On Sat, 26 Jun 1999 17:37:19 -0600 David Farber <dfarber at numenor.com> wrote: 
>so, i "fixed" both of these problems by rewriting addMorph: in ScrollPane to
>add new morphs to the scroller and then update itself. (i also had to make
>changes to initialize.)
>
>and it was Good.
>
>until, in the course...

David,

I wonder if it might be better not to rely on #addMorph: and its variants for the purpose of putting morphs into some sort of scrolling container. Perhaps a different protocol would make the intention clearer and avoid changing behavior that may be needed elsewhere. Enclosed is a small sample. File it in and evaluate "GenericScrollPane test".

Cheers,
Bob

'From Squeak 2.3 of January 14, 1999 on 1 July 1999 at 11:21:48 am'!
ScrollPane subclass: #GenericScrollPane
	instanceVariableNames: 'scrollingMorphHolder '
	classVariableNames: ''
	poolDictionaries: ''
	category: 'Morphic-Windows'!

!GenericScrollPane methodsFor: 'as yet unclassified' stamp: 'RAA 7/1/1999 11:14'!
addScrollingMorph: aMorph

	scrollingMorphHolder addMorphBack: (
		AlignmentMorph newRow 
			color: Color transparent;
			addMorph: aMorph
	).
! !

!GenericScrollPane methodsFor: 'as yet unclassified' stamp: 'RAA 7/1/1999 11:14'!
initialize

	super initialize.
	scroller addMorph: (
		scrollingMorphHolder _ AlignmentMorph newColumn color: Color transparent
	).
! !

!GenericScrollPane methodsFor: 'as yet unclassified' stamp: 'RAA 7/1/1999 11:01'!
layoutChanged

	super layoutChanged.
	self resizeScrollBar; resizeScroller; setScrollDeltas

! !


!GenericScrollPane class methodsFor: 'as yet unclassified' stamp: 'RAA 7/1/1999 11:21'!
test

	"GenericScrollPane test"

	| pane window |
	window _ (SystemWindow labelled: 'GenericScrollPane test') model: self.
	pane _ GenericScrollPane new.
	pane color: Color white.
	pane addScrollingMorph: (EllipseMorph new extent: 50 at 90).
	pane addScrollingMorph: (RectangleMorph new extent: 50 at 90).
	pane addScrollingMorph: (StringMorph contents: 'Hello world').
	pane addScrollingMorph: (TextMorph new).
	pane addScrollingMorph: (EllipseMorph new extent: 300 at 300; color: Color blue).
	window addMorph: pane frame: (0 at 0 extent: 1 at 1).
	window openInWorld
! !