J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.imageio.spi; |
| 27 | |
| 28 | import java.util.Locale; |
| 29 | import javax.imageio.spi.RegisterableService; |
| 30 | import javax.imageio.spi.ServiceRegistry; |
| 31 | |
| 32 | /** |
| 33 | * A superinterface for functionality common to all Image I/O service |
| 34 | * provider interfaces (SPIs). For more information on service |
| 35 | * provider classes, see the class comment for the |
| 36 | * <code>IIORegistry</code> class. |
| 37 | * |
| 38 | * @see IIORegistry |
| 39 | * @see javax.imageio.spi.ImageReaderSpi |
| 40 | * @see javax.imageio.spi.ImageWriterSpi |
| 41 | * @see javax.imageio.spi.ImageTranscoderSpi |
| 42 | * @see javax.imageio.spi.ImageInputStreamSpi |
| 43 | * |
| 44 | */ |
| 45 | public abstract class IIOServiceProvider implements RegisterableService { |
| 46 | |
| 47 | /** |
| 48 | * A <code>String</code> to be returned from |
| 49 | * <code>getVendorName</code>, initially <code>null</code>. |
| 50 | * Constructors should set this to a non-<code>null</code> value. |
| 51 | */ |
| 52 | protected String vendorName; |
| 53 | |
| 54 | /** |
| 55 | * A <code>String</code> to be returned from |
| 56 | * <code>getVersion</code>, initially null. Constructors should |
| 57 | * set this to a non-<code>null</code> value. |
| 58 | */ |
| 59 | protected String version; |
| 60 | |
| 61 | /** |
| 62 | * Constructs an <code>IIOServiceProvider</code> with a given |
| 63 | * vendor name and version identifier. |
| 64 | * |
| 65 | * @param vendorName the vendor name. |
| 66 | * @param version a version identifier. |
| 67 | * |
| 68 | * @exception IllegalArgumentException if <code>vendorName</code> |
| 69 | * is <code>null</code>. |
| 70 | * @exception IllegalArgumentException if <code>version</code> |
| 71 | * is <code>null</code>. |
| 72 | */ |
| 73 | public IIOServiceProvider(String vendorName, |
| 74 | String version) { |
| 75 | if (vendorName == null) { |
| 76 | throw new IllegalArgumentException("vendorName == null!"); |
| 77 | } |
| 78 | if (version == null) { |
| 79 | throw new IllegalArgumentException("version == null!"); |
| 80 | } |
| 81 | this.vendorName = vendorName; |
| 82 | this.version = version; |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Constructs a blank <code>IIOServiceProvider</code>. It is up |
| 87 | * to the subclass to initialize instance variables and/or |
| 88 | * override method implementations in order to ensure that the |
| 89 | * <code>getVendorName</code> and <code>getVersion</code> methods |
| 90 | * will return non-<code>null</code> values. |
| 91 | */ |
| 92 | public IIOServiceProvider() { |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * A callback that will be called exactly once after the Spi class |
| 97 | * has been instantiated and registered in a |
| 98 | * <code>ServiceRegistry</code>. This may be used to verify that |
| 99 | * the environment is suitable for this service, for example that |
| 100 | * native libraries can be loaded. If the service cannot function |
| 101 | * in the environment where it finds itself, it should deregister |
| 102 | * itself from the registry. |
| 103 | * |
| 104 | * <p> Only the registry should call this method. |
| 105 | * |
| 106 | * <p> The default implementation does nothing. |
| 107 | * |
| 108 | * @see ServiceRegistry#registerServiceProvider(Object provider) |
| 109 | */ |
| 110 | public void onRegistration(ServiceRegistry registry, |
| 111 | Class<?> category) {} |
| 112 | |
| 113 | /** |
| 114 | * A callback that will be whenever the Spi class has been |
| 115 | * deregistered from a <code>ServiceRegistry</code>. |
| 116 | * |
| 117 | * <p> Only the registry should call this method. |
| 118 | * |
| 119 | * <p> The default implementation does nothing. |
| 120 | * |
| 121 | * @see ServiceRegistry#deregisterServiceProvider(Object provider) |
| 122 | */ |
| 123 | public void onDeregistration(ServiceRegistry registry, |
| 124 | Class<?> category) {} |
| 125 | |
| 126 | /** |
| 127 | * Returns the name of the vendor responsible for creating this |
| 128 | * service provider and its associated implementation. Because |
| 129 | * the vendor name may be used to select a service provider, |
| 130 | * it is not localized. |
| 131 | * |
| 132 | * <p> The default implementation returns the value of the |
| 133 | * <code>vendorName</code> instance variable. |
| 134 | * |
| 135 | * @return a non-<code>null</code> <code>String</code> containing |
| 136 | * the name of the vendor. |
| 137 | */ |
| 138 | public String getVendorName() { |
| 139 | return vendorName; |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Returns a string describing the version |
| 144 | * number of this service provider and its associated |
| 145 | * implementation. Because the version may be used by transcoders |
| 146 | * to identify the service providers they understand, this method |
| 147 | * is not localized. |
| 148 | * |
| 149 | * <p> The default implementation returns the value of the |
| 150 | * <code>version</code> instance variable. |
| 151 | * |
| 152 | * @return a non-<code>null</code> <code>String</code> containing |
| 153 | * the version of this service provider. |
| 154 | */ |
| 155 | public String getVersion() { |
| 156 | return version; |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Returns a brief, human-readable description of this service |
| 161 | * provider and its associated implementation. The resulting |
| 162 | * string should be localized for the supplied |
| 163 | * <code>Locale</code>, if possible. |
| 164 | * |
| 165 | * @param locale a <code>Locale</code> for which the return value |
| 166 | * should be localized. |
| 167 | * |
| 168 | * @return a <code>String</code> containing a description of this |
| 169 | * service provider. |
| 170 | */ |
| 171 | public abstract String getDescription(Locale locale); |
| 172 | } |