[GUI] Dynamic sizing.

[Wolfgang Thaller]

Glynn Clements wrote:

> Wolfgang Thaller wrote:
>
>> Question to all: Who is not familiar either with Java's GridBagLayout
>> or with Tcl's "grid" geometry manager?  (BTW: Is XmRowColumn the same
>> thing or something different?)
>
> Well, XmRowColumn is a widget class, whereas the other two are
> "standalone" geometry managers.

Yes. I actually think we should be using specialized container widgets, 
not "standalone" geometry managers, because the former can be 
typechecked more easily (see my last e-mail for an example of what I'm 
thinking).

> Motif's "generic" container widget is XmForm. This allows you to place
> the children arbitrarily, with the edges positioned using attachments.

I lost track somewhere, but I think I get the drift (and I'll try 
reading it again tomorrow, when tiredness isn't interfering).
Is there anything that an XmForm do that Grids can't?

I think we should just manually implement a grid-layout manager for the 
Motif backend.
An alternative would be to manually implement something like XmForm on 
all other platforms, but it looks like that is harder than implementing 
a grid.

>> That's the best way of managing dynamic layouts that I know. Any
>> reasons for not using something like that?

> I find that the mechanisms used by Java and Tcl tend to be a bit too
> explicit in the actual placement and sizing of widgets. Motif prefers
> to allow widgets to size themselves, with the size and layout of the
> parent adjusting accordingly.

... as do Java's GridBagLayout and Tcl's grid.

> This simplifies i18n; [...]

Of course. But I don't have to create separate layouts for the Java/Tcl 
grid layout managers, either.

> For more complex layouts, it's common to create a hierarchy of nested
> containers.

Yes, agreed.

Cheers,

Wolfgang