Using Behaviors for Triggering UI Design - Run Time

[Richard Gaskin]

Sannyasin Brahmanathaswami wrote:
 > Let's say we have a series of fields that have just a few words of
 > text in them we want to center vertically. Text varies. Our designers
 > may want to change the words over time.  I don't want to have to go
 > in and manually adjust the top and bottom margins to achieve the
 > position.
 >
 > So then this is were dynamic runtime GUI layout/typesetting may be
 > the way to go. Once the UI is all finished one could turn it off
 > because the properties would be set for the fields.
 >
 > We could create a behavior (ideally an external.livecodescript text
 > file) with this in it
 >
 > command centerTextVertically
 > put the formattedheight of me into tTotalTextHeight
 > put ( the height of me - tTotalTextHeight ) / 2 into tTopBottomMargins
 > set topmargin of me to tTopBottomMargins
 > end centerTextVertically
 >
 > put the long ID of the button that contains that into the field; then
 > make multiple copies of that field place them on the UI.
 >
 > 1)  When, how and what is the most efficient way...to trigger this?
 > in a preopenstack or preopencard handler? so that the UI fields are
 > all centered when the card renders?
 >
 > But then it needs to be a behavior of the stack or card, but then the
 > reference to "me" fails to target the fields which all have the same
 > name.

If it makes sense to put those fields into a group you can use 
preOpenControl.


 > 2) Still waiting on how to set a behavior to an
 > external.livecodescript. Dictionary only descripts the long id of a
 > button method.

Behaviors can be either buttons or stacks, and the stacks need not be 
script-only.

When setting any behavior the syntax is:

   set the behavior of <obj> to <absoluteObjReference>

...where <absoluteObjReference> is usually the long ID of a button, but 
can be any unambiguous object reference.

FWIW you can use "the long id" for any object, even stacks.

In all cases, once set a behavior is resolved to a "rugged long ID", a 
long ID where the stack portion is changed from the full file path as we 
normally find it to just the stack name, allowing portability.

For example:

    button id 1004 of cd id 1003 of stack "/home/rg/something/rsrc.livecode"

...becomes:

    button id of cd id 1003 of stack "rsrc"


So when using a stack as a behavior you can write:

    set the behavior of btn "Something" to the long id of stack "rsrc"

...or even more simply, since stack names are already unique:

    set the behavior of btn "Something" to the name of stack "rsrc"


-- 
  Richard Gaskin
  Fourth World Systems
  Software Design and Development for the Desktop, Mobile, and the Web
  ____________________________________________________________________
  Ambassador at FourthWorld.com                http://www.FourthWorld.com