1 /* ImageOutputStreamSpi.java -- Service provider for image output streams. 2 Copyright (C) 2004, 2005 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., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 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 javax.imageio.spi; 40 41 import java.io.File; 42 import java.io.IOException; 43 44 import javax.imageio.stream.ImageOutputStream; 45 46 /** 47 * An abstract superclass for service providers that create 48 * {@linkplain javax.imageio.stream.ImageOutputStream image output 49 * streams} for a file, URL, byte array or any other target. 50 * 51 * @since 1.4 52 * 53 * @author Sascha Brawer (brawer@dandelis.ch) 54 */ 55 public abstract class ImageOutputStreamSpi 56 extends IIOServiceProvider 57 { 58 /** 59 * Indicates which kind of output is produced by the streams 60 * created by {@link #createOutputStreamInstance(Object)}. 61 */ 62 protected Class<?> outputClass; 63 64 65 /** 66 * Constructs a service provider for image output streams, given no 67 * parameters. It is up to the sub-class to set {@link #vendorName}, 68 * {@link #version} and {@link #outputClass} to non-null values. 69 */ ImageOutputStreamSpi()70 protected ImageOutputStreamSpi() 71 { 72 } 73 74 75 /** 76 * Constructs a service provider for image output streams, given the 77 * vendor name, a version string and the kind of producable output. 78 * 79 * @throws IllegalArgumentException if <code>vendorName</code> 80 * or <code>version</code> is <code>null</code>. 81 */ ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass)82 public ImageOutputStreamSpi(String vendorName, String version, 83 Class<?> outputClass) 84 { 85 super(vendorName, version); 86 this.outputClass = outputClass; 87 } 88 89 90 /** 91 * Determines which kind of output is produced by the streams 92 * created by {@link #createOutputStreamInstance(Object)}. 93 */ getOutputClass()94 public Class<?> getOutputClass() 95 { 96 return outputClass; 97 } 98 99 100 /** 101 * Determines whether <code>ImageOutputStreams</code> created 102 * by this service provider benefit from using a cache file. 103 * 104 * <p>The default behavior is to return <code>false</code>. 105 * 106 * @return <code>true</code> if the created streams are faster or 107 * need less memory when a cache file is being used; 108 * <code>false</code> if no positive effect results from the cache 109 * file. 110 */ canUseCacheFile()111 public boolean canUseCacheFile() 112 { 113 return false; 114 } 115 116 117 /** 118 * Determines whether <code>ImageOutputStreams</code> created 119 * by this service provider require the use of a cache file. 120 * 121 * <p>The default behavior is to return <code>false</code>. 122 * 123 * @return <code>true</code> if the created streams can only work 124 * when a cache file is being used; <code>false</code> if no cache 125 * file is needed. 126 */ needsCacheFile()127 public boolean needsCacheFile() 128 { 129 return false; 130 } 131 132 createOutputStreamInstance( Object output, boolean useCache, File cacheDir)133 public abstract ImageOutputStream createOutputStreamInstance( 134 Object output, boolean useCache, File cacheDir) 135 throws IOException; 136 137 createOutputStreamInstance(Object output)138 public ImageOutputStream createOutputStreamInstance(Object output) 139 throws IOException 140 { 141 return createOutputStreamInstance(output, canUseCacheFile(), null); 142 } 143 } 144