Can bookmarks be added to secured PDFs and can the annotation and highlighting in Javelin be improved?
Secure PDFs are not the same as standard PDFs. You can amend a standard PDF and augment it, because the file format is essentially open and stored on disk as an accessible file that can be changed. With secure (encrypted/encoded) PDFs the file cannot be changed without decrypting it, changing it and re-encrypting it, and that is not possible because the encryption is performed by the publisher not by the end user and the viewable file is never copied to disk/everything is done in memory for security (on all platforms) – it would be technically and security-wise an impractical proposition. HOWEVER, on all platform there is some support for highlighting and annotation (handled by saving data in external files) and in the case of some platforms, e.g. Android, there is support for colour changes, so if you try using Javelin for Android and select the Settings icon on the home page of the app (cogwheel icon) it does allow you to select from a number of colour-related options. This will vary by platform, according to what facilities are available in a secure manner from the PDF rendering engine involved.
Apple’s PDF engines (which we use on iOS and OSX platforms) provide very good rendering and excellent display handling, but are almost completed closed and undocumented, so making changes with these platforms is quite a difficult process. Furthermore, most users will obtain the reader via Apple’s App Stores for OSX and for iOS, so there is always a lengthy process of submission and approval for any changes, and this adds to the complexity and time involved.
For Windows the situation at present is that the PDF rendering engine is quite old and has very limited options for display and augmentation – it works well within the confines of what we need s the core functionality, but is difficult if not impossible to enhance any further. Our plan is to replace this PDF library, hopefully by the end of this year/early next year, in order to be able to do things like display continuous pages, side-by-side, better highlighting, better annotation, but in all cases the over-riding constraint is the security that has to apply, so effectively the document is a tightly ‘locked’ block of encrypted/encoded data rather than an editable entity.