AsTeR can render a given object in more than one way. The listener can switch among any of several predefined renderings for a given object to produce different views, or add to these by defining new rendering rules.
Activating a rendering rule is the simplest way of changing how a given object is rendered. Statement
(activate-rule object-name rule-name)activates rule rule-name for object object-name. Thus, executing (activate-rule 'paragraph 'summarize)
activates rule summarize for object paragraph.
Suppose we wish to skip all instances of verbatim text in a LaTeX document. We could define and activate the following quiet rendering rule for object verbatim:
Later, to hear the verbatim text in a document, the previously activated rule quiet can be deactivated by executing
Notice that at any given time, only one rendering rule is active for any object. Hence, we need only specify the object name when deactivating a rendering rule.
Activating a new rule is a convenient way of changing how instances of a specific object are rendered. Rendering styles enable the user to make more global changes to the renderings. Activating style style-1 by executing
activates rendering rule style-1 for all objects for which this rendering rule is defined. All other objects continue to be rendered as before. This is also true when a sequence of rendering styles is successively activated. Thus, activating rendering styles is a convenient way of progressively customizing the rendering of a complex document.
The effect of activating a style can be undone at any time by executing
AsTeR provides the following rendering styles:
When AsTeR is initialized, the following styles are active, with the leftmost style being the most recently activated style.
Defining a new rendering style is equivalent to defining a collection of rendering rules having the same name. Note that a rendering style need not provide rules for all objects in the document logical structure. As explained earlier, activating a style only affects the renderings of those objects for which the style provides a rule.