"{ 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 $'

! !