feat(icons): Add support for highlight groups in icons in Vim

Author: brianhuster

.editorconfig

@@ -0,0 +1,4 @@
+[*]
+indent_style = space
+indent_size = 2
+tab_width = 2

.gitignore

@@ -449,6 +449,7 @@ func! s:apply_icons() abort
       let l:icon = s:cb_map[id](f)
       if type(l:icon) == v:t_string
         if -1 != match(l:icon, '\S')
+          unlet l:icon
           break
         endif
       endif
@@ -460,15 +461,21 @@ func! s:apply_icons() abort
       elseif s:virttext_feat ==# 'textprop'
         if type(l:icon) == v:t_string
           call prop_add(i, 1, #{type: s:prop_type, text: l:icon})
+        else
+          let l:prop_type = prop_type_get('dirvish.'.l:icon.hl, {})
+          if l:prop_type == {}
+            call prop_type_add('dirvish.'.l:icon.hl, #{highlight: l:icon.hl})
+          endif
+          call prop_add(i, 1, #{type: 'dirvish.'.l:icon.hl, text: l:icon.icon})
         endif
       else
         let isdir = (f[-1:] == s:sep)
         let f = substitute(s:f(f), escape(s:sep,'\').'$', '', 'g')  " Full path, trim slash.
         let tail_esc = escape(fnamemodify(f,':t').(isdir?(s:sep):''), '[,*.^$~\')
         exe 'syntax match DirvishColumnHead =\%'.i.'l^.\{-}\ze'.tail_esc.'$= conceal cchar='.l:icon
       endif
+      unlet l:icon
     endif
-    unlet l:icon
   endfor
 endf
 

autoload/dirvish.vim

@@ -114,12 +114,32 @@ dirvish#add_icon_fn(fn)
     a given path, wins. Best practice: if you don't have anything meaningful
     to show for a given path, return empty string (or whitespace).
 
-    {fn} is any |Funcref| that takes a path (string) and returns a string
-    (the "icon"). Example: >vim
+    {fn} is any |Funcref| that takes a path (string) and returns an `icon-item` as
+    a |string| or a |dict| with the following keys:
+        - "icon" (|string|): the string representing the icon.
+        - "hl"   (|string|): the highlight group to use for the icon.
+
+    Note: If your Vim isn't Vim 9.1+ with |+textprop| or Nvim 0.8+, `icon-item`
+    can only be a character.
+
+    Example that returns a string: >vim
         call dirvish#add_icon_fn({p -> p[-1:]=='/'?'📂':'📄'})
 <
-    Note: multi-character icons are only supported on Nvim 0.8+ or Vim 9.1+
-    with |+textprop|.
+    Example that uses |mini.icons| <https://github.com/echasnovski/mini.icons>
+    0.15.0 as icon provider >lua
+        --- NOTE: mini.icons must be loaded before vim-dirvish
+        vim.fn['dirvish#add_icon_fn'](function(p)
+          local get = require('mini.icons').get
+          local icon, hl
+          if p:sub(-1) == '/' then
+            icon, hl = get('directory', p)
+          else
+            icon, hl = get('file', p)
+          end
+          icon = icon .. ' '
+          return { icon = icon, hl = hl }
+        end)
+<
 
                                                     *dirvish#remove_icon_fn()*
 dirvish#remove_icon_fn(fn_id)