Vocabulary
ui.operations

Word description
An abstraction for an operation which may be performed on a presentation.

Operations have the following slots:

•	predicate - a quotation with stack effect ( obj -- ? )
•	command - a word
•	translator - a quotation with stack effect ( obj -- newobj ), or f
•	hook - a quotation with stack effect ( obj -- newobj ), or f
•	listener? - a boolean

Definition

IN: ui.operations

TUPLE: operation predicate command translator listener? ;

Methods

USING: accessors ui.commands ui.operations ;

M: operation command-description command>> command-description ;

USING: accessors ui.commands ui.operations ;

M: operation command-name command>> command-name ;

USING: accessors ui.commands ui.operations ;

M: operation command-word command>> command-word ;

USING: combinators ui.commands ui.operations ;

M: operation invoke-command operation-quot ( -- ) call-effect ;