Add dynamic sizing padding options

with neovim/neovim#20621 merged in it is now
possible to fully customize the status-column in nvim (the column on the
left containing line-numbers, fold info, signs and borders).

A fair few cool implementations have popped up like:
- https://github.com/CKolkey/config/blob/master/nvim/after/plugin/statuscolumn.lua
- https://github.com/luukvbaal/statuscol.nvim
- and my own personal one (based on CKolkey's fantastic work) https://git.hendrikpeter.net/hendrikpeter/pico-vim/-/blob/main/lua/peva/status_column.lua

The problem with nvim-tree however is that dynamic sizing doesn't take
the custom size of a status column into account and the end of file
names get clipped off. This little patch should fix that (and give some
examples to help other status_column modders get started).

Thanks for looking at this and thanks for making this amazing plugin,
I've been using it for a while and I really like it!

Author: HendrikPetertje

README.md

@@ -74,7 +74,14 @@ require("nvim-tree").setup()
 require("nvim-tree").setup({
   sort_by = "case_sensitive",
   view = {
-    adaptive_size = true,
+    -- adaptive width (use width = number instead for static width)
+    width = {
+      min = 30
+      -- -1 means no limit
+      max = -1,
+      -- set total padding space when resizing (handy for custom status columns)
+      padding = 3
+    }
     mappings = {
       list = {
         { key = "u", action = "dir_up" },

doc/nvim-tree-lua.txt

@@ -734,11 +734,16 @@ Window / buffer setup.
 
         *nvim-tree.view.width.min*
           Minimum dynamic width.
-          Type: `string | number | function`, Default: `30`
+            Type: `string | number | function`, Default: `30`
 
         *nvim-tree.view.width.max*
           Maximum dynamic width, -1 for unbounded.
-          Type: `string | number | function`, Default: `-1`
+            Type: `string | number | function`, Default: `-1`
+
+        *nvim-tree.view.width.padding*
+          dynamic padding when resizing. Useful for custom status-column
+          styles.
+            Type: `number`, Default: `3`
 
     *nvim-tree.view.side*
     Side of the tree, can be `"left"`, `"right"`.

lua/nvim-tree/view.lua

@@ -6,6 +6,7 @@ local log = require "nvim-tree.log"
 
 local DEFAULT_MIN_WIDTH = 30
 local DEFAULT_MAX_WIDTH = -1
+local DEFAULT_PADDING = 3
 
 M.View = {
   adaptive_size = false,
@@ -250,7 +251,7 @@ local function grow()
   local starts_at = M.is_root_folder_visible(require("nvim-tree.core").get_cwd()) and 1 or 0
   local lines = vim.api.nvim_buf_get_lines(M.get_bufnr(), starts_at, -1, false)
   -- 1 column of right-padding to indicate end of path
-  local padding = 3
+  local padding = M.View.padding
   local resizing_width = M.View.initial_width - padding
   local max_width
 
@@ -517,6 +518,7 @@ function M.setup(opts)
     M.View.adaptive_size = true
     M.View.width = options.width.min or DEFAULT_MIN_WIDTH
     M.View.max_width = options.width.max or DEFAULT_MAX_WIDTH
+    M.View.padding = options.width.padding or DEFAULT_PADDING
   else
     M.View.adaptive_size = false
     M.View.width = options.width