treemacs: create and bind toggle project function

layers/+filetree/treemacs/funcs.el

@@ -0,0 +1,22 @@
+;;; packages.el --- Neotree Layer functions File
+;;
+;; Copyright (c) 2012-2018 Sylvain Benner & Contributors
+;;
+;; Author: Sylvain Benner <sylvain.benner@gmail.com>
+;; URL: https://github.com/syl20bnr/spacemacs
+;;
+;; This file is not part of GNU Emacs.
+;;
+;;; License: GPLv3
+
+(defun spacemacs/treemacs-project-toggle ()
+  "Toggle and add the current project to treemacs if not already added."
+  (interactive)
+  (if (eq (treemacs-current-visibility) 'visible)
+      (delete-window (treemacs-get-local-window))
+    (let ((path (projectile-project-root))
+          (name (projectile-project-name)))
+      (unless (treemacs-current-workspace)
+        (treemacs--find-workspace))
+      (treemacs-do-add-project-to-workspace path name)
+      (treemacs-select-window))))

layers/+filetree/treemacs/packages.el

@@ -24,7 +24,8 @@
 
 (defun treemacs/init-treemacs ()
   (use-package treemacs
-    :commands (treemacs-select-window treemacs--window-number-ten)
+    :commands (treemacs-select-window treemacs--window-number-ten
+               treemacs-current-visibility)
     :defer t
     :init
     (progn
@@ -44,7 +45,8 @@
         "ft"    'treemacs
         "fB"    'treemacs-bookmark
         "fT"    'treemacs-find-file
-        "f M-t" 'treemacs-find-tag)
+        "f M-t" 'treemacs-find-tag
+        "pt"    'spacemacs/treemacs-project-toggle)
       (which-key-add-major-mode-key-based-replacements 'treemacs-mode
         "c"     "treemacs-create"
         "o"     "treemacs-visit-node"