Very small contained example in link at the bottom.


PROBLEM:
(1) Grabbing the scrollbar and moving it up or down with a TreeTableView will cause icons to vanish and drift over to the left side (see succinct small example at the end), which gets worse as more nodes are added. Performance can be extremely degraded and looks really bad to customers.

- Happens as low as 50 TreeItems

- My example in the link should happen in a few seconds (at most) for you regardless of the number -- I tried 50 and 50,000 and they acted the same

- Significantly worse when conditions in (2) below are applied.

- has happened in TableView as well in the past for me (~6 months ago, I just assumed I was at fault and didn't know enough about JavaFX, so I didn't report).



POSSIBLY RELATED PROBLEM:
(2) Performance drops significantly when there are 50,000 nodes if hidden *and/or* visible.

- Does not appear to happen in a simple tree (one root and 50k elements), only happens when there is a hierarchy of nodes with lots of children and 20+ of them are parents to more leaves/nodes.

- Does appear if there are lots of nested nodes (at most 4-5 levels and a lot of nodes having 100+ in each)



I bring up (2) here because they may be linked, and (2) brought (1) to the surface in a very painful fashion.

NOTE: I do not have an example for (2) since I can't post 10,000+ lines easily, and I am unsure if it's related. If it ends up being related, I will attempt to create another small example for that one and file a bug report (assuming it's a different bug).



A very small contained (confirmed) example can be found here for issue (1):
http://stackoverflow.com/questions/30133276/javafx-icons-randomly-disappear-from-treetableview-when-scrolling-performance-s