package ar.com.hjg.pngj.chunks;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import ar.com.hjg.pngj.ImageInfo;
import ar.com.hjg.pngj.PngjException;
/**
* iTXt chunk.
* <p>
* see http://www.w3.org/TR/PNG/#11iTXt
*/
public class PngChunkITXT extends PngChunkTextVar {
public final static String ID = ChunkHelper.iTXt;
private boolean compressed = false;
private String langTag = "";
private String translatedTag = "";
// http://www.w3.org/TR/PNG/#11iTXt
public PngChunkITXT(ImageInfo info) {
super(ID, info);
}
@Override
public ChunkRaw createRawChunk() {
if (key == null || key.trim().length() == 0)
throw new PngjException("Text chunk key must be non empty");
try {
ByteArrayOutputStream ba = new ByteArrayOutputStream();
ba.write(ChunkHelper.toBytes(key));
ba.write(0); // separator
ba.write(compressed ? 1 : 0);
ba.write(0); // compression method (always 0)
ba.write(ChunkHelper.toBytes(langTag));
ba.write(0); // separator
ba.write(ChunkHelper.toBytesUTF8(translatedTag));
ba.write(0); // separator
byte[] textbytes = ChunkHelper.toBytesUTF8(val);
if (compressed) {
textbytes = ChunkHelper.compressBytes(textbytes, true);
}
ba.write(textbytes);
byte[] b = ba.toByteArray();
ChunkRaw chunk = createEmptyChunk(b.length, false);
chunk.data = b;
return chunk;
} catch (IOException e) {
throw new PngjException(e);
}
}
@Override
public void parseFromRaw(ChunkRaw c) {
int nullsFound = 0;
int[] nullsIdx = new int[3];
for (int i = 0; i < c.data.length; i++) {
if (c.data[i] != 0)
continue;
nullsIdx[nullsFound] = i;
nullsFound++;
if (nullsFound == 1)
i += 2;
if (nullsFound == 3)
break;
}
if (nullsFound != 3)
throw new PngjException("Bad formed PngChunkITXT chunk");
key = ChunkHelper.toString(c.data, 0, nullsIdx[0]);
int i = nullsIdx[0] + 1;
compressed = c.data[i] == 0 ? false : true;
i++;
if (compressed && c.data[i] != 0)
throw new PngjException("Bad formed PngChunkITXT chunk - bad compression method ");
langTag = ChunkHelper.toString(c.data, i, nullsIdx[1] - i);
translatedTag =
ChunkHelper.toStringUTF8(c.data, nullsIdx[1] + 1, nullsIdx[2] - nullsIdx[1] - 1);
i = nullsIdx[2] + 1;
if (compressed) {
byte[] bytes = ChunkHelper.compressBytes(c.data, i, c.data.length - i, false);
val = ChunkHelper.toStringUTF8(bytes);
} else {
val = ChunkHelper.toStringUTF8(c.data, i, c.data.length - i);
}
}
public boolean isCompressed() {
return compressed;
}
public void setCompressed(boolean compressed) {
this.compressed = compressed;
}
public String getLangtag() {
return langTag;
}
public void setLangtag(String langtag) {
this.langTag = langtag;
}
public String getTranslatedTag() {
return translatedTag;
}
public void setTranslatedTag(String translatedTag) {
this.translatedTag = translatedTag;
}
}