(vc-delete-file): Don't try to resynch the buffer.

[gnu-emacs] / lisp / vc-dispatcher.el

;;; vc-dispatcher.el -- generic command-dispatcher facility.

;; Copyright (C) 2008
;;   Free Software Foundation, Inc.

;; Author:     FSF (see below for full credits)
;; Maintainer: Eric S. Raymond <esr@thyrsus.com>
;; Keywords: tools

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Credits:

;; Designed and implemented by Eric S. Raymond, originally as part of VC mode.
;; Stefan Monnier and Dan Nicolaescu contributed substantial work on the
;; vc-dir front end.

;;; Commentary:

;; Goals:
;;
;; There is a class of front-ending problems that Emacs might be used
;; to address that involves selecting sets of files, or possibly
;; directories, and passing the selection set to slave commands.  The
;; prototypical example, from which this code is derived, is talking
;; to version-control systems.
;;
;; vc-dispatcher.el is written to decouple the UI issues in such front
;; ends from their application-specific logic.  It also provides a
;; service layer for running the slave commands either synchronously
;; or asynchronously and managing the message/error logs from the
;; command runs.
;;
;; Similar UI problems can be expected to come up in applications
;; areas other than VCSes; IDEs and document search are two obvious ones.
;; This mode is intended to ensure that the Emacs interfaces for all such
;; beasts are consistent and carefully designed.  But even if nothing
;; but VC ever uses it, getting the layer separation right will be
;; a valuable thing.

;; Dispatcher's universe:
;;
;; The universe consists of the file tree rooted at the current
;; directory.  The dispatcher's upper layer deduces some subset
;; of the file tree from the state of the currently visited buffer
;; and returns that subset, presumably to a client mode.
;;
;; The user may be looking at either of two different views; a buffer
;; visiting a file, or a directory buffer generated by vc-dispatcher.
;;
;; The lower layer of this mode runs commands in subprocesses, either
;; synchronously or asynchronously.  Commands may be launched in one
;; of two ways: they may be run immediately, or the calling mode can
;; create a closure associated with a text-entry buffer, to be
;; executed when the user types C-c to ship the buffer contents.  In
;; either case the command messages and error (if any) will remain
;; available in a status buffer.

;; Special behavior of dispatcher directory buffers:
;;
;; In dispatcher directory buffers, facilities to perform basic
;; navigation and selection operations are provided by keymap and menu
;; entries that dispatcher sets up itself, so they'll be uniform
;; across all dispatcher-using client modes.  Client modes are
;; expected to append to these to provide mode-specific bindings.
;;
;; The standard map associates a 'state' slot (that the client mode
;; may set) with each directory entry.  The dispatcher knows nothing
;; about the semantics of individual states, but mark and unmark commands
;; treat all entries with the same state as the currently selected one as
;; a unit.

;; The interface:
;;
;; The main interface to the lower level is vc-do-command.  This launches a
;; command, synchronously or asynchronously, making the output available
;; in a command log buffer.  Two other functions, (vc-start-annotation) and
;; (vc-finish-logentry), allow you to associate a command closure with an
;; annotation buffer so that when the user confirms the comment the closure
;; is run (with the comment as part of its context).
;;
;; The interface to the upper level has the two main entry points (vc-dir)
;; and (vc-dispatcher-selection-set) and a couple of convenience functions.
;; (vc-dir) sets up a dispatcher browsing buffer; (vc-dispatcher-selection-set)
;; returns a selection set of files, either the marked files in a browsing
;; buffer or the singleton set consisting of the file visited by the current
;; buffer (when that is appropriate).  It also does what is needed to ensure
;; that on-disk files and the contents of their visiting Emacs buffers
;; coincide.
;;
;; When the client mode adds a local mode-line-hook to a buffer, it
;; will be called with the buffer file name as argument whenever the
;; dispatcher resynchs the buffer.

;; To do:
;;
;; - vc-dir-kill-dir-status-process should not be specific to dir-status,
;;   it should work for other async commands done through vc-do-command
;;   as well,
;;
;; - log buffers need font-locking.
;;
;; - vc-dir needs mouse bindings.
;;
;; - vc-dir toolbar needs more icons.
;;
;; - vc-dir-menu-map-filter hook call needs to be moved to vc.el.
;;

(require 'ewoc)

(eval-when-compile
  (require 'cl))

;; General customization
(defcustom vc-logentry-check-hook nil
  "Normal hook run by `vc-finish-logentry'.
Use this to impose your own rules on the entry in addition to any the
dispatcher client mode imposes itself."
  :type 'hook
  :group 'vc)

(defcustom vc-delete-logbuf-window t
  "If non-nil, delete the log buffer and window after each logical action.
If nil, bury that buffer instead.
This is most useful if you have multiple windows on a frame and would like to
preserve the setting."
  :type 'boolean
  :group 'vc)

(defcustom vc-command-messages nil
  "If non-nil, display run messages from back-end commands."
  :type 'boolean
  :group 'vc)

(defcustom vc-suppress-confirm nil
  "If non-nil, treat user as expert; suppress yes-no prompts on some things."
  :type 'boolean
  :group 'vc)

;; Variables the user doesn't need to know about.

(defvar vc-log-operation nil)
(defvar vc-log-after-operation-hook nil)
(defvar vc-log-fileset)
(defvar vc-log-extra)
(defvar vc-client-mode)

;; In a log entry buffer, this is a local variable
;; that points to the buffer for which it was made
;; (either a file, or a directory buffer).
(defvar vc-parent-buffer nil)
(put 'vc-parent-buffer 'permanent-local t)
(defvar vc-parent-buffer-name nil)
(put 'vc-parent-buffer-name 'permanent-local t)

;; Common command execution logic

(defun vc-process-filter (p s)
  "An alternative output filter for async process P.
One difference with the default filter is that this inserts S after markers.
Another is that undo information is not kept."
  (let ((buffer (process-buffer p)))
    (when (buffer-live-p buffer)
      (with-current-buffer buffer
        (save-excursion
          (let ((buffer-undo-list t)
                (inhibit-read-only t))
            (goto-char (process-mark p))
            (insert s)
            (set-marker (process-mark p) (point))))))))

(defun vc-setup-buffer (buf)
  "Prepare BUF for executing a slave command and make it current."
  (let ((camefrom (current-buffer))
        (olddir default-directory))
    (set-buffer (get-buffer-create buf))
    (kill-all-local-variables)
    (set (make-local-variable 'vc-parent-buffer) camefrom)
    (set (make-local-variable 'vc-parent-buffer-name)
         (concat " from " (buffer-name camefrom)))
    (setq default-directory olddir)
    (let ((buffer-undo-list t)
          (inhibit-read-only t))
      (erase-buffer))))

(defvar vc-sentinel-movepoint)          ;Dynamically scoped.

(defun vc-process-sentinel (p s)
  (let ((previous (process-get p 'vc-previous-sentinel))
        (buf (process-buffer p)))
    ;; Impatient users sometime kill "slow" buffers; check liveness
    ;; to avoid "error in process sentinel: Selecting deleted buffer".
    (when (buffer-live-p buf)
      (when previous (funcall previous p s))
      (with-current-buffer buf
        (setq mode-line-process
              (let ((status (process-status p)))
                ;; Leave mode-line uncluttered, normally.
                (unless (eq 'exit status)
                  (format " (%s)" status))))
        (let (vc-sentinel-movepoint)
          ;; Normally, we want async code such as sentinels to not move point.
          (save-excursion
            (goto-char (process-mark p))
            (let ((cmds (process-get p 'vc-sentinel-commands)))
              (process-put p 'vc-sentinel-commands nil)
              (dolist (cmd cmds)
                ;; Each sentinel may move point and the next one should be run
                ;; at that new point.  We could get the same result by having
                ;; each sentinel read&set process-mark, but since `cmd' needs
                ;; to work both for async and sync processes, this would be
                ;; difficult to achieve.
                (vc-exec-after cmd))))
          ;; But sometimes the sentinels really want to move point.
          (when vc-sentinel-movepoint
            (let ((win (get-buffer-window (current-buffer) 0)))
              (if (not win)
                  (goto-char vc-sentinel-movepoint)
                (with-selected-window win
                  (goto-char vc-sentinel-movepoint))))))))))

(defun vc-set-mode-line-busy-indicator ()
  (setq mode-line-process
        (concat " " (propertize "[waiting...]"
                                'face 'mode-line-emphasis
                                'help-echo
                                "A command is in progress in this buffer"))))

(defun vc-exec-after (code)
  "Eval CODE when the current buffer's process is done.
If the current buffer has no process, just evaluate CODE.
Else, add CODE to the process' sentinel."
  (let ((proc (get-buffer-process (current-buffer))))
    (cond
     ;; If there's no background process, just execute the code.
     ;; We used to explicitly call delete-process on exited processes,
     ;; but this led to timing problems causing process output to be
     ;; lost.  Terminated processes get deleted automatically
     ;; anyway. -- cyd
     ((or (null proc) (eq (process-status proc) 'exit))
      ;; Make sure we've read the process's output before going further.
      (when proc (accept-process-output proc))
      (eval code))
     ;; If a process is running, add CODE to the sentinel
     ((eq (process-status proc) 'run)
      (vc-set-mode-line-busy-indicator)
      (let ((previous (process-sentinel proc)))
        (unless (eq previous 'vc-process-sentinel)
          (process-put proc 'vc-previous-sentinel previous))
        (set-process-sentinel proc 'vc-process-sentinel))
      (process-put proc 'vc-sentinel-commands
                   ;; We keep the code fragments in the order given
                   ;; so that vc-diff-finish's message shows up in
                   ;; the presence of non-nil vc-command-messages.
                   (append (process-get proc 'vc-sentinel-commands)
                           (list code))))
     (t (error "Unexpected process state"))))
  nil)

(defvar vc-post-command-functions nil
  "Hook run at the end of `vc-do-command'.
Each function is called inside the buffer in which the command was run
and is passed 3 arguments: the COMMAND, the FILES and the FLAGS.")

(defvar w32-quote-process-args)

(defun vc-delistify (filelist)
  "Smash a FILELIST into a file list string suitable for info messages."
  ;; FIXME what about file names with spaces?
  (if (not filelist) "."  (mapconcat 'identity filelist " ")))

;;;###autoload
(defun vc-do-command (buffer okstatus command file-or-list &rest flags)
  "Execute a slave command, notifying user and checking for errors.
Output from COMMAND goes to BUFFER, or the current buffer if
BUFFER is t.  If the destination buffer is not already current,
set it up properly and erase it.  The command is considered
successful if its exit status does not exceed OKSTATUS (if
OKSTATUS is nil, that means to ignore error status, if it is
`async', that means not to wait for termination of the
subprocess; if it is t it means to ignore all execution errors).
FILE-OR-LIST is the name of a working file; it may be a list of
files or be nil (to execute commands that don't expect a file
name or set of files).  If an optional list of FLAGS is present,
that is inserted into the command line before the filename."
  ;; FIXME: file-relative-name can return a bogus result because
  ;; it doesn't look at the actual file-system to see if symlinks
  ;; come into play.
  (let* ((files
          (mapcar (lambda (f) (file-relative-name (expand-file-name f)))
                  (if (listp file-or-list) file-or-list (list file-or-list))))
         (full-command
          ;; What we're doing here is preparing a version of the command
          ;; for display in a debug-progress message.  If it's fewer than
          ;; 20 characters display the entire command (without trailing
          ;; newline).  Otherwise display the first 20 followed by an ellipsis.
          (concat (if (string= (substring command -1) "\n")
                      (substring command 0 -1)
                    command)
                  " "
                  (vc-delistify (mapcar (lambda (s) (if (> (length s) 20) (concat (substring s 0 2) "...")  s)) flags))
                  " " (vc-delistify files))))
    (save-current-buffer
      (unless (or (eq buffer t)
                  (and (stringp buffer)
                       (string= (buffer-name) buffer))
                  (eq buffer (current-buffer)))
        (vc-setup-buffer buffer))
      ;; If there's some previous async process still running, just kill it.
      (let ((oldproc (get-buffer-process (current-buffer))))
        ;; If we wanted to wait for oldproc to finish before doing
        ;; something, we'd have used vc-eval-after.
        ;; Use `delete-process' rather than `kill-process' because we don't
        ;; want any of its output to appear from now on.
        (if oldproc (delete-process oldproc)))
      (let ((squeezed (remq nil flags))
            (inhibit-read-only t)
            (status 0))
        (when files
          (setq squeezed (nconc squeezed files)))
        (let ((exec-path (append vc-path exec-path))
              ;; Add vc-path to PATH for the execution of this command.
              (process-environment
               (cons (concat "PATH=" (getenv "PATH")
                             path-separator
                             (mapconcat 'identity vc-path path-separator))
                     process-environment))
              (w32-quote-process-args t))
          (when (and (eq okstatus 'async) (file-remote-p default-directory))
            ;; start-process does not support remote execution
            (setq okstatus nil))
          (if (eq okstatus 'async)
              ;; Run asynchronously.
              (let ((proc
                     (let ((process-connection-type nil))
                       (apply 'start-file-process command (current-buffer)
                              command squeezed))))
                (if vc-command-messages
                    (message "Running %s in background..." full-command))
                ;;(set-process-sentinel proc (lambda (p msg) (delete-process p)))
                (set-process-filter proc 'vc-process-filter)
                (vc-exec-after
                 `(if vc-command-messages
                      (message "Running %s in background... done" ',full-command))))
            ;; Run synchronously
            (when vc-command-messages
              (message "Running %s in foreground..." full-command))
            (let ((buffer-undo-list t))
              (setq status (apply 'process-file command nil t nil squeezed)))
            (when (and (not (eq t okstatus))
                       (or (not (integerp status))
                           (and okstatus (< okstatus status))))
              (unless (eq ?\s (aref (buffer-name (current-buffer)) 0))
                (pop-to-buffer (current-buffer))
                (goto-char (point-min))
                (shrink-window-if-larger-than-buffer))
              (error "Running %s...FAILED (%s)" full-command
                     (if (integerp status) (format "status %d" status) status))))
          ;; We're done.  But don't emit a status message if running
          ;; asynchronously, it would just mislead.
          (if (and vc-command-messages (not (eq okstatus 'async)))
              (message "Running %s...OK = %d" full-command status)))
        (vc-exec-after
         `(run-hook-with-args 'vc-post-command-functions
                              ',command ',file-or-list ',flags))
        status))))

;; These functions are used to ensure that the view the user sees is up to date
;; even if the dispatcher client mode has messed with file contents (as in,
;; for example, VCS keyword expansion).

(declare-function view-mode-exit "view" (&optional return-to-alist exit-action all-win))

(defun vc-position-context (posn)
  "Save a bit of the text around POSN in the current buffer.
Used to help us find the corresponding position again later
if markers are destroyed or corrupted."
  ;; A lot of this was shamelessly lifted from Sebastian Kremer's
  ;; rcs.el mode.
  (list posn
        (buffer-size)
        (buffer-substring posn
                          (min (point-max) (+ posn 100)))))

(defun vc-find-position-by-context (context)
  "Return the position of CONTEXT in the current buffer.
If CONTEXT cannot be found, return nil."
  (let ((context-string (nth 2 context)))
    (if (equal "" context-string)
        (point-max)
      (save-excursion
        (let ((diff (- (nth 1 context) (buffer-size))))
          (when (< diff 0) (setq diff (- diff)))
          (goto-char (nth 0 context))
          (if (or (search-forward context-string nil t)
                  ;; Can't use search-backward since the match may continue
                  ;; after point.
                  (progn (goto-char (- (point) diff (length context-string)))
                         ;; goto-char doesn't signal an error at
                         ;; beginning of buffer like backward-char would
                         (search-forward context-string nil t)))
              ;; to beginning of OSTRING
              (- (point) (length context-string))))))))

(defun vc-context-matches-p (posn context)
  "Return t if POSN matches CONTEXT, nil otherwise."
  (let* ((context-string (nth 2 context))
         (len (length context-string))
         (end (+ posn len)))
    (if (> end (1+ (buffer-size)))
        nil
      (string= context-string (buffer-substring posn end)))))

(defun vc-buffer-context ()
  "Return a list (POINT-CONTEXT MARK-CONTEXT REPARSE).
Used by `vc-restore-buffer-context' to later restore the context."
  (let ((point-context (vc-position-context (point)))
        ;; Use mark-marker to avoid confusion in transient-mark-mode.
        (mark-context (when (eq (marker-buffer (mark-marker)) (current-buffer))
                         (vc-position-context (mark-marker))))
        ;; Make the right thing happen in transient-mark-mode.
        (mark-active nil))
    (list point-context mark-context nil)))

(defun vc-restore-buffer-context (context)
  "Restore point/mark, and reparse any affected compilation buffers.
CONTEXT is that which `vc-buffer-context' returns."
  (let ((point-context (nth 0 context))
        (mark-context (nth 1 context)))
    ;; if necessary, restore point and mark
    (if (not (vc-context-matches-p (point) point-context))
        (let ((new-point (vc-find-position-by-context point-context)))
          (when new-point (goto-char new-point))))
    (and mark-active
         mark-context
         (not (vc-context-matches-p (mark) mark-context))
         (let ((new-mark (vc-find-position-by-context mark-context)))
           (when new-mark (set-mark new-mark))))))

(defun vc-revert-buffer-internal (&optional arg no-confirm)
  "Revert buffer, keeping point and mark where user expects them.
Try to be clever in the face of changes due to expanded version-control
key words.  This is important for typeahead to work as expected.
ARG and NO-CONFIRM are passed on to `revert-buffer'."
  (interactive "P")
  (widen)
  (let ((context (vc-buffer-context)))
    ;; Use save-excursion here, because it may be able to restore point
    ;; and mark properly even in cases where vc-restore-buffer-context
    ;; would fail.  However, save-excursion might also get it wrong --
    ;; in this case, vc-restore-buffer-context gives it a second try.
    (save-excursion
      ;; t means don't call normal-mode;
      ;; that's to preserve various minor modes.
      (revert-buffer arg no-confirm t))
    (vc-restore-buffer-context context)))

(defun vc-resynch-window (file &optional keep noquery)
  "If FILE is in the current buffer, either revert or unvisit it.
The choice between revert (to see expanded keywords) and unvisit
depends on KEEP.  NOQUERY if non-nil inhibits confirmation for
reverting.  NOQUERY should be t *only* if it is known the only
difference between the buffer and the file is due to
modifications by the dispatcher client code, rather than user
editing!"
  (and (string= buffer-file-name file)
       (if keep
           (progn
             (vc-revert-buffer-internal t noquery)
             ;; TODO: Adjusting view mode might no longer be necessary
             ;; after RMS change to files.el of 1999-08-08.  Investigate
             ;; this when we install the new VC.
             (and view-read-only
                  (if (file-writable-p file)
                      (and view-mode
                           (let ((view-old-buffer-read-only nil))
                             (view-mode-exit)))
                    (and (not view-mode)
                         (not (eq (get major-mode 'mode-class) 'special))
                         (view-mode-enter))))
             (run-hook-with-args 'modeline-hook buffer-file-name))
         (kill-buffer (current-buffer)))))

(defun vc-resynch-buffer (file &optional keep noquery)
  "If FILE is currently visited, resynch its buffer."
  (if (string= buffer-file-name file)
      (vc-resynch-window file keep noquery)
    (let ((buffer (get-file-buffer file)))
      (when buffer
        (with-current-buffer buffer
          (vc-resynch-window file keep noquery)))))
  (vc-directory-resynch-file file))

(defun vc-buffer-sync (&optional not-urgent)
  "Make sure the current buffer and its working file are in sync.
NOT-URGENT means it is ok to continue if the user says not to save."
  (when (buffer-modified-p)
    (if (or vc-suppress-confirm
            (y-or-n-p (format "Buffer %s modified; save it? " (buffer-name))))
        (save-buffer)
      (unless not-urgent
        (error "Aborted")))))

;; Command closures

;; Set up key bindings for use while editing log messages

(defun vc-log-edit (fileset)
  "Set up `log-edit' for use on FILE."
  (setq default-directory
        (with-current-buffer vc-parent-buffer default-directory))
  (log-edit 'vc-finish-logentry
            nil
            `((log-edit-listfun . (lambda () ',fileset))
              (log-edit-diff-function . (lambda () (vc-diff nil)))))
  (set (make-local-variable 'vc-log-fileset) fileset)
  (make-local-variable 'vc-log-extra)
  (set-buffer-modified-p nil)
  (setq buffer-file-name nil))

(defun vc-start-logentry (files extra comment initial-contents msg logbuf action &optional after-hook)
  "Accept a comment for an operation on FILES with extra data EXTRA.
If COMMENT is nil, pop up a LOGBUF buffer, emit MSG, and set the
action on close to ACTION.  If COMMENT is a string and
INITIAL-CONTENTS is non-nil, then COMMENT is used as the initial
contents of the log entry buffer.  If COMMENT is a string and
INITIAL-CONTENTS is nil, do action immediately as if the user had
entered COMMENT.  If COMMENT is t, also do action immediately with an
empty comment.  Remember the file's buffer in `vc-parent-buffer'
\(current one if no file).  AFTER-HOOK specifies the local value
for `vc-log-after-operation-hook'."
  (let ((parent
         (if (vc-dispatcher-browsing)
             ;; If we are called from a directory browser, the parent buffer is
             ;; the current buffer.
             (current-buffer)
           (if (and files (equal (length files) 1))
               (get-file-buffer (car files))
             (current-buffer)))))
    (if (and comment (not initial-contents))
        (set-buffer (get-buffer-create logbuf))
      (pop-to-buffer (get-buffer-create logbuf)))
    (set (make-local-variable 'vc-parent-buffer) parent)
    (set (make-local-variable 'vc-parent-buffer-name)
         (concat " from " (buffer-name vc-parent-buffer)))
    (vc-log-edit files)
    (make-local-variable 'vc-log-after-operation-hook)
    (when after-hook
      (setq vc-log-after-operation-hook after-hook))
    (setq vc-log-operation action)
    (setq vc-log-extra extra)
    (when comment
      (erase-buffer)
      (when (stringp comment) (insert comment)))
    (if (or (not comment) initial-contents)
        (message "%s  Type C-c C-c when done" msg)
      (vc-finish-logentry (eq comment t)))))

(defun vc-finish-logentry (&optional nocomment)
  "Complete the operation implied by the current log entry.
Use the contents of the current buffer as a check-in or registration
comment.  If the optional arg NOCOMMENT is non-nil, then don't check
the buffer contents as a comment."
  (interactive)
  ;; Check and record the comment, if any.
  (unless nocomment
    (run-hooks 'vc-logentry-check-hook))
  ;; Sync parent buffer in case the user modified it while editing the comment.
  ;; But not if it is a vc-directory buffer.
  (with-current-buffer vc-parent-buffer
    (or (vc-dispatcher-browsing) (vc-buffer-sync)))
  (unless vc-log-operation
    (error "No log operation is pending"))
  ;; save the parameters held in buffer-local variables
  (let ((logbuf (current-buffer))
        (log-operation vc-log-operation)
        (log-fileset vc-log-fileset)
        (log-extra vc-log-extra)
        (log-entry (buffer-string))
        (after-hook vc-log-after-operation-hook)
        (tmp-vc-parent-buffer vc-parent-buffer))
    (pop-to-buffer vc-parent-buffer)
    ;; OK, do it to it
    (save-excursion
      (funcall log-operation
               log-fileset
               log-extra
               log-entry))
    ;; Remove checkin window (after the checkin so that if that fails
    ;; we don't zap the log buffer and the typing therein).
    ;; -- IMO this should be replaced with quit-window
    (cond ((and logbuf vc-delete-logbuf-window)
           (delete-windows-on logbuf (selected-frame))
           ;; Kill buffer and delete any other dedicated windows/frames.
           (kill-buffer logbuf))
          (logbuf (pop-to-buffer logbuf)
                  (bury-buffer)
                  (pop-to-buffer tmp-vc-parent-buffer)))
    ;; Now make sure we see the expanded headers
    (when log-fileset
      (mapc
       (lambda (file) (vc-resynch-buffer file vc-keep-workfiles t))
       log-fileset))
    (when (vc-dispatcher-browsing)
      (vc-dir-move-to-goal-column))
    (run-hooks after-hook 'vc-finish-logentry-hook)))

;; The ewoc-based vc-directory implementation

(defcustom vc-dir-mode-hook nil
  "Normal hook run by `vc-dir-mode'.
See `run-hooks'."
  :type 'hook
  :group 'vc)

;; Used to store information for the files displayed in the directory buffer.
;; Each item displayed corresponds to one of these defstructs.
(defstruct (vc-dir-fileinfo
            (:copier nil)
            (:type list)            ;So we can use `member' on lists of FIs.
            (:constructor
             ;; We could define it as an alias for `list'.
             vc-dir-create-fileinfo (name state &optional extra marked directory))
            (:conc-name vc-dir-fileinfo->))
  name                                  ;Keep it as first, for `member'.
  state
  ;; For storing client-mode specific information.
  extra
  marked
  ;; To keep track of not updated files during a global refresh
  needs-update
  ;; To distinguish files and directories.
  directory)

;; Used to describe a dispatcher client mode.
(defstruct (vc-client-object
            (:copier nil)
            (:constructor
             vc-create-client-object (name
                                      headers
                                      file-to-info
                                      file-to-state
                                      file-to-extra
                                      updater
                                      extra-menu))
            (:conc-name vc-client-object->))
  name
  headers
  file-to-info
  file-to-state
  file-to-extra
  updater
  extra-menu)

(defvar vc-ewoc nil)
(defvar vc-dir-process-buffer nil
  "The buffer used for the asynchronous call that computes status.")

(defun vc-dir-move-to-goal-column ()
  ;; Used to keep the cursor on the file name column.
  (beginning-of-line)
  ;; Must be in sync with vc-default-status-printer.
  (forward-char 25))

(defun vc-dir-prepare-status-buffer (bname dir &optional create-new)
  "Find a buffer named BNAME showing DIR, or create a new one."
  (setq dir (expand-file-name dir))
  (let*
         ;; Look for another buffer name BNAME visiting the same directory.
         ((buf (save-excursion
                (unless create-new
                  (dolist (buffer (buffer-list))
                    (set-buffer buffer)
                    (when (and (vc-dispatcher-browsing)
                               (string= (expand-file-name default-directory) dir))
                      (return buffer)))))))
    (or buf
        ;; Create a new buffer named BNAME.
        (with-current-buffer (create-file-buffer bname)
          (cd dir)
          (vc-setup-buffer (current-buffer))
          ;; Reset the vc-parent-buffer-name so that it does not appear
          ;; in the mode-line.
          (setq vc-parent-buffer-name nil)
          (current-buffer)))))

(defvar vc-dir-menu-map
  (let ((map (make-sparse-keymap)))
    (define-key map [quit]
      '(menu-item "Quit" quit-window
                  :help "Quit"))
    (define-key map [kill]
      '(menu-item "Kill Update Command" vc-dir-kill-dir-status-process
                  :enable (vc-dir-busy)
                  :help "Kill the command that updates the directory buffer"))
    (define-key map [refresh]
      '(menu-item "Refresh" vc-dir-refresh
                  :enable (not (vc-dir-busy))
                  :help "Refresh the contents of the directory buffer"))
    ;; Movement.
    (define-key map [sepmv] '("--"))
    (define-key map [next-line]
      '(menu-item "Next line" vc-dir-next-line
                  :help "Go to the next line" :keys "n"))
    (define-key map [previous-line]
      '(menu-item "Previous line" vc-dir-previous-line
                  :help "Go to the previous line"))
    ;; Marking.
    (define-key map [sepmrk] '("--"))
    (define-key map [unmark-all]
      '(menu-item "Unmark All" vc-dir-unmark-all-files
                  :help "Unmark all files that are in the same state as the current file\
\nWith prefix argument unmark all files"))
    (define-key map [unmark-previous]
      '(menu-item "Unmark previous " vc-dir-unmark-file-up
                  :help "Move to the previous line and unmark the file"))

    (define-key map [mark-all]
      '(menu-item "Mark All" vc-dir-mark-all-files
                  :help "Mark all files that are in the same state as the current file\
\nWith prefix argument mark all files"))
    (define-key map [unmark]
      '(menu-item "Unmark" vc-dir-unmark
                  :help "Unmark the current file or all files in the region"))

    (define-key map [mark]
      '(menu-item "Mark" vc-dir-mark
                  :help "Mark the current file or all files in the region"))

    (define-key map [sepopn] '("--"))
    (define-key map [open-other]
      '(menu-item "Open in other window" vc-dir-find-file-other-window
                  :help "Find the file on the current line, in another window"))
    (define-key map [open]
      '(menu-item "Open file" vc-dir-find-file
                  :help "Find the file on the current line"))
    map)
  "Menu for dispatcher status")

;; This is used so that client modes can add mode-specific menu
;; items to vc-dir-menu-map.
(defun vc-dir-menu-map-filter (orig-binding)
  (when (and (symbolp orig-binding) (fboundp orig-binding))
    (setq orig-binding (indirect-function orig-binding)))
  (let ((ext-binding
         (funcall (vc-client-object->extra-menu vc-client-mode))))
    (if (null ext-binding)
        orig-binding
      (append orig-binding
              '("----")
              ext-binding))))

(defvar vc-dir-mode-map
  (let ((map (make-keymap)))
    (suppress-keymap map)
    ;; Marking.
    (define-key map "m" 'vc-dir-mark)
    (define-key map "M" 'vc-dir-mark-all-files)
    (define-key map "u" 'vc-dir-unmark)
    (define-key map "U" 'vc-dir-unmark-all-files)
    (define-key map "\C-?" 'vc-dir-unmark-file-up)
    (define-key map "\M-\C-?" 'vc-dir-unmark-all-files)
    ;; Movement.
    (define-key map "n" 'vc-dir-next-line)
    (define-key map " " 'vc-dir-next-line)
    (define-key map "\t" 'vc-dir-next-directory)
    (define-key map "p" 'vc-dir-previous-line)
    (define-key map [backtab] 'vc-dir-previous-directory)
    ;;; Rebind paragraph-movement commands.
    (define-key map "\M-}" 'vc-dir-next-directory)
    (define-key map "\M-{" 'vc-dir-previous-directory)
    (define-key map [C-down] 'vc-dir-next-directory)
    (define-key map [C-up] 'vc-dir-previous-directory)
    ;; The remainder.
    (define-key map "f" 'vc-dir-find-file)
    (define-key map "\C-m" 'vc-dir-find-file)
    (define-key map "o" 'vc-dir-find-file-other-window)
    (define-key map "q" 'quit-window)
    (define-key map "g" 'vc-dir-refresh)
    (define-key map "\C-c\C-c" 'vc-dir-kill-dir-status-process)
    (define-key map [down-mouse-3] 'vc-dir-menu)
    (define-key map [mouse-2] 'vc-dir-toggle-mark)

    ;; Hook up the menu.
    (define-key map [menu-bar vc-dir-mode]
      `(menu-item
        ;; This is used so that client modes can add mode-specific
        ;; menu items to vc-dir-menu-map.
        "*vc-dispatcher*" ,vc-dir-menu-map :filter vc-dir-menu-map-filter))
    map)
  "Keymap for directory buffer.")

(defmacro vc-at-event (event &rest body)
  "Evaluate `body' with point located at event-start of `event'.
If `body' uses `event', it should be a variable,
 otherwise it will be evaluated twice."
  (let ((posn (make-symbol "vc-at-event-posn")))
    `(let ((,posn (event-start ,event)))
       (save-excursion
         (set-buffer (window-buffer (posn-window ,posn)))
         (goto-char (posn-point ,posn))
         ,@body))))

(defun vc-dir-menu (e)
  "Popup the dispatcher status menu."
  (interactive "e")
  (vc-at-event e (popup-menu vc-dir-menu-map e)))

(defvar vc-dir-tool-bar-map
  (let ((map (make-sparse-keymap)))
    (tool-bar-local-item-from-menu 'vc-dir-find-file "open"
                                   map vc-dir-mode-map)
    (tool-bar-local-item "bookmark_add"
                         'vc-dir-toggle-mark 'vc-dir-toggle-mark map
                         :help "Toggle mark on current item")
    (tool-bar-local-item-from-menu 'vc-dir-previous-line "left-arrow"
                                   map vc-dir-mode-map
                                   :rtl "right-arrow")
    (tool-bar-local-item-from-menu 'vc-dir-next-line "right-arrow"
                                   map vc-dir-mode-map
                                   :rtl "left-arrow")
    (tool-bar-local-item-from-menu 'vc-print-log "info"
                                   map vc-dir-mode-map)
    (tool-bar-local-item-from-menu 'vc-dir-refresh "refresh"
                                   map vc-dir-mode-map)
    (tool-bar-local-item-from-menu 'nonincremental-search-forward
                                   "search" map)
    (tool-bar-local-item-from-menu 'vc-dir-kill-dir-status-process "cancel"
                                   map vc-dir-mode-map)
    (tool-bar-local-item-from-menu 'quit-window "exit"
                                   map vc-dir-mode-map)
    map))

(defun vc-dir-update (entries buffer &optional noinsert)
  "Update BUFFER's ewoc from the list of ENTRIES.
If NOINSERT, ignore elements on ENTRIES which are not in the ewoc."
  ;; Add ENTRIES to the vc-dir buffer BUFFER.
  (with-current-buffer buffer
    ;; Insert the entries sorted by name into the ewoc.
    ;; We assume the ewoc is sorted too, which should be the
    ;; case if we always add entries with vc-dir-update.
    (setq entries
          ;; Sort: first files and then subdirectories.
          ;; XXX: this is VERY inefficient, it computes the directory
          ;; names too many times
          (sort entries
                (lambda (entry1 entry2)
                  (let ((dir1 (file-name-directory (expand-file-name (car entry1))))
                        (dir2 (file-name-directory (expand-file-name (car entry2)))))
                    (cond
                     ((string< dir1 dir2) t)
                     ((not (string= dir1 dir2)) nil)
                     ((string< (car entry1) (car entry2))))))))
    ;; Insert directory entries in the right places.
    (let ((entry (car entries))
          (node (ewoc-nth vc-ewoc 0)))
      ;; Insert . if it is not present.
      (unless node
        (let ((rd (file-relative-name default-directory)))
          (ewoc-enter-last
           vc-ewoc (vc-dir-create-fileinfo
                    rd nil nil nil (expand-file-name default-directory))))
        (setq node (ewoc-nth vc-ewoc 0)))

      (while (and entry node)
        (let* ((entryfile (car entry))
               (entrydir (file-name-directory (expand-file-name entryfile)))
               (nodedir
                (or (vc-dir-fileinfo->directory (ewoc-data node))
                    (file-name-directory
                     (expand-file-name
                      (vc-dir-fileinfo->name (ewoc-data node)))))))
          (cond
           ;; First try to find the directory.
           ((string-lessp nodedir entrydir)
            (setq node (ewoc-next vc-ewoc node)))
           ((string-equal nodedir entrydir)
            ;; Found the directory, find the place for the file name.
            (let ((nodefile (vc-dir-fileinfo->name (ewoc-data node))))
              (cond
               ((string-lessp nodefile entryfile)
                (setq node (ewoc-next vc-ewoc node)))
               ((string-equal nodefile entryfile)
                (setf (vc-dir-fileinfo->state (ewoc-data node)) (nth 1 entry))
                (setf (vc-dir-fileinfo->extra (ewoc-data node)) (nth 2 entry))
                (setf (vc-dir-fileinfo->needs-update (ewoc-data node)) nil)
                (ewoc-invalidate vc-ewoc node)
                (setq entries (cdr entries) entry (car entries))
                (setq node (ewoc-next vc-ewoc node)))
               (t
                (ewoc-enter-before vc-ewoc node
                                   (apply 'vc-dir-create-fileinfo entry))
                (setq entries (cdr entries) entry (car entries))))))
           (t
            ;; We need to insert a directory node
            (let ((rd (file-relative-name entrydir)))
              (ewoc-enter-last
               vc-ewoc (vc-dir-create-fileinfo rd nil nil nil entrydir)))
            ;; Now insert the node itself.
            (ewoc-enter-before vc-ewoc node
                               (apply 'vc-dir-create-fileinfo entry))
            (setq entries (cdr entries) entry (car entries))))))
      ;; We're past the last node, all remaining entries go to the end.
      (unless (or node noinsert)
        (let* ((lastnode (ewoc-nth vc-ewoc -1))
               (lastdir
                (or (vc-dir-fileinfo->directory (ewoc-data lastnode))
                    (file-name-directory
                     (expand-file-name
                      (vc-dir-fileinfo->name (ewoc-data lastnode)))))))
          (dolist (entry entries)
            (let ((entrydir (file-name-directory (expand-file-name (car entry)))))
              ;; Insert a directory node if needed.
              (unless (string-equal lastdir entrydir)
                (setq lastdir entrydir)
                (let ((rd (file-relative-name entrydir)))
                  (ewoc-enter-last
                   vc-ewoc (vc-dir-create-fileinfo rd nil nil nil entrydir))))
              ;; Now insert the node itself.
              (ewoc-enter-last vc-ewoc
                               (apply 'vc-dir-create-fileinfo entry)))))))))

(defun vc-dir-busy ()
  (and (buffer-live-p vc-dir-process-buffer)
       (get-buffer-process vc-dir-process-buffer)))

(defun vc-dir-kill-dir-status-process ()
  "Kill the temporary buffer and associated process."
  (interactive)
  (when (buffer-live-p vc-dir-process-buffer)
    (let ((proc (get-buffer-process vc-dir-process-buffer)))
      (when proc (delete-process proc))
      (setq vc-dir-process-buffer nil)
      (setq mode-line-process nil))))

(defun vc-dir-kill-query ()
  ;; Make sure that when the status buffer is killed the update
  ;; process running in background is also killed.
  (if (vc-dir-busy)
    (when (y-or-n-p "Status update process running, really kill status buffer?")
      (vc-dir-kill-dir-status-process)
      t)
    t))

(defun vc-dir-next-line (arg)
  "Go to the next line.
If a prefix argument is given, move by that many lines."
  (interactive "p")
  (with-no-warnings
    (ewoc-goto-next vc-ewoc arg)
    (vc-dir-move-to-goal-column)))

(defun vc-dir-previous-line (arg)
  "Go to the previous line.
If a prefix argument is given, move by that many lines."
  (interactive "p")
  (ewoc-goto-prev vc-ewoc arg)
  (vc-dir-move-to-goal-column))

(defun vc-dir-next-directory ()
  "Go to the next directory."
  (interactive)
  (let ((orig (point)))
    (if
        (catch 'foundit
          (while t
            (let* ((next (ewoc-next vc-ewoc (ewoc-locate vc-ewoc))))
              (cond ((not next)
                     (throw 'foundit t))
                    (t
                     (progn
                       (ewoc-goto-node vc-ewoc next)
                       (vc-dir-move-to-goal-column)
                       (if (vc-dir-fileinfo->directory (ewoc-data next))
                           (throw 'foundit nil))))))))
        (goto-char orig))))

(defun vc-dir-previous-directory ()
  "Go to the previous directory."
  (interactive)
  (let ((orig (point)))
    (if
        (catch 'foundit
          (while t
            (let* ((prev (ewoc-prev vc-ewoc (ewoc-locate vc-ewoc))))
              (cond ((not prev)
                     (throw 'foundit t))
                    (t
                     (progn
                       (ewoc-goto-node vc-ewoc prev)
                       (vc-dir-move-to-goal-column)
                       (if (vc-dir-fileinfo->directory (ewoc-data prev))
                           (throw 'foundit nil))))))))
        (goto-char orig))))

(defun vc-dir-mark-unmark (mark-unmark-function)
  (if (use-region-p)
      (let ((firstl (line-number-at-pos (region-beginning)))
            (lastl (line-number-at-pos (region-end))))
        (save-excursion
          (goto-char (region-beginning))
          (while (<= (line-number-at-pos) lastl)
            (funcall mark-unmark-function))))
    (funcall mark-unmark-function)))

(defun vc-dir-parent-marked-p (arg)
  ;; Return nil if none of the parent directories of arg is marked.
  (let* ((argdata (ewoc-data arg))
         (argdir
          (let ((crtdir (vc-dir-fileinfo->directory argdata)))
            (if crtdir
                crtdir
              (file-name-directory (expand-file-name
                                    (vc-dir-fileinfo->name argdata))))))
         (arglen (length argdir))
         (crt arg)
         data dir)
    ;; Go through the predecessors, checking if any directory that is
    ;; a parent is marked.
    (while (setq crt (ewoc-prev vc-ewoc crt))
      (setq data (ewoc-data crt))
      (setq dir
            (let ((crtdir (vc-dir-fileinfo->directory data)))
              (if crtdir
                  crtdir
                (file-name-directory (expand-file-name
                                      (vc-dir-fileinfo->name data))))))

      (when (and (vc-dir-fileinfo->directory data)
                 (string-equal (substring argdir 0 (length dir)) dir))
        (when (vc-dir-fileinfo->marked data)
          (error "Cannot mark `%s', parent directory `%s' marked"
                 (vc-dir-fileinfo->name argdata)
                 (vc-dir-fileinfo->name data)))))
    nil))

(defun vc-dir-children-marked-p (arg)
  ;; Return nil if none of the children of arg is marked.
  (let* ((argdata (ewoc-data arg))
         (argdir (vc-dir-fileinfo->directory argdata))
         (arglen (length argdir))
         (is-child t)
         (crt arg)
         data dir)
    (while (and is-child (setq crt (ewoc-next vc-ewoc crt)))
      (setq data (ewoc-data crt))
      (setq dir
            (let ((crtdir (vc-dir-fileinfo->directory data)))
              (if crtdir
                  crtdir
                (file-name-directory (expand-file-name
                                      (vc-dir-fileinfo->name data))))))
      (if (string-equal argdir (substring dir 0 arglen))
          (when (vc-dir-fileinfo->marked data)
            (error "Cannot mark `%s', child `%s' marked"
                   (vc-dir-fileinfo->name argdata)
                   (vc-dir-fileinfo->name data)))
        ;; We are done, we got to an entry that is not a child of `arg'.
        (setq is-child nil)))
    nil))

(defun vc-dir-mark-file (&optional arg)
  ;; Mark ARG or the current file and move to the next line.
  (let* ((crt (or arg (ewoc-locate vc-ewoc)))
         (file (ewoc-data crt))
         (isdir (vc-dir-fileinfo->directory file)))
    (when (or (and isdir (not (vc-dir-children-marked-p crt)))
              (and (not isdir) (not (vc-dir-parent-marked-p crt))))
      (setf (vc-dir-fileinfo->marked file) t)
      (ewoc-invalidate vc-ewoc crt)
      (unless (or arg (mouse-event-p last-command-event))
        (vc-dir-next-line 1)))))

(defun vc-dir-mark ()
  "Mark the current file or all files in the region.
If the region is active, mark all the files in the region.
Otherwise mark the file on the current line and move to the next
line."
  (interactive)
  (vc-dir-mark-unmark 'vc-dir-mark-file))

(defun vc-dir-mark-all-files (arg)
  "Mark all files with the same state as the current one.
With a prefix argument mark all files.
If the current entry is a directory, mark all child files.

The commands operate on files that are on the same state.
This command is intended to make it easy to select all files that
share the same state."
  (interactive "P")
  (if arg
      ;; Mark all files.
      (progn
        ;; First check that no directory is marked, we can't mark
        ;; files in that case.
        (ewoc-map
         (lambda (filearg)
           (when (and (vc-dir-fileinfo->directory filearg)
                      (vc-dir-fileinfo->directory filearg))
             (error "Cannot mark all files, directory `%s' marked"
                    (vc-dir-fileinfo->name filearg))))
         vc-ewoc)
        (ewoc-map
         (lambda (filearg)
           (unless (vc-dir-fileinfo->marked filearg)
             (setf (vc-dir-fileinfo->marked filearg) t)
             t))
         vc-ewoc))
    (let ((data (ewoc-data (ewoc-locate vc-ewoc))))
      (if (vc-dir-fileinfo->directory data)
          ;; It's a directory, mark child files.
          (let ((crt (ewoc-locate vc-ewoc)))
            (unless (vc-dir-children-marked-p crt)
              (while (setq crt (ewoc-next vc-ewoc crt))
                (let ((crt-data (ewoc-data crt)))
                  (unless (vc-dir-fileinfo->directory crt-data)
                    (setf (vc-dir-fileinfo->marked crt-data) t)
                    (ewoc-invalidate vc-ewoc crt))))))
        ;; It's a file
        (let ((state (vc-dir-fileinfo->state data))
              (crt (ewoc-nth vc-ewoc 0)))
          (while crt
            (let ((crt-data (ewoc-data crt)))
              (when (and (not (vc-dir-fileinfo->marked crt-data))
                         (eq (vc-dir-fileinfo->state crt-data) state)
                         (not (vc-dir-fileinfo->directory crt-data)))
                (vc-dir-mark-file crt)))
            (setq crt (ewoc-next vc-ewoc crt))))))))

(defun vc-dir-unmark-file ()
  ;; Unmark the current file and move to the next line.
  (let* ((crt (ewoc-locate vc-ewoc))
         (file (ewoc-data crt)))
    (setf (vc-dir-fileinfo->marked file) nil)
    (ewoc-invalidate vc-ewoc crt)
    (unless (mouse-event-p last-command-event)
      (vc-dir-next-line 1))))

(defun vc-dir-unmark ()
  "Unmark the current file or all files in the region.
If the region is active, unmark all the files in the region.
Otherwise mark the file on the current line and move to the next
line."
  (interactive)
  (vc-dir-mark-unmark 'vc-dir-unmark-file))

(defun vc-dir-unmark-file-up ()
  "Move to the previous line and unmark the file."
  (interactive)
  ;; If we're on the first line, we won't move up, but we will still
  ;; remove the mark.  This seems a bit odd but it is what buffer-menu
  ;; does.
  (let* ((prev (ewoc-goto-prev vc-ewoc 1))
         (file (ewoc-data prev)))
    (setf (vc-dir-fileinfo->marked file) nil)
    (ewoc-invalidate vc-ewoc prev)
    (vc-dir-move-to-goal-column)))

(defun vc-dir-unmark-all-files (arg)
  "Unmark all files with the same state as the current one.
With a prefix argument unmark all files.
If the current entry is a directory, unmark all the child files.

The commands operate on files that are on the same state.
This command is intended to make it easy to deselect all files
that share the same state."
  (interactive "P")
  (if arg
      (ewoc-map
       (lambda (filearg)
         (when (vc-dir-fileinfo->marked filearg)
           (setf (vc-dir-fileinfo->marked filearg) nil)
           t))
       vc-ewoc)
    (let* ((crt (ewoc-locate vc-ewoc))
           (data (ewoc-data crt)))
      (if (vc-dir-fileinfo->directory data)
          ;; It's a directory, unmark child files.
          (while (setq crt (ewoc-next vc-ewoc crt))
            (let ((crt-data (ewoc-data crt)))
              (unless (vc-dir-fileinfo->directory crt-data)
                (setf (vc-dir-fileinfo->marked crt-data) nil)
                (ewoc-invalidate vc-ewoc crt))))
        ;; It's a file
        (let ((crt-state (vc-dir-fileinfo->state (ewoc-data crt))))
          (ewoc-map
           (lambda (filearg)
             (when (and (vc-dir-fileinfo->marked filearg)
                        (eq (vc-dir-fileinfo->state filearg) crt-state))
               (setf (vc-dir-fileinfo->marked filearg) nil)
               t))
           vc-ewoc))))))

(defun vc-dir-toggle-mark-file ()
  (let* ((crt (ewoc-locate vc-ewoc))
         (file (ewoc-data crt)))
    (if (vc-dir-fileinfo->marked file)
        (vc-dir-unmark-file)
      (vc-dir-mark-file))))

(defun vc-dir-toggle-mark (e)
  (interactive "e")
  (vc-at-event e (vc-dir-mark-unmark 'vc-dir-toggle-mark-file)))

(defun vc-dir-delete-file ()
  "Delete the marked files, or the current file if no marks."
  (interactive)
  (mapc 'vc-delete-file (or (vc-dir-marked-files)
                            (list (vc-dir-current-file)))))

(defun vc-dir-find-file ()
  "Find the file on the current line."
  (interactive)
  (find-file (vc-dir-current-file)))

(defun vc-dir-find-file-other-window ()
  "Find the file on the current line, in another window."
  (interactive)
  (find-file-other-window (vc-dir-current-file)))

(defun vc-dir-current-file ()
  (let ((node (ewoc-locate vc-ewoc)))
    (unless node
      (error "No file available."))
    (expand-file-name (vc-dir-fileinfo->name (ewoc-data node)))))

(defun vc-dir-marked-files ()
  "Return the list of marked files."
  (mapcar
   (lambda (elem) (expand-file-name (vc-dir-fileinfo->name elem)))
   (ewoc-collect vc-ewoc 'vc-dir-fileinfo->marked)))

(defun vc-dir-marked-only-files ()
  "Return the list of marked files, For marked directories return child files."
  (let ((crt (ewoc-nth vc-ewoc 0))
        result)
    (while crt
      (let ((crt-data (ewoc-data crt)))
        (if (vc-dir-fileinfo->marked crt-data)
            (if (vc-dir-fileinfo->directory crt-data)
                (let* ((dir (vc-dir-fileinfo->directory crt-data))
                       (dirlen (length dir))
                       data)
                  (while
                      (and (setq crt (ewoc-next vc-ewoc crt))
                           (string-equal
                            (substring
                             (progn
                               (setq data (ewoc-data crt))
                               (let ((crtdir (vc-dir-fileinfo->directory data)))
                                 (if crtdir
                                     crtdir
                                   (file-name-directory
                                    (expand-file-name
                                     (vc-dir-fileinfo->name data))))))
                             0 dirlen)
                            dir))
                    (unless (vc-dir-fileinfo->directory data)
                      (push (vc-dir-fileinfo->name data) result))))
              (push (expand-file-name (vc-dir-fileinfo->name crt-data)) result)
              (setq crt (ewoc-next vc-ewoc crt)))
          (setq crt (ewoc-next vc-ewoc crt)))))
    result))

(defun vc-directory-resynch-file (&optional fname)
  "Update the entries for FILE in any directory buffers that list it."
  (let ((file (or fname (expand-file-name buffer-file-name))))
    ;; The vc-dir case
    (let ((found-vc-dir-buf nil))
      (save-excursion
        (dolist (status-buf (buffer-list))
          (set-buffer status-buf)
          ;; look for a vc-dir buffer that might show this file.
          (when (eq major-mode 'vc-dir-mode)
            (setq found-vc-dir-buf t)
            (let ((ddir (expand-file-name default-directory)))
              ;; This test is cvs-string-prefix-p
              (when (eq t (compare-strings file nil (length ddir) ddir nil nil))
                (let*
                    ((file-short (substring file (length ddir)))
                     (state
                      (funcall (vc-client-object->file-to-state vc-client-mode)
                               file))
                     (extra
                      (funcall (vc-client-object->file-to-extra vc-client-mode)
                               file))
                     (entry
                      (list file-short state extra)))
                  (vc-dir-update (list entry) status-buf))))))
        ;; We didn't find any vc-dir buffers, remove the hook, it is
        ;; not needed.
        (unless found-vc-dir-buf (remove-hook 'after-save-hook 'vc-directory-resynch-file))))))

(defun vc-dir-mode (client-object)
  "Major mode for dispatcher directory buffers.
Marking/Unmarking key bindings and actions:
m - marks a file/directory or if the region is active, mark all the files
     in region.
    Restrictions: - a file cannot be marked if any parent directory is marked
                  - a directory cannot be marked if any child file or
                    directory is marked
u - marks a file/directory or if the region is active, unmark all the files
     in region.
M - if the cursor is on a file: mark all the files with the same state as
      the current file
  - if the cursor is on a directory: mark all child files
  - with a prefix argument: mark all files
U - if the cursor is on a file: unmark all the files with the same state
      as the current file
  - if the cursor is on a directory: unmark all child files
  - with a prefix argument: unmark all files


\\{vc-dir-mode-map}"
  (setq mode-name (vc-client-object->name client-object))
  (setq major-mode 'vc-dir-mode)
  (setq buffer-read-only t)
  (use-local-map vc-dir-mode-map)
  (set (make-local-variable 'tool-bar-map) vc-dir-tool-bar-map)
  (set (make-local-variable 'vc-client-mode) client-object)
  (let ((buffer-read-only nil))
    (erase-buffer)
    (set (make-local-variable 'vc-dir-process-buffer) nil)
    (set (make-local-variable 'vc-ewoc)
         (ewoc-create (vc-client-object->file-to-info client-object)
                      (vc-client-object->headers client-object)))
    (add-hook 'after-save-hook 'vc-directory-resynch-file)
    ;; Make sure that if the directory buffer is killed, the update
    ;; process running in the background is also killed.
    (add-hook 'kill-buffer-query-functions 'vc-dir-kill-query nil t)
    (funcall (vc-client-object->updater client-object)))
  (run-hooks 'vc-dir-mode-hook))

(put 'vc-dir-mode 'mode-class 'special)

(defun vc-dispatcher-browsing ()
  "Are we in a directory browser buffer?"
  (derived-mode-p 'vc-dir-mode))

(defun vc-dispatcher-in-fileset-p (fileset)
  (let ((member nil))
    (while (and (not member) fileset)
      (let ((elem (pop fileset)))
        (if (if (file-directory-p elem)
                (eq t (compare-strings buffer-file-name nil (length elem)
                                       elem nil nil))
              (eq (current-buffer) (get-file-buffer elem)))
            (setq member t))))
    member))

(defun vc-dispatcher-selection-set (&optional observer)
  "Deduce a set of files to which to apply an operation.  Return a cons
cell (SELECTION . FILESET), where SELECTION is what the user chose
and FILES is the flist with any directories replaced by the listed files
within them.

If we're in a directory display, the fileset is the list of marked files (if
there is one) else the file on the current line.  If not in a directory
display, but the current buffer visits a file, the fileset is a singleton
containing that file.  Otherwise, throw an error."
  (let ((selection
         (cond
          ;; Browsing with vc-dir
          ((vc-dispatcher-browsing)
           ;; If no files are marked, temporarily mark current file
           ;; and choose on that basis (so we get subordinate files)
           (if (not (vc-dir-marked-files))
                 (prog2
                   (vc-dir-mark-file)
                   (cons (vc-dir-marked-files) (vc-dir-marked-only-files))
                   (vc-dir-unmark-all-files t))
             (cons (vc-dir-marked-files) (vc-dir-marked-only-files))))
          ;; Visiting an eligible file
          ((buffer-file-name)
           (cons (list buffer-file-name) (list buffer-file-name)))
          ;; No eligible file -- if there's a parent buffer, deduce from there
          ((and vc-parent-buffer (or (buffer-file-name vc-parent-buffer)
                                     (with-current-buffer vc-parent-buffer
                                       (vc-dispatcher-browsing))))
           (with-current-buffer vc-parent-buffer
             (vc-dispatcher-selection-set)))
          ;; No good set here, throw error
          (t (error "No fileset is available here")))))
    ;; We assume, in order to avoid unpleasant surprises to the user,
    ;; that a fileset is not in good shape to be handed to the user if the
    ;; buffers visiting the fileset don't match the on-disk contents.
    (if (not observer)
        (save-some-buffers
         nil (lambda () (vc-dispatcher-in-fileset-p (cdr selection)))))
    selection))

(provide 'vc-dispatcher)

;; arch-tag: 7d08b17f-5470-4799-914b-bfb9fcf6a246
;;; vc-dispatcher.el ends here