[boost] Re: GUI library - another one

From: David Abrahams (dave_at_[hidden])
Date: 2004-03-04 11:32:24

"David Turner" <dkturner_at_[hidden]> writes:

> Hi
>
> Dave Abrahams wrote:
>> "David Turner" <dkturner_at_[hidden]> writes:
>>
>>>> Hm...maybe I don't understand why it has to be that way?
>>> [snip]
>>>> why can't we say
>>>>
>>>> window w;
>>>> w.add( button( "Click me" ) ); (*)
>>>>
>>>
>>> As I explained in an earlier post to Peter Dimov, there are technical
>>> reasons why this isn't possible.  Widgets have to be rooted in an owning
>>> window, and it's not possible to transfer widgets from one window to
>>> another.  Therefore, button has to take an owner-window parameter in its
>>> constructor.
>>
>> button("click me") doesn't have to be a widget.  Think expression
>> templates.  It can just build up a type to be used by window to add a
>> button.
>>
>
> Interesting.  But could this be done in such a way that
>
> button b("click me");
> w.add(b);
>
> is also acceptable?

Sure, though I would never call the function "add".  I'd be looking
for declarative DSELs like:

    window("Warning: now entering twilight zone")
    [
        text_field("my favorite color is:"),
        button("OK") | button("cancel")
    ]

Cheers,
-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com