Indicate overflow

[n4n0GH]

What do you want

In all containers there should be an indicator to notify the user that there's more content either up or down from the current rendered content.

Why

It's good UX, why wouldn't you want that?

Implementation hints

Use of ⌃and ⌄ on the right side of the containers would increase UX by at least 6.3214%

[Bios-Marcel]

Needs to be a feature of https://github.com/Bios-Marcel/tview, since cordless doesn't handle the border rendering.

[Bios-Marcel]

I only implemented this for the chatview ... I forgot lists and trees. In order to easily do this, I should make another abstraction of box.