Object subclass:#PrintConverter 

	 instanceVariableNames:'valueToStringBlock stringToValueBlock'

	 classVariableNames:''

	 poolDictionaries:''

	 category:'Interface-Support'

!

!PrintConverter class methodsFor:'documentation'!

version 

"

$Header: /cvs/stx/stx/libview2/PrintConverter.st,v 1.1 1995-05-03 18:15:57 claus Exp $

"

!

documentation

"

    printConverters are used with editFields to convert an object

    to/from some printed representation.

    Conversion is done via two blocks which can be set at instance

    creation time - either as custom blocks ot to one of the

    standard conversions.

    Notice: this class was implemented using protocol information

    from alpha testers - it may not be complete or compatible to

    the corresponding ST-80 class. If you encounter any incompatibilities,

    please forward a note to the ST/X team.

"

!

examples 

"

    |conv|

    conv := (PrintConverter new)

		toPrint:[:date | date printString]

		toRead:[:string | Date readFromString:string].

    (conv printStringFor:(Date today)) inspect.

    (conv readValueFrom:(Date today printString)) inspect

    |conv|

    conv := (PrintConverter new) initForNumber.

    (conv printStringFor:12345) inspect.

    (conv readValueFrom:'12345') inspect

    see concrete uses in the EditField examples.

"

! !

!PrintConverter class methodsFor:'instance creation'!

new

    ^ (super new) 

	toPrint:[:val | val]

	toRead:[:string | string]

! !

!PrintConverter methodsFor:'initialization'!

toPrint:printBlock toRead:readBlock

    valueToStringBlock := printBlock.

    stringToValueBlock := readBlock.

!

initForNumber

    valueToStringBlock := [:num | num printString].

    stringToValueBlock := [:string | Number readFromString:string onError:0]

!

initForNumberOrNil

    valueToStringBlock := [:num | num isNil ifTrue:[''] ifFalse:[num printString]].

    stringToValueBlock := [:string | Number readFromString:string onError:nil]

!

initForString

    valueToStringBlock := [:val | val isNil ifTrue:[''] ifFalse:[val]].

    stringToValueBlock := [:string | string]

!

initForDate

    valueToStringBlock := [:date | date printString].

    stringToValueBlock := [:string | Date readFromString:string onError:[Date today]]

! !

!PrintConverter methodsFor:'converting'!

printStringFor:aValue

    ^ valueToStringBlock value:aValue

!

readValueFrom:aString

    ^ stringToValueBlock value:aString

! !