1;;; mh-compat.el --- make MH-E compatibile with various versions of Emacs 2 3;; Copyright (C) 2006, 2007 Free Software Foundation, Inc. 4 5;; Author: Bill Wohler <wohler@newt.com> 6;; Maintainer: Bill Wohler <wohler@newt.com> 7;; Keywords: mail 8;; See: mh-e.el 9 10;; This file is part of GNU Emacs. 11 12;; GNU Emacs is free software; you can redistribute it and/or modify 13;; it under the terms of the GNU General Public License as published by 14;; the Free Software Foundation; either version 2, or (at your option) 15;; any later version. 16 17;; GNU Emacs is distributed in the hope that it will be useful, 18;; but WITHOUT ANY WARRANTY; without even the implied warranty of 19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20;; GNU General Public License for more details. 21 22;; You should have received a copy of the GNU General Public License 23;; along with GNU Emacs; see the file COPYING. If not, write to the 24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 25;; Boston, MA 02110-1301, USA. 26 27;;; Commentary: 28 29;;; Change Log: 30 31;;; Code: 32 33;; This is a good place to gather code that is used for compatibility 34;; between different versions of Emacs. Please document which versions 35;; of Emacs that the defsubst, defalias, or defmacro applies. That 36;; way, it's easy to occasionally go through this file and see which 37;; macros we can retire. 38 39;; Please use mh-gnus.el when providing compatibility with different 40;; versions of Gnus. 41 42;; Items are listed alphabetically (except for mh-require which is 43;; needed sooner it would normally appear). 44 45(require 'mh-acros) 46 47(mh-do-in-gnu-emacs 48 (defalias 'mh-require 'require)) 49 50(mh-do-in-xemacs 51 (defun mh-require (feature &optional filename noerror) 52 "If feature FEATURE is not loaded, load it from FILENAME. 53If FEATURE is not a member of the list `features', then the feature 54is not loaded; so load the file FILENAME. 55If FILENAME is omitted, the printname of FEATURE is used as the file name. 56If the optional third argument NOERROR is non-nil, 57then return nil if the file is not found instead of signaling an error. 58 59Simulate NOERROR argument in XEmacs which lacks it." 60 (if (not (featurep feature)) 61 (if filename 62 (load filename noerror t) 63 (load (format "%s" feature) noerror t))))) 64 65(defun-mh mh-assoc-string assoc-string (key list case-fold) 66 "Like `assoc' but specifically for strings. 67Case is ignored if CASE-FOLD is non-nil. 68This function is used by Emacs versions that lack `assoc-string', 69introduced in Emacs 22." 70 (if case-fold 71 (assoc-ignore-case key list) 72 (assoc key list))) 73 74;; For XEmacs. 75(defalias 'mh-cancel-timer 76 (if (fboundp 'cancel-timer) 77 'cancel-timer 78 'delete-itimer)) 79 80(defun-mh mh-display-color-cells display-color-cells (&optional display) 81 "Return the number of color cells supported by DISPLAY. 82This function is used by XEmacs to return 2 when 83`device-color-cells' returns nil. This happens when compiling or 84running on a tty and causes errors since `display-color-cells' is 85expected to return an integer." 86 (or (device-color-cells display) 2)) 87 88(defmacro mh-display-completion-list (completions &optional common-substring) 89 "Display the list of COMPLETIONS. 90See documentation for `display-completion-list' for a description of the 91arguments COMPLETIONS and perhaps COMMON-SUBSTRING. 92This macro is used by Emacs versions that lack a COMMON-SUBSTRING 93argument, introduced in Emacs 22." 94 (if (< emacs-major-version 22) 95 `(display-completion-list ,completions) 96 `(display-completion-list ,completions ,common-substring))) 97 98(defmacro mh-face-foreground (face &optional frame inherit) 99 "Return the foreground color name of FACE, or nil if unspecified. 100See documentation for `face-foreground' for a description of the 101arguments FACE, FRAME, and perhaps INHERIT. 102This macro is used by Emacs versions that lack an INHERIT argument, 103introduced in Emacs 22." 104 (if (< emacs-major-version 22) 105 `(face-foreground ,face ,frame) 106 `(face-foreground ,face ,frame ,inherit))) 107 108(defmacro mh-face-background (face &optional frame inherit) 109 "Return the background color name of face, or nil if unspecified. 110See documentation for `back-foreground' for a description of the 111arguments FACE, FRAME, and INHERIT. 112This macro is used by Emacs versions that lack an INHERIT argument, 113introduced in Emacs 22." 114 (if (< emacs-major-version 22) 115 `(face-background ,face ,frame) 116 `(face-background ,face ,frame ,inherit))) 117 118(defun-mh mh-font-lock-add-keywords font-lock-add-keywords 119 (mode keywords &optional how) 120 "XEmacs does not have `font-lock-add-keywords'. 121This function returns nil on that system.") 122 123(defun-mh mh-image-load-path-for-library 124 image-load-path-for-library (library image &optional path no-error) 125 "Return a suitable search path for images used by LIBRARY. 126 127It searches for IMAGE in `image-load-path' (excluding 128\"`data-directory'/images\") and `load-path', followed by a path 129suitable for LIBRARY, which includes \"../../etc/images\" and 130\"../etc/images\" relative to the library file itself, and then 131in \"`data-directory'/images\". 132 133Then this function returns a list of directories which contains 134first the directory in which IMAGE was found, followed by the 135value of `load-path'. If PATH is given, it is used instead of 136`load-path'. 137 138If NO-ERROR is non-nil and a suitable path can't be found, don't 139signal an error. Instead, return a list of directories as before, 140except that nil appears in place of the image directory. 141 142Here is an example that uses a common idiom to provide 143compatibility with versions of Emacs that lack the variable 144`image-load-path': 145 146 ;; Shush compiler. 147 (defvar image-load-path) 148 149 (let* ((load-path (image-load-path-for-library \"mh-e\" \"mh-logo.xpm\")) 150 (image-load-path (cons (car load-path) 151 (when (boundp 'image-load-path) 152 image-load-path)))) 153 (mh-tool-bar-folder-buttons-init))" 154 (unless library (error "No library specified")) 155 (unless image (error "No image specified")) 156 (let (image-directory image-directory-load-path) 157 ;; Check for images in image-load-path or load-path. 158 (let ((img image) 159 (dir (or 160 ;; Images in image-load-path. 161 (mh-image-search-load-path image) 162 ;; Images in load-path. 163 (locate-library image))) 164 parent) 165 ;; Since the image might be in a nested directory (for 166 ;; example, mail/attach.pbm), adjust `image-directory' 167 ;; accordingly. 168 (when dir 169 (setq dir (file-name-directory dir)) 170 (while (setq parent (file-name-directory img)) 171 (setq img (directory-file-name parent) 172 dir (expand-file-name "../" dir)))) 173 (setq image-directory-load-path dir)) 174 175 ;; If `image-directory-load-path' isn't Emacs' image directory, 176 ;; it's probably a user preference, so use it. Then use a 177 ;; relative setting if possible; otherwise, use 178 ;; `image-directory-load-path'. 179 (cond 180 ;; User-modified image-load-path? 181 ((and image-directory-load-path 182 (not (equal image-directory-load-path 183 (file-name-as-directory 184 (expand-file-name "images" data-directory))))) 185 (setq image-directory image-directory-load-path)) 186 ;; Try relative setting. 187 ((let (library-name d1ei d2ei) 188 ;; First, find library in the load-path. 189 (setq library-name (locate-library library)) 190 (if (not library-name) 191 (error "Cannot find library %s in load-path" library)) 192 ;; And then set image-directory relative to that. 193 (setq 194 ;; Go down 2 levels. 195 d2ei (file-name-as-directory 196 (expand-file-name 197 (concat (file-name-directory library-name) "../../etc/images"))) 198 ;; Go down 1 level. 199 d1ei (file-name-as-directory 200 (expand-file-name 201 (concat (file-name-directory library-name) "../etc/images")))) 202 (setq image-directory 203 ;; Set it to nil if image is not found. 204 (cond ((file-exists-p (expand-file-name image d2ei)) d2ei) 205 ((file-exists-p (expand-file-name image d1ei)) d1ei))))) 206 ;; Use Emacs' image directory. 207 (image-directory-load-path 208 (setq image-directory image-directory-load-path)) 209 (no-error 210 (message "Could not find image %s for library %s" image library)) 211 (t 212 (error "Could not find image %s for library %s" image library))) 213 214 ;; Return an augmented `path' or `load-path'. 215 (nconc (list image-directory) 216 (delete image-directory (copy-sequence (or path load-path)))))) 217 218(defun-mh mh-image-search-load-path 219 image-search-load-path (file &optional path) 220 "Emacs 21 and XEmacs don't have `image-search-load-path'. 221This function returns nil on those systems." 222 nil) 223 224;; For XEmacs. 225(defalias 'mh-line-beginning-position 226 (if (fboundp 'line-beginning-position) 227 'line-beginning-position 228 'point-at-bol)) 229 230;; For XEmacs. 231(defalias 'mh-line-end-position 232 (if (fboundp 'line-end-position) 233 'line-end-position 234 'point-at-eol)) 235 236(mh-require 'mailabbrev nil t) 237(defun-mh mh-mail-abbrev-make-syntax-table 238 mail-abbrev-make-syntax-table () 239 "Emacs 21 and XEmacs don't have `mail-abbrev-make-syntax-table'. 240This function returns nil on those systems." 241 nil) 242 243(defun-mh mh-match-string-no-properties 244 match-string-no-properties (num &optional string) 245 "Return string of text matched by last search, without text properties. 246This function is used by XEmacs that lacks `match-string-no-properties'. 247The function `buffer-substring-no-properties' is used instead. 248The argument STRING is ignored." 249 (buffer-substring-no-properties 250 (match-beginning num) (match-end num))) 251 252(defun-mh mh-replace-regexp-in-string replace-regexp-in-string 253 (regexp rep string &optional fixedcase literal subexp start) 254 "Replace REGEXP with REP everywhere in STRING and return result. 255This function is used by XEmacs that lacks `replace-regexp-in-string'. 256The function `replace-in-string' is used instead. 257The arguments FIXEDCASE, SUBEXP, and START, used by 258`replace-in-string' are ignored." 259 (replace-in-string string regexp rep literal)) 260 261;; Copy of constant from url-util.el in Emacs 22; needed by Emacs 21. 262(if (not (boundp 'url-unreserved-chars)) 263 (defconst mh-url-unreserved-chars 264 '( 265 ?a ?b ?c ?d ?e ?f ?g ?h ?i ?j ?k ?l ?m ?n ?o ?p ?q ?r ?s ?t ?u ?v ?w ?x ?y ?z 266 ?A ?B ?C ?D ?E ?F ?G ?H ?I ?J ?K ?L ?M ?N ?O ?P ?Q ?R ?S ?T ?U ?V ?W ?X ?Y ?Z 267 ?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9 268 ?- ?_ ?. ?! ?~ ?* ?' ?\( ?\)) 269 "A list of characters that are _NOT_ reserved in the URL spec. 270This is taken from RFC 2396.")) 271 272(defun-mh mh-url-hexify-string url-hexify-string (str) 273 "Escape characters in a string. 274This is a copy of `url-hexify-string' from url-util.el in Emacs 27522; needed by Emacs 21." 276 (mapconcat 277 (lambda (char) 278 ;; Fixme: use a char table instead. 279 (if (not (memq char mh-url-unreserved-chars)) 280 (if (> char 255) 281 (error "Hexifying multibyte character %s" str) 282 (format "%%%02X" char)) 283 (char-to-string char))) 284 str "")) 285 286(defun-mh mh-view-mode-enter 287 view-mode-enter (&optional return-to exit-action) 288 "Enter View mode. 289This function is used by XEmacs that lacks `view-mode-enter'. 290The function `view-mode' is used instead. 291The arguments RETURN-TO and EXIT-ACTION are ignored." 292 ;; Shush compiler. 293 (if return-to nil) 294 (if exit-action nil) 295 (view-mode 1)) 296 297(defmacro mh-write-file-functions () 298 "Return `write-file-functions' if it exists. 299Otherwise return `local-write-file-hooks'. 300This macro exists purely for compatibility. The former symbol is used 301in Emacs 22 onward while the latter is used in previous versions and 302XEmacs." 303 (if (boundp 'write-file-functions) 304 ''write-file-functions ;Emacs 22 on 305 ''local-write-file-hooks)) ;XEmacs 306 307(provide 'mh-compat) 308 309;; Local Variables: 310;; no-byte-compile: t 311;; indent-tabs-mode: nil 312;; sentence-end-double-space: nil 313;; End: 314 315;; arch-tag: 577b0eab-a5cd-45e1-8d9f-c1a426f4d73c 316;;; mh-compat.el ends here 317