Add symbol-overlay package to spacemacs/navigation layer

Defines a transient state for symbol-overlay, and bind it to ~SPC s o~ and ~SPC s O~.

Updates:

* update due to the signature change of `symbol-overlay-get-list`.
* align the docstring using `^^` and add `quit` button.

CHANGELOG.develop

@@ -589,6 +589,8 @@ Other:
     - =help-fns+=
     - =font-lock+=
   - Remove package =adaptive-wrap=
+  - Added =symbol-overlay= to the =spacemacs-navigation= layer
+    (thanks to kenkangxgwe)
 - Key bindings:
   - New evil text objects =«=, =｢=, =‘= and =“=.
   - Improved buffer transient state with extra bindings and new commands:
@@ -746,6 +748,27 @@ Other:
     (thanks to Rich Alesi)
   - Improved =which-key= replacement regular expressions (thanks to duianto)
   - Added ~SPC o~ which-key prefix name: =user bindings= (thanks to duianto)
+  - Added =symbol-overlay= key bindings (thanks to kenkangxgwe):
+    - ~SPC s o~ calls =spacemacs/symbol-overlay=
+    - ~SPC s O~ calls =symbol-overlay-remove-all=
+  - New symbol overlay transient state, ~SPC s o~ on a symbol:
+    - ~b~ calls =symbol-overlay-switch-backward=
+    - ~c~ calls =symbol-overlay-save-symbol=
+    - ~d~ calls =symbol-overlay-jump-to-definition=
+    - ~e~ calls =symbol-overlay-echo-mark=
+    - ~f~ calls =symbol-overlay-switch-forward=
+    - ~n~ calls =symbol-overlay-jump-next=
+    - ~N~ calls =symbol-overlay-jump-prev=
+    - ~o~ calls =symbol-overlay-put=
+    - ~O~ calls =symbol-overlay-remove-all=
+    - ~p~ calls =symbol-overlay-jump-prev=
+    - ~r~ calls =symbol-overlay-query-replace=
+    - ~R~ calls =symbol-overlay-rename=
+    - ~s~ calls =symbol-overlay-isearch-literally=
+    - ~t~ calls =symbol-overlay-toggle-in-scope=
+    - ~z~ calls =recenter-top-bottom=
+    - ~q~ exits the transient state
+      (thanks to kenkangxgwe)
 - Improvements:
   - Rewrote window layout functions for ~SPC w 1~, ~SPC w 2~, ~SPC w 3~, and
     ~SPC w 4~ (thanks to Codruț Constantin Gușoi):

layers/+spacemacs/spacemacs-navigation/funcs.el

@@ -197,6 +197,39 @@ If the universal prefix argument is used then kill also the window."
    (format spacemacs--symbol-highlight-transient-state-doc
            (spacemacs//symbol-highlight-doc))))
 
+
+;; symbol overlay
+
+(defun spacemacs/symbol-overlay ()
+  "Start symbol-overlay-transient-state."
+  (interactive)
+  (symbol-overlay-put)
+  (spacemacs/symbol-overlay-transient-state/body))
+
+(defun spacemacs//symbol-overlay-doc ()
+        (let* ((symbol-at-point (symbol-overlay-get-symbol))
+               (keyword (symbol-overlay-assoc symbol-at-point))
+               (symbol (car keyword))
+	             (before (symbol-overlay-get-list -1 symbol))
+	             (after (symbol-overlay-get-list 1 symbol))
+	             (count (length before))
+               (scope (format "%s"
+                              (if (cadr keyword)
+                                  "Scope"
+                                "Buffer")))
+               (color (cddr keyword))
+               (x/y (format "[%s/%s]" (+ count 1) (+ count (length after)))))
+            (concat
+             (propertize (format " %s " scope) 'face color))
+             (propertize (format " %s " x/y) 'face
+                         `(:foreground "#ffffff" :background "#000000"))))
+
+(defun spacemacs//symbol-overlay-ts-doc ()
+  (spacemacs//transient-state-make-doc
+   'symbol-overlay
+   (format spacemacs--symbol-overlay-transient-state-doc
+           (spacemacs//symbol-overlay-doc))))
+
 
 ;; golden ratio
 

layers/+spacemacs/spacemacs-navigation/packages.el

@@ -23,6 +23,7 @@
         paradox
         restart-emacs
         (smooth-scrolling :location built-in)
+        symbol-overlay
         winum))
 
 (defun spacemacs-navigation/init-ace-link ()
@@ -370,6 +371,48 @@
     :documentation "Smooth scrolling."
     :evil-leader "tv"))
 
+(defun spacemacs-navigation/init-symbol-overlay ()
+  (use-package symbol-overlay
+    :init
+    (progn
+      (setq spacemacs--symbol-overlay-transient-state-doc "
+%s
+ [_n_] next   [_N_/_p_] prev      [_d_] def           [_f_/_b_] switch [_t_] scope
+ [_e_] echo   [_o_]^^   unoverlay [_O_] unoverlay all [_c_]^^   copy   [_z_] center
+ [_s_] search [_r_]^^   replace   [_R_] rename        ^^^^             [_q_] quit")
+
+      ;; since we are creating our own maps,
+      ;; prevent the default keymap from getting created
+      (setq symbol-overlay-map (make-sparse-keymap)))
+    :config
+    (progn
+      (spacemacs/set-leader-keys
+        "so" 'spacemacs/symbol-overlay
+        "sO" 'symbol-overlay-remove-all)
+
+      ;; transient state
+      (spacemacs|define-transient-state symbol-overlay
+        :title "Symbol Overlay Transient State"
+        :hint-is-doc t
+        :dynamic-hint (spacemacs//symbol-overlay-ts-doc)
+        :bindings
+        ("b" symbol-overlay-switch-backward)
+        ("c" symbol-overlay-save-symbol)
+        ("d" symbol-overlay-jump-to-definition)
+        ("e" symbol-overlay-echo-mark)
+        ("f" symbol-overlay-switch-forward)
+        ("n" symbol-overlay-jump-next)
+        ("N" symbol-overlay-jump-prev)
+        ("o" symbol-overlay-put)
+        ("O" symbol-overlay-remove-all)
+        ("p" symbol-overlay-jump-prev)
+        ("r" symbol-overlay-query-replace)
+        ("R" symbol-overlay-rename)
+        ("s" symbol-overlay-isearch-literally)
+        ("t" symbol-overlay-toggle-in-scope)
+        ("z" recenter-top-bottom)
+        ("q" nil :exit t)))))
+
 (defun spacemacs-navigation/init-winum ()
   (use-package winum
     :config