[squeak-dev] Dependencies on Cursor

Chris Muller asqueaker at gmail.com
Wed Jun 26 22:15:59 UTC 2013


> On 26-06-2013, at 2:49 PM, Chris Muller <asqueaker at gmail.com> wrote:
>> Let me offer another cold, hard example.  Maybe you can tell me here
>> what alternative will "cut it" over the Cursor?  The case of reifying
>> a proxy in a Smalltalk image to its real-object counterpart in a DB.
>> This is something that happens about 100 times per minute depending on
>> many factors.  Flipping the cursor provides a visual, real-time way to
>> understand, not only the frequency of proxy hits, but also the rate
>> which each hit is reifying.  A progress would not provide this
>> information, nor would it be appropriate to popping up 100 progress
>> bars per minute..  What else, then?
>
> Easy; for something like that you might want a simple UI element that flashes on/off as appropriate.

Hmmm, a simple UI element like the busy-Cursor?!   :)  Again, by the
time you ask yourself the question, "What is the system doing?" it's
too late to go back and open some external widget and "hook it up".
There is where the cursor's ubiquity and global-availability for UI
process serves well.  If it is not currently accepting input, then it
must indicate so to avoid user confusion and frustration -- but if it
must do THAT, why not let it provide a little bit more feedback about
what's going on by letting it be any of a number shapes?

>For a slightly more sophisticated feedback, perhaps something that glows brighter or more intense colours as the rate changes, or even a good old VU meter style widget? Even more info needed? How about a rate-sensitive meter and an associated actual log view that can be checked, reviewed, saved to file, whatever?
>
> I've been trying to keep the idea of a faintly exception related mechanism separate from whatever UI widget is best for any particular use; I hope that particular tree hasn't got lost in the woods of this long list of messages. A pop-up progress bar is only one of many options that would be useful.

You should have a look at my "MaClientProcess", which handles
everything you said (graceful pause and resume, graceful cancel,
calculation of rate and time remaining for the progress reporting) and
can even use resumable Notifications for control.  You'd probably like
it, but I never proposed putting it into Squeak because I see it as an
"app-level" thing where I see Squeak as general-purpose, not
necessarily an "app builder".


More information about the Squeak-dev mailing list