| /* |
| * Copyright (c) 1995, 1999, 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</code> argument should be the bitwise inclusive |
| * <b>OR</b> of the following flags: <code>WIDTH</code>, |
| * <code>HEIGHT</code>, <code>PROPERTIES</code>, <code>SOMEBITS</code>, |
| * <code>FRAMEBITS</code>, <code>ALLBITS</code>, <code>ERROR</code>, |
| * <code>ABORT</code>. |
| * |
| * @param img the image being observed. |
| * @param infoflags the bitwise inclusive OR of the following |
| * flags: <code>WIDTH</code>, <code>HEIGHT</code>, |
| * <code>PROPERTIES</code>, <code>SOMEBITS</code>, |
| * <code>FRAMEBITS</code>, <code>ALLBITS</code>, |
| * <code>ERROR</code>, <code>ABORT</code>. |
| * @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</code> if the infoflags indicate that the |
| * image is completely loaded; <code>true</code> 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; |
| } |
