Re: XForms: three questions

T.C. Zhao (
Sat, 21 Feb 1998 14:44:08 -0600

# To subscribers of the xforms list from "T.C. Zhao" <> :

On Feb 20, 10:32am, Stephen Langer wrote:
> (1) Browser double clicks
xforms chose (probably unwisely) to use the continuation model (actually
lazy model) to handle double the double click, meaning that
double click does nothing more than a little extra on top
of a single click. What this really means for the application
program is that double click is not appropriate to do things
that are very different from a single click.

I certainly agree that this model is less flexible than
distinctive single and double clicks. I think the reason
for the existence of a continuation model is to force
some type of consistency in click handlings. In reality
I am not sure this actually work. I will definitely
look into this. What probably will happen is a new option
to select how double click should be handled with the
current behavior being hte default.

> (2) Deleting and freeing grouped objects
there are some inconsistencies in group object handling. To
delete a group, use fl_delete_group() (there is NO reason
why fl_delete_object() would not work, but it doesn't,
it is just the way things currently are). will try to fix.

> (3) Spurious callbacks

> problem may be fixed in 0.88.1. I'm seeing behavior in 0.88 that is
> vaguely similar, and I wonder if it could be the same bug.
Actually no.

> I have input objects in groups. The forms have a bunch of buttons,
> sliders, and canvases on them, and the groups contain buttons, inputs,
> canvases, and text. **When a group is hidden, the callback for the
> first input in the group is invoked.** dbx reports that
> fl_hide_object() is calling lose_focus(), and lose_focus() is calling
> the input object's callback.

This particular behavior is intended although as everything else
in the library, I am open to suggestions. xforms' input object
detects when to call the object's callback by watching focus change,
and losing focus certainly indicates a focus change. I guess I should've
done a better job documenting this.
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