RE: [e4-dev] Dynamic CSS Theme Switcher

[Kevin McGuire <Kevin_McGuire@xxxxxxxxxx>]

That's the conclusion I came to as well.
 

The underlying problem is the interaction between the CSS declarative styling,
and programmatic changes to the widget. In a world where you only expect
CSS to style the widgets then the right answer is as discussed, you reset
the widget to it's default state (typically by use of null in a given setter).


In a world where you have both declarative
and programmatic changes to the widgets ... I'm not sure you can solve
the general problem because you always have the possibility of some code
being run to change the widget state after it's been styled, either because
styling got in too early, or because of some intended dynamic behaviour.
 What constitutes it's 'default' state now?  Unclear, plus there's
the complication of having to track and record the widget state changes.
 You can never be sure that the program has finished with the "default
widget configuration" and that you can now apply the styling.  I
don't know how to do it in a backwards compatible way.  

So I think we should stop trying to
capture the widget state, and instead just reset it to 'factory default'.
 

That said, it's still not clear what the best way is for us to interact
with legacy code.

Regards,
Kevin

PS. The only mix of declarative and
programmatic I can think of is something like:

        widget.configure(WidgetConfigurer
config);

where WidgetConfigurer encapsulates
the programmatic widget mods. It would be run after widget creation but
before declarative styling, and could be run again in the future for implementing
dynamic programmatic changes. This of course also assumes that there is
notification of widget creation, see bug
#260406.  In any case, I
think it's the wrong programming model, since if you're rewriting your
code anyway, you should encode dynamic behaviour through changes in css
class selectors.

"Toedter, Kai" <kai.toedter@xxxxxxxxxxx>
Sent by: e4-dev-bounces@xxxxxxxxxxx

05/29/2009 09:03 AM

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Subject	RE: [e4-dev] Dynamic CSS Theme Switcher

Hi Angelo,

> I think we must not compute default styles but return default SWT
values to reset CSS styles.

Yes, I agree.
I would expect that an SWT based css engine resets all SWT widgets to
the SWT defaults. After the reset, the Look & Feel would be the same
if
the application would not have used css styling at all. Then, after
applying the new css style these defaults would be overwritten.

Best regards,

Kai
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