Fix key bindings.

(electric-help-mode): Use mouse-leave-buffer-hook.
(electric-help-retain): Remove mouse-leave-buffer-hook.
(with-electric-help): New argument minheight.
(electric-help-execute-extended): New function.
(electric-help-ctrl-x-prefix): New function.
(electric-help-command-loop): Make messages more consistent.
Include strategic sit-for 0, so that
pos-visible-in-window-p will return the right thing.
Make 2nd arg of Electric-command-loop return 'noprompt if we
are in isearch-mode.
Eval to-be-executed at the very end.
(ehelp-map): Electrify apropos too.

1 files changed, 67 insertions, 16 deletions

diff --git a/lisp/ehelp.el b/lisp/ehelp.el
index fda84b7a357..756583bfe27 100644
--- a/lisp/ehelp.el
+++ b/lisp/ehelp.el
@@ -45,8 +45,20 @@
 (if electric-help-map
     ()
   (let ((map (make-keymap)))
-    ;; allow all non-self-inserting keys - search, scroll, etc
+    ;; allow all non-self-inserting keys - search, scroll, etc, but
+    ;; let M-x and C-x exit ehelp mode and retain buffer:
     (suppress-keymap map)
+    (define-key map "\C-u" 'electric-help-undefined)
+    (define-key map [?\C-0] 'electric-help-undefined)
+    (define-key map [?\C-1] 'electric-help-undefined)
+    (define-key map [?\C-2] 'electric-help-undefined)
+    (define-key map [?\C-3] 'electric-help-undefined)
+    (define-key map [?\C-4] 'electric-help-undefined)
+    (define-key map [?\C-5] 'electric-help-undefined)
+    (define-key map [?\C-6] 'electric-help-undefined)
+    (define-key map [?\C-7] 'electric-help-undefined)
+    (define-key map [?\C-8] 'electric-help-undefined)
+    (define-key map [?\C-9] 'electric-help-undefined)
     (define-key map (char-to-string help-char) 'electric-help-help)
     (define-key map "?" 'electric-help-help)
     (define-key map " " 'scroll-up)
@@ -60,9 +72,11 @@
     ;;a better key than this?
     (define-key map "r" 'electric-help-retain)
     (define-key map "R" 'electric-help-retain)
+    (define-key map "\ex" 'electric-help-execute-extended)
+    (define-key map "\C-x" 'electric-help-ctrl-x-prefix)
 
     (setq electric-help-map map)))
-   
+
 (defun electric-help-mode ()
   "`with-electric-help' temporarily places its buffer in this mode.
 \(On exit from `with-electric-help', the buffer is put in `default-major-mode'.)"
@@ -71,6 +85,7 @@
   (setq major-mode 'help)
   (setq mode-line-buffer-identification '(" Help:  %b"))
   (use-local-map electric-help-map)
+  (setq mouse-leave-buffer-hook '(electric-help-retain))
   ;; this is done below in with-electric-help
   ;(run-hooks 'electric-help-mode-hook)
   )
@@ -78,10 +93,11 @@
 ;;;###autoload
 (defun with-electric-help (thunk &optional buffer noerase)
   "Pop up an \"electric\" help buffer.
-Arguments are THUNK &optional BUFFER NOERASE.  BUFFER defaults to `*Help*'.
-THUNK is a function of no arguments which is called to initialize
-the contents of BUFFER.  BUFFER will be erased before THUNK is called unless
-NOERASE is non-nil.  THUNK will be called with `standard-output' bound to
+The arguments are THUNK &optional BUFFER NOERASE MINHEIGHT.
+THUNK is a function of no arguments which is called to initialize the
+contents of BUFFER.  BUFFER defaults to `*Help*'.  BUFFER will be
+erased before THUNK is called unless NOERASE is non-nil.  THUNK will
+be called while BUFFER is current and with `standard-output' bound to
 the buffer specified by BUFFER.
 
 If THUNK returns nil, we display BUFFER starting at the top, and
@@ -89,14 +105,21 @@ shrink the window to fit.  If THUNK returns non-nil, we don't do those things.
 
 After THUNK has been called, this function \"electrically\" pops up a window
 in which BUFFER is displayed and allows the user to scroll through that buffer
-in electric-help-mode.
+in electric-help-mode. The window's height will be at least MINHEIGHT if
+this value is non-nil.
+
+If THUNK returns nil, we display BUFFER starting at the top, and
+shrink the window to fit.  If THUNK returns non-nil, we don't do those
+things.
+
 When the user exits (with `electric-help-exit', or otherwise) the help
 buffer's window disappears (i.e., we use `save-window-excursion')
 BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
   (setq buffer (get-buffer-create (or buffer "*Help*")))
   (let ((one (one-window-p t))
         (config (current-window-configuration))
-        (bury nil))
+        (bury nil)
+        (to-be-executed nil))
     (unwind-protect
          (save-excursion
            (if one (goto-char (window-start (selected-window))))
@@ -104,8 +127,9 @@ BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
              (pop-to-buffer buffer))
            (save-excursion
              (set-buffer buffer)
+             (if (and minheight (< (window-height) minheight))
+                 (enlarge-window (- minheight (window-height))))
              (electric-help-mode)
-             (setq buffer-read-only nil)
              (or noerase (erase-buffer)))
            (let ((standard-output buffer))
              (if (not (funcall thunk))
@@ -133,7 +157,8 @@ BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
             ;; so that when we say "Press space to bury" we mean it
             (replace-buffer-in-windows buffer)
             ;; must do this outside of save-window-excursion
-            (bury-buffer buffer))))))
+            (bury-buffer buffer)))
+      (eval to-be-executed))))
 
 (defun electric-help-command-loop ()
   (catch 'exit
@@ -155,9 +180,13 @@ BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
       (Electric-command-loop
         'exit
         (function (lambda ()
+          (sit-for 0) ;necessary if last command was end-of-buffer or 
+                      ;beginning-of-buffer - otherwise pos-visible-in-window-p 
+                      ;will yield a wrong result.
           (let ((min (pos-visible-in-window-p (point-min)))
                 (max (pos-visible-in-window-p (point-max))))
-            (cond ((and min max)
+            (cond (isearch-mode 'noprompt)
+                  ((and min max)
                    (cond (standard "Press q to exit, r to retain ")
                          (neither)
                          (t (setq neither (substitute-command-keys "Press \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
@@ -166,11 +195,11 @@ BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
                          (up)
                          (t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
                   (max
-                   (cond (standard "Press DEL to scroll back, q to exit ")
+                   (cond (standard "Press DEL to scroll back, q to exit, r to retain ")
                          (down)
                          (t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
                   (t
-                   (cond (standard "Press SPC to scroll, DEL to scroll back, q to exit ")
+                   (cond (standard "Press SPC to scroll, DEL to scroll back, q to exit, r to retain ")
                          (both)
                          (t (setq both (substitute-command-keys "Press \\[scroll-up] to scroll, \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))))))
                     t))))
@@ -194,15 +223,20 @@ BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
 \(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET
 will select it.)"
   (interactive)
-  (throw 'exit '(retain)))
+  ;; Make sure that we don't throw twice, even if two events cause
+  ;; calling this function:
+  (if mouse-leave-buffer-hook
+    (progn
+      (setq mouse-leave-buffer-hook nil)
+      (throw 'exit '(retain)))))
 
 
 (defun electric-help-undefined ()
   (interactive)
   (error "%s is undefined -- Press %s to exit"
          (mapconcat 'single-key-description (this-command-keys) " ")
-         (if (eq (key-binding "Q") 'electric-help-exit)
-             "Q"
+         (if (eq (key-binding "q") 'electric-help-exit)
+             "q"
            (substitute-command-keys "\\[electric-help-exit]"))))
 
 
@@ -271,6 +305,22 @@ will select it.)"
         (with-electric-help 'ignore name t))))
 
 
+
+;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then 
+;; continues with execute-extended-command.
+(defun electric-help-execute-extended (prefixarg)
+  (interactive "p")
+  (setq to-be-executed '(execute-extended-command nil))
+  (electric-help-retain))
+
+;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then
+;; continues with ctrl-x prefix.
+(defun electric-help-ctrl-x-prefix (prefixarg)
+  (interactive "p")
+  (setq to-be-executed '(progn (message nil) (setq unread-command-char ?\C-x)))
+  (electric-help-retain))
+
+
 (defun electric-describe-key ()
   (interactive)
   (electric-helpify 'describe-key))
@@ -321,6 +371,7 @@ will select it.)"
 (if ehelp-map
     nil
   (let ((map (copy-keymap help-map))) 
+    (substitute-key-definition 'apropos 'electric-apropos map)
     (substitute-key-definition 'command-apropos 'electric-command-apropos map)
     (substitute-key-definition 'describe-key 'electric-describe-key map)
     (substitute-key-definition 'describe-mode 'electric-describe-mode map)