Adobe acrobat 7.0.5 sdk 用户手册
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Accessibility
Annotations and Accessibility
14
Setting Tab Order
Because most users use the tab key to traverse a form, the tab order of the fields should be
set in a logical way. This is especially important for visually impaired users, as they cannot
rely on mouse movements or visual clues.
set in a logical way. This is especially important for visually impaired users, as they cannot
rely on mouse movements or visual clues.
Pressing the tab (shift-tab) key when there is no form field that has the focus causes the first
(last) field in the tab order on the current page to become active. If there are no form fields
on the page, Acrobat alerts the user of this via a speech cue.
(last) field in the tab order on the current page to become active. If there are no form fields
on the page, Acrobat alerts the user of this via a speech cue.
Annotations and Accessibility
In Acrobat 6.0, annotations in PDF documents were not fully and easily accessible. This
presented a challenge to visually-impaired users who access Acrobat through assistive
technologies, such as screen readers and screen magnifiers.
presented a challenge to visually-impaired users who access Acrobat through assistive
technologies, such as screen readers and screen magnifiers.
The Acrobat 7.0.5 SDK adds a new annotation accessibility API for the generalized interface
between annotations and accessibility so that new and custom annotation types can be
supported more easily and reliably.
between annotations and accessibility so that new and custom annotation types can be
supported more easily and reliably.
A new callback function,
AVAnnotHandlerGetAccessibilityString
, has been
added to the
AVAnnotHandler
record. Note that there is one annotation handler for
each annotation type. For more information, see the Acrobat and PDF Library API Reference.
Tagged Annotations
Annotations can be dynamically associated with a new structure tree that is separate from
the original content of the document. This supports accessibility without modifying the
original content.
the original content of the document. This supports accessibility without modifying the
original content.
Text-To-Speech
Text-To-Speech engines can translate structured text in a PDF document into audible
sound.
sound.
To access the Text-To-Speech engine from Acrobat JavaScript, use the TTS object, which
has methods to render text as digital audio and present it in spoken form to the user.
has methods to render text as digital audio and present it in spoken form to the user.
Accessibility and Security
It is not necessary to sacrifice security in order to make a document accessible: select the
Enable Text Access for Screen Reader Devices for the Visually Impaired option in the
Security section of Document Properties.
Enable Text Access for Screen Reader Devices for the Visually Impaired option in the
Security section of Document Properties.