Sorry for the delayed reply.  Yes absolutely,
ProgressInitiationException is a better candidate to be responsible
for knowing the users preferred location for progress-indication than
DisplayScreen.

I also like the idea of a helper-method that would be able to simplify
the API; e.g., by not requesting an exact Point location for progress
bar (by just excluding that argument) and, in that case, falling back
to the preference.

Requesting an exact point seems like unnecessary flexibility, but
since it's already supported by the Morphs we may as well leave it.
However, being able to simplify all of those hundred+ senders (however
many it is) to not have to repeatedly say, "Display
preferredProgressPosition" or whatever is addition-by-subtraction.
Excellent!

  - Chris


On Thu, Jun 9, 2011 at 4:31 PM, Levente Uzonyi <leves at elte.hu> wrote:
> On Tue, 7 Jun 2011, Chris Muller wrote:
>
>>> Which class will implement the preference? DisplayScreen?
>>
>> Yes, that seems like a very reasonable candidate to me.  My only
>> question is, do we want to maintain #cursorPoint as a viable option
>> for displaying progress bar?  It seems reasonable to me, but then we
>> would have to either have a case check or implement cursorPoint on
>> DisplayScreen..
>>
>
> Thinking a bit about it I came to the following idea:
> The preference would be added to ProgressInitiationException. The values of
> the preference would be symbols, like #cursorPoint, #center, #topCenter,
> etc. The exception would use UIManager to find out what the symbol means.
> The value of the preference would be used when no point would be requested
> (nil value). This way we wouldn't introduce unnecessary dependencies.
> Ideally one would be able to write things like
> 'foo' displayProgressAt: #center from: ...
> Or another helper method using the value of the preference:
> 'foo' displayProgressFrom: ...
>
> This requires a new kind of preference where the user can select it's value
> from a predefined list. I'm sure this would also be useful in other cases.
>
> What do you think?
>
>
> Levente
>