treeview/treemodel with 100K's elements

[Ionutz Borcoman <iborco gmail com>]

Hi,

Playing around with the treemodel, I've discovered that adding a lot of items 
to the model can become slow, if the number of added items is big enough 
(>20K on my PC).

So, is there any way to implement a 'lazy' tree model? By lazy I mean:
1. load only the nodes for the items that are currently displayed, without 
loading their children)
2. add an 'expander' image if the item has children
3. load the children when the node is expanded

An alternative to 2 and 3, if 2 is not possible would be to load only the 
first children and delay the loading of the remaining children till the node 
is expanded.

Any ideas or recommendations?

Thanx.

Johnny