Show conflicts in smerge ts hint

Use a dynamic hint for the smerge transient state in order to show the
current and total numbers of conflicts, and make the full hint toggleable.

* CHANGELOG.develop: Add an entry for this change.
* layers/+source-control/version-control/config.el
(spacemacs--smerge-ts-full-hint-toggle): New variable.
* layers/+source-control/version-control/funcs.el
(spacemacs//smerge-ts-hint): New function.  Return a string indicating the
index of the current conflict and the total number of conflicts detected by
smerge-mode.  If spacemacs--smerge-ts-full-hint-toggle is true, append the
smerge transient state's full hint.
(spacemacs//smerge-ts-toggle-hint): Toggle showing the full hint for the
smerge transient state.
* layers/+source-control/version-control/packages.el
(version-control/init-smerge-mode): Define the transient state in :init so
we can use spacemacs|transient-state-format-hint.  Use
spacemacs//smerge-ts-hint to display a dynamic hint.  Bind the ? key to
spacemacs//smerge-ts-toggle-hint.

CHANGELOG.develop

@@ -2813,6 +2813,8 @@ Other:
   - Added smerge transient state key bindings (thanks to duianto):
     ~SPC g r e >~ ediff
     ~SPC g r K >~ kill current
+  - Added current and total conflicts to smerge transient state's hint
+    (thanks to Miciah Dashiel Butler Masters)
 - New packages:
   - =browse-at-remote= which replaces =github-browse-file=
   (thanks Eugene Yaremenko)

layers/+source-control/version-control/config.el

@@ -9,6 +9,9 @@
 ;;
 ;;; License: GPLv3
 
+(defvar spacemacs--smerge-ts-full-hint-toggle nil
+  "Display smerge transient-state documentation.")
+
 (defvar version-control-global-margin t
   "If non-nil, will show diff margins globally.")
 

layers/+source-control/version-control/funcs.el

@@ -128,3 +128,27 @@
   :off (spacemacs/vcs-disable-margin-globally)
   :documentation "Enable diff margins globally."
   :evil-leader "T C-d")
+
+(defun spacemacs//smerge-ts-hint ()
+  "Return a hint for the smerge transient state.
+Return a string indicating the index of the current conflict and
+the number of conflicts detected by `smerge-mode'."
+  (concat
+   (cl-loop for ol being the overlays
+            with pos = (point)
+            if (eq (overlay-get ol 'smerge) 'conflict)
+            count ol into total
+            and if (<= (overlay-start ol) pos)
+            count ol into idx
+            finally return (format "conflict [%d/%d]" idx total))
+   (if spacemacs--smerge-ts-full-hint-toggle
+       spacemacs--smerge-ts-full-hint
+     (concat "  (["
+             (propertize "?" 'face 'hydra-face-red)
+             "] help)"))))
+
+(defun spacemacs//smerge-ts-toggle-hint ()
+  "Toggle the full hint docstring for the smerge transient state."
+  (interactive)
+  (setq spacemacs--smerge-ts-full-hint-toggle
+        (not spacemacs--smerge-ts-full-hint-toggle)))

layers/+source-control/version-control/packages.el

@@ -263,21 +263,24 @@
     :diminish smerge-mode
     :commands spacemacs/smerge-transient-state/body
     :init
-    (spacemacs/set-leader-keys
-      "gr" 'spacemacs/smerge-transient-state/body)
-    :config
     (progn
-      (spacemacs|define-transient-state smerge
-        :title "Smerge Transient State"
-        :doc "
+      (spacemacs/set-leader-keys
+        "gr" 'spacemacs/smerge-transient-state/body)
+      (spacemacs|transient-state-format-hint smerge
+        spacemacs--smerge-ts-full-hint
+        "\n
  Movement^^^^         Merge Action^^      Diff^^            Other
  ---------------^^^^  ----------------^^  --------------^^  ---------------------------^^
  [_n_]^^   next hunk  [_b_] keep base     [_<_] base/mine   [_C_] combine curr/next hunks
  [_N_/_p_] prev hunk  [_m_] keep mine     [_=_] mine/other  [_u_] undo
  [_j_]^^   next line  [_a_] keep all      [_>_] base/other  [_q_] quit
  [_k_]^^   prev line  [_o_] keep other    [_r_] refine
- ^^^^                 [_c_] keep current  [_e_] ediff
- ^^^^                 [_K_] kill current"
+ ^^^^                 [_c_] keep current  [_e_] ediff       [_?_]^^ toggle help
+ ^^^^                 [_K_] kill current")
+      (spacemacs|define-transient-state smerge
+        :title "Smerge Transient State"
+        :hint-is-doc t
+        :dynamic-hint (spacemacs//smerge-ts-hint)
         :bindings
         ;; move
         ("n" smerge-next)
@@ -301,7 +304,8 @@
         ("C" smerge-combine-with-next)
         ("K" smerge-kill-current)
         ("u" undo-tree-undo)
-        ("q" nil :exit t)))))
+        ("q" nil :exit t)
+        ("?" spacemacs//smerge-ts-toggle-hint)))))
 
 (defun version-control/init-browse-at-remote ()
   (use-package browse-at-remote