Sticky parent items

[xorinzor]

Say you have a tree like this:

          ┌──┐
          │  │
          └──┘

          ┌──┐
          │  │
          └──┘

┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐
│  │ │  │ │  │ │  │ │  │
└──┘ └──┘ └──┘ └──┘ └──┘

And assume the viewport is not wide enough to display the tree in it's full width so a horizontal scrollbar appears.
Would it be possible to have the parent-nodes stick to the side of the viewport until they come into view?

That way you wouldn't have to scroll to the middle of the diagram to see what the children nodes are linked to