Re: [Fxruby-users] Treelist -- can't add new items with data.

[Hugh S. S. E. E. <hg...@dm...>]

On Fri, 15 Aug 2003, Lyle Johnson wrote:

> Hugh Sasse Staff Elec Eng wrote:
>
> > IT DID!  I now find that my items are being added to the treeItem
> > but the item is not actually opened/expanded.
>
> I should have thought of that. Oh well, glad to hear that it's working.

I have made it default to doing that now.
>
> > OK, I can work with this.  What is the semantic difference between
> > opening and expanding in tree lists? At the moment when I want to
> > open I open and expand, and conversely collapse and close together.
> > What is the right thing to do for these?
>
> I think that what you are doing is the right thing to do, for your
> application.

Yes, I suspect so.
>
> When you programmatically open or close an item (i.e. by calling the
> openItem() or closeItem() methods) it only changes that item's state
> from "opened" to "closed", or vice-versa. If that tree item has
> different icons for the open and closed state, such as an opened and
> closed file folder, this will be the only visible cue of the change.

OK, so it doesn't do anything else. Fair enough.
>
> There are some situations where it is useful to make this distinction
> (of opened versus closed); I'll describe one of them in a few

Yes, Windows Explorer does this with the left pane you can open the
directory in the right without expanding on the left.  It's this
sort of feel I wanted to supply to users, so this is good.

> paragraphs. But for your application, this may not be a useful
> distinction. In that, you may want to just use the same icon for both

In fact I haven't drawn or found icons yet, that can wait, but I
agree.
>
>
> I'm not sure I can give you a precise description of the /semantics/ of
> open/close versus expand/collapse.

I think you have actually, but since there is no comment about this
that I can find... I'll have to poke about in the FXRuby 1.0.25 dist
and add some rdocs for others who tread this way, and bowl a patch
in your direction.
>
> This feature of the tree list was specifically added for developing
> Windows Explorer-like widgets, where there's a tree list on the left and
> a different view of the current item's contents on the right. So, if the

Right. This ability to carry experience over is good.

> user clicks *once* on a directory folder in the tree list (e.g. "My
> Documents"), that tree item is *opened*, and that folder's contents are
> shown in the right-hand pane; but the tree item is not *expanded* unless
> the user double-clicks on it.

Thanks.  and the + signs behave slightly differently I think, in
Win, but I'll have to stop "using it by coincidence" and actually
note what happens next time!
>
> Hope this helps,

Yes, that's the info I was after.
>
> Lyle
>
        Hugh