/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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.
*/
/**
* The service provider interface (SPI) for
* <code>ImageInputStream</code>s. For more information on service
* provider interfaces, see the class comment for the
* <code>IIORegistry</code> class.
*
* <p> This interface allows arbitrary objects to be "wrapped" by
* instances of <code>ImageInputStream</code>. For example,
* a particular <code>ImageInputStreamSpi</code> might allow
* a generic <code>InputStream</code> to be used as an input source;
* another might take input from a <code>URL</code>.
*
* <p> By treating the creation of <code>ImageInputStream</code>s as a
* pluggable service, it becomes possible to handle future input
* sources without changing the API. Also, high-performance
* implementations of <code>ImageInputStream</code> (for example,
* native implementations for a particular platform) can be installed
* and used transparently by applications.
*
* @see IIORegistry
* @see javax.imageio.stream.ImageInputStream
*
*/
/**
* A <code>Class</code> object indicating the legal object type
* for use by the <code>createInputStreamInstance</code> method.
*/
/**
* Constructs a blank <code>ImageInputStreamSpi</code>. It is up
* override method implementations in order to provide working
* versions of all methods.
*/
protected ImageInputStreamSpi() {
}
/**
* Constructs an <code>ImageInputStreamSpi</code> with a given set
* of values.
*
* @param vendorName the vendor name.
* @param version a version identifier.
* @param inputClass a <code>Class</code> object indicating the
* legal object type for use by the
* <code>createInputStreamInstance</code> method.
*
* @exception IllegalArgumentException if <code>vendorName</code>
* is <code>null</code>.
* @exception IllegalArgumentException if <code>version</code>
* is <code>null</code>.
*/
Class<?> inputClass) {
super(vendorName, version);
this.inputClass = inputClass;
}
/**
* Returns a <code>Class</code> object representing the class or
* interface type that must be implemented by an input source in
* order to be "wrapped" in an <code>ImageInputStream</code> via
* the <code>createInputStreamInstance</code> method.
*
* <p> Typical return values might include
* <code>InputStream.class</code> or <code>URL.class</code>, but
* any class may be used.
*
* @return a <code>Class</code> variable.
*
* @see #createInputStreamInstance(Object, boolean, File)
*/
return inputClass;
}
/**
* Returns <code>true</code> if the <code>ImageInputStream</code>
* implementation associated with this service provider can
* optionally make use of a cache file for improved performance
* the <code>useCache</code> argument to
* <code>createInputStreamInstance</code> will be ignored.
*
* <p> The default implementation returns <code>false</code>.
*
* @return <code>true</code> if a cache file can be used by the
* input streams created by this service provider.
*/
public boolean canUseCacheFile() {
return false;
}
/**
* Returns <code>true</code> if the <code>ImageInputStream</code>
* implementation associated with this service provider requires
* the use of a cache <code>File</code>. If <code>true</code>,
* the value of the <code>useCache</code> argument to
* <code>createInputStreamInstance</code> will be ignored.
*
* <p> The default implementation returns <code>false</code>.
*
* @return <code>true</code> if a cache file is needed by the
* input streams created by this service provider.
*/
public boolean needsCacheFile() {
return false;
}
/**
* Returns an instance of the <code>ImageInputStream</code>
* implementation associated with this service provider. If the
* use of a cache file is optional, the <code>useCache</code>
* parameter will be consulted. Where a cache is required, or
* not applicable, the value of <code>useCache</code> will be ignored.
*
* @param input an object of the class type returned by
* <code>getInputClass</code>.
* @param useCache a <code>boolean</code> indicating whether a
* cache file should be used, in cases where it is optional.
* @param cacheDir a <code>File</code> indicating where the
* cache file should be created, or <code>null</code> to use the
* system directory.
*
* @return an <code>ImageInputStream</code> instance.
*
* @exception IllegalArgumentException if <code>input</code> is
* not an instance of the correct class or is <code>null</code>.
* @exception IllegalArgumentException if a cache file is needed
* but <code>cacheDir</code> is non-<code>null</code> and is not a
* directory.
* @exception IOException if a cache file is needed but cannot be
* created.
*
* @see #getInputClass
* @see #canUseCacheFile
* @see #needsCacheFile
*/
public abstract ImageInputStream
boolean useCache,
/**
* Returns an instance of the <code>ImageInputStream</code>
* implementation associated with this service provider. A cache
* file will be created in the system-dependent default
* temporary-file directory, if needed.
*
* @param input an object of the class type returned by
* <code>getInputClass</code>.
*
* @return an <code>ImageInputStream</code> instance.
*
* @exception IllegalArgumentException if <code>input</code> is
* not an instance of the correct class or is <code>null</code>.
* @exception IOException if a cache file is needed but cannot be
* created.
*
* @see #getInputClass()
*/
throws IOException {
}
}