GtkTreeView and lazy population

["Sam Thursfield" <ssssam gmail com>]

Hi,
I have developed a tree model which takes a long time to find all its
root nodes. Short batches of 50-100 execute in negligible time, but it
will be operate in cases with upwards of 100k root nodes.

It seems as though the first thing GtkTreeView does on receiving the
model is to iterate through every root node, calling iter_has_child
and iter_next for each until iter_next returns FALSE. This then leads
to my question - does anyone think it possible to modify GtkTreeView
to give it much lazier population? To display itself, surely it only
needs however many rows are visible .. and even these could be left
blank and drawn as its queries return.

My initial instinct is that the only issue would be the scroll bar
going nuts, which I'm sure could be solved with an
tree_model_estimate_n_children or something stupid. Can anyone advise
me on if this seems like a good/bad plan, or a problem that's been
tackled before?

Thanks for any help
Sam