I don't know the best solution, but I checked change history to see where
the problem originated.

Prior to Morphic-mt.1512 of September 2019, UpdatingStringMorph
implemented #contents: and the implementation sent #changed if the
contents were changed.  Now we have #contents: only in the superclass
StringMorph, and it does not send #changed:.

Perhaps we should again override #contents: in UpdatingStringMorph
to detect the change?

UpdatingStringMorph>>contents: newContents 
	contents = newContents
		ifTrue: [super contents: newContents]
		ifFalse: [super contents: newContents.
			self changed]


I note that the old version of UpdatingStringMorph>>contents: (method stamp
aoy 2/17/2003) has this in its comment:

   "This is the original StringMorph implementation of #contents:, restored
    down in UpdatingStringMorph because a recent 'optimization' of the
    StringMorph version of this method broke UpdatingStringMorphs."

So it looks like the 2003 version was a bit of a hack to work around some
previous problem, and the 2019 version got rid of the hack but lost the
#changed notification.

Dave

On Sun, Jan 05, 2020 at 06:19:48PM +0100, karl ramberg wrote:
> We should make fitContens a bit smarter/ dumber. It should send changed
> even if extent is the same
> 
> UpdatingStringMorph>>fitContents
> 
> | newExtent |
> newExtent := self measureContents.
> newExtent := ((newExtent x max: self minimumWidth) min: self maximumWidth)
> @ newExtent y.
> (self extent = newExtent) ifFalse:
> [self extent: newExtent.
> self changed]
> 
> Best,
> Karl
> 
> On Sun, Jan 5, 2020 at 6:06 PM St??phane Rollandin <lecteur at zogotounga.net>
> wrote:
> 
> > Hello,
> >
> > As I already indicated one week ago, UpdatingStringMorph is currently
> > broken in trunk.
> >
> > If you do
> >
> >    (UpdatingStringMorph on: Time selector: #now) openInWorld.
> >
> > you will see that the display is not consistently updated as it should
> > via the #step method.
> >
> >
> > This can be fixed by adding a #changed in StringMorph>>#contents: as
> > follow:
> >
> >
> > StringMorph>>#contents: newContents
> >
> >         newContents isText
> >                 ifTrue: [^ self initializeFromText: newContents].
> >
> >         contents = newContents
> >                 ifTrue: [^ self "no substantive change"].
> >
> >         contents := newContents.
> >
> >         self fitContents; changed
> >
> >
> > Now maybe the #changed should be added to #fitContents itself.
> >
> > Stef
> >
> >

>