(defgroup save-place nil
"Automatically save place in files."
:group 'data)
(defvar save-place-alist nil
"Alist of saved places to go back to when revisiting files.
Each element looks like (FILENAME . POSITION);
visiting file FILENAME goes automatically to position POSITION
rather than the beginning of the buffer.
This alist is saved between Emacs sessions.")
(defcustom save-place nil
"*Non-nil means automatically save place in each file.
This means when you visit a file, point goes to the last place
where it was when you previously visited the same file.
This variable is automatically buffer-local.
If you wish your place in any file to always be automatically saved,
simply put this in your `~/.emacs' file:
\(setq-default save-place t\)"
:type 'boolean
:group 'save-place)
(make-variable-buffer-local 'save-place)
(defcustom save-place-file (convert-standard-filename "~/.emacs-places")
"*Name of the file that records `save-place-alist' value."
:type 'file
:group 'save-place)
(defcustom save-place-version-control nil
"*Controls whether to make numbered backups of master save-place file.
It can have four values: t, nil, `never', and `nospecial'. The first
three have the same meaning that they do for the variable
`version-control', and the final value `nospecial' means just use the
value of `version-control'."
:type '(radio (const :tag "Unconditionally" t)
(const :tag "For VC Files" nil)
(const never)
(const :tag "Use value of `version-control'" nospecial))
:group 'save-place)
(defvar save-place-loaded nil
"Non-nil means that the `save-place-file' has been loaded.")
(defcustom save-place-limit nil
"Maximum number of entries to retain in the list; nil means no limit."
:type '(choice (integer :tag "Entries" :value 1)
(const :tag "No Limit" nil))
:group 'save-place)
(defun toggle-save-place (&optional parg)
"Toggle whether to save your place in this file between sessions.
If this mode is enabled, point is recorded when you kill the buffer
or exit Emacs. Visiting this file again will go to that position,
even in a later Emacs session.
If called with a prefix arg, the mode is enabled if and only if
the argument is positive.
To save places automatically in all files, put this in your `.emacs' file:
\(setq-default save-place t\)"
(interactive "P")
(if (not buffer-file-name)
(message "Buffer `%s' not visiting a file" (buffer-name))
(if (and save-place (or (not parg) (<= parg 0)))
(progn
(message "No place will be saved in this file")
(setq save-place nil))
(message "Place will be saved")
(setq save-place t))))
(defun save-place-to-alist ()
(or save-place-loaded (load-save-place-alist-from-file))
(if buffer-file-name
(progn
(let ((cell (assoc buffer-file-name save-place-alist))
(position (if (not (eq major-mode 'hexl-mode))
(point)
(1+ (hexl-current-address)))))
(if cell
(setq save-place-alist (delq cell save-place-alist)))
(if (and save-place
(not (= position 1))) (setq save-place-alist
(cons (cons buffer-file-name position)
save-place-alist)))))))
(defun save-place-alist-to-file ()
(let ((file (expand-file-name save-place-file)))
(save-excursion
(message "Saving places to %s..." file)
(set-buffer (get-buffer-create " *Saved Places*"))
(delete-region (point-min) (point-max))
(print save-place-alist (current-buffer))
(let ((version-control
(cond
((null save-place-version-control) nil)
((eq 'never save-place-version-control) 'never)
((eq 'nospecial save-place-version-control) version-control)
(t
t))))
(write-file file)
(kill-buffer (current-buffer))
(message "Saving places to %s...done" file)))))
(defun load-save-place-alist-from-file ()
(if (not save-place-loaded)
(progn
(setq save-place-loaded t)
(let ((file (expand-file-name save-place-file)))
(if (file-readable-p file)
(save-excursion
(message "Loading places from %s..." save-place-file)
(set-buffer (get-buffer-create " *Saved Places*"))
(delete-region (point-min) (point-max))
(insert-file-contents file)
(goto-char (point-min))
(setq save-place-alist
(car (read-from-string
(buffer-substring (point-min) (point-max)))))
(if save-place-limit
(if (<= save-place-limit 0)
(setq save-place-alist nil)
(let ((s save-place-alist)
(count 1))
(while s
(if (>= count save-place-limit)
(setcdr s nil)
(setq count (1+ count)))
(setq s (cdr s))))))
(kill-buffer (current-buffer))
(message "Loading places from %s...done" file)))
nil))))
(defun save-places-to-alist ()
(let ((buf-list (buffer-list)))
(while buf-list
(save-excursion
(set-buffer (car buf-list))
(and buffer-file-name (save-place-to-alist))
(setq buf-list (cdr buf-list))))))
(defun save-place-find-file-hook ()
(or save-place-loaded (load-save-place-alist-from-file))
(let ((cell (assoc buffer-file-name save-place-alist)))
(if cell
(progn
(or after-find-file-from-revert-buffer
(goto-char (cdr cell)))
(setq save-place t)))))
(defun save-place-kill-emacs-hook ()
(save-places-to-alist)
(if save-place-loaded
(save-place-alist-to-file)))
(add-hook 'find-file-hooks 'save-place-find-file-hook t)
(add-hook 'kill-emacs-hook 'save-place-kill-emacs-hook)
(add-hook 'kill-buffer-hook 'save-place-to-alist)
(provide 'saveplace)