private static void validate(Chunk chunk) {
if (chunk == null) throw new IllegalArgumentException("Input chunk is null");
if (chunk.getChunkType() != ChunkType.TEXT
&& chunk.getChunkType() != ChunkType.ZTXT
&& chunk.getChunkType() != ChunkType.ITXT) {
throw new IllegalArgumentException("Not a valid textual chunk.");
}
}
/**
* @param decodedChunk
* @return
*/
public PNGChunk encode(Chunk decodedChunk) {
String chunkTypeString = decodedChunk.getChunkType();
byte[] chunkType = chunkTypeString.getBytes();
byte[] data = decodedChunk.toByteArray();
int length = data.length;
PNGChunk encodedChunk = new PNGChunk(length, chunkType, data, 0, 0);
return encodedChunk;
}
// Read text chunks to a String
public void read() throws IOException {
StringBuilder sb = new StringBuilder(1024);
byte[] data = chunk.getData();
switch (chunk.getChunkType()) {
case ZTXT:
{
int keyword_len = 0;
while (data[keyword_len] != 0) keyword_len++;
this.keyword = new String(data, 0, keyword_len, "UTF-8");
InflaterInputStream ii =
new InflaterInputStream(
new ByteArrayInputStream(data, keyword_len + 2, data.length - keyword_len - 2));
InputStreamReader ir = new InputStreamReader(ii, "UTF-8");
BufferedReader br = new BufferedReader(ir);
String read = null;
while ((read = br.readLine()) != null) {
sb.append(read);
sb.append("\n");
}
br.close();
break;
}
case TEXT:
{
int keyword_len = 0;
while (data[keyword_len] != 0) keyword_len++;
this.keyword = new String(data, 0, keyword_len, "UTF-8");
sb.append(new String(data, keyword_len + 1, data.length - keyword_len - 1, "UTF-8"));
break;
}
case ITXT:
{
// System.setOut(new PrintStream(new File("TextChunk.txt"),"UTF-8"));
/**
* Keyword: 1-79 bytes (character string) Null separator: 1 byte Compression flag: 1 byte
* Compression method: 1 byte Language tag: 0 or more bytes (character string) Null
* separator: 1 byte Translated keyword: 0 or more bytes Null separator: 1 byte Text: 0 or
* more bytes
*/
int keyword_len = 0;
int trans_keyword_len = 0;
int lang_flg_len = 0;
boolean compr = false;
while (data[keyword_len] != 0) keyword_len++;
sb.append(new String(data, 0, keyword_len, "UTF-8"));
if (data[++keyword_len] == 1) compr = true;
keyword_len++; // Skip the compression method byte.
while (data[++keyword_len] != 0) lang_flg_len++;
//////////////////////
sb.append("(");
if (lang_flg_len > 0)
sb.append(new String(data, keyword_len - lang_flg_len, lang_flg_len, "UTF-8"));
while (data[++keyword_len] != 0) trans_keyword_len++;
if (trans_keyword_len > 0) {
sb.append(" ");
sb.append(
new String(data, keyword_len - trans_keyword_len, trans_keyword_len, "UTF-8"));
}
sb.append(")");
this.keyword = sb.toString().replaceFirst("\\(\\)", "");
sb.setLength(0); // Reset StringBuilder
/////////////////////// End of key.
if (compr) { // Compressed text
InflaterInputStream ii =
new InflaterInputStream(
new ByteArrayInputStream(data, keyword_len + 1, data.length - keyword_len - 1));
InputStreamReader ir = new InputStreamReader(ii, "UTF-8");
BufferedReader br = new BufferedReader(ir);
String read = null;
while ((read = br.readLine()) != null) {
sb.append(read);
sb.append("\n");
}
br.close();
} else { // Uncompressed text
sb.append(new String(data, keyword_len + 1, data.length - keyword_len - 1, "UTF-8"));
sb.append("\n");
}
sb.deleteCharAt(sb.length() - 1);
break;
}
default:
throw new IllegalArgumentException("Not a valid textual chunk.");
}
this.text = sb.toString();
}