/**
* If the frame body's values have been modified, then resize the raw binary buffer and store the
* new values there. When finished, the dirty flag is reset to indicate that the buffer is up to
* date, and the frame is now ready to be saved to the .mp3 file.
*/
@Override
public void setBuffer() {
if (isDirty()) {
byte[] mimeTypeBytes = stringToBytes(Encoding.ISO_8859_1, mimeType);
byte[] filenameBytes = stringToBytes(encoding, filename);
byte[] descriptionBytes = stringToBytes(encoding, description);
int index = 0;
buffer =
new byte
[1
+ mimeTypeBytes.length
+ filenameBytes.length
+ descriptionBytes.length
+ object.length];
buffer[index] = (byte) encoding.ordinal();
System.arraycopy(mimeTypeBytes, 0, buffer, 0, mimeTypeBytes.length);
index = mimeTypeBytes.length;
System.arraycopy(filenameBytes, 0, buffer, index, filenameBytes.length);
index += filenameBytes.length;
System.arraycopy(descriptionBytes, 0, buffer, index, descriptionBytes.length);
index += descriptionBytes.length;
System.arraycopy(object, 0, buffer, index, object.length);
dirty = false;
}
}
/**
* parses the raw bytes of the frame body and stores the parsed values in the frame's fields.
*
* @throws IllegalArgumentException if an invalid value is detected while parsing the frame body's
* raw bytes.
*/
@Override
public void parse() throws IllegalArgumentException {
try {
setEncoding(Encoding.valueOf(buffer[0]));
} catch (
IllegalArgumentException
ex) { // ignore the bad value and set it to ISO-8859-1 so we can continue parsing the
// tag
setEncoding(Encoding.ISO_8859_1);
}
nullTerminatorIndex = getNextNullTerminator(1, Encoding.ISO_8859_1);
mimeType =
new String(buffer, 1, nullTerminatorIndex - 1, Encoding.ISO_8859_1.getCharacterSet())
.trim();
nullTerminatorIndex++;
nextNullTerminatorIndex = getNextNullTerminator(nullTerminatorIndex, encoding);
filename =
new String(
buffer,
nullTerminatorIndex,
nextNullTerminatorIndex - nullTerminatorIndex,
encoding.getCharacterSet())
.trim();
nullTerminatorIndex = nextNullTerminatorIndex + encoding.getNumBytesInNullTerminator();
nextNullTerminatorIndex = getNextNullTerminator(nullTerminatorIndex, encoding);
description =
new String(
buffer,
nullTerminatorIndex,
nextNullTerminatorIndex - nullTerminatorIndex,
encoding.getCharacterSet())
.trim();
nullTerminatorIndex = nextNullTerminatorIndex + encoding.getNumBytesInNullTerminator();
object = new byte[buffer.length - nullTerminatorIndex];
System.arraycopy(buffer, nullTerminatorIndex, object, 0, object.length);
dirty =
false; // we just read in the frame info, so the frame body's internal byte buffer is up to
// date
}