Ah – because that appearance stream is then added by Acrobat at the time of rendering, which means the file has been modified!
Appearances are optional, EXCEPT in this case – for security reasons.
Thank you lrosenth,
But adding an appearance stream for each annotation type, especially for ink annotations, is very tough, so how can I avoid adding
appearance stream, or adding a fake appearance, that is not processed by Acrobat, but still considered to be existed ?
I guess it depends on where you come from. For many, adding a digital signature and/or timestamp would be more difficult than drawing an ink annotation.
But yes, if you are going to sign, then you have to apply the appearance. You can add a fake appearance, but then the user will see the fake appearance and not the real thing – which is probably not what you want.
I am already able to add many annotation types, including ink annotations, for pdfs with rotated pages. But I feel that this is easier than
creating appearance streams with low-level drawing commands, is there a way to build the appearance stream from the annotation properites;
color, stroke with, inklist, etc.
Thank you Rog.
The way to build the appearance stream is to read all the properties and then use them to build the appearance stream.
The Acrobat SDK already provides APIs for doing all this.
I was eble to add an ink annotation with an appearance stream, and then signing the document with digital signature goes fine with no problems
( No "Annotations Modified" ) message appearing in the signature panel, but adding a freetext annotation with an appearance stream and then signing, is causing acrobat to show "At least one signature requires validating" message in the signature bar, and by validating the signature manually by pressing "Validate All" in the signature panel, the original problem appears again stating "Annotations Modified". So is freetext annotations should be considered in a different way than other annotation types ?
its becouse the document was changed maybe...