Re-implement the feature of showing eldoc info after editing.

* emacs-lisp/eldoc.el (eldoc-post-insert-mode): Remove.
(eldoc-edit-message-commands): New function.
(eldoc-print-after-edit): New variable.
(eldoc-pre-command-refresh-echo-area): Emit message only by
eldoc-message-commands.
(eldoc-mode): Restrict eldoc-message-commands to editing commands
if eldoc-print-after-edit is set. 

* progmodes/octave.el (octave-mode-menu): Adapt to change in
eldoc.

Fixes: debbugs:16346

4 files changed, 45 insertions, 30 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 60aff3c7be0..786162d3e0a 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,17 @@
+2014-01-12  Leo Liu  <sdl.web@gmail.com>
+
+        Re-implement the feature of showing eldoc info after editing.
+        * emacs-lisp/eldoc.el (eldoc-post-insert-mode): Remove.
+        (eldoc-edit-message-commands): New function.
+        (eldoc-print-after-edit): New variable.
+        (eldoc-pre-command-refresh-echo-area): Emit message only by
+        eldoc-message-commands.
+        (eldoc-mode): Restrict eldoc-message-commands to editing commands
+        if eldoc-print-after-edit is set.  (Bug#16346)
+
+        * progmodes/octave.el (octave-mode-menu): Adapt to change in
+        eldoc.
+
 2014-01-11  Eric S. Raymond  <esr@thyrsus.com>
 
         * version.el (emacs-repository-get-version): Enhancee so the
diff --git a/lisp/emacs-lisp/eldoc.el b/lisp/emacs-lisp/eldoc.el
index 8bd9ebc1e63..1c64e28c76b 100644
--- a/lisp/emacs-lisp/eldoc.el
+++ b/lisp/emacs-lisp/eldoc.el
@@ -1,4 +1,4 @@
-;;; eldoc.el --- show function arglist or variable docstring in echo area
+;;; eldoc.el --- show function arglist or variable docstring in echo area  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 1996-2014 Free Software Foundation, Inc.
 
@@ -62,6 +62,12 @@ If this variable is set to 0, no idle time is required."
   :type 'number
   :group 'eldoc)
 
+(defcustom eldoc-print-after-edit nil
+  "If non-nil eldoc info is only shown when editing.
+Changing the value requires toggling `eldoc-mode'."
+  :type 'boolean
+  :group 'eldoc)
+
 ;;;###autoload
 (defcustom eldoc-minor-mode-string (purecopy " ElDoc")
   "String to display in mode line when ElDoc Mode is enabled; nil for none."
@@ -150,6 +156,16 @@ This is used to determine if `eldoc-idle-delay' is changed by the user.")
   "The function used by `eldoc-message' to display messages.
 It should receive the same arguments as `message'.")
 
+(defun eldoc-edit-message-commands ()
+  (let ((cmds (make-vector 31 0))
+        (re (regexp-opt '("delete" "insert" "edit" "electric" "newline"))))
+    (mapatoms (lambda (s)
+                (and (commandp s)
+                     (string-match-p re (symbol-name s))
+                     (intern (symbol-name s) cmds)))
+              obarray)
+    cmds))
+
 
 ;;;###autoload
 (define-minor-mode eldoc-mode
@@ -168,25 +184,13 @@ expression point is on."
   (setq eldoc-last-message nil)
   (if eldoc-mode
       (progn
+        (when eldoc-print-after-edit
+          (setq-local eldoc-message-commands (eldoc-edit-message-commands)))
         (add-hook 'post-command-hook 'eldoc-schedule-timer nil t)
         (add-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t))
-   (remove-hook 'post-command-hook 'eldoc-schedule-timer)
-   (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area)))
-
-;;;###autoload
-(define-minor-mode eldoc-post-insert-mode nil
-  :group 'eldoc :lighter (:eval (if eldoc-mode ""
-                                  (concat eldoc-minor-mode-string "|i")))
-  (setq eldoc-last-message nil)
-  (let ((prn-info (lambda ()
-                    (unless eldoc-mode
-                      (eldoc-print-current-symbol-info)))))
-    (if eldoc-post-insert-mode
-        (add-hook 'post-self-insert-hook prn-info nil t)
-      (remove-hook 'post-self-insert-hook prn-info t))))
-
-;; FIXME: This changes Emacs's behavior when the file is loaded!
-(add-hook 'eval-expression-minibuffer-setup-hook 'eldoc-post-insert-mode)
+    (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)))
 
 ;;;###autoload
 (defun turn-on-eldoc-mode ()
@@ -264,8 +268,10 @@ Otherwise work like `message'."
 ;; This doesn't seem to be required for Emacs 19.28 and earlier.
 (defun eldoc-pre-command-refresh-echo-area ()
   (and eldoc-last-message
-       (if (eldoc-display-message-no-interference-p)
-           (eldoc-message eldoc-last-message)
+       (if (and (eldoc-display-message-no-interference-p)
+                (symbolp this-command)
+                (intern-soft (symbol-name this-command) eldoc-message-commands))
+           (eldoc-message eldoc-last-message)
          (setq eldoc-last-message nil))))
 
 ;; Decide whether now is a good time to display a message.
@@ -283,9 +289,7 @@ Otherwise work like `message'."
 ;; Check various conditions about the current environment that might make
 ;; it undesirable to print eldoc messages right this instant.
 (defun eldoc-display-message-no-interference-p ()
-  (and eldoc-mode
-       (not executing-kbd-macro)
-       (not (and (boundp 'edebug-active) edebug-active))))
+  (not (or executing-kbd-macro (bound-and-true-p edebug-active))))
 
 
 ;;;###autoload
@@ -309,7 +313,7 @@ Emacs Lisp mode) that support ElDoc.")
   ;; This is run from post-command-hook or some idle timer thing,
   ;; so we need to be careful that errors aren't ignored.
   (with-demoted-errors "eldoc error: %s"
-    (and (or (eldoc-display-message-p) eldoc-post-insert-mode)
+    (and (eldoc-display-message-p)
          (if eldoc-documentation-function
              (eldoc-message (funcall eldoc-documentation-function))
            (let* ((current-symbol (eldoc-current-symbol))
diff --git a/lisp/progmodes/octave.el b/lisp/progmodes/octave.el
index e2ef492a9ad..1378e8fdb59 100644
--- a/lisp/progmodes/octave.el
+++ b/lisp/progmodes/octave.el
@@ -154,12 +154,8 @@ parenthetical grouping.")
     ["Insert Function"              octave-insert-defun t]
     ["Update Function File Comment" octave-update-function-file-comment t]
     "---"
-    ["Function Syntax Hints" (call-interactively
-                              (if (fboundp 'eldoc-post-insert-mode)
-                                  'eldoc-post-insert-mode
-                                'eldoc-mode))
-     :style toggle :selected (or (bound-and-true-p eldoc-post-insert-mode)
-                                 (bound-and-true-p eldoc-mode))
+    ["Function Syntax Hints" (eldoc-mode 'toggle)
+     :style toggle :selected (bound-and-true-p eldoc-mode)
      :help "Display function signatures after typing `SPC' or `('"]
     ["Delimiter Matching"           show-paren-mode
      :style toggle :selected show-paren-mode
diff --git a/lisp/simple.el b/lisp/simple.el
index 5c2f3c3db1d..ae18ae65fb5 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1387,6 +1387,7 @@ display the result of expression evaluation."
         (lambda ()
           (add-hook 'completion-at-point-functions
                     #'lisp-completion-at-point nil t)
+          (eldoc-mode 1)
           (run-hooks 'eval-expression-minibuffer-setup-hook))
       (read-from-minibuffer prompt initial-contents
                             read-expression-map t