Adobe Acrobat SDK
Introduction
Developing Plug-ins and Applications
Acrobat core API objects 18
Acrobat Support layer
The Acrobat Support (AS) layer provides a variety of utility methods, including platform-independent
memory allocation and fixed-point math utilities. In addition, it allows plug-ins to replace low-level file
system routines used by Acrobat (including read, write, reopen, remove file, rename file, and other
directory operations). This enables Acrobat to be used with other file systems, such as on-line systems.
Cos layer
The Cos Object System (Cos) layer provides access to the building blocks used to construct PDF
documents. Cos methods allow plug-ins and PDF Library applications to manipulate low-level data in a
PDF file, such as dictionary and data streams. For information, see
“Working with Cos Objects” on
page 178
.
Platform-specific methods
In addition to the method groups represented in the previous diagram, the Acrobat core API includes
platform-specific plug-in utilities to handle issues that are unique to Windows, Mac OS and Linux
platforms. For information about these methods, see the
Acrobat and PDF Library API Reference
.
Acrobat core API objects
Most objects accessible through AV and PD layer methods are opaque. That is, they are neither pointers
nor pointers to pointers. They provide equivalent functionality in that they reference an object’s data
rather than storing it. If you assign one object to another variable, both variables affect the same internal
object.
Objects are typically named using the following conventions:
●
The name of the concrete definition for a complex type ends in
Rec
(for record).
●
A pointer to a simple or complex type ends in
P
(for pointer).
●
Opaque types do not contain a
P
suffix. For example, a
PDDoc
object references a PDF document.
●
Three names identify complex types that provide callback methods:
Monitor
: A set of callbacks for an enumeration method.
Server
: An implementation of a service added by a plug-in.
Handler
: An implementation for a subtype of object handled by a plug-in
●
Callback method names typically contain the suffix
Proc
(for procedure).