ui/treemacs: refactor

Treemacs enables treemacs-filewatch-mode and treemacs-git-mode itself.
Also removes settings that are the same as the defaults.

modules/ui/treemacs/config.el

@@ -1,19 +1,16 @@
 ;;; ui/treemacs/config.el -*- lexical-binding: t; -*-
 
 (setq treemacs-follow-after-init t
-      treemacs-width 35
-      treemacs-position 'left
       treemacs-is-never-other-window t
-      treemacs-silent-refresh nil
+      treemacs-sorting 'alphabetic-case-insensitive-desc
-      treemacs-indentation 2
-      treemacs-sorting 'alphabetic-desc
-      treemacs-show-hidden-files t
-      treemacs-goto-tag-strategy 'refetch-index
-      treemacs-display-in-side-window t
       treemacs-persist-file (concat doom-cache-dir "treemacs-persist"))
 
 (after! treemacs-persistence
-  (setq treemacs--last-error-persist-file (concat doom-cache-dir "treemacs-persist-at-last-error")))
+  ;; This variable is defined with defconst, so we must wait to change it until
+  ;; it has loaded.
+  (setq treemacs--last-error-persist-file
+        (concat doom-cache-dir
+                "treemacs-persist-at-last-error")))
 
 
 (after! treemacs
@@ -23,29 +20,13 @@
     :quit nil
     :ttl 0)
 
-  (defvar +treemacs-use-git-mode
-    (pcase (cons (not (null (executable-find "git")))
-                 (not (null (executable-find "python3"))))
-      (`(t . t) 'extended)
-      (`(t)     'simple))
-    "Type of git integration for `treemacs-git-mode'.
-There are 2 possible values:
-1) simple, which highlights only files based on their git status, and is
-   slightly faster
-2) extended, which highlights both files and directories, but requires python")
-
-  (defvar treemacs-collapse-dirs
-    (if (executable-find "python3") 3 0))
-
   (defun +treemacs|improve-hl-line-contrast ()
     "`hl-line' doesn't stand out enough in some themes."
     (face-remap-add-relative 'hl-line 'region))
   (add-hook 'treemacs-mode-hook #'+treemacs|improve-hl-line-contrast)
 
+  ;; Don't follow the cursor
   (treemacs-follow-mode -1)
-  (treemacs-filewatch-mode t)
-  (when (memq +treemacs-use-git-mode '(simple extended))
-    (treemacs-git-mode +treemacs-use-git-mode))
 
   (after! ace-window
     (setq aw-ignored-buffers (delq 'treemacs-mode aw-ignored-buffers))))