[e4-dev] Re: Some comments on XWT

[Kevin McGuire <Kevin_McGuire@xxxxxxxxxx>]

Just to add a few points to Yves' reply:

> So it seems that XWT is now going to be the chosen
> technology for declarative SWT UIs, right? Unfortunately, I lost track
> of this topic a bit. But I'm happy to see that the syntax is simple
and
> straight forward.

e4 is an incubator and as such there
can be many overlapping technologies being explored (this is good!).  To
that aim, I believe Hallvard was going to contribute his work which AFAIK
is being put through the IP process as we speak (Hallvard is this correct?).
 Plus we should not forget UFaceKit which pre-existed e4 but is relevant
nonetheless (just happens to be in a different project).

So no there's been no decision, and
in fact there won't be until a given technology "graduates" to
the main development stream (e.g. 4.0, 4.1, possibly even 3.x).  This
is what we've said all along but likely hasn't been clear.  Once we
ship 0.9 in August then there will be increasing pressure to define what
the 4.0 platform will be, presumably based on maturation of code base,
support, and interest from the community.

> This brings up the namespace topic again: do
we really need namespaces?
> If yes, then we should probably support them in CSS too. I know Angelo,
> you want to have them anyway ;-), I'm still hesitating - I'd prefer
to
> keep the CSS simple...

I'm missing something... how does existance
(or lack) of namespaces in XWT and CSS related to each other?  Do
you envision them referring to each other?  Or are just saying that
the same reasons that drive the need for namespace in XWT probably also
argue for them in CSS?

I'd like to avoid namespaces in CSS
for as long as we can get away with it since it then gets us on the hook
for CSS3 which will require a different parser.  If people come forward
to do a new parser then fantastic but it's a significant undertaking which
I don't want to make a *requirement* for the e4 CSS work.

Kevin

yves.yang@xxxxxxxxxxx

03/02/2009 09:45 AM

To	"Ralf Sternberg" <rsternberg@xxxxxxxxxxxxxxxxx>
cc	Kevin McGuire/Ottawa/IBM@IBMCA, "Yves YANG" <yves.yang@xxxxxxxxxxx>, "Angelo zerr" <angelo.zerr@xxxxxxxxx>, e4-dev@xxxxxxxxxxx
Subject	Re: Some comments on XWT

Hi Ralf,

I'm glad you have tried out XWT. Thanks for your feedback. I think it
should be an open issue. So I cc e4-dev.

Please see my comment below:
>
> first of all, congratulations to the first e4 milestone! We played
with
> it a bit and got a simple e4 demo application running on RAP :-) I
also
> tried the new declarative UI stuff and built some simple UIs with
XWT.
> It looks great! So it seems that XWT is now going to be the chosen
> technology for declarative SWT UIs, right? Unfortunately, I lost track
> of this topic a bit. But I'm happy to see that the syntax is simple
and
> straight forward.
>
> I'm wondering right now whether there could be potential conflicts
> between element and attribute names used in XWT and in our CSS flavor.
> I think that even though the CSS is not directly applied to the XWT,
it's
> a good idea to keep the naming in sync in order to avoid confusion
and
> to leave the door open.

You are right, we have not yet worked on the integration between XWT and
CSS. I have created a bug:
   https://bugs.eclipse.org/bugs/show_bug.cgi?id=264825

>
> One thing I noticed is that the content of the style attribute mimics
> the way of or-ing style flags together in SWT code. If they were
> separated by spaces instead, then they could be directly referred
to by
> CSS like this:
>
>   <Table x:style="BORDER MULTI" ...
>
>   Table[style=~BORDER] { ...
>
> This brings up the namespace topic again: do we really need namespaces?

In XWT, we do need nemspaces. They are used to indicate the package in
Java.

> If yes, then we should probably support them in CSS too. I know Angelo,
> you want to have them anyway ;-), I'm still hesitating - I'd prefer
to
> keep the CSS simple...
>
> Another thing that catched my attention: is there a reason for uppercase
> attributes like "HeaderVisible". Of course, there's no technical
> constraint but I think those uppercase attributes are rather uncommon
in
> XML and calling it "headerVisible" would be a better match
to XML *and*
> Java conventions.

XWT supports both cases: HeaderVisible and headerVisible.

yves
>
> Do you think this makes sense? Is there still room for discussion?
And
> what do you think is the best platform for this?
>
> Best regards,
> Ralf
>
>