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

Wilhelm Sanke sanke at hrz.uni-kassel.de
Sat Aug 7 05:16:35 EDT 2010

On Fri Aug 6, 2010, Richard Gaskin ambassador at fourthworld.com

> Wilhelm Sanke wrote:
> > Actually, there are at least two bugs: The problem of "setting" the loc
> > and that of "keeping" the loc - although the lockloc of the image is set
> > to true. "Lockloc" in the context of the definition above is also 
> broken.
> > After having succesfully centered the image, it will - as reported -
> > revert to a topleft position in the group
> Yes, with the default dynamic behavior of groups this is what most folks
> will experience.  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.
> --
>   Richard Gaskin


Thanks for this really valuable information.

"set the boundingrect of group x to the rect of group x" solves the 
complete list of problems, the "setting" and "keeping" bugs are no 
longer interfering and all side effects have gone away - like with the 
magic button, but with even less effort.

They must be a great amount of similarities between what the 
boundingrect and the magic button achieve,  and if the Rev engineers 
will still try to fix the "set the loc" bug they should also look how 
the boundingrect is coded in the engine.

The Revolution docs/dictionary should be updated to reflect the 
dependency of "set the loc" in groups on the "boundingrect" property.

Regards and many thanks,


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