Fix up comment convention on the arch-tag lines.

[bpt/emacs.git] / lisp / gnus / gnus-spec.el

;;; gnus-spec.el --- format spec functions for Gnus

;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; 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, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

;; For Emacs < 22.2.
(eval-and-compile
  (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
(eval-when-compile (require 'cl))
(defvar gnus-newsrc-file-version)

(require 'gnus)

(defcustom gnus-use-correct-string-widths (featurep 'xemacs)
  "*If non-nil, use correct functions for dealing with wide characters."
  :version "22.1"
  :group 'gnus-format
  :type 'boolean)

(defcustom gnus-make-format-preserve-properties (featurep 'xemacs)
  "*If non-nil, use a replacement `format' function which preserves
text properties. This is only needed on XEmacs, as FSF Emacs does this anyway."
  :version "22.1"
  :group 'gnus-format
  :type 'boolean)

;;; Internal variables.

(defvar gnus-summary-mark-positions nil)
(defvar gnus-group-mark-positions nil)
(defvar gnus-group-indentation "")

;; Format specs.  The chunks below are the machine-generated forms
;; that are to be evaled as the result of the default format strings.
;; We write them in here to get them byte-compiled.  That way the
;; default actions will be quite fast, while still retaining the full
;; flexibility of the user-defined format specs.

;; First we have lots of dummy defvars to let the compiler know these
;; are really dynamic variables.

(defvar gnus-tmp-unread)
(defvar gnus-tmp-replied)
(defvar gnus-tmp-score-char)
(defvar gnus-tmp-indentation)
(defvar gnus-tmp-opening-bracket)
(defvar gnus-tmp-lines)
(defvar gnus-tmp-name)
(defvar gnus-tmp-closing-bracket)
(defvar gnus-tmp-subject-or-nil)
(defvar gnus-tmp-subject)
(defvar gnus-tmp-marked)
(defvar gnus-tmp-marked-mark)
(defvar gnus-tmp-subscribed)
(defvar gnus-tmp-process-marked)
(defvar gnus-tmp-number-of-unread)
(defvar gnus-tmp-group-name)
(defvar gnus-tmp-group)
(defvar gnus-tmp-article-number)
(defvar gnus-tmp-unread-and-unselected)
(defvar gnus-tmp-news-method)
(defvar gnus-tmp-news-server)
(defvar gnus-tmp-article-number)
(defvar gnus-mouse-face)
(defvar gnus-mouse-face-prop)
(defvar gnus-tmp-header)
(defvar gnus-tmp-from)

(declare-function gnus-summary-from-or-to-or-newsgroups "gnus-sum"
                  (header gnus-tmp-from))

(defun gnus-summary-line-format-spec ()
  (insert gnus-tmp-unread gnus-tmp-replied
	  gnus-tmp-score-char gnus-tmp-indentation)
  (gnus-put-text-property
   (point)
   (progn
     (insert
      (format "%c%4s: %-23s%c" gnus-tmp-opening-bracket gnus-tmp-lines
	      (let ((val
		     (inline
		       (gnus-summary-from-or-to-or-newsgroups
			gnus-tmp-header gnus-tmp-from))))
		(if (> (length val) 23)
		    (substring val 0 23)
		  val))
	      gnus-tmp-closing-bracket))
     (point))
   gnus-mouse-face-prop gnus-mouse-face)
  (insert " " gnus-tmp-subject-or-nil "\n"))

(defvar gnus-summary-line-format-spec
  (gnus-byte-code 'gnus-summary-line-format-spec))

(defun gnus-summary-dummy-line-format-spec ()
  (insert "*  ")
  (gnus-put-text-property
   (point)
   (progn
     (insert ":				 :")
     (point))
   gnus-mouse-face-prop gnus-mouse-face)
  (insert " " gnus-tmp-subject "\n"))

(defvar gnus-summary-dummy-line-format-spec
  (gnus-byte-code 'gnus-summary-dummy-line-format-spec))

(defun gnus-group-line-format-spec ()
  (insert gnus-tmp-marked-mark gnus-tmp-subscribed
	  gnus-tmp-process-marked
	  gnus-group-indentation
	  (format "%5s: " gnus-tmp-number-of-unread))
  (gnus-put-text-property
   (point)
   (progn
     (insert gnus-tmp-group "\n")
     (1- (point)))
   gnus-mouse-face-prop gnus-mouse-face))
(defvar gnus-group-line-format-spec
  (gnus-byte-code 'gnus-group-line-format-spec))

(defvar gnus-format-specs
  `((version . ,emacs-version)
    (gnus-version . ,(gnus-continuum-version))
    (group "%M\%S\%p\%P\%5y: %(%g%)\n" ,gnus-group-line-format-spec)
    (summary-dummy "*  %(:                          :%) %S\n"
		   ,gnus-summary-dummy-line-format-spec)
    (summary "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n"
	     ,gnus-summary-line-format-spec))
  "Alist of format specs.")

(defvar gnus-default-format-specs gnus-format-specs)

(defvar gnus-article-mode-line-format-spec nil)
(defvar gnus-summary-mode-line-format-spec nil)
(defvar gnus-group-mode-line-format-spec nil)

;;; Phew.  All that gruft is over with, fortunately.

;;;###autoload
(defun gnus-update-format (var)
  "Update the format specification near point."
  (interactive
   (list
    (save-excursion
      (eval-defun nil)
      ;; Find the end of the current word.
      (re-search-forward "[ \t\n]" nil t)
      ;; Search backward.
      (when (re-search-backward "\\(gnus-[-a-z]+-line-format\\)" nil t)
	(match-string 1)))))
  (let* ((type (intern (progn (string-match "gnus-\\([-a-z]+\\)-line" var)
			      (match-string 1 var))))
	 (entry (assq type gnus-format-specs))
	 value spec)
    (when entry
      (setq gnus-format-specs (delq entry gnus-format-specs)))
    (set
     (intern (format "%s-spec" var))
     (gnus-parse-format (setq value (symbol-value (intern var)))
			(symbol-value (intern (format "%s-alist" var)))
			(not (string-match "mode" var))))
    (setq spec (symbol-value (intern (format "%s-spec" var))))
    (push (list type value spec) gnus-format-specs)

    (pop-to-buffer "*Gnus Format*")
    (erase-buffer)
    (lisp-interaction-mode)
    (insert (gnus-pp-to-string spec))))

(defun gnus-update-format-specifications (&optional force &rest types)
  "Update all (necessary) format specifications.
Return a list of updated types."
  ;; Make the indentation array.
  ;; See whether all the stored info needs to be flushed.
  (when (or force
	    (not gnus-newsrc-file-version)
	    (not (equal (gnus-continuum-version)
			(gnus-continuum-version gnus-newsrc-file-version)))
	    (not (equal emacs-version
			(cdr (assq 'version gnus-format-specs)))))
    (setq gnus-format-specs nil))
  ;; Flush the group format spec cache if there's the grouplens stuff
  ;; or it doesn't support decoded group names.
  (when (memq 'group types)
    (let* ((spec (assq 'group gnus-format-specs))
	   (sspec (gnus-prin1-to-string (nth 2 spec))))
      (when (or (string-match " gnus-tmp-grouplens[ )]" sspec)
		(not (string-match " gnus-tmp-decoded-group[ )]" sspec)))
	(setq gnus-format-specs (delq spec gnus-format-specs)))))

  ;; Go through all the formats and see whether they need updating.
  (let (new-format entry type val updated)
    (while (setq type (pop types))
      ;; Jump to the proper buffer to find out the value of the
      ;; variable, if possible.  (It may be buffer-local.)
      (save-excursion
	(let ((buffer (intern (format "gnus-%s-buffer" type))))
	  (when (and (boundp buffer)
		     (setq val (symbol-value buffer))
		     (gnus-buffer-exists-p val))
	    (set-buffer val))
	  (setq new-format (symbol-value
			    (intern (format "gnus-%s-line-format" type)))))
	(setq entry (cdr (assq type gnus-format-specs)))
	(if (and (car entry)
		 (equal (car entry) new-format))
	    ;; Use the old format.
	    (set (intern (format "gnus-%s-line-format-spec" type))
		 (cadr entry))
	  ;; This is a new format.
	  (setq val
		(if (not (stringp new-format))
		    ;; This is a function call or something.
		    new-format
		  ;; This is a "real" format.
		  (gnus-parse-format
		   new-format
		   (symbol-value
		    (intern (format "gnus-%s-line-format-alist" type)))
		   (not (string-match "mode$" (symbol-name type))))))
	  ;; Enter the new format spec into the list.
	  (if entry
	      (progn
		(setcar (cdr entry) val)
		(setcar entry new-format))
	    (push (list type new-format val) gnus-format-specs))
	  (set (intern (format "gnus-%s-line-format-spec" type)) val)
	  (push type updated))))

    (unless (assq 'version gnus-format-specs)
      (push (cons 'version emacs-version) gnus-format-specs))
    updated))

(defvar gnus-mouse-face-0 'highlight)
(defvar gnus-mouse-face-1 'highlight)
(defvar gnus-mouse-face-2 'highlight)
(defvar gnus-mouse-face-3 'highlight)
(defvar gnus-mouse-face-4 'highlight)

(defun gnus-mouse-face-function (form type)
  `(gnus-put-text-property
    (point) (progn ,@form (point))
    gnus-mouse-face-prop
    ,(if (equal type 0)
	 'gnus-mouse-face
       `(quote ,(symbol-value (intern (format "gnus-mouse-face-%d" type)))))))

(defvar gnus-face-0 'bold)
(defvar gnus-face-1 'italic)
(defvar gnus-face-2 'bold-italic)
(defvar gnus-face-3 'bold)
(defvar gnus-face-4 'bold)

(defun gnus-face-face-function (form type)
  `(gnus-add-text-properties
    (point) (progn ,@form (point))
    '(gnus-face t face ,(symbol-value (intern (format "gnus-face-%d" type))))))

(defun gnus-balloon-face-function (form type)
  `(gnus-put-text-property
    (point) (progn ,@form (point))
    ,(if (fboundp 'balloon-help-mode)
	 ''balloon-help
       ''help-echo)
    ,(intern (format "gnus-balloon-face-%d" type))))

(defun gnus-spec-tab (column)
  (if (> column 0)
      `(insert-char ?  (max (- ,column (current-column)) 0))
    (let ((column (abs column)))
      `(if (> (current-column) ,column)
	   (let ((end (point)))
	     (if (= (move-to-column ,column) ,column)
		 (delete-region (point) end)
	       (delete-region (1- (point)) end)
	       (insert " ")))
	 (insert-char ?  (max (- ,column (current-column)) 0))))))

(defun gnus-correct-length (string)
  "Return the correct width of STRING."
  (apply #'+ (mapcar #'char-width string)))

(defun gnus-correct-substring (string start &optional end)
  (let ((wstart 0)
	(wend 0)
	(wseek 0)
	(seek 0)
	(length (length string))
	(string (concat string "\0")))
    ;; Find the start position.
    (while (and (< seek length)
		(< wseek start))
      (incf wseek (char-width (aref string seek)))
      (incf seek))
    (setq wstart seek)
    ;; Find the end position.
    (while (and (<= seek length)
		(or (not end)
		    (<= wseek end)))
      (incf wseek (char-width (aref string seek)))
      (incf seek))
    (setq wend seek)
    (substring string wstart (1- wend))))

(defun gnus-string-width-function ()
  (cond
   (gnus-use-correct-string-widths
    'gnus-correct-length)
   ((fboundp 'string-width)
    'string-width)
   (t
    'length)))

(defun gnus-substring-function ()
  (cond
   (gnus-use-correct-string-widths
    'gnus-correct-substring)
   ((fboundp 'string-width)
    'gnus-correct-substring)
   (t
    'substring)))

(defun gnus-tilde-max-form (el max-width)
  "Return a form that limits EL to MAX-WIDTH."
  (let ((max (abs max-width))
	(length-fun (gnus-string-width-function))
	(substring-fun (gnus-substring-function)))
    (if (symbolp el)
	`(if (> (,length-fun ,el) ,max)
	     ,(if (< max-width 0)
		  `(,substring-fun ,el (- (,length-fun ,el) ,max))
		`(,substring-fun ,el 0 ,max))
	   ,el)
      `(let ((val (eval ,el)))
	 (if (> (,length-fun val) ,max)
	     ,(if (< max-width 0)
		  `(,substring-fun val (- (,length-fun val) ,max))
		`(,substring-fun val 0 ,max))
	   val)))))

(defun gnus-tilde-cut-form (el cut-width)
  "Return a form that cuts CUT-WIDTH off of EL."
  (let ((cut (abs cut-width))
	(length-fun (gnus-string-width-function))
	(substring-fun (gnus-substring-function)))
    (if (symbolp el)
	`(if (> (,length-fun ,el) ,cut)
	     ,(if (< cut-width 0)
		  `(,substring-fun ,el 0 (- (,length-fun ,el) ,cut))
		`(,substring-fun ,el ,cut))
	   ,el)
      `(let ((val (eval ,el)))
	 (if (> (,length-fun val) ,cut)
	     ,(if (< cut-width 0)
		  `(,substring-fun val 0 (- (,length-fun val) ,cut))
		`(,substring-fun val ,cut))
	   val)))))

(defun gnus-tilde-ignore-form (el ignore-value)
  "Return a form that is blank when EL is IGNORE-VALUE."
  (if (symbolp el)
      `(if (equal ,el ,ignore-value)
	   "" ,el)
    `(let ((val (eval ,el)))
       (if (equal val ,ignore-value)
	   "" val))))

(defun gnus-pad-form (el pad-width)
  "Return a form that pads EL to PAD-WIDTH accounting for multi-column
characters correctly. This is because `format' may pad to columns or to
characters when given a pad value."
  (let ((pad (abs pad-width))
	(side (< 0 pad-width))
	(length-fun (gnus-string-width-function)))
    (if (symbolp el)
	`(let ((need (- ,pad (,length-fun ,el))))
	   (if (> need 0)
	       (concat ,(when side '(make-string need ?\ ))
		       ,el
		       ,(when (not side) '(make-string need ?\ )))
	     ,el))
      `(let* ((val (eval ,el))
	      (need (- ,pad (,length-fun val))))
	 (if (> need 0)
	     (concat ,(when side '(make-string need ?\ ))
		     val
		     ,(when (not side) '(make-string need ?\ )))
	   val)))))

(defun gnus-parse-format (format spec-alist &optional insert)
  ;; This function parses the FORMAT string with the help of the
  ;; SPEC-ALIST and returns a list that can be eval'ed to return the
  ;; string.  If the FORMAT string contains the specifiers %( and %)
  ;; the text between them will have the mouse-face text property.
  ;; If the FORMAT string contains the specifiers %[ and %], the text between
  ;; them will have the balloon-help text property.
  (let ((case-fold-search nil))
    (if (string-match