package org.jaudiotagger.audio.asf.io;
import org.jaudiotagger.audio.asf.data.Chunk;
import org.jaudiotagger.audio.asf.data.GUID;
import org.jaudiotagger.audio.asf.data.LanguageList;
import org.jaudiotagger.audio.asf.util.Utils;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
/**
* Reads and interprets the "Language List Object" of ASF files.<br>
*
* @author Christian Laireiter
*/
public class LanguageListReader implements ChunkReader {
/**
* The GUID this reader {@linkplain #getApplyingIds() applies to}
*/
private final static GUID[] APPLYING = { GUID.GUID_LANGUAGE_LIST };
/**
* {@inheritDoc}
*/
public boolean canFail() {
return false;
}
/**
* {@inheritDoc}
*/
public GUID[] getApplyingIds() {
return APPLYING.clone();
}
/**
* {@inheritDoc}
*/
public Chunk read(final GUID guid, final InputStream stream,
final long streamPosition) throws IOException {
assert GUID.GUID_LANGUAGE_LIST.equals(guid);
final BigInteger chunkLen = Utils.readBig64(stream);
final int readUINT16 = Utils.readUINT16(stream);
final LanguageList result = new LanguageList(streamPosition, chunkLen);
for (int i = 0; i < readUINT16; i++) {
final int langIdLen = (stream.read() & 0xFF);
final String langId = Utils
.readFixedSizeUTF16Str(stream, langIdLen);
// langIdLen = 2 bytes for each char and optionally one zero
// termination character
assert langId.length() == langIdLen / 2 - 1
|| langId.length() == langIdLen / 2;
result.addLanguage(langId);
}
return result;
}
}