WinTag

This structure provides the type of tags, which is used to identify sub-objects of views.

Signature of WinTag

List of Import References :
See BOOL
See Char
See Com
See DENOTATION
See Nat
See Option
See Real
See Seq
See Set
See String
See Void
See WinInternal
See WinTclTk

SIGNATURE WinTag

$Date: 2010-09-30 18:24:17 +0200 (Do, 30. Sep 2010) $ ($Revision: 616 $)

IMPORT  Com[tag]        ONLY com

The type of tags is re-exported from the internal level:

IMPORT  WinInternal     ONLY tag  : SORT 
                             tag  : denotation -> tag
                             name : tag -> denotation

FUN  = <        : tag ** tag    -> bool

The developer may freely create tags from denotations such as in tag("myTag"), in which case he is responsible for correctly managing the tag name spaces. Usually, each view which uses tags (such as canvases or text views) has its own name space. The names admissable for tags must start with a lower or upper letter (but not with "_"), and continue with digits or letters.

If one just wants to create some distinct tags and the naming doesn't matter, the command genTag is appropriate:

FUN  genTag     : com[tag]

This command creates an application unique tag distinct from all other tags. Generated tags start with an "_". This command may e.g. be used in constant definitions such as

DEF myTag == EXEC(genTag)

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