Preference refactoring again

> > sounds cool.
> > For me the most important aspect is that preferenceCollector (our
> > current preference class should be a removable layer on top
> > of the system that are declaring preference.
> >
> > Is is correct that
> >
> >  PreferenceCollector whenChanged: #gradientButtonLook inClass:
> > PrefProvider notify: self using: #gradientButtonLookIsNow: .
> >
> > means that PrefProvider will receive the message
> >         gradientButtonLookIsNow:
>  

> >
> > Stef
> >
> >
> > On Mar 1, 2009, at 10:05 AM, Alain Plantec wrote:
> >
>  
>> >> Hi all,
>> >>
>> >> joined Zoo package is a attempt to translate in code what we
>> >> discussed  here before about preference refactoring.
>> >>
>> >> The framework is made of 3 classes: PreferenceCollector,
>> >> PreferenceDefinition and PreferenceValue.
>> >> In Zoo there are also 2 classes for testing: PrefProvider and
>> >> PrefChangeListener.
>> >> PrefProvider class declares some preferences and PrefChangeListener
>> >> is here to test preference change notification.
>> >>
>> >> PrefChangeListener>>initialize
>> >>   super initialize.
>> >>   PreferenceCollector whenChanged: #gradientButtonLook inClass:
>> >> PrefProvider notify: self using: #gradientButtonLookIsNow: .
>> >>   PreferenceCollector whenChanged: #gradientButtonLook inClass:
>> >> PrefProvider notify: self using: #gradientLook:
>> >>
>> >> PrefChangeListener class>>test
>> >>   "self test"
>> >>   PrefChangeListener new inspect.
>> >>   PrefProvider  gradientButtonLook: PrefProvider gradientButtonLook
>> >> value not.
>> >>   PrefProvider  gradientButtonLook: PrefProvider gradientButtonLook
>> >> value not.
>> >>   PrefProvider  gradientButtonLook: PrefProvider gradientButtonLook
>> >> value not.
>> >>
>> >>
>> >> From PreferenceCollector comment:
>> >> --------------------------------------
>> >> A PreferenceCollector automatically collects all preferences.
>> >> A preference is represented by a PreferenceDefinition.
>> >> All  PreferenceDefinition are stored in the preferences instance
>> >> variable.
>> >>
>> >> Instance Variables
>> >>   preferences:        OrderedCollection of PreferenceDefinition
>> >>
>> >> preferences
>> >>   - contains all PreferenceDefinition which are automatically built
>> >> from pragma found in preference getters
>> >>
>> >>
>> >> ADDING A PREFERENCE
>> >> PreferenceCollector makes use of the SystemChangeNotifier in order to
>> >> automate the adding, the removing and the updating of preferences.
>> >> See #PreferenceCollector>>event:  to see how preferences update is
>> >> implemented.
>> >>
>> >> Editing a new method with a preference pragma or inserting a
>> >> preference pragma in an existing method are
>> >> the two ways for preference definition adding.
>> >> The only way to remove a preference definition is to remove the
>> >> corresponding method.
>> >>
>> >> Example of a "blackAndWhite" preference.
>> >> Methods below are defined by the preference provider
>> >> APreferencePrivider class.
>> >> Note that the value stored in BlackAndWhite class variable is an
>> >> instance of PreferenceValue.
>> >> In this example, the default value is directly given with the pragma:
>> >> -------------
>> >> APreferencePrivider class>>blackAndWhite
>> >>   <preference: 'Use black and white' type: #Boolean set:
>> >> #blackAndWhite: defaultValue: false description: 'Use black and white'>
>> >>   ^ BlackAndWhite
>> >>       ifNil: [BlackAndWhite := PreferenceValue value: false location:
>> >> self selector: #blackAndWhite]
>> >>
>> >> APreferencePrivider class>>blackAndWhite: aBoolean
>> >>       self blackAndWhite value: aBoolean
>> >> -------------
>> >>
>> >> If a default value can't be specified in the pragma, another way
>> >> consists in using a selector which
>> >> represents the message to send to the class in order to get the
>> >> default value:
>> >>
>> >> -------------
>> >> APreferencePrivider class>>standardFont
>> >>   <preference: 'The default system font' type: #LogicalFont set:
>> >> #standardFont: default: #defaultStandardFont description: 'The
>> >> default system font'>
>> >>   ^ StandardFont
>> >>       ifNil: [StandardFont := PreferenceValue value: self
>> >> defaultStandardFont location: self selector: #standardFont]
>> >>
>> >> APreferencePrivider class>>standardFont: aFont
>> >>   self standardFont value: aFont
>> >>  APreferencePrivider class>>defaultStandardFont
>> >>           ^ LogicalFont
>> >>                       familyName: 'Arial'
>> >>                       fallbackFamilyNames: nil
>> >>                       pointSize: 12
>> >>                       stretchValue: 5
>> >>                       weightValue: 400
>> >>                       slantValue: 0
>> >> -------------
>> >>
>> >> LISTENING TO A PREFERENCE VALUE CHANGE
>> >> Any object can register itself as a preference value change listener.
>> >> See #PreferenceCollector class>>whenChanged: inClass:notify:using:.
>> >>
>> >> Each time a preference value is changed, #preference:
>> >> inClass:changedWith: is sent to the PreferenceCollector class.
>> >>
>> >> Example of code a listener can implement in order to be notified each
>> >> time a gradientButtonLook preference defined by a PrefProvider class
>> >> is changed.
>> >> In this example, the listener ask to be notified by a send of
>> >> #gradientButtonLookIsNow: message.
>> >> The argument given to gradientButtonLookIsNow: is the new preference
>> >> value.
>> >> -------------
>> >>   ....
>> >>   PreferenceCollector whenChanged: #gradientButtonLook inClass:
>> >> PrefProvider notify: self using: #gradientButtonLookIsNow:.
>> >>   ....
>> >> -------------
>> >>
>> >> What do you think ?
>> >>
>> >> cheers
>> >> Alain
>> >>
>> >>
>> >> <Zoo-alain_plantec.10.mcz>_______________________________________________
>> >>
>> >> Pharo-project mailing list
>> >> [hidden email]
>> >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
>>    
> >
> >
> >
>