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	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E

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CHAPTER 23. PRESENTATION TYPES

5. The translator's tester returned true. If there is no tester, the translator behaves as though
   there is a tester that always returns true.
   
   
6. If there are parameters in the input context type and the tester is not declared to be
   definitive, the value returned by body of the translator must be presentation-typep of
   the context type.
   

Note that the type parameters from the presentation's type have no effect on translator lookup.

find-presentation-translator is responsible for the first two steps of the matching algorithm,
and test-presentation-translator is responsible for the remaining steps.

When a single translator is being chosen (such as is done by throw-highlighted-presentation),
it is possible that more than one translator having the same gesture may be applicable to the
presentation in the specified input context. In this case, the translator having the highest pri-
ority will be chosen. If there is more than one having the same priority, it is unspecified what
translator will be chosen.

The matching algorithm is somewhat more complicated in face of nested presentations and
nested input contexts. In this case, the applicable presentation is the smallest presentation that
matches the innermost input context.

Sometimes there may be nested presentations that have exactly the same bounding rectangle. In
this case, it is not possible for a user to unambiguously point to just one of the nested presenta-
tions. Therefore, when CLIM has located the innermost applicable presentation in the innermost
input context, it must then search for outer presentations having exactly the same bounding rect-
angle, checking to see if there are any applicable translators for those presentations. If there are
multiple applicable translators, the one having the highest priority is chosen. find-applicable-
translators, call-presentation-menu, throw-highlighted-presentation, and the compu-
tation of pointer documentation must all take this situation into account.

The translators are searched in the order that they are returned by find-presentation-
translators. The rules for the ordering of the translators are described under that function.

23.8 Standard Presentation Types

The following sections document the presentation types supplied by CLIM. Any presentation
type with the same name as a Common Lisp type accepts the same parameters as the Common
Lisp type (and additional parameters in a few cases).

23.8.1 Basic Presentation Types

=> t [Presentation Type]
The supertype of all other presentation types.

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Page 234	Table of Contents	Index	Page 236
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E