Adobe acrobat 7.0.5 sdk User Manual

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Technologies Supported by the Acrobat SDK
Plug-ins
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Acrobat Support
The Acrobat Support (AS) layer provides platform-independent utility functions and allows 
plug-ins to override the built-in file-handling mechanisms.
Cos Layer
The Cos Object System (Cos) layer provides access to the building blocks used to construct 
documents. Cos methods allow plug-ins to manipulate low-level data such as dictionary 
and string objects in a PDF file.
Whenever possible, you should use higher level APIs to access and manipulate PDF files. 
Though you can use the Cos layer APIs to perform most types of access or manipulation of a 
PDF file, it can be very difficult and requires in-depth knowledge of PDF file structure.
Platform-Specific Methods
In addition to the method groups represented in 
, the core API includes 
platform-specific plug-in utilities to handle issues that are unique to Macintosh, Windows 
and UNIX platforms. For more information, see the Acrobat SDK Plug-in Guide.
Extended APIs For Plug-ins
Plug-ins may expose their own functionality and make it available to other plug-ins, in the 
same way that Acrobat functionality is available through the core API. For example, Acrobat 
contains several plug-ins, such as Search and Digital Signatures, whose APIs are available to 
plug-ins. In fact, the Acrobat architecture encourages the use of plug-ins to “expose” APIs 
for use by other plug-ins. Acrobat uses many plug-ins to implement features; some of these 
plug-ins expose their APIs.
API “exposure” is accomplished through a mechanism called the Host Function Table (HFT). 
A plug-in can export an HFT for use by other plug-ins, and it can import the HFTs of other 
plug-ins.
To learn how to import and export HFTs, see the Acrobat SDK Plug-in Guide and the Acrobat 
and PDF LIbrary API Overview
.
Plug-in APIs
The following are the plug-ins that export HFTs. For more information, see the Acrobat and 
PDF Library Overview
 and the Acrobat and PDF Library Reference.
The Catalog Plug-in creates full-text indices, searchable with the Acrobat Search plug-in.
The Digital Signature Plug-in handles the generic functions common to all digital 
signatures. You can write a plug-in that handles your specific kinds of signatures 
(signing methods), such as public-private key (PPK), handwriting, retinal scans, or 
fingerprints. 
The Forms Plug-in helps make Acrobat a more powerful and comprehensive tool for 
creating and filling out electronic forms. With it, you can convert a PDF file into an 
electronic form that looks just like the original paper form. 
The PDF Consultant Plug-in allows you to inspect, analyze, and repair PDF documents.