From: Lyle Johnson <lyle@...>
Date: 2002-12-12T03:40:30+09:00
Subject: Re: FXRuby : Setting Default Height/Width in an FXList

Jason Persampieri wrote:

> I tried to redefine the getHeight method for my
> container, but that didn't seem to have any effect. 
> That is, I could call obj.getHeight and it would get
> the value from my function, but the parent still sees
> the height differently.  Does that make sense?  

Yes. The getWidth() and getHeight() functions in the C++ library aren't 
virtual functions and so there's no point in overriding them in your 
Ruby classes. In other words, even if you were writing your GUI in C++ 
and not in Ruby there wouldn't be any point in overriding either of 
those functions.

If you want a window to have a fixed height, pass in the 
LAYOUT_FIX_HEIGHT layout hint when you create it and then set its height 
to whatever (fixed) value you like:

     fixedHeightLabel = FXLabel.new(parent, "Label", nil,
         LABEL_NORMAL | LAYOUT_FIX_HEIGHT)
     fixedHeightLabel.height = 50

> Each widget is an FXParameterRow, which is a class I
> made to show a key and value... the current
> implementation is a GroupBox titled with the key
> containing an FXText box with the edittable value...
> whew.

This sounds fine, but just out of curiosity, you do know that there is 
both an FXTextField widget (for single-line text inputs) and FXText (for 
multi-line text), right? For what you're describing, FXTextField is 
*probably* the appropriate choice -- it's like Tk's Entry widget (but 
not like Tk's Text widget).

> I thought of another option though... If I could do
> this as an FXList, that should handle all of the size
> issues appropriately... however, it doesn't seem like
> a widget can be an FXListItem (even with
> subclassing)... is this correct?

Correct. An FXListItem is, more or less, a basic data object and not a 
widget as such. It is not (ultimately) derived from FXWindow like 
regular widgets are.

> Anyway, I still think that there should be a way to
> tell a container to re-evaluate it's height... and it
> should do so automatically after a child gets
> destroyed.  Wouldn't that make sense?

Generally speaking, containers *do* re-evaluate their width and height 
when a child widget is added or removed (... or hidden or shown, etc.) 
If this doesn't seem to be happening you can force a widget to 
recalculate its layout by calling recalc(), e.g.

     FXLabel.new(aContainer, "myLabel")
     FXTextField(aContainer, 6)
     aContainer.recalc

but as I said this usually isn't necessary.