Limiting an element to content-box while attaching to window/scrollParent

[kizu]

I have a case a bit similar to the content-visible one: I need to have an element that would be attached to the visible parts of another element, like in the example, but with a condition: it should never leave the bounds of the .content-box. It should pin to its top and bottom when it is placed outside the .content-box, while in all other time be positioned to a visible part of it.

Is it possible using constraints? I couldn't make it so, the most closest thing that I thought should work like I'd like was

  constraints: [
    {
      to: '.content-box',
      pin: true
    },
  ]

But it just doing anything and I couldn't find anything that would make it work.

Is it possible with Tether at all?

[kizu]

Ok, I've overlooked that while you can use “selector string of an element” for element and target, you can't use it for to in constraints, only the “A DOM element” would work.

Using the DOM element would do exactly what I need, so I'm closing this issue.