Guyren G Howe wrote recently
I feel obliged herein to insert my occasional comment that, RB's
docs notwithstanding, the preferred method of class extension in
REALbasic is to use events, not method overriding.
I don't necessarily agree but it made me think about dispatching overhead.
Events on controls in windows are bound at editing time (even earlier
than compile-time) which is why the IDE knows to hide an event in the
editor if it is handled in a parent class.
I infer that they are not dispatched through a virtual method lookup.
This implies, if you have a method you want called often enough for
it to be important to optimise, that events would be better than
methods (eg: something called per pixel, processing every frame of a
movie or in a large image).
However, thinking about it, I'm not sure there's enough context for
early binding to occur in events used outside of windows.
Maybe outside a window, event calls are straight virtual function calls.
Maybe they always are?
_______________________________________________
Unsubscribe or switch delivery mode:
<http://www.realsoftware.com/support/listmanager/>
Search the archives of this list here:
<http://www.realsoftware.com/listarchives/lists.html>
|