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keith

More on TreeViews & Models...

Another quick question on TreeViews (and models, I guess).
I have a TreeView, and an external Tree model I use to manipulate some
data. Periodically, I synchronize things by updating the TreeView's
default model with the data I'm working with. This works fine, but at
each synchronization, the TreeView refreshes and expands all nodes
-even the one's I've collapsed explicitly.
Is there a way to turn off "auto expansion" when updating a Tree's
model from an external source?

Thanks,

KeithB

Chris Uppal-3

Re: More on TreeViews & Models...

Keith,

> I have a TreeView, and an external Tree model I use to manipulate some
> data. Periodically, I synchronize things by updating the TreeView's
> default model with the data I'm working with. This works fine, but at
> each synchronization, the TreeView refreshes and expands all nodes

How are you doing the synchronisation ? One of my complaints about TreeView is
that it /collapses/ itself too often, I haven't noticed a tendency to open up
when I don't want it to.

-- chris

keith

Re: More on TreeViews & Models...

Hi Chris,
I've written a tree adaptor that I use to assist in synchronization on
demand, then essentially replacing the tree's model when I'm ready. I
guess I probably should have used the VirtualTree, but....

Anyway, I don't have any problems with the TreeView collapsing at all.
Everything works nicely *except* when I update the model, everything
expands (which kind of defeats the purpose of collapsing some nodes).

Keith

Chris Uppal wrote:

> Keith,
>
> > I have a TreeView, and an external Tree model I use to manipulate some
> > data. Periodically, I synchronize things by updating the TreeView's
> > default model with the data I'm working with. This works fine, but at
> > each synchronization, the TreeView refreshes and expands all nodes
>
> How are you doing the synchronisation ? One of my complaints about TreeView is
> that it /collapses/ itself too often, I haven't noticed a tendency to open up
> when I don't want it to.
>
> -- chris

Chris Uppal-3

Re: More on TreeViews & Models...

Keith,

> I've written a tree adaptor that I use to assist in synchronization on
> demand, then essentially replacing the tree's model when I'm ready.

Yes, but /how/ do you do that ?

Something like:
treePresenter model: newTree.
? Or do you clear out the old tree (in place) and then iterate over the new
one, using #add:asChildOf: for each node ? Or is your adaptor more like a
VirtualTreeModel ? Or what ?

-- chris

keith

Re: More on TreeViews & Models...

Hey Chris,
As Homer Simpson would say "D'oh!"
Sorry for my brain-cramp in not fully getting your question before...I
guess my brain was only on 3 cylinders :-)

Yes, I use
treePresenter model: newTree

where the newTree has been adapted from an OrderedCollection one of my
other components owns and manipulates.

I played a bit with the VirtualTree last night, but my results were
about the same. Every element add expanded the tree. I'm convinced I'm
missing something (probably something small), but don't know what...

Keith

Chris Uppal wrote:

> Keith,
>
> > I've written a tree adaptor that I use to assist in synchronization on
> > demand, then essentially replacing the tree's model when I'm ready.
>
> Yes, but /how/ do you do that ?
>
> Something like:
> treePresenter model: newTree.
> ? Or do you clear out the old tree (in place) and then iterate over the new
> one, using #add:asChildOf: for each node ? Or is your adaptor more like a
> VirtualTreeModel ? Or what ?
>
> -- chris

Chris Uppal-3

Re: More on TreeViews & Models...

Keith,

> Yes, I use
> treePresenter model: newTree

Hmm, I think there must be something else that you are doing (some event
handler perhaps ?) which is causing the expansion. An ordinary TreeView
doesn't do that. For instance.

tp := TreePresenter show.

I can now evaluate either of the following as often as I want, and in each case
the tree closes itself up completely when the model is changed (even if the
replacement model contains the old selected node).

tp model: ClassHierarchyModel withAllClasses.
tp model: PackageSelector defaultModel.

Is that what you see ?

-- chris

keith

Re: More on TreeViews & Models...

Hey Chris,
Thanks for all your help. As it turns out, I wasn't setting the
hasLinesAtRoot attribute for my view, so the #basicRefreshContents:
method in the TreeView automatically expanded the nodes every time. I
missed that detail, but it was the source of my problems.

Thanks again,

Keith

Chris Uppal wrote:

> Keith,
>
> > Yes, I use
> > treePresenter model: newTree
>
> Hmm, I think there must be something else that you are doing (some event
> handler perhaps ?) which is causing the expansion. An ordinary TreeView
> doesn't do that. For instance.
>
> tp := TreePresenter show.
>
> I can now evaluate either of the following as often as I want, and in each case
> the tree closes itself up completely when the model is changed (even if the
> replacement model contains the old selected node).
>
> tp model: ClassHierarchyModel withAllClasses.
> tp model: PackageSelector defaultModel.
>
> Is that what you see ?
>
> -- chris

Chris Uppal-3

Re: More on TreeViews & Models...

Keith,

> As it turns out, I wasn't setting the
> hasLinesAtRoot attribute for my view,

Well, well, well... I had no idea #hasLinesAtRoot = false had that effect!

Live and learn.

Cheers!

-- chris