This is new implementation of the Visual Smalltalk event
system for Squeak.

I think that it could make a great event system for Morphic. 
it is very flexible in wiring models to interfaces (and other 
models).

Here's some quick examples of how it's used:

1)  Wiring an interface to a model

aButton when: #clicked do: [ "something interesting with the model"].

2) Wiring a model to an interface

in the interface code:

     aVechicle when: #passengerAdded: send: #addItem: to: aListBox.

in the model code:

     aVehice triggerEvent: #passengerAdded: with: aPassenger

This will result in ListBox>>addItem: being called with aPassenger
as the parameter. (Note that this example is from Visual Smalltalk,
none of the widgets in Squeak generate events).

At the risk of being obvious, you can attach any number of
interfaces to a model, and vice versa.

Note:

When you add events to a subclass of EventModel (by changing the
contructEventsTriggered class method) you must run the
initializeEventsTriggered method for that class before the
new events will be useable.

Most of the event system is implemented in methods in class object
(with just additions, no modifications to the base image). If you 
want to use subclasses of EventModel with this event system you need do
nothing extra; but if you want to use it with objects that
are not, you need to implement the method 'actionLists';
see the implementation of this method for the EventModel
class.

I could have placed an implementation in object, using a 
global variable to hold all of the actions lists for all 
objects by default; but can lead to the defeat of smalltalk's 
garbage collection so I didn't bother. Weak references, anyone? :)

This software is (c) 1997 by Tim Jones
You can reach me via tim@thregecy.com