SWT theme?

[Greg Brown <gk...@mac.com>]

Someone on a java.net thread was asking if Pivot supported native L&F. I explained that we intentionally don't support that because it is too much of a moving target, etc. But it got me thinking that we (or someone, anyways) could theoretically create a theme that is backed by native components (for example, via SWT). The fact that we pass a Graphics2D object to our paint() method doesn't really matter in that case since those components are painted by the native peer anyways. We wouldn't be able to use decorators since those rely on Java2D, but there are ways around that (such as providing our own graphics abstraction, which is something we have talked about in the past).

Basically, every skin would have a native peer. Layout containers could simply use an empty container peer and just perform layout on the native children. Navigation containers could just use the native equivalent. If a native equivalent doesn't exist, that component just wouldn't be supported (or could be emulated, if a Pivot-native graphics API existed).

I think it is an interesting idea. This would allow developers to use Pivot to build applications that could be deployed via Eclipse RCP as well as our existing application contexts. It would work on Android and iPhone as well, assuming that Java can be made to run there (which, based on some recent announcements, seems possible).

I'm curious to know what others think about this idea.

G

Re: SWT theme?

[Greg Brown <gk...@mac.com>]

> I think it's a good idea but I'm not sure how this would differentiate
> pivot

I just thought it might be a quick-and-dirty way to add native L&F support to Pivot, since at least one developer was asking about it. I'm not sure if it it is a good idea or a bad one - just wanted to put it out there for the sake of discussion.

> typical "skin" attributes such as colors and other things may need to
> migrate back to the model instead of the skin to ensure that they are
> available in all "rendered" versions of the skin

The styles wouldn't need to move to the component level. The skins would simply delegate the style properties to the underlying native components.

This is actually a good example why we designed the styles API the way we did: not all themes (native or otherwise) can be customized the same way and can't realistically support the same set of styles. This is OK, though - a developer who wants complete control over an application's appearance probably wants to use a cross-platform L&F with lots of customizable styles. A developer who wants an application to appear "native" on all platforms probably isn't going to do much, if any, style customization, since that might produce a UI that looks inconsistent compared to other native apps.

G

RE: SWT theme?

[aappddeevv <aa...@verizon.net>]

I think it's a good idea but I'm not sure how this would differentiate
pivot--unless you think it's a checklist to be in the set of choices by
architects and developers. SWT already is cross-platform and includes a
web-enabled version (called RAP) and e4 already includes XWT which has a
"renderer" model that can be replaced by any rendering technology so that
there are actually two levels of replacement on the UI side (SWT and the
rendering layer). Soyatec's eface (straight-up XAML for java) has 3 backends
for rendering (soyatec's main architect contributed the renderer layer in
XWT to eclipse).

I think some more thought is needed on whether a pure skin layer can handle
rendering they way you think. If its just the capability to render, it
probably could, but if you are trying to be more cross-platform from the
same codebase especially including a certain level of styling attributes,
then typical "skin" attributes such as colors and other things may need to
migrate back to the model instead of the skin to ensure that they are
available in all "rendered" versions of the skin or an entire skin
superclass layer is then needed. Food for thought.



-----Original Message-----
From: Greg Brown [mailto:gkbrown@mac.com] 
Sent: Sunday, September 12, 2010 7:40 PM
To: Pivot Dev
Subject: SWT theme?

Someone on a java.net thread was asking if Pivot supported native L&F. I
explained that we intentionally don't support that because it is too much of
a moving target, etc. But it got me thinking that we (or someone, anyways)
could theoretically create a theme that is backed by native components (for
example, via SWT). The fact that we pass a Graphics2D object to our paint()
method doesn't really matter in that case since those components are painted
by the native peer anyways. We wouldn't be able to use decorators since
those rely on Java2D, but there are ways around that (such as providing our
own graphics abstraction, which is something we have talked about in the
past).

Basically, every skin would have a native peer. Layout containers could
simply use an empty container peer and just perform layout on the native
children. Navigation containers could just use the native equivalent. If a
native equivalent doesn't exist, that component just wouldn't be supported
(or could be emulated, if a Pivot-native graphics API existed).

I think it is an interesting idea. This would allow developers to use Pivot
to build applications that could be deployed via Eclipse RCP as well as our
existing application contexts. It would work on Android and iPhone as well,
assuming that Java can be made to run there (which, based on some recent
announcements, seems possible).

I'm curious to know what others think about this idea.

G