libjava/java/awt/image/ImageObserver.java

   1 /* ImageObserver.java -- Java interface for asynchronous updates to an image
   2    Copyright (C) 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.image;
  40
  41 import java.awt.Image;
  42
  43 /**
  44  * An object implementing the <code>ImageObserver</code> interface can
  45  * receive updates on image construction from an
  46  * <code>ImageProducer</code> asynchronously.
  47  *
  48  * @see ImageProducer
  49  * @author C. Brian Jones (cbj@gnu.org)
  50  */
  51 public interface ImageObserver
  52 {
  53     /**
  54      * The width of the image has been provided as the
  55      * <code>width</code> argument to <code>imageUpdate</code>.
  56      *
  57      * @see #imageUpdate
  58      */
  59     int WIDTH = 1;
  60
  61     /**
  62      * The height of the image has been provided as the
  63      * <code>height</code> argument to <code>imageUpdate</code>.
  64      *
  65      * @see #imageUpdate
  66      */
  67     int HEIGHT = 2;
  68
  69     /**
  70      * The properties of the image have been provided.
  71      *
  72      * @see #imageUpdate
  73      * @see java.awt.Image#getProperty (java.lang.String, java.awt.image.ImageObserver)
  74      */
  75     int PROPERTIES = 4;
  76
  77     /**
  78      * More pixels are now available for drawing a scaled variation of
  79      * the image.
  80      *
  81      * @see #imageUpdate
  82      */
  83     int SOMEBITS = 8;
  84
  85     /**
  86      * All the pixels needed to draw a complete frame of a multi-frame
  87      * image are available.
  88      *
  89      * @see #imageUpdate
  90      */
  91     int FRAMEBITS = 16;
  92
  93     /**
  94      * An image with a single frame, a static image, is complete.
  95      *
  96      * @see #imageUpdate
  97      */
  98     int ALLBITS = 32;
  99
 100     /**
 101      * An error was encountered while producing the image.
 102      *
 103      * @see #imageUpdate
 104      */
 105     int ERROR = 64;
 106
 107     /**
 108      * Production of the image was aborted.
 109      *
 110      * @see #imageUpdate
 111      */
 112     int ABORT = 128;
 113
 114     /**
 115      * This is a callback method for an asynchronous image producer to
 116      * provide updates on the production of the image as it happens.
 117      *
 118      * @param image the image the update refers to
 119      * @param flags a bit mask indicating what is provided with this update
 120      * @param x the x coordinate of the image
 121      * @param y the y coordinate of the image
 122      * @param width the width of the image
 123      * @param height the height of the image
 124      *
 125      * @see java.awt.Image
 126      */
 127     boolean imageUpdate(Image image, int flags, int x,
 128                                         int y, int width, int height);
 129 }