DLI Implementation and Reference Guide - Datalogics

6.2 DLI Implementation and Reference Guide
Introduction to Page Interface
Concepts and Facilities: Guide to the DL Pager Composition System
DLI presumes that pages will be added to the end of the document only. This is
required for optimal generation of the PDF Page Tree Structures, and matches the
most common modes for creating documents. If output to PDF is desired and local
PostScript is not, you may use DLI to create most pages, and then add pages out of
order to the document via the COS Layer interface. If local PostScript is enabled, these
added pages will be placed as if they were following the last page.
Page Structure
A page is represented in DLI by the data structure DLPDFPAGE. These data
structures, one per page, are tracked within the package and destroyed when the
document is destroyed. Pointers to these structures remain valid until the document is
destroyed.
Page Interface Calls
Calls available to the Page Interface in DLI are:
dlpdfpagefindfromnumber
This procedure will return the DLPDFPAGE construct for the specified page. This is
provided to allow pages to be modified after creation without having to keep pointers
to all of the pages in the application. If the page number specified has not yet been
created, a NULL pointer will be returned. The first page is considered to be page
number one.
dlpdfpagecreate
This procedure will create a new page in the current document. It will be positioned
following all other pages in the current document. If the specified document does not