Files · Explorer: a folder as a list, tiles or columns, with one path and one order

FileExplorer shows the folder at the end of a path three ways: the
directory listing, a grid of tiles, or a column per folder along the
path with the next folder lit. Its name, its count and a switch of views
sit above one path bar that climbs. A folder opens in place; a file goes
to the host, which lists each folder it goes to. A pick in an earlier
column closes the columns past it, and a new deepest column scrolls into
view. The directory listing takes its pick from its owner and reports
it, so the pick carries across views; its path bar and its first order
are shared. The gallery walks a small file system and shows the tree,
the context menu, renaming in place and a drop zone in use.

src/files/grid.rs

@@ -6,7 +6,7 @@ use gpui::{
     rems, transparent_black,
 };
 
-use super::FileIcon;
+use super::{FileIcon, OnEntry};
 use crate::{
     forms::OnValue,
     layout::{columns_for, seeded::use_seeded},
@@ -16,8 +16,6 @@ use crate::{
     typography::{LEADING, MiddleEllipsis},
 };
 
-type OnEntry = Rc<dyn Fn(&DirEntry, &mut Window, &mut App)>;
-
 /// The tile a key moves to from `at` in `count` tiles laid `columns` a row: across by one, up and down by a row, Home and End to the ends; down from over a short last row lands on its last tile.
 pub(crate) fn stepped(at: usize, count: usize, columns: usize, key: &str) -> Option<usize> {
     let last = count.checked_sub(1)?;