I'm writing this post to ask if these things are already planned or if it would be easy to have them implemented.
- Flexibility as to decide if when you append an item to a treeview it should expand the group or not.
Right now the default value is true.
When you try to create a load on-demand tree we should need the flexibility to set the items to be collapsed when we append them (if they have children items) so we can make use of the expand event to fill them with their children. - Some kind of animation for the splitters when you collapse/expand them?
Even nowadays there are people not used to the web environment, and if the collapsible pane just hides instantly (or almost) they will first think 'Where did my *whatever* went!?' so having some kind of easing they would see where did it go.