/**
* This will overlay two documents onto each other. The overlay document is repeatedly overlayed
* onto the destination document for every page in the destination.
*
* @param overlay The document to copy onto the destination
* @param destination The file that the overlay should be placed on.
* @return The destination pdf, same as argument passed in.
* @throws IOException If there is an error accessing data.
*/
public PDDocument overlay(PDDocument overlay, PDDocument destination) throws IOException {
pdfOverlay = overlay;
pdfDocument = destination;
PDDocumentCatalog overlayCatalog = pdfOverlay.getDocumentCatalog();
collectLayoutPages(overlayCatalog.getAllPages());
COSDictionary saveGraphicsStateDic = new COSDictionary();
saveGraphicsStateStream =
new COSStream(saveGraphicsStateDic, pdfDocument.getDocument().getScratchFile());
OutputStream saveStream = saveGraphicsStateStream.createUnfilteredStream();
saveStream.write(" q\n".getBytes("ISO-8859-1"));
saveStream.flush();
restoreGraphicsStateStream =
new COSStream(saveGraphicsStateDic, pdfDocument.getDocument().getScratchFile());
OutputStream restoreStream = restoreGraphicsStateStream.createUnfilteredStream();
restoreStream.write(" Q\n".getBytes("ISO-8859-1"));
restoreStream.flush();
PDDocumentCatalog pdfCatalog = pdfDocument.getDocumentCatalog();
processPages(pdfCatalog.getAllPages());
return pdfDocument;
}
private COSStream makeUniqObjectNames(Map objectNameMap, COSStream stream) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream(10240);
byte[] buf = new byte[10240];
int read;
InputStream is = stream.getUnfilteredStream();
while ((read = is.read(buf)) > -1) {
baos.write(buf, 0, read);
}
buf = baos.toByteArray();
baos = new ByteArrayOutputStream(buf.length + 100);
StringBuffer sbObjectName = new StringBuffer(10);
boolean bInObjectIdent = false;
boolean bInText = false;
boolean bInEscape = false;
for (int i = 0; i < buf.length; i++) {
byte b = buf[i];
if (!bInEscape) {
if (!bInText && b == '(') {
bInText = true;
}
if (bInText && b == ')') {
bInText = false;
}
if (b == '\\') {
bInEscape = true;
}
if (!bInText && !bInEscape) {
if (b == '/') {
bInObjectIdent = true;
} else if (bInObjectIdent && Character.isWhitespace((char) b)) {
bInObjectIdent = false;
// System.err.println(sbObjectName);
// String object = sbObjectName.toString();
String objectName = sbObjectName.toString().substring(1);
String newObjectName = objectName + "overlay";
baos.write('/');
baos.write(newObjectName.getBytes("ISO-8859-1"));
objectNameMap.put(objectName, COSName.getPDFName(newObjectName));
sbObjectName.delete(0, sbObjectName.length());
}
}
if (bInObjectIdent) {
sbObjectName.append((char) b);
continue;
}
} else {
bInEscape = false;
}
baos.write(b);
}
COSDictionary streamDict = new COSDictionary();
streamDict.setInt(COSName.LENGTH, baos.size());
COSStream output = new COSStream(streamDict, pdfDocument.getDocument().getScratchFile());
output.setFilters(stream.getFilters());
OutputStream os = output.createUnfilteredStream();
baos.writeTo(os);
os.close();
return output;
}