Make help and view-mode work with new buffer display facilities.

* help.el (help-window): Remove variable.
(help-window-point-marker, temp-buffer-max-height)
(temp-buffer-resize-mode, help-window-select): Rewrite doc-strings.
(help-print-return-message): Don't set help-window.
(resize-temp-buffer-window): Rewrite cod eand doc-string.
(help-window-setup-finish): Remove.
(help-window-display-message, help-window-setup)
(with-help-window): Major rewrite based on new
display-buffer-window variable.

* help-mode.el (help-mode-finish): Remove help-window related
code.

* view.el (view-exits-all-viewing-windows): Remove reference to
view-return-to-alist in doc-string.
(view-return-to-alist): Make obsolete.
(view-buffer): Call pop-to-buffer-same-window and remove
undo-window code.
(view-buffer-other-window): Call pop-to-buffer-other-window and
simplify code.  Ignore second argument.
(view-buffer-other-frame): Call pop-to-buffer-other-frame and
simplify code.  Ignore second argument.
(view-return-to-alist-update): Make obsolete.
(view-mode-enter): Rename second argument to QUIT-RESTORE.
Rewrite using quit-restore window parameters.
(view-mode-exit): Rename second argument to EXIT-ONLY.  Rewrite
using quit-restore-window.
(View-exit, View-exit-and-edit, View-leave, View-quit)
(View-quit-all, View-kill-and-leave): Call view-mode-exit with
appropriate arguments.
(view-end-message): Use quit-restore window parameter.

lisp/ChangeLog

@@ -1,5 +1,37 @@
 2011-06-13  Martin Rudalics  <rudalics@gmx.at>
 
+	* help.el (help-window): Remove variable.
+	(help-window-point-marker, temp-buffer-max-height)
+	(temp-buffer-resize-mode, help-window-select): Rewrite doc-strings.
+	(help-print-return-message): Don't set help-window.
+	(resize-temp-buffer-window): Rewrite cod eand doc-string.
+	(help-window-setup-finish): Remove.
+	(help-window-display-message, help-window-setup)
+	(with-help-window): Major rewrite based on new
+	display-buffer-window variable.
+
+	* help-mode.el (help-mode-finish): Remove help-window related
+	code.
+
+	* view.el (view-exits-all-viewing-windows): Remove reference to
+	view-return-to-alist in doc-string.
+	(view-return-to-alist): Make obsolete.
+	(view-buffer): Call pop-to-buffer-same-window and remove
+	undo-window code.
+	(view-buffer-other-window): Call pop-to-buffer-other-window and
+	simplify code.  Ignore second argument.
+	(view-buffer-other-frame): Call pop-to-buffer-other-frame and
+	simplify code.  Ignore second argument.
+	(view-return-to-alist-update): Make obsolete.
+	(view-mode-enter): Rename second argument to QUIT-RESTORE.
+	Rewrite using quit-restore window parameters.
+	(view-mode-exit): Rename second argument to EXIT-ONLY.  Rewrite
+	using quit-restore-window.
+	(View-exit, View-exit-and-edit, View-leave, View-quit)
+	(View-quit-all, View-kill-and-leave): Call view-mode-exit with
+	appropriate arguments.
+	(view-end-message): Use quit-restore window parameter.
+
 	* window.el (display-buffer-function): Rewrite doc-string.
 	(display-buffer-window, display-buffer-alist): New variables.
 	(display-buffer-split-specifiers)

lisp/help-mode.el

@@ -305,23 +305,6 @@ Commands:
 
 ;;;###autoload
 (defun help-mode-finish ()
-  (if (eq help-window t)
-      ;; If `help-window' is t, `view-return-to-alist' is handled by
-      ;; `with-help-window'.  In this case set `help-window' to the
-      ;; selected window since now is the only moment where we can
-      ;; unambiguously identify it.
-      (setq help-window (selected-window))
-    (let ((entry (assq (selected-window) view-return-to-alist)))
-      (if entry
-	  ;; When entering Help mode from the Help window,
-	  ;; such as by following a link, preserve the same
-	  ;; meaning for the q command.
-	  ;; (setcdr entry (cons (selected-window) help-return-method))
-	  nil
-	(setq view-return-to-alist
-	      (cons (cons (selected-window) help-return-method)
-		    view-return-to-alist)))))
-
   (when (eq major-mode 'help-mode)
     ;; View mode's read-only status of existing *Help* buffer is lost
     ;; by with-output-to-temp-buffer.

lisp/help.el

@@ -55,7 +55,7 @@
 ;; nowhere before exiting.  Currently used by `view-lossage' to assert
 ;; that the last keystrokes are always visible.
 (defvar help-window-point-marker (make-marker)
-  "Marker to override default `window-point' of `help-window'.")
+  "Marker to override default `window-point' in help windows.")
 
 (defvar help-map
   (let ((map (make-sparse-keymap)))
@@ -144,8 +144,6 @@ It computes a message, and applies the optional argument FUNCTION to it.
 If FUNCTION is nil, it applies `message', thus displaying the message.
 In addition, this function sets up `help-return-method', which see, that
 specifies what to do when the user exits the help buffer."
-  ;; Reset `help-window' here to avoid confusing `help-mode-finish'.
-  (setq help-window nil)
   (and (not (get-buffer-window standard-output))
        (let ((first-message
 	      (cond ((or
@@ -914,6 +912,7 @@ appeared on the mode-line."
   ;; In order to list up all minor modes, minor-mode-list
   ;; is used here instead of minor-mode-alist.
   (delq nil (mapcar 'symbol-name minor-mode-list)))
+
 (defun describe-minor-mode-from-symbol (symbol)
   "Display documentation of a minor mode given as a symbol, SYMBOL"
   (interactive (list (intern (completing-read
@@ -937,6 +936,7 @@ appeared on the mode-line."
 		     (t
 		      i))))
 		minor-mode-alist)))
+
 (defun describe-minor-mode-from-indicator (indicator)
   "Display documentation of a minor mode specified by INDICATOR.
 If you call this function interactively, you can give indicator which
@@ -972,28 +972,32 @@ is currently activated with completion."
 		  minor-modes nil)
 	  (setq minor-modes (cdr minor-modes)))))
     result))
-
 
 ;;; Automatic resizing of temporary buffers.
-
 (defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
   "Maximum height of a window displaying a temporary buffer.
 This is effective only when Temp Buffer Resize mode is enabled.
-The value is the maximum height (in lines) which `resize-temp-buffer-window'
+The value is the maximum height (in lines) which
-will give to a window displaying a temporary buffer.
+`resize-temp-buffer-window' will give to a window displaying a
-It can also be a function to be called to choose the height for such a buffer.
+temporary buffer.  It can also be a function to be called to
-It gets one argumemt, the buffer, and should return a positive integer."
+choose the height for such a buffer.  It gets one argumemt, the
+buffer, and should return a positive integer.  At the time the
+function is called, the window to be resized is selected."
   :type '(choice integer function)
   :group 'help
   :version "20.4")
 
 (define-minor-mode temp-buffer-resize-mode
-  "Toggle the mode which makes windows smaller for temporary buffers.
+  "Toggle mode which makes windows smaller for temporary buffers.
-With prefix argument ARG, turn the resizing of windows displaying temporary
+With prefix argument ARG, turn the resizing of windows displaying
-buffers on if ARG is positive or off otherwise.
+temporary buffers on if ARG is positive or off otherwise.
-This makes the window the right height for its contents, but never
+
-more than `temp-buffer-max-height' nor less than `window-min-height'.
+This mode makes a window the right height for its contents, but
-This applies to `help', `apropos' and `completion' buffers, and some others."
+never more than `temp-buffer-max-height' nor less than
+`window-min-height'.
+
+This mode is used by `help', `apropos' and `completion' buffers,
+and some others."
   :global t :group 'help
   (if temp-buffer-resize-mode
       ;; `help-make-xrefs' may add a `back' button and thus increase the
@@ -1003,29 +1007,26 @@ This applies to `help', `apropos' and `completion' buffers, and some others."
 
 (defun resize-temp-buffer-window ()
   "Resize the selected window to fit its contents.
-Will not make it higher than `temp-buffer-max-height' nor smaller than
+Will not make it higher than `temp-buffer-max-height' nor smaller
-`window-min-height'.  Do nothing if it is the only window on its frame, if it
+than `window-min-height'.  Do nothing if the selected window is
-is not as wide as the frame or if some of the window's contents are scrolled
+not vertically combined or some of its contents are scrolled out
-out of view."
+of view."
-  (unless (or (one-window-p 'nomini)
+  (when (and (pos-visible-in-window-p (point-min))
-              (not (pos-visible-in-window-p (point-min)))
+	     (window-iso-combined-p))
-              (not (window-full-width-p)))
     (fit-window-to-buffer
-     (selected-window)
+     nil
      (if (functionp temp-buffer-max-height)
-	 (funcall temp-buffer-max-height (current-buffer))
+	 (funcall temp-buffer-max-height (window-buffer))
        temp-buffer-max-height))))
 
-
+;;; Help windows.
-;;; help-window
-
 (defcustom help-window-select 'other
     "Non-nil means select help window for viewing.
 Choices are:
  never (nil) Select help window only if there is no other window
              on its frame.
  other       Select help window unless the selected window is the
-             only other window on its frame.
+             only other window on the help window's frame.
  always (t)  Always select the help window.
 
 This option has effect if and only if the help window was created
@@ -1036,95 +1037,38 @@ by `with-help-window'"
   :group 'help
   :version "23.1")
 
-(defun help-window-display-message (quit-part window &optional other)
+(defun help-window-display-message (quit-part window &optional scroll)
   "Display message telling how to quit and scroll help window.
 QUIT-PART is a string telling how to quit the help window WINDOW.
-Optional argument OTHER non-nil means return text telling how to
+Optional argument SCROLL non-nil means tell how to scroll WINDOW.
-scroll the \"other\" window."
+SCROLL equal `other' means tell how to scroll the \"other\"
+window."
   (let ((scroll-part
 	 (cond
+	  ;; If we don't have QUIT-PART we probably reuse a window
+	  ;; showing the same buffer so we don't show any message.
+	  ((not quit-part) nil)
 	  ((pos-visible-in-window-p
 	    (with-current-buffer (window-buffer window)
-	      (point-max)) window)
+	      (point-max)) window t)
-	   ;; Buffer end is visible.
+	   ;; Buffer end is at least partially visible, no need to talk
+	   ;; about scrolling.
 	   ".")
-	  (other ", \\[scroll-other-window] to scroll help.")
+	  ((eq scroll 'other)
-	  (t ", \\[scroll-up] to scroll help."))))
+	   ", \\[scroll-other-window] to scroll help.")
+	  (scroll ", \\[scroll-up] to scroll help."))))
     (message "%s"
      (substitute-command-keys (concat quit-part scroll-part)))))
 
-(defun help-window-setup-finish (window &optional reuse keep-frame)
+(defun help-window-setup ()
-  "Finish setting up help window WINDOW.
+  "Set up help window for `with-help-window'.
-Select WINDOW according to the value of `help-window-select'.
+This relies on `display-buffer-window' being correctly set up by
-Display message telling how to scroll and eventually quit WINDOW.
+`display-buffer'."
-
+  (let* ((help-window (car-safe display-buffer-window))
-Optional argument REUSE non-nil means WINDOW has been reused by
+	 (help-buffer (when (window-live-p help-window)
-`display-buffer'.  Optional argument KEEP-FRAME non-nil means
+			(window-buffer help-window)))
-that quitting should not delete WINDOW's frame."
+	 (help-value (cdr-safe display-buffer-window)))
-  (let ((number-of-windows
+    (when help-buffer
-	 (length (window-list (window-frame window) 'no-mini window))))
-    (cond
-     ((eq window (selected-window))
-      ;; The help window is the selected window, probably the
-      ;; `pop-up-windows' nil case.
-      (help-window-display-message
-       (if reuse
-	   "Type \"q\" to restore this window"
-	 ;; This should not be taken.
-	 "Type \"q\" to quit") window))
-     ((= number-of-windows 1)
-      ;; The help window is alone on a frame and not the selected
-      ;; window, could be the `pop-up-frames' t case.
-      (help-window-display-message
-       (cond
-	(keep-frame "Type \"q\" to delete this window")
-	(reuse "Type \"q\" to restore this window")
-	(view-remove-frame-by-deleting "Type \"q\" to delete this frame")
-	(t "Type \"q\" to iconify this frame"))
-       window))
-     ((and (= number-of-windows 2)
-	   (eq (window-frame window) (window-frame (selected-window))))
-      ;; There are two windows on the help window's frame and the other
-      ;; window is the selected one.
-      (if (memq help-window-select '(nil other))
-	  ;; Do not select the help window.
-	  (help-window-display-message
-	   (if reuse
-	       ;; Offer `display-buffer' for consistency with
-	       ;; `help-print-return-message'.  This is hardly TRT when
-	       ;; the other window and the selected window display the
-	       ;; same buffer but has been handled this way ever since.
-	       "Type \\[display-buffer] RET to restore the other window"
-	     ;; The classic "two windows" configuration.
-	     "Type \\[delete-other-windows] to delete the help window")
-	   window t)
-	;; Select help window and tell how to quit.
-	(select-window window)
-	(help-window-display-message
-	 (if reuse
-	     "Type \"q\" to restore this window"
-	   "Type \"q\" to delete this window") window)))
-     (help-window-select
-      ;; Issuing a message with 3 or more windows on the same frame
-      ;; without selecting the help window doesn't make any sense.
-      (select-window window)
-      (help-window-display-message
-       (if reuse
-	   "Type \"q\" to restore this window"
-	 "Type \"q\" to delete this window") window)))))
-
-(defun help-window-setup (list-of-frames list-of-window-tuples)
-  "Set up help window.
-LIST-OF-FRAMES and LIST-OF-WINDOW-TUPLES are the lists of frames
-and window quadruples built by `with-help-window'.  The help
-window itself is specified by the variable `help-window'."
-  (let* ((help-buffer (window-buffer help-window))
-	 ;; `help-buffer' now denotes the help window's buffer.
-	 (view-entry
-	  (assq help-window
-		(buffer-local-value 'view-return-to-alist help-buffer)))
-	 (help-entry (assq help-window list-of-window-tuples)))
-
       ;; Handle `help-window-point-marker'.
       (when (eq (marker-buffer help-window-point-marker) help-buffer)
 	(set-window-point help-window help-window-point-marker)
@@ -1132,79 +1076,40 @@ window itself is specified by the variable `help-window'."
 	(set-marker help-window-point-marker nil))
 
       (cond
-     (view-entry
+       ((or (eq help-window (selected-window))
-      ;; `view-return-to-alist' has an entry for the help window.
+	    (and (or (eq help-window-select t)
+		     (and (eq help-window-select 'other)
+			  (eq (window-frame help-window) (selected-frame))
+			  (> (length (window-list nil 'no-mini)) 2)))
+		 (select-window help-window)))
+	;; The help window is or gets selected ...
+	(help-window-display-message
 	 (cond
-       ((eq help-window (selected-window))
+	  ((eq help-value 'new-window)
-	;; The help window is the selected window, probably because the
+	   ;; ... and is new, ...
-	;; user followed a backward/forward button or a cross reference.
+	   "Type \"q\" to delete this window")
-	;; In this case just purge stale entries from
+	  ((eq help-value 'new-frame)
-	;; `view-return-to-alist' but leave the entry alone and don't
+	   ;; ... is on a new frame ...
-	;; display a message.
+	   "Type \"q\" to delete this frame")
-	(view-return-to-alist-update help-buffer))
+	  ((eq help-value 'reuse-other-window)
-       ((and help-entry (eq (cadr help-entry) help-buffer))
+	   ;; ... or displayed some other buffer before.
-	;; The help window was not selected but displayed the help
+	   "Type \"q\" to restore previous buffer"))
-	;; buffer.  In this case reuse existing exit information but try
+	 help-window t))
-	;; to get back to the selected window when quitting.  Don't
+       ((and (eq (window-frame help-window) (selected-frame))
-	;; display a message since the user must have seen one before.
+	     (= (length (window-list nil 'no-mini)) 2))
-	(view-return-to-alist-update
+	;; There are two windows on the help window's frame and the
-	 help-buffer (cons help-window
+	;; other one is the selected one.
-			   (cons (selected-window) (cddr view-entry)))))
+	(help-window-display-message
-       (help-entry
+	 (cond
-	;; The help window was not selected, did display the help buffer
+	  ((eq help-value 'new-window)
-	;; earlier, but displayed another buffer when help was invoked.
+	   "Type \\[delete-other-windows] to delete the help window")
-	;; Set up things so that quitting will show that buffer again.
+	  ((eq help-value 'reuse-other-window)
-	(view-return-to-alist-update
+	   "Type \\[switch-to-prev-buffer] RET to restore previous buffer"))
-	 help-buffer (cons help-window
+	 help-window 'other))
-			   (cons (selected-window) (cdr help-entry))))
-	(help-window-setup-finish help-window t))
        (t
-	;; The help window is new but `view-return-to-alist' had an
+	;; Not much to say here.
-	;; entry for it.  This should never happen.
+	(help-window-display-message
-	(view-return-to-alist-update
+	 "Type \"q\" in help window to quit" help-window))))))
-	 help-buffer (cons help-window
-			   (cons (selected-window) 'quit-window)))
-	(help-window-setup-finish help-window t))))
-     (help-entry
-      ;; `view-return-to-alist' does not have an entry for help window
-      ;; but `list-of-window-tuples' does.  Hence `display-buffer' must
-      ;; have reused an existing window.
-      (if (eq (cadr help-entry) help-buffer)
-	  ;; The help window displayed `help-buffer' before but no
-	  ;; `view-return-to-alist' entry was found probably because the
-	  ;; user manually switched to the help buffer.  Set up things
-	  ;; for `quit-window' although `view-exit-action' should be
-	  ;; able to handle this case all by itself.
-	  (progn
-	    (view-return-to-alist-update
-	     help-buffer (cons help-window
-			       (cons (selected-window) 'quit-window)))
-	    (help-window-setup-finish help-window t))
-	;; The help window displayed another buffer before.  Set up
-	;; things in a way that quitting can orderly show that buffer
-	;; again.  The window-start and window-point information from
-	;; `list-of-window-tuples' provide the necessary information.
-	(view-return-to-alist-update
-	 help-buffer (cons help-window
-			   (cons (selected-window) (cdr help-entry))))
-	(help-window-setup-finish help-window t)))
-     ((memq (window-frame help-window) list-of-frames)
-      ;; The help window is a new window on an existing frame.  This
-      ;; case must be handled specially by `help-window-setup-finish'
-      ;; and `view-mode-exit' to ascertain that quitting does _not_
-      ;; inadvertently delete the frame.
-      (view-return-to-alist-update
-       help-buffer (cons help-window
-			 (cons (selected-window) 'keep-frame)))
-      (help-window-setup-finish help-window nil t))
-     (t
-      ;; The help window is shown on a new frame.  In this case quitting
-      ;; shall handle both, the help window _and_ its frame.  We changed
-      ;; the default of `view-remove-frame-by-deleting' to t in order to
-      ;; intuitively DTRT here.
-      (view-return-to-alist-update
-       help-buffer (cons help-window (cons (selected-window) t)))
-      (help-window-setup-finish help-window)))))
 
 ;; `with-help-window' is a wrapper for `with-output-to-temp-buffer'
 ;; providing the following additional twists:
@@ -1212,50 +1117,35 @@ window itself is specified by the variable `help-window'."
 ;; (1) Issue more accurate messages telling how to scroll and quit the
 ;; help window.
 
-;; (2) Make `view-mode-exit' DTRT in more cases.
+;; (2) An option (customizable via `help-window-select') to select the
-
-;; (3) An option (customizable via `help-window-select') to select the
 ;; help window automatically.
 
-;; (4) A marker (`help-window-point-marker') to move point in the help
+;; (3) A marker (`help-window-point-marker') to move point in the help
 ;; window to an arbitrary buffer position.
 
 ;; Note: It's usually always wrong to use `help-print-return-message' in
 ;; the body of `with-help-window'.
 (defmacro with-help-window (buffer-name &rest body)
-  "Display buffer BUFFER-NAME in a help window evaluating BODY.
+  "Display buffer with name BUFFER-NAME in a help window evaluating BODY.
 Select help window if the actual value of the user option
-`help-window-select' says so.  Return last value in BODY."
+`help-window-select' says so.  Return last value in BODY.
+
+You can specify where and how to show the buffer by binding the
+variable `temp-buffer-show-specifiers' to an appropriate value."
   (declare (indent 1) (debug t))
-  ;; Bind list-of-frames to `frame-list' and list-of-window-tuples to a
+  `(progn
-  ;; list of one <window window-buffer window-start window-point> tuple
+     ;; Reset `display-buffer-window': `display-buffer' is
-  ;; for each live window.
+     ;; supposed to set this to the window displaying the buffer plus
-  `(let ((list-of-frames (frame-list))
+     ;; some additional information.
-	 (list-of-window-tuples
+     (setq display-buffer-window nil)
-	  (let (list)
+     ;; Make `help-window-point-marker' point nowhere.  The only place
-	    (walk-windows
+     ;; where this should be set to a buffer position is within BODY.
-	     (lambda (window)
-	       (push (list window (window-buffer window)
-			   (window-start window) (window-point window))
-		     list))
-	     'no-mini t)
-	    list)))
-     ;; Make `help-window' t to trigger `help-mode-finish' to set
-     ;; `help-window' to the actual help window.
-     (setq help-window t)
-     ;; Make `help-window-point-marker' point nowhere (the only place
-     ;; where this should be set to a buffer position is within BODY).
      (set-marker help-window-point-marker nil)
      (prog1
 	 ;; Return value returned by `with-output-to-temp-buffer'.
 	 (with-output-to-temp-buffer ,buffer-name
 	   (progn ,@body))
-       (when (windowp help-window)
+       (when display-buffer-window (help-window-setup)))))
-	 ;; Set up help window.
-	 (help-window-setup list-of-frames list-of-window-tuples))
-       ;; Reset `help-window' to nil to avoid confusing future calls of
-       ;; `help-mode-finish' with plain `with-output-to-temp-buffer'.
-       (setq help-window nil))))
 
 ;; Called from C, on encountering `help-char' when reading a char.
 ;; Don't print to *Help*; that would clobber Help history.

lisp/view.el

@@ -55,10 +55,6 @@
    :type 'face
    :group 'view)
 
-;; `view-mode-auto-exit' is replaced by the following option variable which
-;; only says if scrolling past buffer end should leave view mode or not, it
-;; doesn't say if leaving view mode should restore windows or not.  The latter
-;; is now controlled by the presence of a value in `view-return-to-alist'.
 (defcustom view-scroll-auto-exit nil
   "Non-nil means scrolling past the end of buffer exits View mode.
 A value of nil means attempting to scroll past the end of the buffer,
@@ -80,17 +76,14 @@ for all scroll commands in view mode."
 If nil, make an icon of the frame.  If non-nil, delete the frame."
   :type 'boolean
   :group 'view
-  ;; Changed the default of this to t for Emacs 23.  Users consider
-  ;; frame iconification annoying.
   :version "23.1")
 
 (defcustom view-exits-all-viewing-windows nil
   "Non-nil means restore all windows used to view buffer.
-Commands that restore windows when finished viewing a buffer, apply to all
+Commands that restore windows when finished viewing a buffer,
-windows that display the buffer and have restore information in
+apply to all windows that display the buffer and have restore
-`view-return-to-alist'.
+information.  If `view-exits-all-viewing-windows' is nil, only
-If `view-exits-all-viewing-windows' is nil, only the selected window is
+the selected window is considered for restoring."
-considered for restoring."
   :type 'boolean
   :group 'view)
 
@@ -140,6 +133,8 @@ subtracted from by `view-mode-exit' when finished viewing the buffer.
 
 See RETURN-TO-ALIST argument of function `view-mode-exit' for the format of
 `view-return-to-alist'.")
+(make-obsolete-variable
+ 'view-return-to-alist "this variable is no more used." "24.1")
 (make-variable-buffer-local 'view-return-to-alist)
 (put 'view-return-to-alist 'permanent-local t)
 
@@ -322,63 +317,48 @@ EXIT-ACTION to `kill-buffer-if-not-modified' avoids this."
       (progn
 	(switch-to-buffer buffer)
 	(message "Not using View mode because the major mode is special"))
-    (let ((undo-window (list (window-buffer) (window-start) (window-point))))
+    (pop-to-buffer-same-window buffer)
-      (switch-to-buffer buffer)
+    (view-mode-enter nil exit-action)))
-      (view-mode-enter (cons (selected-window) (cons nil undo-window))
-		       exit-action))))
 
 ;;;###autoload
 (defun view-buffer-other-window (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another window.
-Return to previous buffer when done, unless optional NOT-RETURN is
+Emacs commands editing the buffer contents are not available;
-non-nil.  Emacs commands editing the buffer contents are not available;
+instead, a special set of commands (mostly letters and
-instead, a special set of commands (mostly letters and punctuation) are
+punctuation) are defined for moving around in the buffer.
-defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.
 For a list of all View commands, type H or h while viewing.
 
 This command runs the normal hook `view-mode-hook'.
 
+Optional argument NOT-RETURN is ignored.
+
 Optional argument EXIT-ACTION is either nil or a function with buffer as
 argument.  This function is called when finished viewing buffer.  Use
 this argument instead of explicitly setting `view-exit-action'."
   (interactive "bIn other window view buffer:\nP")
-  (let* ((win				; This window will be selected by
+  (pop-to-buffer-other-window buffer)
-	  (get-lru-window))		; switch-to-buffer-other-window below.
+  (view-mode-enter nil exit-action))
-	 (return-to
-	  (and (not not-return)
-	       (cons (selected-window)
-		     (if (eq win (selected-window))
-			 t			; Has to make new window.
-		       (list
-			(window-buffer win)	; Other windows old buffer.
-			(window-start win)
-			(window-point win)))))))
-    (switch-to-buffer-other-window buffer)
-    (view-mode-enter (and return-to (cons (selected-window) return-to))
-		     exit-action)))
 
 ;;;###autoload
 (defun view-buffer-other-frame (buffer &optional not-return exit-action)
   "View BUFFER in View mode in another frame.
-Return to previous buffer when done, unless optional NOT-RETURN is
+Emacs commands editing the buffer contents are not available;
-non-nil.  Emacs commands editing the buffer contents are not available;
+instead, a special set of commands (mostly letters and
-instead, a special set of commands (mostly letters and punctuation) are
+punctuation) are defined for moving around in the buffer.
-defined for moving around in the buffer.
 Space scrolls forward, Delete scrolls backward.
 For a list of all View commands, type H or h while viewing.
 
 This command runs the normal hook `view-mode-hook'.
 
+Optional argument NOT-RETURN is ignored.
+
 Optional argument EXIT-ACTION is either nil or a function with buffer as
 argument.  This function is called when finished viewing buffer.  Use
 this argument instead of explicitly setting `view-exit-action'."
   (interactive "bView buffer in other frame: \nP")
-  (let ((return-to
+  (pop-to-buffer-other-frame buffer)
-	 (and (not not-return) (cons (selected-window) t)))) ; Old window.
+  (view-mode-enter nil exit-action))
-    (switch-to-buffer-other-frame buffer)
-    (view-mode-enter (and return-to (cons (selected-window) return-to))
-		     exit-action)))
 
 ;;;###autoload
 (define-minor-mode view-mode
@@ -536,38 +516,27 @@ entry for the selected window, purge that entry from
     (when item
       (setq view-return-to-alist
 	    (cons item view-return-to-alist)))))
+(make-obsolete 'view-return-to-alist-update "this function has no effect." "24.1")
 
 ;;;###autoload
-(defun view-mode-enter (&optional return-to exit-action)
+(defun view-mode-enter (&optional quit-restore exit-action)
   "Enter View mode and set up exit from view mode depending on optional arguments.
-RETURN-TO non-nil means add RETURN-TO as an element to the buffer
+Optional argument QUIT-RESTORE if non-nil must specify a valid
-local alist `view-return-to-alist'.  Save EXIT-ACTION in buffer
+entry for quitting and restoring any window showing the current
-local variable `view-exit-action'.  It should be either nil or a
+buffer.  This entry replaces any parameter installed by
+`display-buffer' and is used by `view-mode-exit'.
+
+Optional argument EXIT-ACTION, if non-nil, must specify a
 function that takes a buffer as argument.  This function will be
 called by `view-mode-exit'.
 
-RETURN-TO is either nil, meaning do nothing when exiting view
-mode, or must have the format (WINDOW OLD-WINDOW . OLD-BUF-INFO).
-WINDOW is the window used for viewing.  OLD-WINDOW is nil or the
-window to select after viewing.  OLD-BUF-INFO tells what to do
-with WINDOW when exiting.  It is one of:
-1) nil            Do nothing.
-2) t              Delete WINDOW or, if it is the only window and
-                  `view-remove-frame-by-deleting' is non-nil, its
-                  frame.
-3) (OLD-BUFF START POINT)  Display buffer OLD-BUFF with displayed text
-                  starting at START and point at POINT in WINDOW.
-4) quit-window    Do `quit-window' in WINDOW.
-5) keep-frame     Like case 2) but do not delete the frame.
-
 For a list of all View commands, type H or h while viewing.
 
 This function runs the normal hook `view-mode-hook'."
-  (when return-to
+  (when quit-restore
-    (let ((entry (assq (car return-to) view-return-to-alist)))
+    (dolist (window (get-buffer-window-list nil nil t))
-      (if entry
+      (set-window-parameter window 'quit-restore quit-restore)))
-	  (setcdr entry (cdr return-to))
+
-	(setq view-return-to-alist (cons return-to view-return-to-alist)))))
   (when exit-action
     (setq view-exit-action exit-action))
 
@@ -579,115 +548,45 @@ This function runs the normal hook `view-mode-hook'."
 	       (substitute-command-keys "\
 View mode: type \\[help-command] for help, \\[describe-mode] for commands, \\[View-quit] to quit.")))))
 
-(defun view-mode-exit (&optional return-to-alist exit-action all-win)
+;; This is awful because it assumes that the selected window shows the
-  "Exit View mode in various ways, depending on optional arguments.
+;; current buffer when this is called.
-RETURN-TO-ALIST, EXIT-ACTION and ALL-WIN determine what to do
+(defun view-mode-exit (&optional exit-only exit-action all-windows)
-after exit.  EXIT-ACTION is nil or a function that is called with
+  "Exit View mode in various ways.
-current buffer as argument.
+If all arguments are nil, remove the current buffer from the
+selected window using the `quit-restore' information associated
+with the selected window.  If optional argument ALL-WINDOWS or
+`view-exits-all-viewing-windows' are non-nil, remove the current
+buffer from all windows showing it.
 
-RETURN-TO-ALIST is an alist that, for some of the windows
+Optional argument EXIT-ONLY non-nil means just exit `view-mode'
-displaying the current buffer, maintains information on what to
+\(unless `view-no-disable-on-exit' is non-nil) but do not change
-do when exiting those windows.  If ALL-WIN is non-nil or the
+the associations of any windows with the current buffer.
-variable `view-exits-all-viewing-windows' is non-nil,
-view-mode-exit attempts to restore all windows showing the
-current buffer to their old state.  Otherwise, only the selected
-window is affected (provided it is on RETURN-TO-ALIST).
 
-Elements of RETURN-TO-ALIST must have the format
+EXIT-ACTION, if non-nil, must specify a function that is called
-  (WINDOW OLD-WINDOW . OLD-BUF-INFO) where
+with the current buffer as argument and is called after disabling
-
+`view-mode' and removing any associations of windows with the
-WINDOW is a window displaying the current buffer and OLD-WINDOW
+current buffer. "
-is either nil or a window to select after viewing.  OLD-BUF-INFO
+  (when view-mode
-provides information on what to do with WINDOW and may be one of:
+    (let ((buffer (window-buffer)))
-1) nil            Do nothing.
-2) t              Delete WINDOW and, if it is the only window and
-                  `view-remove-frame-by-deleting' is non-nil, its
-                  frame.
-3) (OLD-BUF START POINT)  Display buffer OLD-BUF with displayed text
-                  starting at START and point at POINT in WINDOW.
-4) quit-window    Do `quit-window' in WINDOW.
-5) keep-frame     Like case 2) but do not delete the frame.
-
-If one of the WINDOW in RETURN-TO-ALIST is the selected window
-and the corresponding OLD-WINDOW is a live window, then select
-OLD-WINDOW."
-  (when view-mode		    ; Only do something if in view mode.
-    (setq all-win
-	  (and return-to-alist
-	       (or all-win view-exits-all-viewing-windows)))
-    (let* ((buffer (current-buffer))
-	   window notlost
-	   (sel-old (assq (selected-window) return-to-alist))
-	   (alist (cond
-		   (all-win		   ; Try to restore all windows.
-		    (append return-to-alist nil)) ; Copy.
-		   (sel-old			; Only selected window.
-		    (list sel-old))))
-	   (old-window (if sel-old (car (cdr sel-old)))))
-      (if all-win			 ; Follow chains of old-windows.
-	  (let ((c (length alist)) a)
-	    (while (and (> c 0)	  ; Safety if mutually refering windows.
-			(or (not (window-live-p old-window))
-			    (eq buffer (window-buffer old-window)))
-			(setq a (assq old-window alist)))
-	      (setq c (1- c))
-	      (setq old-window (car (cdr a))))
-	    (if (or (zerop c) (not (window-live-p old-window)))
-		(setq old-window (selected-window)))))
       (unless view-no-disable-on-exit
 	(view-mode-disable))
-      (while alist			    ; Restore windows with info.
+
-	(setq notlost nil)
+      (unless exit-only
-	(when (and (window-live-p (setq window (car (car alist))))
-		   (eq buffer (window-buffer window)))
-	  (let ((frame (window-frame window))
-		(old-buf-info (cdr (cdr (car alist)))))
-	    (if all-win (select-window window))
 	(cond
-	     ((consp old-buf-info)		; Case 3.
+	 ((or all-windows view-exits-all-viewing-windows)
-	      (if (buffer-live-p (car old-buf-info))
+	  (dolist (window (get-buffer-window-list))
-		  (progn
+	    (quit-restore-window window)))
-		    (set-window-buffer window (car old-buf-info)) ; old-buf
+	 ((eq (window-buffer) (current-buffer))
-		    (set-window-start window (car (cdr old-buf-info)))
+	  (quit-restore-window)))
-		    (set-window-point window (car (cdr (cdr old-buf-info)))))
+
-		(bury-buffer)))
-	     ((eq old-buf-info 'quit-window)
-	      (quit-window))			; Case 4.
-	     (old-buf-info			; Case 2 or 5.
-	      (cond
-	       ((not (one-window-p t))		; Not only window.
-		(delete-window))
-	       ((eq old-buf-info 'keep-frame)	; Case 5.
-		(bury-buffer))
-	       ((not (eq frame (next-frame)))  ; Case 2 and only window.
-		;; Not the only frame, so can safely be removed.
-		(if view-remove-frame-by-deleting
-		    (delete-frame frame)
-		  (setq notlost t)	   ; Keep the window.  See below.
-		  (iconify-frame frame))))))))
-	;; If a frame is removed by iconifying it, the window is not
-	;; really lost.  In this case we keep the entry in
-	;; `view-return-to-alist' so that if the user deiconifies the
-	;; frame and then hits q, the frame is iconified again.
-	(unless notlost
-	  (with-current-buffer buffer
-	    (setq view-return-to-alist
-		  (delete (car alist) view-return-to-alist))))
-	(setq alist (cdr alist)))
-      (when (window-live-p old-window)
-	;; old-window is still alive => select it.
-	(select-window old-window))
 	(when exit-action
-	;; Don't do that: If the user wants to quit the *Help* buffer a
-	;; second time it won't have any effect.
-	;;(setq view-exit-action nil)
 	  (funcall exit-action buffer))
-      (force-mode-line-update))))
+	(force-mode-line-update)))))
 
 (defun View-exit ()
   "Exit View mode but stay in current buffer."
   (interactive)
-  (view-mode-exit))
+  (view-mode-exit t))
 
 ;;;###autoload
 (defun View-exit-and-edit ()
@@ -695,31 +594,31 @@ OLD-WINDOW."
   (interactive)
   (let ((view-old-buffer-read-only nil)
 	(view-no-disable-on-exit nil))
-    (view-mode-exit)))
+    (view-mode-exit t)))
 
 (defun View-leave ()
   "Quit View mode and maybe switch buffers, but don't kill this buffer."
   (interactive)
-  (view-mode-exit view-return-to-alist))
+  (view-mode-exit))
 
 (defun View-quit ()
   "Quit View mode, trying to restore window and buffer to previous state.
 Maybe kill this buffer.  Try to restore selected window to previous state
 and go to previous buffer or window."
   (interactive)
-  (view-mode-exit view-return-to-alist view-exit-action))
+  (view-mode-exit nil view-exit-action))
 
 (defun View-quit-all ()
   "Quit View mode, trying to restore windows and buffers to previous state.
 Maybe kill current buffer.  Try to restore all windows viewing buffer to
 previous state and go to previous buffer or window."
   (interactive)
-  (view-mode-exit view-return-to-alist view-exit-action t))
+  (view-mode-exit nil view-exit-action t))
 
 (defun View-kill-and-leave ()
   "Quit View mode, kill current buffer and return to previous buffer."
   (interactive)
-  (view-mode-exit view-return-to-alist (or view-exit-action 'kill-buffer) t))
+  (view-mode-exit nil (or view-exit-action 'kill-buffer) t))
 
 
 ;;; Some help routines.
@@ -863,7 +762,7 @@ invocations return to earlier marks."
 (defun view-end-message ()
   ;; Tell that we are at end of buffer.
   (goto-char (point-max))
-  (if view-return-to-alist
+  (if (window-parameter nil 'quit-restore)
       (message "End of buffer.  Type %s to quit viewing."
 	       (substitute-command-keys
 		(if view-scroll-auto-exit "\\[View-scroll-page-forward]"