Harry Potter's magic button - a solution to another tricky group bug

Wilhelm Sanke sanke at hrz.uni-kassel.de
Sun Aug 8 06:29:48 CDT 2010

On Sat Aug 7, 2010, Richard Gaskin ambassador at fourthworld.com wrote:

> For the main dictionary entry, use the Documentation specifier when
> filing the request in the RQCC.
> > If the boundingrect of a group is such a powerful property I wonder why
> > the default for groups isn't "boundingrect not empty" and is
> > automatically set to the coordinates when a group is created or 
> resized ?
> It depends what you want to do with the group......  Altering that 
> behavior with the boundingRect is useful for making
> canvas-like regions, but if you're not after a canvas you may prefer 
> the default behavior.


I think *you* are the most competent person to re-write the 
"boundingrect" entry of the Dictionary and to specify the details more 
accurately and understandably, after all, as you mentioned, it was you 
who requested such a feature from Scott Raney. And this was probably one 
of the last additions Scott Raney made to the MetaTalk language, as the 
"boundingrect" did not find its way into the Help index of the Metacard 
IDE as we still use it today.

On August 6 you wrote:

> But some time ago I needed more canvas-like behaviors,
> and Scott Raney accommodated me by adding the boundingRect property for
> groups.
> Similar to SuperCard's backSize property, the boundingRect lets you
> define a rect for the scrollable area of a group regardless of its 
> contents.

Question: Can we not achieve the same effect for a fixed scrollable area 
when we simply "set the rect", i.e. not the boundingrect, and the 
locLocation to true? What is the difference for a scrollable area when 
you use "boundingrect" instead?

On August 7 you wrote:

> Yeah, the boundingRect property been a godsend on some projects, and I
> was quite pleased when Raney added it.  Makes short work of things that
> can get quite complicated without it.

Could you possibly provide us - the revolution users - with more details 
and examples, why the boundingrect is a "godsend" and and how it 
simplifies things that otherwise remain complicated?-

Of course, the "boundingrect" is one of the solutions to the "set the 
loc of objects in a group" problem, identical (in that) to the effect of 
the "magic button", and very similar to the effect of Jacqueline's 
proposal to switch off the scrollbars of a group if the image is smaller 
than the group. The only difference when focusing on this bug - as it 
were "on the surface", but not only - is that with the "boundingsrect"  
scrollbars are tolerated with smaller images whereas with Jacqueline's 
proposal you have to turn the scrollbars off.

If would be surely very nice of you and helpful for Revolution users if 
you would tell us more about the other features coming with the 
"boundingrect" property that provide canvas-like behaviors and simplify 
otherwise complicated things.

Thanks very much in advance.

Wilhelm Sanke

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