[Embedlets-dev] Getting back on the horse

[James C. <ca...@vi...>]

Ok... So I fired up the embedlets code and starting getting my head back
around it.

I want to comment on the Event mechanism.. Java itself has events,
especially if it has a graphical interface, it even has it's own
'prescribed' way of handling events - The Producer/Listener model and
this is the event model I have used also for muvium in the APT -
(Abstract Peripheral Toolkit). 

One good thing about Producer/Listeners is that it is very concrete who
is receiving events from who. The Embedlet container Event mechanism
does not use this mechanism opting for it's own Embedlet Event
mechanism. What is not clear to me at this stage is how an instance of a
specific embedlet may register to receive events generated by another
specific embedlet instance. As it stands all Embedlets seem to receive
all Events or at least they must apply some type of filter to the events
they receive. 

I suppose in the general sense if this filter specifies the specific
instance then it will receive only those events.. So you have a filter
based event/listener model.

In a graphical representation embedlets can be thought of being tied
together by their events... Again easy to see how this works in a
Producer/Listener model but how is it indended this will work in the
Embedlet model. I suppose you need the XML configuration to specify the
filter to the level needed to emulate the Producer/Listener model.

I guess at the end of the day I am trying to understand why we are not
using the Producer/Listener model common to the Java event handling
mechanism seen both in Java itself, Swing & AWT, and also in the
Real-Time Java specification.

James Caska

www.muvium.com
uVM - 'Java Bred for Embedded'