Kismet

[Boudewijn Rempt]

On Monday 08 March 2004 12:29, Patrick Julien wrote:

> I don't think your goal should be to remove the enumeration, but peaceful
> coexistence.  For widgets, you probably want a mediator to fill in a
> list/icon/whatever item the send it off.  The key for the result can be
> this simple enumeration that you match back to the originating object.

Well, I'm not completely done thinking, which is why none of this code is used 
yet... I primarily want to get rid of the enums because they:

1. lead to switch statements all over the place
2. are hard to translate to UI.
3. hard to extend without changing code in a lot of places

Having, say, an image type or a paint operation as a self contained class that 
exposes and uses a small subset of an API, means that it's easy to add image 
types and so on as plugins. Then the internal Krita classes can simply use 
the objects provided by the plugins to perform the action, instead of 
switching.

>
> Also, now that I see more clearly what you are doing, you should make your
> image types flyweights.  Now that I think about it even more, you should
> probably add these members to the color space strategies.
>

I must admit it's getting hard to see a real difference between an image type 
and a colour strategy. Except, of course, that a colour strategy should 
ideally work whatever the bit depth of the colour channels, and an image type 
determines the bit depth. So what I wanted to do was to make the list of 
supported image types a member of colour strategy.

> >
> > The start of that is KisImageTypeRGBA -- I was hesitating beween having
> > very specialized types (RGBA _and_ RGB), or slightly less specialized
> > types.
>
> There is slight difference here, the common implementation also happens to
> be the class you are returning from the mediator.  Here, this is no longer
> true. The common implementation is now a hidden middle class.
>

Mmm. I'm not sure I'm following you here -- possibly because my own thoughs 
aren't quite finished yet.

-- 
Boudewijn Rempt | http://www.valdyas.org/fading/index.cgi