Michael Rueger wrote:
> Andreas Raab wrote:
>> I'm not sure if having multiple listeners is useful at this level - 
>> all EventSensor does is pulling the events from the VM, packaging them 
>> up and passing them into the event queue for any downstream consumers. 
>> If there were multiple listeners in a morphic environment, they should 
>> probably be registering with the hand (which has such a listener 
>> mechanism already), not with Sensor. What's the use case for this 
>> refactoring?
> 
> The refactoring allows for listeners *outside* the morphic environment 
> to listen to input and window events, supporting alternative UI 
> frameworks like e.g. Miro.

Miro must be an unusual framework then (where is it?). Generally 
speaking, Squeak UI frameworks all have the need for some sort of 
top-level desktop (representing Display) which is the natural (and 
generally only) receiver for events from Sensor. That is true for MVC, 
Morphic, Tweak etc. The only situation in which I could imagine not 
having a desktop representative is when it comes to native windows (in 
which case there is a native desktop that Squeak doesn't control) and 
here one obviously wants to dispatch events to all the different 
windows. Although even here I would probably opt for a dispatch table in 
Sensor mapping window IDs to event queues instead of a straightforward 
listener.

Cheers,
   - Andreas