karl wrote:

> Dave Mason wrote:
>
>> I'm trying to do something that should be very simple.  I have a clock
>> model that I want to tick over every second.  Then I want to hand that
>> model to a Morphic viewer to display.
>>
>> I initially set up a ticker process, based on some code in Mark
>> Guzdial's Squeak&MMA book, section 4.2.  It worked fine, except
>> periodically morphic windows that were being updated would be trashed.
>>
>> So, figuring that I had an unfortunate timing issue between the Morphic
>> updater and the asynch process, I changed my clock model to extend Morph
>> and use the #step method to update the clock (which led to a crash
>> documented on Mantis, but I was directed to a work-around).  It now
>> works fine, except the step method gets called once for every view I
>> have open, as well as the intended one, so my clock goes up in
>> increments of 2 or 3 seconds per second.
>>
>> My original thought was to have the ticker insert events into Morphic's
>> event queue, but (a) I couldn't quite track it down, and (b) from what I
>> found, it seemed to test the class of the events rather than simply
>> dispatch them.
>>  
>>
> The step method is not accurate enough to simulate a clock. Time 
> between steps vary and your
> clock will soon be out of sync. You can however use it to sync up to 
> Time>>now and update the
> morph accordingly. 

Look at class ClockMorph

Karl