Slide animation in NSOutlineView

Question

I have done quite a lot of Googling, but still have not found a suitable solution for animating the NSOutlineView extension. I am trying to imitate a "rolling" animation when expanding / collapsing lines. Does anyone know a good strategy for this?

Animation:

}} Folder 1

To expand and look like this:

}} Folder 1

}}}}} Paragraph 1

}}}}} Point 2

}}}}} Point 3

Answer 1

Take a look at this project: TLAnimatingOutlineview

Answer 2

, . expandItem:/collapseItem: NSOutlineView - animator.

NSOutline *outlineView = ...;
id item = ...;
[[outlineView animator] collapseItem:item];

, / , nil.

: NSAnimatablePropertyContainer