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jlechner |
/* ImageInputStreamSpi.java -- Service provider for image input streams.
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Copyright (C) 2004, 2005 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package javax.imageio.spi;
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import java.io.File;
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import java.io.IOException;
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import javax.imageio.stream.ImageInputStream;
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/**
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* An abstract superclass for service providers that create
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* {@linkplain javax.imageio.stream.ImageInputStream image input
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* streams} for a file, URL, byte array or any other source.
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*
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* @since 1.4
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*
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* @author Sascha Brawer (brawer@dandelis.ch)
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*/
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public abstract class ImageInputStreamSpi
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extends IIOServiceProvider
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{
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/**
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* Indicates which kind of input is processable by the streams
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* created by {@link #createInputStreamInstance(Object)}.
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*/
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protected Class inputClass;
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/**
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* Constructs a service provider for image input streams, given no
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* parameters. It is up to the sub-class to set {@link #vendorName},
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* {@link #version} and {@link #inputClass} to non-null values.
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*/
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protected ImageInputStreamSpi()
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{
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}
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/**
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* Constructs a service provider for image input streams, given the
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* vendor name and a version string.
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*
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* @throws IllegalArgumentException if <code>vendorName</code>
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* or <code>version</code> is <code>null</code>.
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*/
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public ImageInputStreamSpi(String vendorName, String version,
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Class inputClass)
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{
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super(vendorName, version);
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this.inputClass = inputClass;
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}
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/**
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* Determines which kind of input is processable by the streams
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* created by {@link #createInputStreamInstance(Object)}.
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*/
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public Class getInputClass()
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{
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return inputClass;
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}
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/**
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* Determines whether <code>ImageInputStreams</code> created
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* by this service provider benefit from using a cache file.
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*
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* <p>The default behavior is to return <code>false</code>.
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*
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* @return <code>true</code> if the created streams are faster or
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* need less memory when a cache file is being used;
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* <code>false</code> if no positive effect results from the cache
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* file.
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*/
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public boolean canUseCacheFile()
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{
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return false;
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}
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/**
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* Determines whether <code>ImageInputStreams</code> created
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* by this service provider require the use of a cache file.
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*
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* <p>The default behavior is to return <code>false</code>.
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*
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* @return <code>true</code> if the created streams can only work
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* when a cache file is being used; <code>false</code> if no cache
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* file is needed.
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*/
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public boolean needsCacheFile()
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{
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return false;
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}
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public abstract ImageInputStream createInputStreamInstance(Object input,
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boolean useCache,
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File cacheDir)
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throws IOException;
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public ImageInputStream createInputStreamInstance(Object input)
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throws IOException
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{
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return createInputStreamInstance(input, canUseCacheFile(), null);
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}
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}
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