bug#41438: [PATCH] Allow windmove keys to be bound without prefix or modifiers

[Philip K.]

Juri Linkov <juri@linkov.net> writes:

>> Another question I'd like to ask before trying it out: Would there be
>> any interest in adding user options for the "default" modifiers that
>> windmove should use? If yes, one could add a :set function that
>> automatically calls the apropriate bindings function, when it's value
>> is non-nil. I have a very customize-centric configuration, where something
>> this would fit in very well.
>
> I think that adding defcustoms (including a new const `none')
> would be the most natural way to customize windmove modifiers
> (provided that the existing functions should remain).

I made a first concept, but it doesn't work unless windmove is explicity
required (see below). As far as I know, autoloading variables isn't good
style, so is there any other way to invoke the :set property of a user
option?

-- 
        Philip K.

>From b35173936e681e170172eb3d4548a2f91f70dad3 Mon Sep 17 00:00:00 2001
From: Philip K <philip@warpmail.net>
Date: Fri, 22 May 2020 20:21:59 +0200
Subject: [PATCH] Implement user options for windmove modifiers and prefixes

---
 lisp/windmove.el | 103 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 95 insertions(+), 8 deletions(-)

diff --git a/lisp/windmove.el b/lisp/windmove.el
index 3d7f86b9af..95f74bfb81 100644
--- a/lisp/windmove.el
+++ b/lisp/windmove.el
@@ -162,6 +162,19 @@ windmove-window-distance-delta
 (make-obsolete-variable 'windmove-window-distance-delta
                         "no longer used." "27.1")
 
+(defconst windmove-modifier-type
+  '(choice (set :tag "Modifier Symbols"
+                :greedy t
+                ;; See `(elisp) Keyboard Events'
+                (const :tag "Meta" meta)
+                (const :tag "Control" control)
+                (const :tag "Shift" shift)
+                (const :tag "Hyper" hyper)
+                (const :tag "Super" super)
+                (const :tag "Alt" alt))
+           (const :tag "No modifier" none))
+  "Customisation type for windmove modifiers")
+
 
 ;; Note:
 ;;
@@ -419,6 +432,7 @@ windmove-down
   (interactive "P")
   (windmove-do-window-select 'down (and arg (prefix-numeric-value arg))))
 
+(defvar windmove-modifiers)
 
 ;;; set up keybindings
 ;; Idea for this function is from iswitchb.el, by Stephen Eglen
@@ -433,9 +447,10 @@ windmove-default-keybindings
 where MODIFIERS is either a list of modifiers or a single modifier.
 If MODIFIERS is `none', the keybindings will be directly bound to
 the arrow keys.
-Default value of MODIFIERS is `shift'."
+Default value of MODIFIERS is stored in `windmove-modifiers'."
   (interactive)
-  (unless modifiers (setq modifiers 'shift))
+  (unless modifiers
+    (setq modifiers windmove-modifiers))
   (when (eq modifiers 'none) (setq modifiers nil))
   (unless (listp modifiers) (setq modifiers (list modifiers)))
   (global-set-key (vector (append modifiers '(left)))  'windmove-left)
@@ -443,6 +458,25 @@ windmove-default-keybindings
   (global-set-key (vector (append modifiers '(up)))    'windmove-up)
   (global-set-key (vector (append modifiers '(down)))  'windmove-down))
 
+;; has to be declared AFTER windmove-default-keybindings, or else
+;; windmove is recursivly loaded
+;;;###autoload
+(defcustom windmove-modifiers '(shift super)
+  "Modifiers for `windmove-default-keybindings'.
+Can either be a symbol or list of modifier symbols,
+i.e. `meta',`control', `shift', `hyper', `super', or `alt'
+representing modifier keys to use with the arrow keys.
+
+If the value is just `none', the arrow keys will be directly
+bound to the windmove functions."
+  :type windmove-modifier-type
+  :require 'windmove
+  :initialize #'custom-initialize-changed
+  :set (lambda (sym val)
+         (when val
+           (windmove-swap-states-default-keybindings val))
+         (set-default sym val)))
+
 
 ;;; Directional window display and selection
 
@@ -565,6 +599,8 @@ windmove-display-new-tab
   (interactive "P")
   (windmove-display-in-direction 'new-tab arg))
 
+(defvar windmove-display-modifiers)
+
 ;;;###autoload
 (defun windmove-display-default-keybindings (&optional modifiers)
   "Set up keybindings for directional buffer display.
@@ -573,7 +609,7 @@ windmove-display-default-keybindings
 where MODIFIERS is either a list of modifiers or a single modifier.
 If MODIFIERS is `none', the keybindings will be directly bound to
 the arrow keys.
-Default value of MODIFIERS is `shift-meta'."
+Default value of MODIFIERS is stored in `windmove-display-modifiers'."
   (interactive)
   (unless modifiers (setq modifiers '(shift meta)))
   (when (eq modifiers 'none) (setq modifiers nil))
@@ -586,6 +622,17 @@ windmove-display-default-keybindings
   (global-set-key (vector (append modifiers '(?f)))    
'windmove-display-new-frame)
   (global-set-key (vector (append modifiers '(?t)))    
'windmove-display-new-tab))
 
+(defcustom windmove-display-modifiers '(shift meta)
+  "Modifiers for `windmove-display-default-keybindings'.
+Analogous to `windmove-modifiers'."
+  :type windmove-modifier-type
+  :require 'windmove
+  :initialize #'custom-initialize-changed
+  :set (lambda (sym val)
+         (when val
+           (windmove-display-default-keybindings val))
+         (set-default sym val)))
+
 
 ;;; Directional window deletion
 
@@ -640,6 +687,9 @@ windmove-delete-down
   (interactive "P")
   (windmove-delete-in-direction 'down arg))
 
+(defvar windmove-delete-prefix)
+(defvar windmove-delete-modifiers)
+
 ;;;###autoload
 (defun windmove-delete-default-keybindings (&optional prefix modifiers)
   "Set up keybindings for directional window deletion.
@@ -649,12 +699,13 @@ windmove-delete-default-keybindings
 a single modifier.
 If PREFIX is `none', no prefix is used. If MODIFIERS is `none', the keybindings
 are directly bound to the arrow keys.
-Default value of PREFIX is `C-x' and MODIFIERS is `shift'."
+The default values for PREFIX and MODIFIERS are stored in 
`windmove-delete-prefix'
+and `windmove-delete-modifiers' respectively."
   (interactive)
-  (unless prefix (setq prefix '(?\C-x)))
+  (unless prefix (setq prefix (list windmove-delete-prefix)))
   (when (eq prefix 'none) (setq prefix nil))
   (unless (listp prefix) (setq prefix (list prefix)))
-  (unless modifiers (setq modifiers '(shift)))
+  (unless modifiers (setq modifiers windmove-delete-modifiers))
   (when (eq modifiers 'none) (setq modifiers nil))
   (unless (listp modifiers) (setq modifiers (list modifiers)))
   (global-set-key (vector prefix (append modifiers '(left)))  
'windmove-delete-left)
@@ -662,6 +713,28 @@ windmove-delete-default-keybindings
   (global-set-key (vector prefix (append modifiers '(up)))    
'windmove-delete-up)
   (global-set-key (vector prefix (append modifiers '(down)))  
'windmove-delete-down))
 
+(defcustom windmove-delete-prefix (kbd "C-x")
+  "Prefix for `windmove-delete-default-keybindings'."
+  :type 'key-sequence
+  :require 'windmove
+  :initialize #'custom-initialize-changed
+  :set (lambda (sym val)
+         (windmove-delete-default-keybindings
+          val windmove-delete-modifiers)
+         (set-default sym val)))
+
+(defcustom windmove-delete-modifiers '(shift)
+  "Modifiers for `windmove-delete-default-keybindings'.
+See `windmove-modifiers' for more details"
+  :type windmove-modifier-type
+  :require 'windmove
+  :initialize #'custom-initialize-changed
+  :set (lambda (sym val)
+         (when val
+           (windmove-delete-default-keybindings
+            windmove-delete-prefix val))
+         (set-default sym val)))
+
 
 ;;; Directional window swap states
 
@@ -700,6 +773,8 @@ windmove-swap-states-right
   (interactive)
   (windmove-swap-states-in-direction 'right))
 
+(defvar windmove-swap-states-modifiers)
+
 ;;;###autoload
 (defun windmove-swap-states-default-keybindings (&optional modifiers)
   "Set up keybindings for directional window swap states.
@@ -709,9 +784,10 @@ windmove-swap-states-default-keybindings
 or a single modifier.
 If MODIFIERS is `none', the keybindings will be directly bound to the
 arrow keys.
-Default value of MODIFIERS is `shift-super'."
+Default value of MODIFIERS is stored in `windmove-swap-states-modifiers'."
   (interactive)
-  (unless modifiers (setq modifiers '(shift super)))
+  (unless modifiers
+    (setq modifiers windmove-swap-states-modifiers))
   (when (eq modifiers 'none) (setq modifiers nil))
   (unless (listp modifiers) (setq modifiers (list modifiers)))
   (global-set-key (vector (append modifiers '(left)))  
'windmove-swap-states-left)
@@ -719,6 +795,17 @@ windmove-swap-states-default-keybindings
   (global-set-key (vector (append modifiers '(up)))    
'windmove-swap-states-up)
   (global-set-key (vector (append modifiers '(down)))  
'windmove-swap-states-down))
 
+(defcustom windmove-swap-states-modifiers
+  '(shift super)
+  "Modifiers for `windmove-swap-states-default-keybindings'.
+Analogous to `windmove-modifiers'."
+  :type windmove-modifier-type
+  :require 'windmove
+  :initialize #'custom-initialize-changed
+  :set (lambda (sym val)
+         (windmove-swap-states-default-keybindings val)
+         (set-default sym val)))
+
 
 (provide 'windmove)
 
-- 
2.20.1