/**
* read an entire PDFObject. The intro line, which looks something like "4 0 obj" has already been
* read.
*
* @param objNum the object number of the object being read, being the first number in the intro
* line (4 in "4 0 obj")
* @param objGen the object generation of the object being read, being the second number in the
* intro line (0 in "4 0 obj").
* @param decrypter the decrypter to use
*/
private PDFObject readObjectDescription(int objNum, int objGen, PDFDecrypter decrypter)
throws IOException {
// we've already read the 4 0 obj bit. Next thing up is the object.
// object descriptions end with the keyword endobj
long debugpos = this.buf.position();
PDFObject obj = readObject(objNum, objGen, decrypter);
// see if it's a dictionary. If so, this could be a stream.
PDFObject endkey = readObject(objNum, objGen, decrypter);
if (endkey.getType() != PDFObject.KEYWORD && endkey.getType() != PDFObject.STREAM) {
PDFDebugger.debug(
"WARNING: Expected 'stream' or 'endobj' but was "
+ endkey.getType()
+ " "
+ String.valueOf(endkey.getStringValue()));
}
if (obj.getType() == PDFObject.DICTIONARY
&& endkey.getStringValue() != null
&& endkey.getStringValue().equals("stream")) {
// skip until we see \n
readLine();
ByteBuffer data = readStream(obj);
if (data == null) {
data = ByteBuffer.allocate(0);
}
obj.setStream(data);
endkey = readObject(objNum, objGen, decrypter);
}
// at this point, obj is the object, keyword should be "endobj"
String endcheck = endkey.getStringValue();
if (endcheck == null || !endcheck.equals("endobj")) {
PDFDebugger.debug("WARNING: object at " + debugpos + " didn't end with 'endobj'");
}
obj.setObjectId(objNum, objGen);
return obj;
}
/**
* read the stream portion of a PDFObject. Calls decodeStream to un-filter the stream as
* necessary.
*
* @param dict the dictionary associated with this stream.
* @return a ByteBuffer with the encoded stream data
*/
private ByteBuffer readStream(PDFObject dict) throws IOException {
// pointer is at the start of a stream. read the stream and
// decode, based on the entries in the dictionary
PDFObject lengthObj = dict.getDictRef("Length");
int length = -1;
if (lengthObj != null) {
length = lengthObj.getIntValue();
}
if (length < 0) {
throw new PDFParseException("Unknown length for stream");
}
// slice the data
int start = this.buf.position();
ByteBuffer streamBuf = this.buf.slice();
streamBuf.limit(length);
// move the current position to the end of the data
this.buf.position(this.buf.position() + length);
int ending = this.buf.position();
if (!nextItemIs("endstream")) {
PDFDebugger.debug("read " + length + " chars from " + start + " to " + ending);
throw new PDFParseException("Stream ended inappropriately");
}
return streamBuf;
// now decode stream
// return PDFDecoder.decodeStream(dict, streamBuf);
}
