/**
* Rollback document $steps number of revisions.
* This method must be invoked before any changes, applied to the document.
* Otherwise behavior is undefined.
*
* @param integer $steps
*/
public function rollback($steps)
{
for ($count = 0; $count < $steps; $count++) {
if ($this->_trailer->getPrev() !== null && $this->_trailer->getPrev()->Root !== null) {
$this->_trailer = $this->_trailer->getPrev();
} else {
break;
}
}
$this->_objFactory->setObjectCount($this->_trailer->Size->value);
// Mark content as modified to force new trailer generation at render time
$this->_trailer->Root->touch();
$this->pages = array();
$this->_loadPages($this->_trailer->Root->Pages);
}
/**
* Object constructor
*
* Note: PHP duplicates string, which is sent by value, only of it's updated.
* Thus we don't need to care about overhead
*
* @param mixed $source
* @param Zend_Pdf_ElementFactory $factory
* @param boolean $load
* @throws Zend_Exception
*/
public function __construct($source, Zend_Pdf_ElementFactory $factory, $load)
{
if ($load) {
if (($pdfFile = @fopen($source, 'rb')) === false) {
throw new Zend_Pdf_Exception("Can not open '{$source}' file for reading.");
}
$byteCount = filesize($source);
$data = '';
while ($byteCount > 0 && ($nextBlock = fread($pdfFile, $byteCount)) != false) {
$data .= $nextBlock;
$byteCount -= strlen($nextBlock);
}
fclose($pdfFile);
$this->_stringParser = new Zend_Pdf_StringParser($data, $factory);
} else {
$this->_stringParser = new Zend_Pdf_StringParser($source, $factory);
}
$pdfVersionComment = $this->_stringParser->readComment();
if (substr($pdfVersionComment, 0, 5) != '%PDF-') {
throw new Zend_Pdf_Exception('File is not a PDF.');
}
$pdfVersion = (double) substr($pdfVersionComment, 5);
if ($pdfVersion < 0.9 || $pdfVersion >= 1.61) {
/**
* @todo
* To support PDF versions 1.5 (Acrobat 6) and PDF version 1.7 (Acrobat 7)
* Stream compression filter must be implemented (for compressed object streams).
* Cross reference streams must be implemented
*/
throw new Zend_Pdf_Exception(sprintf('Unsupported PDF version. Zend_Pdf supports PDF 1.0-1.4. Current version - \'%f\'', $pdfVersion));
}
$this->_stringParser->offset = strrpos($this->_stringParser->data, '%%EOF');
if ($this->_stringParser->offset === false || strlen($this->_stringParser->data) - $this->_stringParser->offset > 7) {
throw new Zend_Pdf_Exception('Pdf file syntax error. End-of-fle marker expected at the end of file.');
}
$this->_stringParser->offset--;
/**
* Go to end of cross-reference table offset
*/
while (Zend_Pdf_StringParser::isWhiteSpace(ord($this->_stringParser->data[$this->_stringParser->offset])) && $this->_stringParser->offset > 0) {
$this->_stringParser->offset--;
}
/**
* Go to the start of cross-reference table offset
*/
while (!Zend_Pdf_StringParser::isWhiteSpace(ord($this->_stringParser->data[$this->_stringParser->offset])) && $this->_stringParser->offset > 0) {
$this->_stringParser->offset--;
}
/**
* Go to the end of 'startxref' keyword
*/
while (Zend_Pdf_StringParser::isWhiteSpace(ord($this->_stringParser->data[$this->_stringParser->offset])) && $this->_stringParser->offset > 0) {
$this->_stringParser->offset--;
}
/**
* Go to the white space (eol marker) before 'startxref' keyword
*/
$this->_stringParser->offset -= 9;
$nextLexeme = $this->_stringParser->readLexeme();
if ($nextLexeme != 'startxref') {
throw new Zend_Pdf_Exception(sprintf('Pdf file syntax error. \'startxref\' keyword expected. Offset - 0x%X.', $this->_stringParser->offset - strlen($nextLexeme)));
}
$startXref = $this->_stringParser->readLexeme();
if (!ctype_digit($startXref)) {
throw new Zend_Pdf_Exception(sprintf('Pdf file syntax error. Cross-reference table offset must contain only digits. Offset - 0x%X.', $this->_stringParser->offset - strlen($nextLexeme)));
}
$this->_trailer = $this->_loadXRefTable($startXref);
$factory->setObjectCount($this->_trailer->Size->value);
}
