[UI] A small change... for a start

[Igor Stasenko]

On 21/03/2008, Gary Chambers <gazzaguru2 at btinternet.com> wrote:
> P.S. Just rectangular fills as a proof of concept for the moment.
>
>
>  > -----Original Message-----
>  > From: ui-bounces at lists.squeakfoundation.org
>
> > [mailto:ui-bounces at lists.squeakfoundation.org]On Behalf Of Gary Chambers
>  > Sent: 21 March 2008 5:59 PM
>  > To: Squeak's User Interface
>
> > Subject: RE: [UI] A small change... for a start
>  >
>  >
>  > Pinesoft-Widgets-gvc.302 on SqueakMap. Nebraska not included in
>  > changes (may do a separate package for that if there is interest).
>  >
>  > Added CompositeFillStyle. Canvas double-dispatches to the
>  > fillstyle/color/infiniteForm.
>  > Should allow more complex fills through subclassing(like pieced
>  > together from forms for a button, top-left image, top image etc.).
>  >
>  > Have fun!
>  >

It looks double-dispatch needed from a BaloonEngine, not from Canvas.
A fillStyle needs method #registerFillWith: engine.

So, it will dispatch back to BalloonEngine with messages like:

^ engine registerSolidFill: self.  "For single color fill"

^ engine registerGradientFill: self "For gradient fill"

^ engine registerBitmapFill: self "For bitmap fill"

And BaloonEngine>>registerFill: aFill should look like:
^ aFill registerFillWith: self.

Otherwise we need to extend canvas protocol with methods:

#fillRectangle:color:
#fillRectangle:gradient:
#fillRectangle:bitmap:

I don't like that there is need in additional checking for fill type
later, after canvas receives
#fillRectangle:basicFillStyle:
i think it would be better to be precise after dispatch, what basic
fill type should be used.

>  > Gary
>  >
-- 
Best regards,
Igor Stasenko AKA sig.