From: Lyle Johnson <lyle@...>
Date: 2002-12-12T00:59:07+09:00
Subject: Re: FXRuby : Setting Default Height/Width in an FXList

Jason Persampieri wrote:

> I'm attempting to wipe everything from one area and
> replace it with some other widgets.  I have two
> strategies.
> 
> (1) delete and recreate the parent
> newParent = FXVerticalFrame.new(parent.parent, ...)
> parent.destroy
> parent = newParent
> parent.create
> 
> this is sloppy, but I figured it'd work. 
> Unfortunately, the parent disappears, but the new one
> doesn't take it's place (although it DOES exist out
> there)

Calling FXWindow#destroy destroys the server-side resources (e.g. the X 
window associated with the parent widget) but it doesn't make the 
underlying object go away. Another way to look at it is that 
FXWindow#destroy is the opposite of FXWindow#create. What you want to do 
is blow away the parent window object altogether, and to do that you 
want to call FXWindow#removeChild:

     grandParent = parent.parent
     grandParent.removeChild(parent)
     parent = FXVerticalFrame.new(grandParent, ...)

> (2) delete all the child widgets of parent
> 0.upto(parent.numChildren-1) do |childNum|
>   parent.childAt(childNum).destroy
> end

This would also work, if you replace the calls to FXWindow#destroy with 
a removeChild from the parent, i.e.

     (numChildren - 1).downto(0) do |childNum|
       parent.removeChild(parent.childAt(childNum))
     end

Note that I also changed it from "count up from zero" to "count down 
from numChildren-1". The reason is that each time you call 
removeChild(i) you've shifted all of the child widgets with index > i 
down a slot.