RE: [platform-swt-dev] ordering problem adding buttons to a GridLayout

[Mike Wilson <Mike_Wilson@xxxxxxxxxx>]

"Brad O'Hearne" <brado@xxxxxxxxxxxxx>
wrote on 22/10/2003 13:30:15:

> > 2) From the SWT Home Page, "SWT component is designed to
provide
> > efficient, portable, access to the user-interface facilitites
of
> > the operating system", not facilitate GUI builders.
> 
> I'm not going to debate this one with you, but this statement doesn't
> preclude or forbid thoughtful design decisions to facilitate easier
use of
> the API.  I have a hard time believing the SWT effort was launched
with a
> staunch "developer programming only" intent and aimed to
be deaf to the
> concerns of API usage.  Perhaps it is a style choice, perhaps
it is
> something more significant, but that will remain a matter of opinion
I
> suppose.  I read the last thread many months ago on this, and
if history
> serves, I don't see another debate as ending in something productive.
 I'll
> just leave it with this piece of advice: any API that intends to be
as
> user-friendly as possible and desires to see extensive automation
built on
> top of it needs to provide classes with parameterless (default)
> constructors....period.  Otherwise, dynamically creating instances
via
> ClassLoaders cannot be done.
> 
Here's the problem: The platform APIs that SWT is
built on, require a parent when widgets are created (er....period). There
were two choices, either mirror this in the API, or duplicate every bit
of state the widget maintains so that the widget could exist in an un-parented
state (state stored locally) or a parented state (state stored in the OS).
Even assuming that this could have been implemented without consistancy
problems (and I have never seen evidence that *any* system that attempted
to do this was 100% successful) it would have meant significant overhead
in *every* widget API as the code checked which state it was in and handled
the situations differently. 

In addition, zero argument constructors are not a
requirement for building automation. There has been extensive discussion
of this in the SWT mailing list in the past. Both GUI builders, and "robots"
can be/are being built on top of SWT in its current form. If you would
like to turn the discussion to how this might be achieved, you're much
more likely to get a constructive discussion going here.

McQ.