How do you make a button Morph tell three StringMorphs to change their contents?
Just for grins, I reconstructed the MultiTargetButtonMorph:
'From Squeak 1.31 of Feb 4, 1998 on 29 April 1998 at 12:45:29 pm'! SimpleButtonMorph subclass: #MultiTargetButtonMorph instanceVariableNames: '' classVariableNames: '' poolDictionaries: '' category: 'Morphic-Widgets'!
!MultiTargetButtonMorph methodsFor: 'initialization' stamp: 'bc 4/29/98 12:19'! initialize
super initialize. target := OrderedCollection new.! !
!MultiTargetButtonMorph methodsFor: 'events' stamp: 'bc 4/29/98 12:38'! doButtonAction "Perform the action of this button. Subclasses may override this method. The default behavior is to send the button's actionSelector to its target object with its arguments."
(target ~~ nil and: [actionSelector ~~ nil]) ifTrue: [ Cursor normal showWhile: [ target do: [ :item | item perform: actionSelector withArguments: arguments]]]. ! !
!MultiTargetButtonMorph methodsFor: 'menu' stamp: 'bc 4/29/98 12:35'! addCustomMenuItems: aCustomMenu hand: aHandMorph
super addCustomMenuItems: aCustomMenu hand: aHandMorph. ((self world rootMorphsAt: aHandMorph targetOffset) size > 1) ifTrue: [ aCustomMenu add: 'add to target' action: #addToTarget:. aCustomMenu add: 'remove from target' action: #removeFromTarget:].
! !
!MultiTargetButtonMorph methodsFor: 'menu' stamp: 'bc 4/29/98 12:21'! addToTarget: evt
| rootMorphs | rootMorphs _ self world rootMorphsAt: evt hand targetOffset. rootMorphs size > 1 ifTrue: [target addLast: (rootMorphs at: 2)] ifFalse: [^ self]. ! !
!MultiTargetButtonMorph methodsFor: 'menu' stamp: 'bc 4/29/98 12:21'! removeFromTarget: evt
| rootMorphs | rootMorphs _ self world rootMorphsAt: evt hand targetOffset. rootMorphs size > 1 ifTrue: [target remove: (rootMorphs at: 2)] ifFalse: [^ self]. ! !
!MultiTargetButtonMorph methodsFor: 'menu' stamp: 'bc 4/29/98 12:27'! setTarget: evt
| rootMorphs | rootMorphs _ self world rootMorphsAt: evt hand targetOffset. target := OrderedCollection new. rootMorphs size > 1 ifTrue: [target addLast: (rootMorphs at: 2)] ifFalse: [^ self]. ! !