Dependencies Question

Hi

I'm building a breakOut for my book and I have the following problem.

I have one object that contains the score of the game that get increased 
each time a brick is destroyed.

Now I copied a bit the code of the SameGame to get a list of button around 
my game field and in particular I want to display the score. So here is my 
question.

In VisualWorks I would changed the Field score instance variable into a 
value holder and I will initialize the BreakOut class to get notify 
whether the score variable changes.


How can I do the same in Squeak?

I started to

Field>>score: aNumber

        score := aNumber.
        self changed


BreakOut>>initializeToStandAlone

        ...
        self field addDependent: self


BreakOut>>udpate

        Transcript show: 'Breakout update' ; cr

But I got nothing.

I checked a bit and I was surprised to see that dependents are still 
managed in Squeak via the DependentFields. I read in old VW tutorials and 
books that this way of doing things was bad because all the dependents 
were stored in the same dict. I checked and Model is there :)
But Morph does not implement a different ways of storing dependents.


Then I checked

Morph>>changed
        "Report that the area occupied by this morph should be redrawn."
        ^fullBounds
                ifNil:[self invalidRect: self outerBounds]
                ifNotNil:[self invalidRect: fullBounds]

And realized that Morph was simply breaking the dependency 
protocol.....(no comment)

So here is my question:
        - how do we get notification and registration in Squeak for a morph?


Stef

PS: The dependencies mechanism start to be old and broadcasting too much. 
Is there somebody thinking about a new architecture? Events or 
DependencyTransformer like in VW ....




Dr. Stéphane DUCASSE (ducasse@xxxxxxxxxxxx) 
http://www.iam.unibe.ch/~ducasse/
 "if you knew today was your last day on earth, what would you do
 different? ... especially if, by doing something different, today
 might not be your last day on earth" Calvin&Hobbes