Re: Problem with NSColorWell

[David Chisnall]

On 24 Feb 2011, at 23:37, Fred Kiefer wrote:

> Am 24.02.2011 21:14, schrieb Philippe Roussel:
>> Le lundi 24 janvier 2011 à 12:58 +0100, Fred Kiefer a écrit :
>> 
>> [snip]
>> 
>>> This seems to be the problem here. There actually are two versions of
>>> GSColorSliderCell loaded. One from loading the wheel picker and one from
>>> loading the standard picker. It is exactly the same class coming from
>>> the same file. But of course your code is correct about warning when a
>>> class gets replaced by another one.
>> 
>> Just a reminder so this problem won't be forgotten.
>> 
>> I would like to help on this but my only idea is to move the
>> GSColorSliderCell class to gui as a helper but I don't think you would
>> like this...
> 
> You are right, I don't like this idea too much. The code in these class
> would need a bit of rework to have it directly in the main gui code. But
> if this is the only way to get GNUstep gui working for you with libobjc2
> we will have to do that step. I was hoping for David to resolve the
> issue in a compatible way in libobjc2.

In the current version, I've simply disabled this check.  I'd like to reenable 
it in the future.  Currently the Apple runtime logs a warning when you load a 
class twice and tells you that the one that will be used is undefined.  One of 
my aims with libobjc2 is to remove cases of undefined behaviour and turn them 
into hard errors.  It's easy for libobjc2 to ignore this, but -gui is 
definitely doing the wrong thing by loading two copies of the same class, so it 
is worth fixing.

The experimental code that was catching them is part of the developer mode 
extension, which is designed to allow you to inject new definitions of a class 
into the runtime and transparently upgrade them (where possible).  This is 
unfinished, and will require some cooperation from the compiler - it's mainly 
intended for use with LanguageKit, but I'll probably integrate it with clang 
for fix-and-continue support in an ObjC IDE.

David