Java example source code file (ImageProducer.java)

This example Java source code file (ImageProducer.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

imageproducer

The ImageProducer.java Java example source code

/*
 * Copyright (c) 1995, 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 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 with the
     * <code>ImageProducer for access to the image data
     * during a later reconstruction of the <code>Image.
     * The <code>ImageProducer may, at its discretion,
     * start delivering the image data to the consumer
     * using the <code>ImageConsumer interface immediately,
     * or when the next available image reconstruction is triggered
     * by a call to the <code>startProduction method.
     * @param ic the specified <code>ImageConsumer
     * @see #startProduction
     */
    public void addConsumer(ImageConsumer ic);

    /**
     * Determines if a specified <code>ImageConsumer
     * object is currently registered with this
     * <code>ImageProducer as one of its consumers.
     * @param ic the specified <code>ImageConsumer
     * @return <code>true if the specified
     *         <code>ImageConsumer is registered with
     *         this <code>ImageProducer;
     *         <code>false otherwise.
     */
    public boolean isConsumer(ImageConsumer ic);

    /**
     * Removes the specified <code>ImageConsumer 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 should stop sending data
     * to this consumer as soon as is feasible.
     * @param ic the specified <code>ImageConsumer
     */
    public void removeConsumer(ImageConsumer ic);

    /**
     * Registers the specified <code>ImageConsumer 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
     * @see #addConsumer
     */
    public void startProduction(ImageConsumer ic);

    /**
     * Requests, on behalf of the <code>ImageConsumer,
     * that the <code>ImageProducer 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 is free to
     * ignore this call if it cannot resend the data in that
     * order.  If the data can be resent, the
     * <code>ImageProducer should respond by executing
     * the following minimum set of <code>ImageConsumer
     * method calls:
     * <pre>{@code
     *  ic.setHints(TOPDOWNLEFTRIGHT | < otherhints >);
     *  ic.setPixels(...);      // As many times as needed
     *  ic.imageComplete();
     * }</pre>
     * @param ic the specified <code>ImageConsumer
     * @see ImageConsumer#setHints
     */
    public void requestTopDownLeftRightResend(ImageConsumer ic);
}