code>setPixels</code> for any single pixel.
     *
     * @see #setHints
     * @see #setPixels 
     */
    int SINGLEPASS = 8;

    /**
     * The pixels will be delivered with multiple calls to
     * <code>setPixels</code>.  The image contains a single frame
     * which ends when <code>imageComplete</code> is called with the
     * <code>STATICIMAGEDONE</code> flag.  If the image is constantly
     * changing such as with video then the end of each frame is
     * marked by a similar call to <code>imageComplete</code> with the
     * <code>SINGLEFRAMEDONE</code> flag.
     * 
     * @see #setHints
     * @see #imageComplete 
     */
    int SINGLEFRAME = 16;

    /**
     * Indicates an error occurred while producing an image.
     *
     * @see #imageComplete
     */
    int IMAGEERROR = 1;

    /**
     * A single frame is complete but more will follow.
     * 
     * @see #imageComplete
     */
    int SINGLEFRAMEDONE = 2;

    /**
     * The image is complete and no more pixels or frames will follow.
     *
     * @see #imageComplete
     */
    int STATICIMAGEDONE = 3;

    /**
     * Production of the image has been aborted.
     *
     * @see #imageComplete
     */
    int IMAGEABORTED = 4;

    /**
     * An <code>ImageProducer</code> indicates the size of the image
     * being produced using this method.
     * 
     * @param width the width of the image
     * @param height the height of the image 
     */
    void setDimensions(int width, int height);

    /**
     * An <code>ImageProducer</code> can set a list of properties
     * associated with this image by using this method.
     *
     * @param props the list of properties associated with this image 
     */
    void setProperties(Hashtable props);

    /**
     * This <code>ColorModel</code> should indicate the model used by
     * the majority of calls to <code>setPixels</code>.  Each call to
     * <code>setPixels</code> could however indicate a different
     * <code>ColorModel</code>.
     *
     * @param model the color model to be used most often by setPixels
     * @see ColorModel 
     */
    void setColorModel(ColorModel model);

    /**
     * The <code>ImageProducer</code> should call this method with a
     * bit mask of hints from any of <code>RANDOMPIXELORDER</code>,
     * <code>TOPDOWNLEFTRIGHT</code>, <code>COMPLETESCANLINES</code>,
     * <code>SINGLEPASS</code>, <code>SINGLEFRAME</code>.
     * 
     * @param flags a bit mask of hints
     */
    void setHints(int flags);

    /**
     * Deliver a subset of an ImageProducer's pixels to this ImageConsumer.
     *
     * Each element of the pixels array represents one pixel.  The
     * pixel data is formatted according to the color model model.
     * The x and y parameters are the coordinates of the block of
     * pixels being delivered to this ImageConsumer.  They are
     * specified relative to the top left corner of the image being
     * produced.  Likewise, w and h are the pixel block's dimensions.
     *
     * @param x x coordinate of pixel block
     * @param y y coordinate of pixel block
     * @param w width of pixel block
     * @param h height of pixel block
     * @param model color model used to interpret pixel data
     * @param pixels pixel block data
     * @param offset offset into pixels array
     * @param scansize width of one row in the pixel block
     */
    void setPixels(int x, int y, int w, int h, 
	   ColorModel model, byte[] pixels, int offset, int scansize);

    /**
     * Deliver a subset of an ImageProducer's pixels to this ImageConsumer.
     *
     * Each element of the pixels array represents one pixel.  The
     * pixel data is formatted according to the color model model.
     * The x and y parameters are the coordinates of the rectangular
     * region of pixels being delivered to this ImageConsumer,
     * specified relative to the top left corner of the image being
     * produced.  Likewise, w and h are the pixel region's dimensions.
     *
     * @param x x coordinate of pixel block
     * @param y y coordinate of pixel block
     * @param w width of pixel block
     * @param h height of pixel block
     * @param model color model used to interpret pixel data
     * @param pixels pixel block data
     * @param offset offset into pixels array
     * @param scansize width of one row in the pixel block
     */
    void setPixels(int x, int y, int w, int h, 
           ColorModel model, int[] pixels, int offset, int scansize);

    /**
     * The <code>ImageProducer</code> calls this method to indicate a
     * single frame or the entire image is complete.  The method is
     * also used to indicate an error in loading or producing the
     * image.  
     *
     * @param status the status of image production, represented by a
     * bitwise OR of ImageConsumer flags
     */
    void imageComplete(int status);
}