* lisp/completion-preview.el: Fix use in non-GUI session

Fix loading in non-GUI sessions where `mwheel` is not preloaded.
Not requiring `mwheel` would be a lot more complex, since it would
require delaying the construction of `completion-preview--mouse-map`.

* lisp/completion-preview.el (<toplevel>): Require `mwheel`.
Remove correspondingly redundant `defvar`s.
(completion-preview--mouse-map): Use `key-description` rather than mimicking
it with `format`.

1 files changed, 10 insertions, 8 deletions

diff --git a/lisp/completion-preview.el b/lisp/completion-preview.el
index baadb4714b1..3bb5ef24e9d 100644
--- a/lisp/completion-preview.el
+++ b/lisp/completion-preview.el
@@ -52,6 +52,8 @@
 
 ;;; Code:
 
+(require 'mwheel)
+
 (defgroup completion-preview nil
   "In-buffer completion preview."
   :group 'completion)
@@ -128,19 +130,19 @@ If this option is nil, these commands do not display any message."
   ;; "M-p" #'completion-preview-prev-candidate
   )
 
-(defvar mouse-wheel-up-event)
-(defvar mouse-wheel-up-alternate-event)
-(defvar mouse-wheel-down-event)
-(defvar mouse-wheel-down-alternate-event)
 (defvar-keymap completion-preview--mouse-map
   :doc "Keymap for mouse clicks on the completion preview."
   "<down-mouse-1>" #'completion-preview-insert
   "C-<down-mouse-1>" #'completion-at-point
   "<down-mouse-2>" #'completion-at-point
-  (format "<%s>" mouse-wheel-up-event)             #'completion-preview-prev-candidate
-  (format "<%s>" mouse-wheel-up-alternate-event)   #'completion-preview-prev-candidate
-  (format "<%s>" mouse-wheel-down-event)           #'completion-preview-next-candidate
-  (format "<%s>" mouse-wheel-down-alternate-event) #'completion-preview-next-candidate)
+  (key-description (vector mouse-wheel-up-event))
+  #'completion-preview-prev-candidate
+  (key-description (vector mouse-wheel-up-alternate-event))
+  #'completion-preview-prev-candidate
+  (key-description (vector mouse-wheel-down-event))
+  #'completion-preview-next-candidate
+  (key-description (vector mouse-wheel-down-alternate-event))
+  #'completion-preview-next-candidate)
 
 (defvar-local completion-preview--overlay nil)