; Revert "Replace eldoc-documentation-function with a hook"

[gnu-emacs] / lisp / emacs-lisp / eldoc.el

diff --git a/lisp/emacs-lisp/eldoc.el b/lisp/emacs-lisp/eldoc.el
index d527d676d5192a8dca5294dce23e301d001ff8bf..6c2f869f260ab632b053721f1a317b8b8fa1994d 100644 (file)
--- a/lisp/emacs-lisp/eldoc.el
+++ b/lisp/emacs-lisp/eldoc.el
@@ -1,6 +1,6 @@
 ;;; eldoc.el --- Show function arglist or variable docstring in echo area  -*- lexical-binding:t; -*-
 
-;; Copyright (C) 1996-2015 Free Software Foundation, Inc.
+;; Copyright (C) 1996-2016 Free Software Foundation, Inc.
 
 ;; Author: Noah Friedman <friedman@splode.com>
 ;; Maintainer: friedman@splode.com
@@ -197,12 +197,23 @@ expression point is on."
    (t
     (kill-local-variable 'eldoc-message-commands)
     (remove-hook 'post-command-hook 'eldoc-schedule-timer t)
-    (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t))))
+    (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t)
+    (when eldoc-timer
+      (cancel-timer eldoc-timer)
+      (setq eldoc-timer nil)))))
 
 ;;;###autoload
 (define-minor-mode global-eldoc-mode
-  "Enable `eldoc-mode' in all buffers where it's applicable."
-  :group 'eldoc :global t
+  "Toggle Global Eldoc mode on or off.
+With a prefix argument ARG, enable Global Eldoc mode if ARG is
+positive, and disable it otherwise.  If called from Lisp, enable
+the mode if ARG is omitted or nil, and toggle it if ARG is ‘toggle’.
+
+If Global Eldoc mode is on, `eldoc-mode' will be enabled in all
+buffers where it's applicable.  These are buffers that have modes
+that have enabled eldoc support.  See `eldoc-documentation-function'."
+  :group 'eldoc
+  :global t
   :initialize 'custom-initialize-delay
   :init-value t
   (setq eldoc-last-message nil)
@@ -222,7 +233,7 @@ expression point is on."
            (memq eldoc-timer timer-idle-list)) ;FIXME: Why?
       (setq eldoc-timer
             (run-with-idle-timer
-            eldoc-idle-delay t
+            eldoc-idle-delay nil
             (lambda ()
                (when (or eldoc-mode
                          (and global-eldoc-mode
@@ -261,7 +272,7 @@ Otherwise work like `message'."
                        mode-line-format)))
           (setq eldoc-mode-line-string
                 (when (stringp format-string)
-                  (apply 'format format-string args)))
+                  (apply #'format-message format-string args)))
           (force-mode-line-update)))
     (apply 'message format-string args)))
 
@@ -274,7 +285,7 @@ Otherwise work like `message'."
                ;; eldoc-last-message so eq test above might succeed on
                ;; subsequent calls.
                ((null (cdr args)) (car args))
-               (t (apply 'format args))))
+               (t (apply #'format-message args))))
     ;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages
     ;; are recorded in a log.  Do not put eldoc messages in that log since
     ;; they are Legion.
@@ -337,8 +348,8 @@ and the face `eldoc-highlight-function-argument', if they are to have any
 effect.
 
 Major modes should modify this variable using `add-function', for example:
-  (add-function :before-until (local 'eldoc-documentation-function)
-                #'foo-mode-eldoc-function)
+  (add-function :before-until (local \\='eldoc-documentation-function)
+                #\\='foo-mode-eldoc-function)
 so that the global documentation function (i.e. the default value of the
 variable) is taken into account if the major mode specific function does not
 return any documentation.")
@@ -354,7 +365,32 @@ return any documentation.")
                nil))
         (eldoc-message (funcall eldoc-documentation-function)))))
 
-\f
+;; If the entire line cannot fit in the echo area, the symbol name may be
+;; truncated or eliminated entirely from the output to make room for the
+;; description.
+(defun eldoc-docstring-format-sym-doc (prefix doc &optional face)
+  (when (symbolp prefix)
+    (setq prefix (concat (propertize (symbol-name prefix) 'face face) ": ")))
+  (let* ((ea-multi eldoc-echo-area-use-multiline-p)
+         ;; Subtract 1 from window width since emacs will not write
+         ;; any chars to the last column, or in later versions, will
+         ;; cause a wraparound and resize of the echo area.
+         (ea-width (1- (window-width (minibuffer-window))))
+         (strip (- (+ (length prefix) (length doc)) ea-width)))
+    (cond ((or (<= strip 0)
+               (eq ea-multi t)
+               (and ea-multi (> (length doc) ea-width)))
+           (concat prefix doc))
+          ((> (length doc) ea-width)
+           (substring (format "%s" doc) 0 ea-width))
+          ((>= strip (string-match-p ":? *\\'" prefix))
+           doc)
+          (t
+           ;; Show the end of the partial symbol name, rather
+           ;; than the beginning, since the former is more likely
+           ;; to be unique given package namespace conventions.
+           (concat (substring prefix strip) doc)))))
+
 ;; When point is in a sexp, the function args are not reprinted in the echo
 ;; area after every possible interactive command because some of them print
 ;; their own messages in the echo area; the eldoc functions would instantly
@@ -385,6 +421,7 @@ return any documentation.")
 \f
 ;; Prime the command list.
 (eldoc-add-command-completions
+ "back-to-indentation"
  "backward-" "beginning-of-" "delete-other-windows" "delete-window"
  "down-list" "end-of-" "exchange-point-and-mark" "forward-" "goto-"
  "handle-select-window" "indent-for-tab-command" "left-" "mark-page"