Keyboard interface (C-f10) to `mouse-buffer-menu' (C-down-mouse-1).

* lisp/mouse.el (mouse-buffer-menu-map): Extract from `mouse-buffer-menu'.
(mouse-buffer-menu): Use `mouse-buffer-menu-map'.
* lisp/menu-bar.el (menu-bar-buffer-vector): Extract from
`menu-bar-update-buffers'.
(menu-bar-update-buffers): Use `menu-bar-buffer-vector'.
(buffer-menu-open): New user command, bound globally to C-f10,
provides a keyboard interface to `mouse-buffer-menu' (C-down-mouse-1).
(mouse-buffer-menu-keymap): Use `menu-bar-buffer-vector' to
convert the value returned by `mouse-buffer-menu-map' to a list
acceptable to `popup-menu' for `buffer-menu-open'.

etc/NEWS

@@ -183,6 +183,8 @@ for Unicode 8.0.  This includes full support for directional isolates
 and the Bidirectional Parentheses Algorithm (BPA) specified by these
 Unicode standards.
 
+** You can access `mouse-buffer-menu' (C-down-mouse-1) using C-f10.
+
 
 * Changes in Specialized Modes and Packages in Emacs 25.1
 ** ido

lisp/ChangeLog

@@ -1,3 +1,17 @@
+2014-12-18  Sam Steingold  <sds@gnu.org>
+
+	Keyboard interface (C-f10) to `mouse-buffer-menu' (C-down-mouse-1).
+	* mouse.el (mouse-buffer-menu-map): Extract from `mouse-buffer-menu'.
+	(mouse-buffer-menu): Use `mouse-buffer-menu-map'.
+	* menu-bar.el (menu-bar-buffer-vector): Extract from
+	`menu-bar-update-buffers'.
+	(menu-bar-update-buffers): Use `menu-bar-buffer-vector'.
+	(buffer-menu-open): New user command, bound globally to C-f10,
+	provides a keyboard interface to `mouse-buffer-menu' (C-down-mouse-1).
+	(mouse-buffer-menu-keymap): Use `menu-bar-buffer-vector' to
+	convert the value returned by `mouse-buffer-menu-map' to a list
+	acceptable to `popup-menu' for `buffer-menu-open'.
+
 2014-12-18  Artur Malabarba  <bruce.connor.am@gmail.com>
 
 	* let-alist.el (let-alist): Evaluate the `alist' argument only

lisp/menu-bar.el

@@ -1938,6 +1938,19 @@ Buffers menu is regenerated."
   "Function to select the buffer chosen from the `Buffers' menu-bar menu.
 It must accept a buffer as its only required argument.")
 
+(defun menu-bar-buffer-vector (alist)
+  ;; turn ((name . buffer) ...) into a menu
+  (let ((buffers-vec (make-vector (length alist) nil))
+        (i (length alist)))
+    (dolist (pair alist)
+      (setq i (1- i))
+      (aset buffers-vec i
+            (cons (car pair)
+                  `(lambda ()
+                     (interactive)
+                     (funcall menu-bar-select-buffer-function ,(cdr pair))))))
+    buffers-vec))
+
 (defun menu-bar-update-buffers (&optional force)
   ;; If user discards the Buffers item, play along.
   (and (lookup-key (current-global-map) [menu-bar buffer])
@@ -1973,17 +1986,7 @@ It must accept a buffer as its only required argument.")
 				      name)
                                     ))
                              alist))))
-		 ;; Now make the actual list of items.
+		 (list (menu-bar-buffer-vector alist))))
-                 (let ((buffers-vec (make-vector (length alist) nil))
-                       (i (length alist)))
-                   (dolist (pair alist)
-                     (setq i (1- i))
-                     (aset buffers-vec i
-			   (cons (car pair)
-                                 `(lambda ()
-                                    (interactive)
-                                    (funcall menu-bar-select-buffer-function ,(cdr pair))))))
-                   (list buffers-vec))))
 
 	 ;; Make a Frames menu if we have more than one frame.
 	 (when (cdr frames)
@@ -2311,6 +2314,25 @@ If FRAME is nil or not given, use the selected frame."
 
 (global-set-key [f10] 'menu-bar-open)
 
+(defun buffer-menu-open ()
+  "Start key navigation of the buffer menu.
+This is the keyboard interface to \\[mouse-buffer-menu]."
+  (interactive)
+  (popup-menu (mouse-buffer-menu-keymap)
+              (posn-at-x-y 0 0 nil t)))
+
+(global-set-key [C-f10] 'buffer-menu-open)
+
+(defun mouse-buffer-menu-keymap ()
+  (let* ((menu (mouse-buffer-menu-map))
+         (km (make-sparse-keymap (pop menu))))
+    (dolist (item (nreverse menu))
+      (let* ((name (pop item)))
+        (define-key km (vector (intern name))
+          (list name 'keymap name
+                (menu-bar-buffer-vector item)))))
+    km))
+
 (defvar tty-menu-navigation-map
   (let ((map (make-sparse-keymap)))
     ;; The next line is disabled because it breaks interpretation of

lisp/mouse.el

@@ -1516,8 +1516,17 @@ This switches buffers in the window that you clicked on,
 and selects that window."
   (interactive "e")
   (mouse-minibuffer-check event)
-  (let ((buffers (buffer-list))  alist menu split-by-major-mode sum-of-squares)
+  (let ((buf (x-popup-menu event (mouse-buffer-menu-map)))
-    ;; Make an alist of elements that look like (MENU-ITEM . BUFFER).
+        (window (posn-window (event-start event))))
+    (when buf
+      (select-window
+       (if (framep window) (frame-selected-window window)
+         window))
+      (switch-to-buffer buf))))
+
+(defun mouse-buffer-menu-map ()
+  ;; Make an alist of elements that look like (MENU-ITEM . BUFFER).
+  (let ((buffers (buffer-list)) split-by-major-mode sum-of-squares)
     (dolist (buf buffers)
       ;; Divide all buffers into buckets for various major modes.
       ;; Each bucket looks like (MODE NAMESTRING BUFFERS...).
@@ -1581,18 +1590,10 @@ and selects that window."
 		     (setq subdivided-menus
 			   (cons (cons "Others" others-list)
 				 subdivided-menus)))))
-	  (setq menu (cons "Buffer Menu" (nreverse subdivided-menus))))
+          (cons "Buffer Menu" (nreverse subdivided-menus)))
-      (progn
+      (cons "Buffer Menu"
-	(setq alist (mouse-buffer-menu-alist buffers))
+            (mouse-buffer-menu-split "Select Buffer"
-	(setq menu (cons "Buffer Menu"
+                                     (mouse-buffer-menu-alist buffers))))))
-			 (mouse-buffer-menu-split "Select Buffer" alist)))))
-    (let ((buf (x-popup-menu event menu))
-	  (window (posn-window (event-start event))))
-      (when buf
-	(select-window
-	 (if (framep window) (frame-selected-window window)
-	   window))
-	(switch-to-buffer buf)))))
 
 (defun mouse-buffer-menu-alist (buffers)
   (let (tail