showWithEffect for colapse and expand

[KSergeyP]

I looked at the router menu today)
Its submenus smoothly collapse and expand. While one collapses, another expands.
Is there a similar functionality in TGUI? For example, for TreeView

[texus]

With TreeView you could collapse things in your code when receiving a callback from onExpand.
Smooth transitions is something that isn't supported and won't be possible unless you write it yourself entirely.