Update promotion and demotion conventions and apply them to markdown

doc/CONVENTIONS.org

@@ -301,7 +301,8 @@ In normal mode Vim style movement should be enabled with these keybindings:
 
 *** Promotion, Demotion and element movement
 Promotion, demotion and movement of headings or list elements (whatever is
-possible) should be enabled with the following keys in any mode
+possible) should be enabled with the following keys when in Vim style or
+Hybrid with hjkl movements enabled:
 
 | Key Binding | Description                  |
 |-------------+------------------------------|
@@ -310,6 +311,16 @@ possible) should be enabled with the following keys in any mode
 | ~M-k~       | Move element up              |
 | ~M-l~       | Demote heading by one level  |
 
+In all editing styles promotion and demotion can be done with the following
+keys:
+
+| Key Binding | Description                  |
+|-------------+------------------------------|
+| ~M-down~    | Move element down            |
+| ~M-left~    | Promote heading by one level |
+| ~M-right~   | Demote heading by one level  |
+| ~M-up~      | Move element up              |
+
 *** Table editing
 If table specific commands are available the they are grouped under the
 ~SPC m t~ group.

layers/+lang/markdown/README.org

@@ -188,12 +188,12 @@ To generate a table of contents type on top of the buffer:
 
 ** Promotion, Demotion
 
-| Evil  | Holy        | Command            |
-|-------+-------------+--------------------|
-| ~M-k~ | ~C-c C-x u~ | markdown-move-up   |
-| ~M-j~ | ~C-c C-x d~ | markdown-move-down |
-| ~M-h~ | ~C-c C-x l~ | markdown-promote   |
-| ~M-l~ | ~C-c C-x r~ | markdown-demote    |
+| Key Binding        | Command            |
+|--------------------+--------------------|
+| ~M-k~ or ~M-up~    | markdown-move-up   |
+| ~M-j~ or ~M-down~  | markdown-move-down |
+| ~M-h~ or ~M-left~  | markdown-promote   |
+| ~M-l~ or ~M-right~ | markdown-demote    |
 
 ** Toggles
 

layers/+lang/markdown/funcs.el

@@ -51,3 +51,15 @@ Will work on both org-mode and any mode that accepts plain html."
                                  :back back)))
     (dolist (mode markdown--key-bindings-modes)
       (mmm-add-mode-ext-class mode nil class))))
+
+(defun spacemacs//markdown-hjkl-promotion-demotion (style)
+  "Set promotion/demotiion on 'hjkl' for the given editing STYLE."
+  (when (or (eq 'vim style)
+            (and (eq 'hybrid style)
+                 hybrid-mode-enable-hjkl-bindings))
+    (dolist (s '(normal insert))
+      (evil-define-key s markdown-mode-map
+        (kbd "M-h") 'markdown-promote
+        (kbd "M-j") 'markdown-move-down
+        (kbd "M-k") 'markdown-move-up
+        (kbd "M-l") 'markdown-demote))))

layers/+lang/markdown/packages.el

@@ -143,13 +143,13 @@
         ;; next visible heading is not exactly what we want but close enough
         "gl" 'outline-next-visible-heading)
       ;; Promotion, Demotion
-      (mapc (lambda (state)
-              (evil-define-key state markdown-mode-map
-                (kbd "M-h") 'markdown-promote
-                (kbd "M-j") 'markdown-move-down
-                (kbd "M-k") 'markdown-move-up
-                (kbd "M-l") 'markdown-demote))
-            '(normal insert)))))
+      (add-hook 'spacemacs-editing-style-hook
+                'spacemacs//markdown-hjkl-promotion-demotion)
+      (spacemacs//markdown-hjkl-promotion-demotion dotspacemacs-editing-style)
+      (define-key markdown-mode-map (kbd "M-<down>") 'markdown-move-down)
+      (define-key markdown-mode-map (kbd "M-<left>") 'markdown-promote)
+      (define-key markdown-mode-map (kbd "M-<right>") 'markdown-demote)
+      (define-key markdown-mode-map (kbd "M-<up>") 'markdown-move-up))))
 
 (defun markdown/init-markdown-toc ()
   (use-package markdown-toc