/**
*
* @param int $offset
* @return PdfIndirectObject
* @throws PdfException
*/
protected function parseObjectFromOffset($offset)
{
$matches = array();
$object = array();
$this->stream->seek($offset);
// assert "<x> <y> obj"
if (false === $this->stream->consume([['/[0-9]/', '+'], ['/\\s/', '+'], ['/[0-9]/', '+'], ['/\\s/', '+'], 'obj', ['/[^a-z]/']], $matches)) {
throw new PdfException('No object at ' . $offset);
}
$this->stream->seek(-1, SEEK_CUR);
$object['id'] = (int) $matches[0];
$object['revision'] = (int) $matches[2];
// Load PDF object
list($endPos, $value) = $this->objectParser->getNextObjectFromString($this->source, $this->stream->tell());
$this->stream->seek($endPos);
// Assert key word
if (false === $this->stream->consume([['/\\s/', '*'], ['/[a-z]/', '+'], ['/[^a-z]/']], $matches)) {
throw new PdfException('No key word found at ' . $this->stream->tell());
}
$this->stream->seek(-1, SEEK_CUR);
$keyWord = $matches[1];
switch ($keyWord) {
case 'stream':
if (!$value instanceof PdfDictionary) {
throw new PdfException('Value has to be a dictionary');
}
$this->stream->push();
$length = $this->resolveRef($value->get('/Length'));
$this->stream->pop();
$chars = $this->stream->read(2);
if ($chars === "\r\n") {
// nop
} elseif ($chars[0] === "\n") {
$this->stream->seek(-1, SEEK_CUR);
} else {
throw new PdfException('Expected \\n or \\r\\n after stream key word');
}
$value = new PdfStreamObject($value, $this->stream->tell(), $length);
$this->stream->seek($length, SEEK_CUR);
// Assert "endstream"
if (!$this->stream->consume([['/\\s/', '*'], 'endstream'])) {
throw new PdfException('Expected endstream key word');
}
// Assert "endobj"
if (!$this->stream->consume([['/\\s/', '*'], 'endobj'])) {
throw new PdfException('Expected endobj key word');
}
break;
case 'endobj':
// nop
break;
default:
throw new PdfException('Unexpected key word ' . $keyWord);
break;
}
$object['value'] = $value;
return new PdfIndirectObject($object['id'], $object['revision'], $object['value']);
}
/**
*
* @param PdfStream $stream
* @return PdfDictionary
* @throws PdfException
*/
protected function parseTrailer(PdfStream $stream)
{
if (trim($stream->gets()) !== 'trailer') {
throw new PdfException('trailer expected');
}
list(, $object) = $this->objectParser->getNextObjectFromString($stream->getContents(), 0);
if (!$object instanceof PdfDictionary) {
throw new PdfException('No dictionary found in trailer');
}
return $object;
}
