| /* | |
| * 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; | |
| import java.awt.Image; | |
| /** | |
| * An asynchronous update interface for receiving notifications about | |
| * Image information as the Image is constructed. | |
| * | |
| * @author Jim Graham | |
| */ | |
| public interface ImageObserver { | |
| /** | |
| * This method is called when information about an image which was | |
| * previously requested using an asynchronous interface becomes | |
| * available. Asynchronous interfaces are method calls such as | |
| * getWidth(ImageObserver) and drawImage(img, x, y, ImageObserver) | |
| * which take an ImageObserver object as an argument. Those methods | |
| * register the caller as interested either in information about | |
| * the overall image itself (in the case of getWidth(ImageObserver)) | |
| * or about an output version of an image (in the case of the | |
| * drawImage(img, x, y, [w, h,] ImageObserver) call). | |
| * | |
| * <p>This method | |
| * should return true if further updates are needed or false if the | |
| * required information has been acquired. The image which was being | |
| * tracked is passed in using the img argument. Various constants | |
| * are combined to form the infoflags argument which indicates what | |
| * information about the image is now available. The interpretation | |
| * of the x, y, width, and height arguments depends on the contents | |
| * of the infoflags argument. | |
| * <p> | |
| * The {@code infoflags} argument should be the bitwise inclusive | |
| * <b>OR</b> of the following flags: {@code WIDTH}, | |
| * {@code HEIGHT}, {@code PROPERTIES}, {@code SOMEBITS}, | |
| * {@code FRAMEBITS}, {@code ALLBITS}, {@code ERROR}, | |
| * {@code ABORT}. | |
| * | |
| * @param img the image being observed. | |
| * @param infoflags the bitwise inclusive OR of the following | |
| * flags: {@code WIDTH}, {@code HEIGHT}, | |
| * {@code PROPERTIES}, {@code SOMEBITS}, | |
| * {@code FRAMEBITS}, {@code ALLBITS}, | |
| * {@code ERROR}, {@code ABORT}. | |
| * @param x the <i>x</i> coordinate. | |
| * @param y the <i>y</i> coordinate. | |
| * @param width the width. | |
| * @param height the height. | |
| * @return {@code false} if the infoflags indicate that the | |
| * image is completely loaded; {@code true} otherwise. | |
| * | |
| * @see #WIDTH | |
| * @see #HEIGHT | |
| * @see #PROPERTIES | |
| * @see #SOMEBITS | |
| * @see #FRAMEBITS | |
| * @see #ALLBITS | |
| * @see #ERROR | |
| * @see #ABORT | |
| * @see Image#getWidth | |
| * @see Image#getHeight | |
| * @see java.awt.Graphics#drawImage | |
| */ | |
| public boolean imageUpdate(Image img, int infoflags, | |
| int x, int y, int width, int height); | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * the width of the base image is now available and can be taken | |
| * from the width argument to the imageUpdate callback method. | |
| * @see Image#getWidth | |
| * @see #imageUpdate | |
| */ | |
| public static final int WIDTH = 1; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * the height of the base image is now available and can be taken | |
| * from the height argument to the imageUpdate callback method. | |
| * @see Image#getHeight | |
| * @see #imageUpdate | |
| */ | |
| public static final int HEIGHT = 2; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * the properties of the image are now available. | |
| * @see Image#getProperty | |
| * @see #imageUpdate | |
| */ | |
| public static final int PROPERTIES = 4; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * more pixels needed for drawing a scaled variation of the image | |
| * are available. The bounding box of the new pixels can be taken | |
| * from the x, y, width, and height arguments to the imageUpdate | |
| * callback method. | |
| * @see java.awt.Graphics#drawImage | |
| * @see #imageUpdate | |
| */ | |
| public static final int SOMEBITS = 8; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * another complete frame of a multi-frame image which was previously | |
| * drawn is now available to be drawn again. The x, y, width, and height | |
| * arguments to the imageUpdate callback method should be ignored. | |
| * @see java.awt.Graphics#drawImage | |
| * @see #imageUpdate | |
| */ | |
| public static final int FRAMEBITS = 16; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * a static image which was previously drawn is now complete and can | |
| * be drawn again in its final form. The x, y, width, and height | |
| * arguments to the imageUpdate callback method should be ignored. | |
| * @see java.awt.Graphics#drawImage | |
| * @see #imageUpdate | |
| */ | |
| public static final int ALLBITS = 32; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * an image which was being tracked asynchronously has encountered | |
| * an error. No further information will become available and | |
| * drawing the image will fail. | |
| * As a convenience, the ABORT flag will be indicated at the same | |
| * time to indicate that the image production was aborted. | |
| * @see #imageUpdate | |
| */ | |
| public static final int ERROR = 64; | |
| /** | |
| * This flag in the infoflags argument to imageUpdate indicates that | |
| * an image which was being tracked asynchronously was aborted before | |
| * production was complete. No more information will become available | |
| * without further action to trigger another image production sequence. | |
| * If the ERROR flag was not also set in this image update, then | |
| * accessing any of the data in the image will restart the production | |
| * again, probably from the beginning. | |
| * @see #imageUpdate | |
| */ | |
| public static final int ABORT = 128; | |
| } |