"
COPYRIGHT (c) 1992 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
Object subclass:#Model
instanceVariableNames:'dependents'
classVariableNames:''
poolDictionaries:''
category:'Interface-Support-Models'
!
!Model class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1992 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
!
documentation
"
Models are things that are presented in views. Instances keep track of
which views are dependent of them and inform them of any changes.
Actually the Model class is not really needed; since the dependency
mechanism is inherited by Object, you can take any object as a model.
However, instances of Model (and subclasses) keep the dependents locally
in an instance variable; thus speeding up access a bit.
Instance variables:
dependents Collection those objects which depend on me.
To save some storage, the dependent is
kept directly here, IFF there os only one.
Otherwise, a collection of dependents is
held here.
"
! !
!Model methodsFor:'copying'!
postCopy
"release dependents after copying"
self dependents:nil
! !
!Model methodsFor:'dependents access'!
addDependent:anObject
"make the argument, anObject be a dependent of the receiver"
[
|deps|
deps := dependents.
"/
"/ store the very first dependent directly in
"/ the dependents instVar
"/
(deps isNil and:[anObject isCollection not]) ifTrue:[
dependents := anObject
] ifFalse:[
"/
"/ store more dependents in the dependents collection
"/
deps isCollection ifTrue:[
deps add:anObject
] ifFalse:[
dependents := IdentitySet with:dependents with:anObject
]
]
] valueUninterruptably
"Modified: 19.4.1996 / 12:24:46 / cg"
!
dependents
"return a Collection of dependents - nil if there is none"
dependents isNil ifTrue:[^ nil].
dependents isCollection ifTrue:[
^ dependents
].
^ IdentitySet with:dependents
"Modified: 19.4.1996 / 12:22:04 / cg"
!
dependents:aCollection
"set the collection of dependents"
|dep|
aCollection size == 1 ifTrue:[
dep := aCollection first.
dep isCollection ifFalse:[
dependents := aCollection first.
^ self
]
].
dependents := aCollection
"Modified: 19.4.1996 / 12:23:05 / cg"
!
dependentsDo:aBlock
"evaluate aBlock for all of my dependents"
|deps|
deps := dependents.
deps notNil ifTrue:[
deps isCollection ifTrue:[
deps do:aBlock
] ifFalse:[
aBlock value:deps
]
]
!
release
"remove all dependencies from the receiver"
dependents := nil
"Modified: 19.4.1996 / 10:31:35 / cg"
!
removeDependent:anObject
"make the argument, anObject be independent of the receiver"
[
|deps sz dep|
deps := dependents.
deps notNil ifTrue:[
deps isCollection ifTrue:[
deps remove:anObject ifAbsent:[].
(sz := deps size) == 0 ifTrue:[
dependents := nil
] ifFalse:[
sz == 1 ifTrue:[
(dep := deps first) isCollection ifFalse:[
dependents := dep
]
]
]
] ifFalse:[
dependents := nil
]
]
] valueUninterruptably
"Modified: 19.4.1996 / 12:24:24 / cg"
! !
!Model methodsFor:'dependents access (non weak)'!
addNonWeakDependent:anObject
"make the argument, anObject be a dependent of the receiver.
Since all dependencies are nonWeak in Model, this is simply
forwarded to addDependent:"
^ self addDependent:anObject
"Created: 19.4.1996 / 10:28:53 / cg"
!
interrests
"return a Collection of interrests - nil if there is none.
Here, we use the normal dependents collection for interrests."
^ self dependents
"Created: 19.4.1996 / 12:28:23 / cg"
"Modified: 19.4.1996 / 18:07:12 / cg"
!
nonWeakDependents
"return a Collection of dependents - nil if there is none.
Since all dependencies are nonWeak in Model, this is a dummy."
^ self dependents
"Created: 19.4.1996 / 10:29:43 / cg"
"Modified: 19.4.1996 / 18:07:31 / cg"
!
removeNonWeakDependent:anObject
"make the argument, anObject be independent of the receiver.
Since all dependencies are nonWeak in Model, this is simply
forwarded to removeDependent:"
^ self removeDependent:anObject
"Created: 19.4.1996 / 12:19:40 / cg"
! !
!Model methodsFor:'drawing'!
displayOn:aGraphicsContext
"display myself in aGraphicsContext"
^ self subclassResponsibility
!
displayOn:aGraphicsContext clippingBox:aRectangle
"display a part of me in aGraphicsContext"
^ self subclassResponsibility
! !
!Model class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libview2/Model.st,v 1.22 1996-04-19 16:07:39 cg Exp $'
! !