Re: |PATCH| describe-minor-mode and describe-minor-mode-from-indicator

[Masatake YAMATO]

I've updated my patch.

I wrote:
    1. M-x describe-minor-mode
       The user of describe-minor-mode can give its argument
       with completion. The completion table is built from the
       name of minor modes activated on the current buffer.

    2. M-x describe-minor-mode-from-indicator
       Almost the same as describe-minor-mode but the user 
       can pass an indicator instead of minor mode name to
       get help. I could not implment completion.
       (You will be not satisfied with "without completion".)

    3. I added "Describe `MinorMode'" menu item to "Minor Modes" 
       popup menu. The user can get help about a minor mode with mouse-3.

Richard Stallman wrote:
    This is a very useful feature.  It could be more useful if the user
    could click on a minor mode name in the mode line and get a
    description of it.  This could work for mahor modes too.  Right now
    only mouse-3 is used on this part of the mode line.

    (It is not hard to call completing-read--did you find this
    difficult?).

Thank you for your comment.
The update patch supports:

2' M-x describe-minor-mode-from-indicator
   uses completing-read to read indicator.

3' Added popup menu for major mode. I introduced just another
   popup menu for major mode. 

Tell me when I should write ChangeLog entry:)
Masatake YAMATO
    
Index: help.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/help.el,v
retrieving revision 1.255
diff -u -r1.255 help.el
--- help.el     13 Jan 2003 08:04:46 -0000      1.255
+++ help.el     20 Jan 2003 17:09:59 -0000
@@ -611,6 +611,75 @@
          (setq minor-modes (cdr minor-modes))))
       (print-help-return-message))))
 
+(defun describe-minor-mode (minor-mode)
+  "Display documentation of a minor mode given as MINOR-MODE."
+  (interactive (list (intern (completing-read 
+                             "Minor mode: "
+                             (delete nil (mapcar
+                                          (function (lambda (x)
+                                                      (if (eval (car x))
+                                                          (symbol-name (car 
x)))))
+                                          minor-mode-alist))))))
+  (if (fboundp minor-mode)
+      (describe-function minor-mode)
+    (describe-variable minor-mode)))
+
+(defun describe-minor-mode-from-indicator (indicator)
+  "Display documentation of a minor mode specified by INDICATOR."
+  (interactive (list 
+               (completing-read 
+                "Minor mode indicator: "
+                (delete nil 
+                        (mapcar
+                         #'(lambda (x)
+                             (if (eval (car x))
+                                 (let ((i (expand-minor-mode-indicator-object 
(cadr x))))
+                                   (if (and (< 0 (length i))
+                                            (string= " " (substring i 0 1)))
+                                       (substring i 1)
+                                     i))))
+                         minor-mode-alist)))))
+  (let ((minor-mode (lookup-minor-mode-from-indicator indicator)))
+    (if minor-mode
+       (describe-minor-mode minor-mode)
+      (error "Cannot find minor mode for `%s'" indicator))))
+
+(defun lookup-minor-mode-from-indicator (indicator)
+  "Return a minor mode symbol from its indicator on the modeline."
+  (if (and (< 0 (length indicator)) 
+          (not (string= " " (substring indicator 0 1))))
+      (setq indicator (concat " " indicator)))
+  (let ((minor-modes minor-mode-alist)
+       result)
+    (while minor-modes
+      (let* ((minor-mode (car (car minor-modes)))
+            (anindicator (car (cdr (car minor-modes)))))
+       (setq anindicator (expand-minor-mode-indicator-object anindicator))
+       (if (and (stringp anindicator) 
+                (string= anindicator indicator))
+           (setq result minor-mode
+                 minor-modes nil)
+         (setq minor-modes (cdr minor-modes)))))
+    result))
+
+(defun expand-minor-mode-indicator-object (obj)
+  "Expand OBJ that represents a minor-mode indicator.
+cdr part of a `minor-mode-alist' element(indicator object) is the
+indicator of minor mode that is in car part.  Normally indicator
+object is a string. However, in some case it is more compound object
+like cons cell. This function tries to make the compound object a string."
+  ;; copied from describe-mode
+  (while (and obj (symbolp obj)
+             (boundp obj)
+             (not (eq obj (symbol-value obj))))
+    (setq obj (symbol-value obj)))
+  ;; eval :eval
+  (if (and (consp obj) 
+          (keywordp (car obj))
+          (eq :eval (car obj)))
+      (setq obj (eval (cadr obj))))
+  obj)
+
 
 ;;; Automatic resizing of temporary buffers.
 
Index: bindings.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/bindings.el,v
retrieving revision 1.112
diff -u -r1.112 bindings.el
--- bindings.el 21 Dec 2002 20:19:37 -0000      1.112
+++ bindings.el 20 Jan 2003 17:09:59 -0000
@@ -249,6 +249,9 @@
 
 (make-variable-buffer-local 'mode-line-modified)
 
+(defvar mode-line-major-mode-keymap nil "\
+Keymap to display on major mode.")
+
 ;; Actual initialization is below.
 (defvar mode-line-position nil
   "Mode-line control for displaying line number, column number and fraction.")
@@ -257,12 +260,17 @@
   "Mode-line control for displaying major and minor modes.")
 
 (defvar mode-line-minor-mode-keymap nil "\
-Keymap to display on major and minor modes.")
+Keymap to display on minor modes.")
+
+;; Menu of major mode.
+(let ((map (make-sparse-keymap)))
+  (define-key map [mode-line down-mouse-3] 'mode-line-major-mode-menu-1)
+  (setq mode-line-major-mode-keymap map))
 
 ;; Menu of minor modes.
 (let ((map (make-sparse-keymap)))
-  (define-key map [mode-line down-mouse-3] 'mode-line-mode-menu-1)
-  (define-key map [header-line down-mouse-3] 'mode-line-mode-menu-1)
+  (define-key map [mode-line down-mouse-3] 'mode-line-minor-mode-menu-1)
+  (define-key map [header-line down-mouse-3] 'mode-line-minor-mode-menu-1)
   (setq mode-line-minor-mode-keymap map))
 
 (let* ((help-echo
@@ -292,8 +300,13 @@
   (setq-default mode-line-modes
     (list
      (propertize "%[(" 'help-echo help-echo)
-     `(:propertize ("" mode-name mode-line-process minor-mode-alist)
-                  help-echo "mouse-3: minor mode menu"
+     ;; major mode
+     `(:propertize ("" mode-name) 
+                  help-echo "mouse-3: major mode menu"
+                  local-map ,mode-line-major-mode-keymap)
+     ;; minor modes
+     `(:propertize ("" mode-line-process minor-mode-alist)
+                  help-echo "mouse-3: minor modes menu"
                   local-map ,mode-line-minor-mode-keymap)
      (propertize "%n" 'help-echo "mouse-2: widen"
                 'local-map (make-mode-line-mouse-map
@@ -359,63 +372,104 @@
   (interactive)
   (switch-to-buffer (other-buffer)))
 
-(defvar mode-line-mode-menu (make-sparse-keymap "Minor Modes") "\
-Menu of mode operations in the mode line.")
+(defvar mode-line-major-mode-menu (make-sparse-keymap "Major Mode") "\
+Menu of major mode operations in the mode line.")
 
-(defun mode-line-mode-menu-1 (event)
-  (interactive "e")
+(defvar mode-line-minor-mode-menu (make-sparse-keymap "Minor Modes") "\
+Menu of minor modes operations in the mode line.")
+
+(defun mode-line-mode-menu-1 (event menu)
   (save-selected-window
     (select-window (posn-window (event-start event)))
-    (let* ((selection (mode-line-mode-menu event))
-          (binding (and selection (lookup-key mode-line-mode-menu
+    (let* ((selection (funcall menu event))
+          (binding (and selection (lookup-key (eval menu)
                                               (vector (car selection))))))
       (if binding
          (call-interactively binding)))))
+  
+(defun mode-line-major-mode-menu-1 (event)
+  (interactive "e")
+  (mode-line-mode-menu-1 event 'mode-line-major-mode-menu))
+
+(defun mode-line-minor-mode-menu-1 (event)
+  (interactive "e")
+  (mode-line-mode-menu-1 event 'mode-line-minor-mode-menu))
 
 (defmacro bound-and-true-p (var)
   "Return the value of symbol VAR if it is bound, else nil."
   `(and (boundp (quote ,var)) ,var))
 
-(define-key mode-line-mode-menu [overwrite-mode]
+(define-key mode-line-major-mode-menu [describe-mode]
+  `(menu-item ,'(format "Describe `%s'" 
+                       mode-line-mode-menu-grab-mode-indicator)
+             describe-mode
+             :visible (and mode-line-mode-menu-grab-mode-indicator
+                           (not (string= " " (substring 
mode-line-mode-menu-grab-mode-indicator 0 1))))))
+
+(define-key mode-line-minor-mode-menu [overwrite-mode]
   `(menu-item ,(purecopy "Overwrite (Ovwrt)") overwrite-mode
              :button (:toggle . overwrite-mode)))
-(define-key mode-line-mode-menu [outline-minor-mode]
+(define-key mode-line-minor-mode-menu [outline-minor-mode]
   `(menu-item ,(purecopy "Outline (Outl)") outline-minor-mode
              :button (:toggle . (bound-and-true-p outline-minor-mode))))
-(define-key mode-line-mode-menu [line-number-mode]
+(define-key mode-line-minor-mode-menu [line-number-mode]
   `(menu-item ,(purecopy "Line number") line-number-mode
              :button (:toggle . line-number-mode)))
-(define-key mode-line-mode-menu [highlight-changes-mode]
+(define-key mode-line-minor-mode-menu [highlight-changes-mode]
   `(menu-item ,(purecopy "Highlight changes (Chg)") highlight-changes-mode
              :button (:toggle . highlight-changes-mode)))
-(define-key mode-line-mode-menu [glasses-mode]
+(define-key mode-line-minor-mode-menu [glasses-mode]
   `(menu-item ,(purecopy "Glasses (o^o)") glasses-mode
              :button (:toggle . (bound-and-true-p glasses-mode))))
-(define-key mode-line-mode-menu [hide-ifdef-mode]
+(define-key mode-line-minor-mode-menu [hide-ifdef-mode]
   `(menu-item ,(purecopy "Hide ifdef (Ifdef)") hide-ifdef-mode
              :button (:toggle . (bound-and-true-p hide-ifdef-mode))))
-(define-key mode-line-mode-menu [font-lock-mode]
+(define-key mode-line-minor-mode-menu [font-lock-mode]
   `(menu-item ,(purecopy "Font Lock") font-lock-mode
              :button (:toggle . font-lock-mode)))
-(define-key mode-line-mode-menu [flyspell-mode]
+(define-key mode-line-minor-mode-menu [flyspell-mode]
   `(menu-item ,(purecopy "Flyspell (Fly)") flyspell-mode
              :button (:toggle . (bound-and-true-p flyspell-mode))))
-(define-key mode-line-mode-menu [column-number-mode]
+(define-key mode-line-minor-mode-menu [column-number-mode]
   `(menu-item ,(purecopy "Column number") column-number-mode
              :button (:toggle . column-number-mode)))
-(define-key mode-line-mode-menu [auto-fill-mode]
+(define-key mode-line-minor-mode-menu [auto-fill-mode]
   `(menu-item ,(purecopy "Auto Fill (Fill)") auto-fill-mode
              :button (:toggle . auto-fill-function)))
-(define-key mode-line-mode-menu [auto-revert-mode]
+(define-key mode-line-minor-mode-menu [auto-revert-mode]
   `(menu-item ,(purecopy "Auto revert (ARev)") auto-revert-mode
              :button (:toggle . auto-revert-mode)))
-(define-key mode-line-mode-menu [abbrev-mode]
+(define-key mode-line-minor-mode-menu [abbrev-mode]
   `(menu-item ,(purecopy "Abbrev (Abbrev)") abbrev-mode
              :button (:toggle . abbrev-mode)))
 
-(defun mode-line-mode-menu (event)
+(autoload 'describe-minor-mode-from-indicator "help"
+  "Display documentation of a minor mode given as MINOR-MODE." t)
+(define-key mode-line-minor-mode-menu [describe-minor-mode]
+  `(menu-item ,'(format "Describe `%s'" 
+                       (substring mode-line-mode-menu-grab-mode-indicator 1))
+             (lambda () 
+               (interactive)
+               (describe-minor-mode-from-indicator 
+                mode-line-mode-menu-grab-mode-indicator))
+             :visible (and mode-line-mode-menu-grab-mode-indicator
+                           (string= " " (substring 
mode-line-mode-menu-grab-mode-indicator 0 1)))))
+
+(defun get-mode-indicator-from-event (event)
+  (car (nth 4 (car (cdr event)))))
+(defvar mode-line-mode-menu-grab-mode-indicator nil)
+
+(defun mode-line-mode-menu (event menu)
+  (setq mode-line-mode-menu-grab-mode-indicator (get-mode-indicator-from-event 
event))
+  (x-popup-menu event menu))
+
+(defun mode-line-major-mode-menu (event)
+  (interactive "@e")
+  (mode-line-mode-menu event mode-line-major-mode-menu))
+
+(defun mode-line-minor-mode-menu (event)
   (interactive "@e")
-  (x-popup-menu event mode-line-mode-menu))
+  (mode-line-mode-menu event mode-line-minor-mode-menu))
 
 ;; Add menu of buffer operations to the buffer identification part
 ;; of the mode line.or header line.