>
>> I'm teaching myself Objective-C and Cocoa, by working on a simple (so I
>> thought) modification to the default AudioUnit effect project. But in this
>> project, I create my own views programmatically instead of using the NIB.
>> (I know - why??? Just go with me, ok? :-))
>>
>> I have a hierarchy of NSView descendants, and ones below a certain
>> "base" class in the hierarchy need to respond to mouse clicks. (Other
>> branches do not.)
>>
>> My first attempt was to add -mouseUp: and -mouseDown: to the "base"
>> class that directly inherits from NSView, and then only override those in
>> subclasses that need changes to the default behavior. However, none of my
>> subclasses of that "base" class respond to mouse clicks when I do it that
>> way.
>
>
> If I've understood this correctly, what you suppose should happen, should
> happen.
>
> If you have NSView -> Subclass A -> Subclass B and subclass A overrides
> mouseDown: and mouseUp:, then subclass B should get that implementation.
>
>> Shouldn't all derived classes inherit the behavior of their ancestors,
>> including those functions?
>
> Yep, they should.
>
>> I'm *guessing* that is has something to do with the way events are
>> handled, and that some kind of check is done to make sure the class
>> implementing those functions is in fact the same class as the target of the
>> event, but that's just a guess. My alternate guess is that's the way
>> Objective-C works.
>
> No. You must have made a mistake.
>
> Are you sure you're overriding the right method? it must match the original
> method's signature exactly. Are you sure you are inheriting the right class,
> i.e. subclass B inherits subclass A, not NSView?
>
> Show your actual code.
>
> --Graham
You're quite correct. It works as it should now. The problem was that there
was a single letter capitalized that shouldn't have been in one of my names,
and only a warning was issued when compiling (which I promptly forgot about and
didn't get back to). After fixing errors in other classes, recompiling skipped
that one class because I didn't change anything there. That let the code
compile, but meant that one of my classes (which I in turn tested the
mouseUp/mouseDown code in) was NOT actually part of the hierarchy! (I found
that by doing a Quick Model on the sources.)
I fixed the problem, and now it behaves as I thought it should. My base class
behavior works fine for those classes that don't want to change it, and the
classes that do want custom behavior get it. (Ok, only one class changes it so
far, but it works! :-))
Lesson for the day: NEVER ignore the warnings, ESPECIALLY the "may not respond
to" ones! :-)
Thanks, Graham...
Howard
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