"{ Package: 'stx:libview2' }"

ProtocolAdaptor subclass:#DictionaryAdaptor
	instanceVariableNames:'myAspect'
	classVariableNames:''
	poolDictionaries:''
	category:'Interface-Support-Models'
!

!DictionaryAdaptor class methodsFor:'documentation'!

documentation
"
    Similar to AspectAdaptor, but accesses a Dictionary instead of
    a classes instance variables.

    [author:]
        Stefan Vogel (stefan@zwerg)

    [instance variables:]

    [class variables:]

    [see also:]

"
!

examples
"
                                                                        [exBegin]
        |dialog dict dataModel|

        dict := Dictionary new.
        dict
            at:#field1 put:'hello';
            at:#field2 put:'one';
            at:#field3 put:'two';
            at:#field4 put:'three'.

        dialog := DialogBox new.
        dialog addTextLabel:'1:'.
        dialog addInputFieldOn:(DictionaryAdaptor new
                                        subject:dict; 
                                        aspect:#field1). 
        dialog addTextLabel:'2:'.
        dialog addInputFieldOn:(DictionaryAdaptor new
                                        subject:dict; 
                                        forAspect:#field2).
        dialog addTextLabel:'3:'.
        dialog addInputFieldOn:(DictionaryAdaptor new
                                        subject:dict; 
                                        aspect:#field3). 
        dialog addTextLabel:'4:'.
        dialog addInputFieldOn:(DictionaryAdaptor new
                                        subject:dict; 
                                        forAspect:#field4).
        dialog addOkButton.
        dict inspect.
        dialog open.
        dialog accepted ifTrue:[
            Transcript showCR:'data now: ' , dict printString
        ]
                                                                        [exEnd]
"
! !

!DictionaryAdaptor class methodsFor:'instance creation'!

forAspect:anAspect
    "create and return a new adaptor, which forwards requests
     to anObject, using anAspect to access a Dictionary. 
     The returned object can be used in place of a ValueHolder"

    ^ self new forAspect:anAspect
!

subject:anObject sendsUpdates:aBoolean aspect:aspect
    "create and return a new adaptor, which forwards requests
     to anObject, using #at:aspect and #at:aspect put: for access.
     The returned object can be used in place of a ValueHolder"

    ^ (self subject:anObject sendsUpdates:aBoolean) aspect:aspect
! !

!DictionaryAdaptor methodsFor:'accessing-spec'!

aspect:aSelector
    "set the adapters change aspect - this is the aspect of the update message,
     on which the adaptor reacts"

    myAspect := aSelector.
!

forAspect
    "get the adapters aspect"

    ^ myAspect
!

forAspect:aSelector
    "set the adapters aspect"

    myAspect := aSelector.
! !

!DictionaryAdaptor methodsFor:'accessing-value'!

setValue:newValue
    "set the value - this forwards a putMessage to the target"

    |target oldValue|

    target := self subjectValue.
    target isNil ifTrue:[^ nil].

    oldValue := target at:myAspect.
    oldValue ~~ newValue ifTrue:[
        target at:myAspect put:newValue.
    ]
!

value
    "translate a query for my value from my user
     into an aspect access towards my subject"

    |target|

    target := self subjectValue.
    target isNil ifTrue:[^ nil].
    ^ target at:myAspect ifAbsent:[].
!

value:newValue
    "set the value - this changes the target with #at:put:
     and sends out a changeNotification if the value did really change."

    |target oldValue|

    target := self subjectValue.
    target isNil ifTrue:[^ self].

    oldValue := target at:myAspect ifAbsent:[].
    oldValue ~~ newValue ifTrue:[
        target at:myAspect put:newValue.
        subjectSendsUpdates ifFalse:[
            self changed:#value
        ]
    ]
! !

!DictionaryAdaptor methodsFor:'change & update'!

update:something with:aParameter from:changedObject
    "translate an update from the model into a #value-change
     via my depenedents ..."

    ((changedObject == subject and:[something == myAspect])
    or:[changedObject == subjectChannel]) ifTrue:[
        self changed:#value
    ].
! !

!DictionaryAdaptor class methodsFor:'documentation'!

version
    ^ '$Header: /cvs/stx/stx/libview2/DictionaryAdaptor.st,v 1.2 2009-09-18 16:14:09 cg Exp $'
! !