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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

 *

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package java.awt.image;

/**

 * The interface for objects which can produce the image data for Images.

 * Each image contains an ImageProducer which is used to reconstruct

 * the image whenever it is needed, for example, when a new size of the

 * Image is scaled, or when the width or height of the Image is being

 * requested.

 *

 * @see ImageConsumer

 *

 * @author      Jim Graham

 */

public interface ImageProducer {

    /**

     * Registers an <code>ImageConsumer</code> with the

     * <code>ImageProducer</code> for access to the image data

     * during a later reconstruction of the <code>Image</code>.

     * The <code>ImageProducer</code> may, at its discretion,

     * start delivering the image data to the consumer

     * using the <code>ImageConsumer</code> interface immediately,

     * or when the next available image reconstruction is triggered

     * by a call to the <code>startProduction</code> method.

     * @param ic the specified <code>ImageConsumer</code>

     * @see #startProduction

     */

    public void addConsumer(ImageConsumer ic);

    /**

     * Determines if a specified <code>ImageConsumer</code>

     * object is currently registered with this

     * <code>ImageProducer</code> as one of its consumers.

     * @param ic the specified <code>ImageConsumer</code>

     * @return <code>true</code> if the specified

     *         <code>ImageConsumer</code> is registered with

     *         this <code>ImageProducer</code>;

     *         <code>false</code> otherwise.

     */

    public boolean isConsumer(ImageConsumer ic);

    /**

     * Removes the specified <code>ImageConsumer</code> object

     * from the list of consumers currently registered to

     * receive image data.  It is not considered an error

     * to remove a consumer that is not currently registered.

     * The <code>ImageProducer</code> should stop sending data

     * to this consumer as soon as is feasible.

     * @param ic the specified <code>ImageConsumer</code>

     */

    public void removeConsumer(ImageConsumer ic);

    /**

     * Registers the specified <code>ImageConsumer</code> object

     * as a consumer and starts an immediate reconstruction of

     * the image data which will then be delivered to this

     * consumer and any other consumer which might have already

     * been registered with the producer.  This method differs

     * from the addConsumer method in that a reproduction of

     * the image data should be triggered as soon as possible.

     * @param ic the specified <code>ImageConsumer</code>

     * @see #addConsumer

     */

    public void startProduction(ImageConsumer ic);

    /**

     * Requests, on behalf of the <code>ImageConsumer</code>,

     * that the <code>ImageProducer</code> attempt to resend

     * the image data one more time in TOPDOWNLEFTRIGHT order

     * so that higher quality conversion algorithms which

     * depend on receiving pixels in order can be used to

     * produce a better output version of the image.  The

     * <code>ImageProducer</code> is free to

     * ignore this call if it cannot resend the data in that

     * order.  If the data can be resent, the

     * <code>ImageProducer</code> should respond by executing

     * the following minimum set of <code>ImageConsumer</code>

     * method calls:

     * <pre>{@code

     *  ic.setHints(TOPDOWNLEFTRIGHT | < otherhints >);

     *  ic.setPixels(...);      // As many times as needed

     *  ic.imageComplete();

     * }</pre>

     * @param ic the specified <code>ImageConsumer</code>

     * @see ImageConsumer#setHints

     */

    public void requestTopDownLeftRightResend(ImageConsumer ic);

}