KeyboardMake all functionality operable via a keyboard interface.
All functionality of the content is operable in a non time-dependent manner through a keyboard interface, except where the task requires analog, time-dependent input.
PDF documents provide interaction with the keyboard and mouse using the following features as described in Chapter 8, Interactive Features of the PDF Reference 1.6. This is a summary of the interactive items that need to be investigated in more detail.
Document and page level navigation
Document level navigation must be supported via the keyboard. PDF documents must provide navigation via one or more of the following mechanisms:
· Outlines (Bookmarks Tab)
· Thumbnail images (Pages Tab)
· Table of Contents
Page level navigation via:
· Page labels which can be different than the page index
· Article threads
· Presentations which are similar to slide shows in PowerPoint. Pages can be advanced automatically (specifying a time for the page to be displayed) or manually.
· Links within pages to content within the PDF document or external references
Annotations associate objects (movies, audio, text boxes) with locations in the PDF document. Users interact with the object using the keyboard or mouse. When the user activates the annotation by selecting it with the mouse or keyboard, the object’s action is performed. For example, a text box is displayed or a movie is played. PDF supports navigating between annotations in the document, usually using the tab key.
· Annotation appearance schemes support different visual looks. For example, a different look can be specified for rollover or down appearance schemes. Need to verify this supports action with the keyboard as well as the mouse.
· An extensive list of annotation types are defined including popup, movie, sound, text, link and highlight.
Actions can be applied to annotations or outline items to launch a specific action other than navigating to a place in the document.
· Actions can be chained together using Next entry so a single activating the object might launch multiple actions without user intervention. Might not be a keyboard issue, but may be an issue for keyboard users if these actions are not “visible” to assistive technology.
· Trigger Events can be defined for annotations, interactive form fields, page objects. Trigger events defined in the PDF Reference 1.6 specifically call out mouse actions and will need to be reviewed to ensure they support keyboard interaction as well.
Interactive forms support gathering information from a user. Users must be able to use the keyboard to navigate to and activate all fields. Field types include:
· Button fields (pushbutton, checkbox, radio button)
· Text fields (single line, multiline, password, rich text)
· Choice fields (list boxes, combo boxes)
· Signature fields
Measurement properties enable you to specify information about the scale and unit of measurement of objects such as graphics from CAD software. This is listed as an interactive object, but the link to keyboard access is unclear. There may be issues for screen reader users.
Adobe supports embedding a variety of media types in PDF files. Keyboard accessibility of the specific media is out of the scope of this working group as is the keyboard support of the player for the media. However, keyboard access to the object is within the scope. The user must be able to navigate to the multimedia object and activate it using only the keyboard.
Reference WCAG 2.0 Guideline 2.1 Make all functionality operable via a keyboard interface.
If the user can enter the content using the keyboard, then the user can exit the content using the keyboard.