Re: accessing bitmap representation, NSImage

[Riccardo Mottola]

Hi,

Dr. H. Nikolaus Schaller wrote:
> Finally, you can alloc+init an NSImage and use addRepresentation to add exactly 
> this rep. And then you can draw. Even if it then magically converts it into a 
> NSCachedImageRep, you still have access to the original.
>
> Maybe this caching is triggered by the first draw operation, so if you get the 
> representations before doing any draw operation on the NSImage, you could also 
> get the uncached version first and retain it…
I came to similar conclusions and initially I had the same ideas, thus 
they look god and you confirmed the path to follow. I implemented it in 
a NSImage subclass.

In initWithData I set a pointer to the representation (only on at this 
point) and also retain it. This way if later the drawin code replaces it 
I can still access it.
I thought that in the representations array I would have several 
device-dependent versions, but that the first rep would be my original. 
Since it is not the case, this way I can always access it.
Of course, I added an accessor to this representation which just returns 
the pointer.

At release, I send an additional release to it.

I had to modify PRICE to use my accessor instead of the representation 
array when I need direct access to the data
Furthermore, when doing a copy of the image, instead of instantiating 
every time a new image and copying the representation, I implemented the 
copyWithZone method, so that my original representation can be copied.

It works uite fine on the Mac, on GNUstep however I get horrible 
crashes, I'll clean up the code first then try to be more precise about 
the conditions that trigger it on GNUstep. But I fear it is GS problem now.

Riccardo