Thanks a lot for your response Jeremias. I have now done the following:

- Added 'void warnRevision3PermissionsIgnored(Object source);' (and its 
javadoc) to PDFEventProducer in the org.apache.fop.render.pdf package and added 
a corresponding entry to the xml. Removed the 
org.apache.fop.pdf.PDFEventProducer class and xml.
- Created org.apache.fop.pdf.PDFEventListener interface containing just 'void 
warnRevision3PermissionsIgnored(Object source);'.
- Created PDFLibraryEventAdaptor in the org.apache.fop.render.pdf package that 
extends the PDFEventListener. (Currently just contains my new event. Should I 
also add the existing 2 render.pdf events to this class?)

 I can also see how to obtain the PDFDocument object from the
PDFEncryptionJCE class via the getDocumentSafely() method. But I am not sure 
how to get the event broadcaster from that object. How is this done?



On 11/05/11 19:46, Jeremias Maerki wrote:
Hi Michael

Creating a new EventBroadcaster is obviously wrong. The idea is that the
user can get events for each FOP rendering run separately (unlike
logging where concurrent runs get mixed up). So you have to get hold of
that EventBroadcaster applicable to the current rendering run. Obviously,
you don't have access to the FOUserAgent in the PDF library. That is
intentional because the PDF library should remain reasonably independent
of as much FOP code as possible for the case that we ever factor it out
into a separate component/module or move it to XML Graphics Commons.

My suggestion is to follow a similar path as done in
org.apache.fop.fonts: Create an interface for the events coming out of
the PDF library (see FontEventListener). Let's call it PDFEventListener
or something like that and put it in the org.apache.fop.pdf package.
Then move your PDFEventProducer (corresponds to FontEventProducer) into
org.apache.fop.render.pdf as this package makes the glue between FOP and
PDF output. Then create a PDFLibraryEventAdapter (implements PDFEventListener)
in the org.apache.fop.render.pdf package (corresponds to
FontEventAdapter). The PDFLibraryEventAdapter will get the
EventBroadcaster from the PDFDocumentHandler which is responsible for
instantiating the PDFDocument and PDFLibraryEventAdapter. The adapter is
then added as listener to a List<PDFEventListener>  that you can add to
PDFDocument. From PDFEncryptionJCE you should have access to the
PDFDocument via the getDocumentSafely() method. That nicely decouples
FOP's event subsystem from the PDF library.


On 11.05.2011 15:47:49 Michael Rubin wrote:
?Hello there. I have been busy implementing 128 bit PDF encryption for FOP. I 
have already got it working successfully but one issue remains that I have a 
question about.

In the org.apache.fop.pdf.PDFEncriptionJCE.init() method there is one place where I want 
to broadcast an event message. I looked 
at  to learn about events. However it 
just shows "EventBroadcaster broadcaster = [get it from somewhere];" and 
doesn't show how I should be getting the broadcaster. After looking in the code in the 
AFP package for existing examples I put together the following which seems to work on 

FopFactory fopFactory = FopFactory.newInstance();
FOUserAgent agent = fopFactory.newFOUserAgent();
EventBroadcaster eventBroadcaster = agent.getEventBroadcaster();
PDFEventProducer eventProducer = 

This creates a new FopFactory, from which I create a new FOUserAgent, from 
which I can get the event broadcaster to supply to my event producer. (I had to 
create a PDFEventProducer which extends EventProducer. Plus 
PDFEventProducer.xml which contains the message mapping.)

In this case the EventBroadcaster will be created new every time so I am not 
sure existing listeners will pick up. So is there a recommended way that I can 
get an existing event broadcaster to use? Or is the above way the correct way 
to do it after all?

Version of FOP is v1.0. Platform is Ubuntu Linux, running from within the 
Eclipse IDE.



Michael Rubin

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