[squeak-dev] Execute code when a Morph is destroyed

Bert Freudenberg bert at freudenbergs.de
Tue Jan 6 20:57:58 UTC 2009

On 06.01.2009, at 20:48, Igor Stasenko wrote:

> 2009/1/6 Séverin Lemaignan <skadge at gmail.com>:
>> Hello,
>> I would like to execute some code (closing a serial port) when a  
>> morph
>> is destroyed by an user (either by clicking on the cross or by
>> drag&dropping the morph to the bin). Do you know how to do that?

You could override #delete.

> Use finalization for closing any external resources being used by
> squeak-based objects.

Finalization should be used only as a last measure to avoid leaking  
system resources. It can take a very long time from the point where an  
object becomes unreachable until it is finalized.

> As a bonus question, is it possible to detect, on the contrary, when a
> morph is restored from the bin (to reestablish the communication) ?

Implementing #intoWorld: and #outOfWorld: should work (instead of  
putting this into #delete).

- Bert -

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