operation
Factor handbook » UI framework » Implementing new gadgets » UI gestures » Operations

Next:define-operation ( pred command flags -- )


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

TUPLE: operation predicate command translator listener? ;


Methods