BackgroundBehavior Question OR a bug

Devin Asay devin_asay at byu.edu
Wed Jun 15 13:56:18 EDT 2011


On Jun 15, 2011, at 10:59 AM, Timothy Bleiler wrote:

> Thanks Devin,
> 
> You are correct. I messed up and was running 4.5.2 on the Mac. So,  
> what this means is that from 4.6 on backgroundBehavior = true for  
> groups on >1 card is the expected behavior? Anyone know why this  
> change was made? It seems like a pain in terms of message passing for  
> groups that are intended to act like self contained controls rather  
> than a shared resource on multiple cards.

There was a long discussion about this at the time. If you have access to the Quality Control Center bug database you can look at bug #1197. You can see the discussion that took place on the mail list at http://lists.runrev.com/pipermail/use-livecode/ if you look at the archives from 25 to 27 June 2008.

It boiled down to this: if a group is placed on more than 1 card it becomes by definition a background, and IDE sets the backgroundbehavior to true. But since you used to be able to set it back to false, it created ambiguity and some problems in message passing. So as of 4.6 the development team at runrev made the decision to enforce this behavior. 

I guess the answer to your question would be that a group intended to act like a custom control (like a datagrid) should have a separate instance on each card it's used on, rather than trying to place it as a background. 

HTH

Devin


Devin Asay
Humanities Technology and Research Support Center
Brigham Young University





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