SetOptionalContentVisible

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   Hi group,I am trying to use SetOptionalContentGroupVisible to hide some PDF layers in an existing PDF,
and then use the RenderPageToFile option to save a page as a new image file.
The image file always comes out blank.

Using Debenu 9.13, Delphi 2006

Here is my code:

         i := pdf.UnlockKey(<REGISTRATIONKEY>); // single developer licence code
         if i<>1 then raiseError;

         i := pdf.LoadFromFile(FPDFfilename,'');
         if i<>1 then raiseError;

         // get PDF layer names
         pdf.UseUnsafeContentStreams(1);
         imax := pdf.OptionalContentGroupCount;
         OutputDebugString(pchar(Format('PDF Layer Count: %d',[imax])));
         for i:=1 to imax do begin
            id := pdf.GetOptionalContentGroupID(i);
            s := pdf.GetOptionalContentGroupName(id);
            OutputDebugString(pchar(Format('PDF Layer: %d Name: %s',[id,s])));
         end;
         // turn off anno layer?
         pdf.SetOptionalContentGroupVisible(1476395013,Ord(false));

         i := pdf.RenderPageToFile(FRes,FPageNum,FImageFmt,FPDFTempImage);
         if i<>1 then raiseError;

The image created by RenderPageToFile always comes out blank if I try to use SetOptionalContentGroupVisible to hide any of the layers in the PDF file.
Am I calling the functions in the right order?
Anything else I am doing wrong?

Thanks,

Chris

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ChrisMorgan Members Profile Find Members Posts Beginner Joined: 23 Apr 13 Location: United Kingdom Status: Offline Points: 4	Post Options Post Reply Quote ChrisMorgan Report Post Thanks(0) Quote Reply Topic: SetOptionalContentVisible Posted: 23 Apr 13 at 5:47PM
	Hi group, I am trying to use SetOptionalContentGroupVisible to hide some PDF layers in an existing PDF, and then use the RenderPageToFile option to save a page as a new image file. The image file always comes out blank. Using Debenu 9.13, Delphi 2006 Here is my code: i := pdf.UnlockKey(<REGISTRATIONKEY>); // single developer licence code if i<>1 then raiseError; i := pdf.LoadFromFile(FPDFfilename,''); if i<>1 then raiseError; // get PDF layer names pdf.UseUnsafeContentStreams(1); imax := pdf.OptionalContentGroupCount; OutputDebugString(pchar(Format('PDF Layer Count: %d',[imax]))); for i:=1 to imax do begin id := pdf.GetOptionalContentGroupID(i); s := pdf.GetOptionalContentGroupName(id); OutputDebugString(pchar(Format('PDF Layer: %d Name: %s',[id,s]))); end; // turn off anno layer? pdf.SetOptionalContentGroupVisible(1476395013,Ord(false)); i := pdf.RenderPageToFile(FRes,FPageNum,FImageFmt,FPDFTempImage); if i<>1 then raiseError; The image created by RenderPageToFile always comes out blank if I try to use SetOptionalContentGroupVisible to hide any of the layers in the PDF file. Am I calling the functions in the right order? Anything else I am doing wrong? Thanks, Chris

ChrisMorgan Members Profile Find Members Posts Beginner Joined: 23 Apr 13 Location: United Kingdom Status: Offline Points: 4	Post Options Post Reply Quote ChrisMorgan Report Post Thanks(0) Quote Reply Posted: 24 Apr 13 at 3:48PM
	An update to my previous post. If I add pdf.SaveToFile('c:\temp.pdf'); after calling SetOptionalContentGroupVisible, then the temp.pdf has the specified layer correctly turned off. It is just the RenderPageToFile function which seems to be ignoring my layer visibility preferences. Any help? Thanks, Chris

Rowan Members Profile Find Members Posts Moderator Group Joined: 10 Jan 09 Status: Offline Points: 398	Post Options Post Reply Quote Rowan Report Post Thanks(0) Quote Reply Posted: 01 May 13 at 5:31AM
	Hi Chris, Some changes that you make to a PDF won't be applied until the PDF is saved. So try adding SaveToString and then LoadFromString prior to rendering the page. I hope this helps. Cheers, - Rowan.

ChrisMorgan Members Profile Find Members Posts Beginner Joined: 23 Apr 13 Location: United Kingdom Status: Offline Points: 4	Post Options Post Reply Quote ChrisMorgan Report Post Thanks(0) Quote Reply Posted: 07 May 13 at 9:34AM
	Hi Rowan, I am afraid this makes no difference. I have tried various combinations of SaveToString/LoadFromString and even SaveToFile/LoadFromFile. The reloaded PDF does have the layer visibility that I set, but the image that is created by RenderPageToFile either shows all of the layers or none of the layers - a blank image. Thanks, Chris

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 08 May 13 at 1:53PM
	Chris, There has been some recent work done in this area of the library but these changes should be in 9.13 already. Can you create an official support case and send me the problem PDF file and I will see what is going on. http://www.debenu.com/support/contact/ Andrew.

ChrisMorgan Members Profile Find Members Posts Beginner Joined: 23 Apr 13 Location: United Kingdom Status: Offline Points: 4	Post Options Post Reply Quote ChrisMorgan Report Post Thanks(0) Quote Reply Posted: 08 May 13 at 2:03PM
	Hi Andrew, I have already created a support case - 18739. On 1/5/2013 I sent a sample PDF and a source code for a simple Delphi 2006 console program that illustrates my problem. I can send it again if needed. Thanks, Chris