At 9:25 AM +1200 2002/04/12, Chris Tutty wrote:
>More importantly, why document them at all if an undocumented
>set of common operating system functions will throw them away. 
>It's similar to having a function call mechanism that will
>randomly fail to action the function call.  I really can't see how
>it's usable.

I agree that in the general case this could be a problem. However, custom events are 
potentially useful when used under restricted circumstances. For example... by knowing 
that any nested event loop may cause you to lose these user-defined events (in the 
same way you could, for example, lose a key down event) one would then restrict their 
use to areas of the application where ether 1.) that situation would never occur, or 
2.) loss of the event is acceptable.

We know the situation as it exists today (and has existed since Palm OS 1.0) is not 
perfect, and personally I've been concerned about our continued use of nested event 
loops for some time now (including the incorrect re-ordering "put-back" of events 
which cause the nested loop to exit... and that annoying beep from deep within 
SysHandleEvent when an unhanded virtual character occurs... but that's another story).

Unfortunately, removing these limitations is very difficult and potentially very risky 
because a great number of existing applications rely on the event flow as implemented. 
And changing it would almost certainly break these applications. Bummer, eh?

Regards,

Jim Schram
PalmSource Inc.
Partner Engineering

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