emacs: help: remove duplicate bindings

If the user (or a mode) overrides a keybinding from the common keymap
in one of the modes then both help lines appear in the help screen
even though only one of them is applicable.

Fix this by checking if we already have that key binding. We do this
by constructing an list of (key . docstring) pairs so it is easy to
check if we have already had that binding. Then the actual print help
routine changes these pairs into strings "key \t docstring"
This commit is contained in:
Mark Walters 2013-11-12 20:10:55 +00:00 committed by David Bremner
parent 6f616bd733
commit 9d0174b11c

View file

@ -237,11 +237,12 @@ This is basically just `format-kbd-macro' but we also convert ESC to M-."
(concat desc " ")))) (concat desc " "))))
(defun notmuch-describe-keymap (keymap ua-keys &optional prefix tail) (defun notmuch-describe-keymap (keymap ua-keys &optional prefix tail)
"Return a list of strings, each describing one binding in KEYMAP. "Return a list of cons cells, each describing one binding in KEYMAP.
Each string gives a human-readable description of the key and a Each cons cell consists of a string giving a human-readable
one-line description of the bound function. See `notmuch-help' description of the key, and a one-line description of the bound
for an overview of how this documentation is extracted. function. See `notmuch-help' for an overview of how this
documentation is extracted.
UA-KEYS should be a key sequence bound to `universal-argument'. UA-KEYS should be a key sequence bound to `universal-argument'.
It will be used to describe bindings of commands that support a It will be used to describe bindings of commands that support a
@ -254,18 +255,23 @@ prefix argument. PREFIX and TAIL are used internally."
(notmuch-describe-keymap (notmuch-describe-keymap
binding ua-keys (notmuch-prefix-key-description key) tail))) binding ua-keys (notmuch-prefix-key-description key) tail)))
(binding (binding
(let ((key-string (concat prefix (format-kbd-macro (vector key)))))
;; We don't include documentation if the key-binding is
;; over-ridden. Note, over-riding a binding
;; automatically hides the prefixed version too.
(unless (assoc key-string tail)
(when (and ua-keys (symbolp binding) (when (and ua-keys (symbolp binding)
(get binding 'notmuch-prefix-doc)) (get binding 'notmuch-prefix-doc))
;; Documentation for prefixed command ;; Documentation for prefixed command
(let ((ua-desc (key-description ua-keys))) (let ((ua-desc (key-description ua-keys)))
(push (concat ua-desc " " prefix (format-kbd-macro (vector key)) (push (cons (concat ua-desc " " prefix (format-kbd-macro (vector key)))
"\t" (get binding 'notmuch-prefix-doc)) (get binding 'notmuch-prefix-doc))
tail))) tail)))
;; Documentation for command ;; Documentation for command
(push (concat prefix (format-kbd-macro (vector key)) "\t" (push (cons key-string
(or (and (symbolp binding) (get binding 'notmuch-doc)) (or (and (symbolp binding) (get binding 'notmuch-doc))
(notmuch-documentation-first-line binding))) (notmuch-documentation-first-line binding)))
tail)))) tail))))))
keymap) keymap)
tail) tail)
@ -278,7 +284,8 @@ prefix argument. PREFIX and TAIL are used internally."
(let* ((keymap-name (substring doc (match-beginning 1) (match-end 1))) (let* ((keymap-name (substring doc (match-beginning 1) (match-end 1)))
(keymap (symbol-value (intern keymap-name))) (keymap (symbol-value (intern keymap-name)))
(ua-keys (where-is-internal 'universal-argument keymap t)) (ua-keys (where-is-internal 'universal-argument keymap t))
(desc-list (notmuch-describe-keymap keymap ua-keys))) (desc-alist (notmuch-describe-keymap keymap ua-keys))
(desc-list (mapcar (lambda (arg) (concat (car arg) "\t" (cdr arg))) desc-alist)))
(mapconcat #'identity desc-list "\n"))))) (mapconcat #'identity desc-list "\n")))))
(setq doc (replace-match desc 1 1 doc))) (setq doc (replace-match desc 1 1 doc)))
(setq beg (match-end 0))) (setq beg (match-end 0)))