Improve horizontal scrolling to maxime view of the selected region

[jpmvferreira]

Summary

This package should maximize the view of the selected region when scrolling through the tree using the keyboard. This has only happened to me today when I added a project that had a massive folder name.

Motivation

Because this is the expected behavior, nobody wants to have unnecessary cropping, and tree view seems to be doing it right when going down the file tree, but not when going up.

Describe alternatives you've considered

I haven't, there doesn't seem to be any tree view in Atom.

Additional context

As I said, I have a project with a folder with massive name and, when going up in the file tree with my keyboard, it will always keep my horizontal scroll bar somewhat to the right, when it was going down it was being actively and properly adjusted.

Here's a few pictures to exemplify what I mean.

In this first picture I have manually pulled the horizontal scroll to the left:

Now I moved the selection down by using the down arrow key and it adjusted properly to my selection, maximizing the space in which interesting stuff is actually happening, which is great:

Now I moved the selection down once again, and it did exactly the same behavior (it's slightly cut off due to lack of print screen skills), which is what I expected:

However, if I now move the selection upwards, I expected to see what it looks like in picture number 2, but it doesn't, it remains fixed:

Essentially I just expected that the package would return to the state as we have seen in figure number 2, which is much nicer to see the contents of the directory and where it fits in the global structure, even if that means slightly cutting of the name, which in this case, it doesn't.