Is it possible to write a plugin for Finder?

Question

Objective-C

Hello.
There is a task: we need to extend the functionality of the desktop Finder.app under Mac OS by adding a new type of file display to it. In other words, Finder now has a display of files in tiles, tables, columns and galleries. We need to add a fifth button to this row, which would include another file display mode. Suppose there is his design.
How difficult is it to do? In which direction to dig?

Answer 1

Extensions can be written, but they work like external applications. For example - open a terminal for the current folder. You won't be able to customize the appearance of the Finder.