;;; psgml-html.el --- HTML mode in conjunction with PSGML

;; Copyright (C) 1994 Nelson Minar.
;; Copyright (C) 1995 Nelson Minar and Ulrik Dickow.
;; Copyright (C) 1996 Ben Wing.

;; This file is part of XEmacs.

;; XEmacs 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 2, or (at your option)
;; any later version.

;; XEmacs 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 XEmacs; see the file COPYING.  If not, write to the Free
;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Synched up with: FSF 19.30.

;;; Author: Ben Wing.

;;; Commentary:

; Parts were taken from html-helper-mode and from code by Alastair Burt.

;;; Code:

(require 'psgml)
(require 'derived)
(require 'iso-sgml)
(require 'tempo)			;essential part of html-helper-mode

;;{{{ user variables

;; Set this to be whatever signature you want on the bottom of your pages.
(defvar html-helper-address-string
  (concat "<a href=\"mailto:" user-mail-address "\">"
	  (user-full-name) "</a>")
  "*The default author string of each file.")

(defvar html-helper-htmldtd-version "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML//EN\">\n"
  "*Version of HTML DTD you're using.")

(defvar html-helper-do-write-file-hooks t
  "*If not nil, then modify `local-write-file-hooks' to do timestamps.")

(defvar html-helper-build-new-buffer t
  "*If not nil, then insert `html-helper-new-buffer-strings' for new buffers.")

(defvar html-helper-timestamp-hook 'html-helper-default-insert-timestamp
  "*Hook called for timestamp insertion.
Override this for your own timestamp styles.")

;; strings you might want to change

(defvar html-helper-new-buffer-template
  '(html-helper-htmldtd-version
    "<html>\n"
    "  <head>\n"
    "    <title>" (p "Document Title: " title) "</title>\n"
    "  </head>\n"
    "\n"
    "  <body>\n"
    "      <h1>" (s title) "</h1>\n\n"
    p
    "\n\n      <hr>\n"
    "      <address>" html-helper-address-string "</address>\n"
    (html-helper-return-created-string)
    html-helper-timestamp-start
    html-helper-timestamp-end
    "\n  </body>\n</html>\n")
  "*Template for new buffers.
Inserted by `html-helper-insert-new-buffer-strings' if
`html-helper-build-new-buffer' is set to t")

(defvar html-helper-timestamp-start "<!-- hhmts start -->\n"
  "*Start delimiter for timestamps.
Everything between `html-helper-timestamp-start' and
`html-helper-timestamp-end' will be deleted and replaced with the output
of the functions `html-helper-timestamp-hook' if
`html-helper-do-write-file-hooks' is t")

(defvar html-helper-timestamp-end "<!-- hhmts end -->"
  "*End delimiter for timestamps.
Everything between `html-helper-timestamp-start' and
`html-helper-timestamp-end' will be deleted and replaced with the output
of the function `html-helper-insert-timestamp' if
`html-helper-do-write-file-hooks' is t")

;; control over what types of tags to load. By default, we load all the
;; ones we know of.

(defvar html-helper-types-to-install
  '(anchor header logical phys list textel entity image head form)
  "*List of tag types to install when html-helper-mode is first loaded.
If you want to not install some type of tag, override this variable.
Order is significant: menus go in this order.")

;;}}} end of user variables
;;{{{ type based keymap and menu variable and function setup

;; html-helper-mode has a concept of "type" of tags. Each type is a
;; list of tags that all go together in one keymap and one menu.
;; Types can be added to the system after html-helper has been loaded,
;; briefly by doing html-helper-add-type-to-alist, then
;; html-helper-install-type, then html-helper-add-tag (for each tag)
;; then html-helper-rebuild-menu. See the mode documentation for more detail.

(defconst html-helper-type-alist nil
  "Alist: type of tag -> keymap, keybinding, menu, menu string.
Add to this with `html-helper-add-type-to-alist'.")

;;{{{ accessor functions for html-helper-type-alist

(defun html-helper-keymap-for (type)
  "Accessor function for alist: for type, return keymap or nil"
  (nth 0 (cdr-safe (assq type html-helper-type-alist))))

(defun html-helper-key-for (type)
  "Accessor function for alist: for type, return keybinding or nil"
  (nth 1 (cdr-safe (assq type html-helper-type-alist))))

(defun html-helper-menu-for (type)
  "Accessor function for alist: for type, return menu or nil"
  (nth 2 (cdr-safe (assq type html-helper-type-alist))))

(defun html-helper-menu-string-for (type)
  "Accessor function for alist: for type, return menustring or nil"
  (nth 3 (cdr-safe (assq type html-helper-type-alist))))

(defun html-helper-normalized-menu-for (type)
  "Helper function for building menus from submenus: add on string to menu."
  (cons (html-helper-menu-string-for type)
	(eval (html-helper-menu-for type))))

;;}}}

(define-derived-mode html-mode sgml-mode "HTML"
  "Major mode for editing HTML documents.
This is based on PSGML mode, and has a sophisticated SGML parser in it.
It knows how to properly indent HTML/SGML documents, and it can do
  a form of document validation (use \\[sgml-next-trouble-spot\\] to find
  the next error in your document).
Commands beginning with C-z insert various types of HTML tags
  (prompting for the required information); to iconify or suspend,
  use C-z C-z.
To literally insert special characters such as < and &, use C-c followed
  by the character.
Use \\[sgml-insert-end-tag] to insert the proper closing tag.
Use \\[sgml-edit-attributes] to edit the attributes for a tag.
Use \\[sgml-show-context] to show the current HTML context.

More specifically:
\\{html-mode-map}
"
  (make-local-variable 'sgml-declaration)
  (make-local-variable 'sgml-default-doctype-name)
  (setq sgml-declaration             (expand-file-name "html.decl"
						       sgml-data-directory)
	sgml-default-doctype-name    "html"
	sgml-always-quote-attributes t 
	sgml-indent-step             2
	sgml-indent-data	     t
	sgml-inhibit-indent-tags     '("pre")
	sgml-minimize-attributes     nil
	sgml-omittag                 t
	sgml-shortag                 t)

  ;; font-lock setup for various emacsen: XEmacs, Emacs 19.29+, Emacs <19.29.
  ;; By Ulrik Dickow <dickow@nbi.dk>.  (Last update: 05-Sep-1995).
  (cond	((string-match "XEmacs\\|Lucid" (emacs-version)) ; XEmacs/Lucid
	 (put major-mode 'font-lock-keywords-case-fold-search t))
	;; XEmacs (19.13, at least) guesses the rest correctly.
	;; If any older XEmacsen don't, then tell me.
	;;
	((string-lessp "19.28.89" emacs-version) ; Emacs 19.29 and later
	 (make-local-variable 'font-lock-defaults)
	 (setq font-lock-defaults '(html-font-lock-keywords t t)))
	;;
	(t ; Emacs 19.28 and older
	 (make-local-variable 'font-lock-keywords-case-fold-search)
	 (make-local-variable 'font-lock-keywords)
	 (make-local-variable 'font-lock-no-comments)
	 (setq font-lock-keywords-case-fold-search t)
	 (setq font-lock-keywords html-font-lock-keywords)
	 (setq font-lock-no-comments t)))
  
  (if html-helper-do-write-file-hooks
      (add-hook 'local-write-file-hooks 'html-helper-update-timestamp))

  (if (and html-helper-build-new-buffer (zerop (buffer-size)))
      (html-helper-insert-new-buffer-strings))

  (set (make-local-variable 'sgml-custom-markup)
       '(("<A>" "<A HREF=\"\">\r</a>")))
  ; sigh ...  need to call this now to get things working.
  (sgml-build-custom-menus)
  (add-submenu nil sgml-html-menu "SGML")
  (delete-menu-item '("SGML")))

(defun html-helper-add-type-to-alist (type)
  "Add a type specification to the alist.
The spec goes (type . (keymap-symbol keyprefix menu-symbol menu-string)).
See code for an example."
  (setq html-helper-type-alist (cons type html-helper-type-alist)))

;; Here are the types provided by html-helper-mode.
(mapcar 'html-helper-add-type-to-alist
  '((entity  . (nil nil html-helper-entity-menu "Insert Character Entities"))
    (textel  . (nil nil html-helper-textel-menu "Insert Text Elements"))
    (head    . (html-helper-head-map "\C-zb" html-helper-head-menu "Insert Structural Elements"))
    (header  . (html-helper-base-map "\C-z" html-helper-header-menu "Insert Headers"))
    (anchor  . (html-helper-base-map "\C-z" html-helper-anchor-menu "Insert Hyperlinks"))
    (logical . (html-helper-base-map "\C-z" html-helper-logical-menu "Insert Logical Styles"))
    (phys    . (html-helper-base-map "\C-z" html-helper-phys-menu "Insert Physical Styles"))
    (list    . (html-helper-list-map "\C-zl" html-helper-list-menu "Insert List Elements"))
    (form    . (html-helper-form-map "\C-zf" html-helper-form-menu "Insert Form Elements"))
    (image   . (html-helper-image-map "\C-zm" html-helper-image-menu "Insert Inlined Images"))))

;; Once html-helper-mode is aware of a type, it can then install the
;; type: arrange for keybindings, menus, etc.

(defconst html-helper-installed-types nil
  "The types that have been installed (used when building menus).
There is no support for removing a type once it has been installed.")

(defun html-helper-install-type (type)
  "Install a new tag type: add it to the keymap, menu structures, etc.
For this to work, the type must first have been added to the list of types
with html-helper-add-type-to-alist."
  (setq html-helper-installed-types (cons type html-helper-installed-types))
  (let ((keymap (html-helper-keymap-for type))
	(key (html-helper-key-for type))
	(menu (html-helper-menu-for type))
	(menu-string (html-helper-menu-string-for type)))
    (and key
	 (progn
	   (set keymap nil)
	   (define-prefix-command keymap)
	   (define-key html-mode-map key keymap)))
    (and menu
	 (progn
	   (set menu nil)))))

;; install the default types.
(mapcar 'html-helper-install-type html-helper-types-to-install)

;;}}}

;;{{{ html-helper-add-tag function for building basic tags

(defvar html-helper-tempo-tags nil
  "List of tags used in completion.")

;; this while loop is awfully Cish
;; isn't there an emacs lisp function to do this?
(defun html-helper-string-to-symbol (input-string)
  "Given a string, downcase it and replace spaces with -.
We use this to turn menu entries into good symbols for functions.
It's not entirely successful, but fortunately emacs lisp is forgiving."
  (let* ((s (copy-sequence input-string))
	 (l (1- (length s))))
    (while (> l 0)
      (if (char-equal (aref s l) ?\ )
	  (aset s l ?\-))
      (setq l (1- l)))
    (concat "html-" (downcase s))))


(defun html-helper-add-tag (l)
  "Add a new tag to html-helper-mode.
Builds a tempo-template for the tag and puts it into the
appropriate keymap if a key is requested. Format:
`(html-helper-add-tag '(type keybinding completion-tag menu-name template doc)'"
  (let* ((type (car l))
	 (keymap (html-helper-keymap-for type))
	 (menu (html-helper-menu-for type))
	 (key (nth 1 l))
	 (completer (nth 2 l))
	 (name (nth 3 l))
	 (tag (nth 4 l))
	 (doc (nth 5 l))
	 (command (tempo-define-template (html-helper-string-to-symbol name)
					 tag completer doc
					 'html-helper-tempo-tags)))

    (if (null (memq type html-helper-installed-types))    ;type loaded?
	t                                                 ;no, do nothing.
      (if (stringp key)			                  ;bind key somewhere?
	  (if keymap			                  ;special keymap?
	      (define-key (eval keymap) key command)      ;t:   bind to prefix
	    (define-key html-mode-map key command))	  ;nil: bind to global
	t)
      (if menu				                  ;is there a menu?
	  (set menu			                  ;good, cons it in
	       (cons (vector name command t) (eval menu))))
      )))

;;}}}

;;{{{ most of the HTML tags

;; These tags are an attempt to be HTML/2.0 compliant, with the exception
;; of container <p>, <li>, <dd>, <dt> (we adopt 3.0 behaviour).
;; For reference see <URL:http://www.w3.org/hypertext/WWW/MarkUp/MarkUp.html>

;; order here is significant: within a tag type, menus and mode help
;; go in the reverse order of what you see here. Sorry about that, it's
;; not easy to fix.

(mapcar
 'html-helper-add-tag
 '(
   ;;entities
   (entity  "\C-c#"   "&#"              "Ascii Code"      ("&#" (r "Ascii: ") ";"))
   (entity  "\C-c\""  "&quot;"          "Quotation mark"  ("&quot;"))
   (entity  "\C-c$"   "&reg;"           "Registered"      ("&reg;"))
   (entity  "\C-c@"   "&copy;"          "Copyright"       ("&copy;"))
   (entity  "\C-c-"   "&shy;"           "Soft Hyphen"     ("&shy;"))
   (entity  "\C-c "   "&nbsp;"		"Nonbreaking Space"  ("&nbsp;"))
   (entity  "\C-c&"   "&amp;"		"Ampersand"	  ("&amp;"))
   (entity  "\C-c>"   "&gt;"	  	"Greater Than"       ("&gt;"))
   (entity  "\C-c<"   "&lt;"		"Less Than"	  ("&lt;"))
   
   ;; logical styles
   (logical "q"       "<blockquote>"	"Blockquote"     	  ("<blockquote>" (r "Quote: ") "</blockquote>"))
   (logical "c"       "<code>"		"Code"           	  ("<code>" (r "Code: ") "</code>"))
   (logical "x"       "<samp>"		"Sample"         	  ("<samp>" (r "Sample code") "</samp>"))
   (logical "r"       "<cite>"		"Citation"       	  ("<cite>" (r "Citation: ") "</cite>"))
   (logical "k"       "<kbd>"		"Keyboard Input"       	  ("<kbd>" (r "Keyboard: ") "</kbd>"))
   (logical "v"       "<var>"		"Variable"       	  ("<var>" (r "Variable: ") "</var>"))
   (logical "d"       "<dfn>"		"Definition"     	  ("<dfn>" (r "Definition: ") "</dfn>"))
   (logical "a"	      "<address>"	"Address"		  ("<address>" r "</address>"))
   (logical "e"       "<em>"		"Emphasized"     	  ("<em>" (r "Text: ") "</em>"))
   (logical "s"       "<strong>"	"Strong"         	  ("<strong>" (r "Text: ") "</strong>"))
   (logical "p"       "<pre>"		"Preformatted"   	  ("<pre>" (r "Text: ") "</pre>"))

   ;;physical styles
   (phys    "-"       "<strike>"	"Strikethru"         ("<strike>" (r "Text: ") "</strike>"))
   (phys    "u"       "<u>"		"Underline"          ("<u>" (r "Text: ") "</u>"))
   (phys    "o"       "<i>"		"Italic"             ("<i>" (r "Text: ") "</i>"))
   (phys    "b"	      "<b>"    		"Bold"               ("<b>" (r "Text: ") "</b>"))
   (phys    "t"       "<tt>"		"Fixed"              ("<tt>" (r "Text: ") "</tt>"))

   ;;headers
   (header  "6"       "<h6>"		"Header 6"       	  ("<h6>" (r "Header: ") "</h6>"))
   (header  "5"       "<h5>"		"Header 5"       	  ("<h5>" (r "Header: ") "</h5>"))
   (header  "4"       "<h4>"		"Header 4"       	  ("<h4>" (r "Header: ") "</h4>"))
   (header  "3"       "<h3>"		"Header 3"       	  ("<h3>" (r "Header: ") "</h3>"))
   (header  "2"       "<h2>"		"Header 2"       	  ("<h2>" (r "Header: ") "</h2>"))
   (header  "1"	      "<h1>"     	"Header 1"       	  ("<h1>" (r "Header: ") "</h1>"))

   ;; forms
   (form    "o"       "<option>"        "Option"                 (& "<option>" > ))
   (form    "v"       "<option value"   "Option with Value"      (& "<option value=\"" (r "Value: ") "\">" >))
   (form    "s"       "<select"		"Selections"	          ("<select name=\"" (p "Name: ") "\">\n<option>" > "\n</select>")"<select")
   (form    "z"	      "<input"		"Reset Form"    	  ("<input type=\"RESET\" value=\"" (p "Reset button text: ") "\">"))
   (form    "b"	      "<input"		"Submit Form"   	  ("<input type=\"SUBMIT\" value=\"" (p "Submit button text: ") "\">"))
   (form    "i"	      "<input"		"Image Field"   	  ("<input type=\"IMAGE\" name=\"" (p "Name: ") "\" src=\"" (p "Image URL: ") "\">"))
   (form    "h"       "<input"          "Hidden Field"            ("<input type=\"HIDDEN\" name=\"" (p "Name: ") "\" value=\"" (p "Value: ") "\">"))
   (form    "p"	      "<textarea"	"Text Area"	  ("<textarea name=\"" (p "Name: ") "\" rows=\"" (p "Rows: ") "\" cols=\"" (p "Columns: ") "\">" r "</textarea>"))
   (form    "c"	      "<input"		"Checkbox"   	          ("<input type=\"CHECKBOX\" name=\"" (p "Name: ") "\">"))
   (form    "r"	      "<input"		"Radiobutton"   	  ("<input type=\"RADIO\" name=\"" (p "Name: ") "\">"))
   (form    "t"	      "<input"		"Text Field"	          ("<input type=\"TEXT\" name=\"" (p "Name: ") "\" size=\"" (p "Size: ") "\">"))
   (form    "f"	      "<form"           "Form"		          ("<form action=\"" (p "Action: ") "\" method=\"" (p "Method: ") "\">\n</form>\n"))

   ;;lists
   (list    "t"       "<dt>"            "Definition Item"         (& "<dt>" > (p "Term: ") "\n<dd>" > (r "Definition: ")))
   (list    "l"       "<li>"            "List Item"               (& "<li>" > (r "Item: ")))
   (list    "r"	      "<dir>"		"DirectoryList"      	  (& "<dir>" > "\n<li>" > (r "Item: ") "\n</dir>" >))
   (list    "m"	      "<menu>"		"Menu List"		  (& "<menu>" > "\n<li>" > (r "Item: ") "\n</menu>" >))
   (list    "o"	      "<ol>"		"Ordered List"   	  (& "<ol>" > "\n<li>" > (r "Item: ") "\n</ol>" >))
   (list    "d"	      "<dl>"		"Definition List" 	  (& "<dl>" > "\n<dt>" > (p "Term: ") "\n<dd>" > (r "Definition: ") "\n</dl>" >))
   (list    "u"	      "<ul>"		"Unordered List" 	  (& "<ul>" > "\n<li>" > (r "Item: ") "\n</ul>" >))

   ;;anchors
   (anchor  "n"	      "<a name="	"Link Target"	  ("<a name=\"" (p "Anchor name: ") "\">" (r "Anchor text: ") "</a>"))
   (anchor  "h"	      "<a href="        "Hyperlink"          	  ("<a href=\"" (p "URL: ") "\">" (r "Anchor text: ") "</a>"))                

   ;;graphics
   (image   "a"       nil               "Aligned Image"	  ("<img align=\"" (r "Alignment: ") "\" src=\"" (r "Image URL: ") "\">"))
   (image   "i"       "<img src="	"Image"		  ("<img src=\"" (r "Image URL: ") "\">"))
   (image   "e"       "<img align="     "Aligned Image With Alt. Text"	  ("<img align=\"" (r "Alignment: ") "\" src=\"" (r "Image URL: ") "\" alt=\"" (r "Text URL: ") "\">"))
   (image   "t"       "<img alt="	"Image With Alternate Text"	  ("<img alt=\"" (r "Text URL: ") "\" src=\"" (r "Image URL: ") "\">"))

   ;;text elements
   (textel  "\C-c="    nil		"Horizontal Line"	  (& "<hr>\n"))
   (textel  "\C-c\C-m" nil		"Line Break"		  ("<br>\n"))
   (textel  "\e\C-m"  nil		"Paragraph"	  ("<p>" (progn (sgml-indent-line) nil) "\n"))

   ;;head elements
   (head    "H"       "<head>"          "Head"            ("<head>\n" "</head>\n"))
   (head    "B"       "<body>"          "Body"            ("<body>\n" "</body>\n"))
   (head    "i"	      "<isindex>"	"Isindex"         ("<isindex>\n"))
   (head    "n"	      "<nextid>"	"Nextid"          ("<nextid>\n"))
   (head    "h"       "<meta http-equiv=" "HTTP Equivalent" ("<meta http-equiv=\"" (p "Equivalent: ") "\" content=\"" (r "Content: ") "\">\n"))
   (head    "m"       "<meta name="     "Meta Name"       ("<meta name=\"" (p "Name: ") "\" content=\"" (r "Content: ") "\">\n"))
   (head    "l"	      "<link"		"Link"            ("<link href=\"" p "\">"))
   (head    "b"       "<base"		"Base"            ("<base href=\"" r "\">"))
   (head    "t"	      "<title>"		"Title"           ("<title>" (r "Document title: ") "</title>"))
   ))

;;}}}
;;{{{ html-helper-smart-insert-item

;; there are two different kinds of items in HTML - those in regular
;; lists <li> and those in dictionaries <dt>..<dd>
;; This command will insert the appropriate one depending on context.

(defun html-helper-smart-insert-item (&optional arg)
  "Insert a new item, either in a regular list or a dictionary."
  (interactive "*P")
  (let ((case-fold-search t))
    (if
        (save-excursion
          (re-search-backward "<li>\\|<dt>\\|<ul>\\|<ol>\\|<dd>\\|<menu>\\|<dir>\\|<dl>" nil t)
          (looking-at "<dt>\\|<dl>\\|<dd>"))
        (tempo-template-html-definition-item arg)
      (tempo-template-html-list-item arg))))

;; special keybindings in the prefix maps (not in the list of tags)
(and (boundp 'html-helper-base-map)
     (define-key html-helper-base-map "i" 'html-helper-smart-insert-item))

(define-key html-mode-map "\C-z\C-z" 'suspend-or-iconify-emacs)
(define-key html-mode-map "\C-zg" 'html-insert-mailto-reference-from-click)

;; and, special menu bindings
(and (boundp 'html-helper-list-menu)
     (setq html-helper-list-menu
	   (cons '["List Item" html-helper-smart-insert-item t] html-helper-list-menu)))

;;}}}
;;{{{ patterns for font-lock

; Old patterns from html-mode.el
;(defvar html-font-lock-keywords
;  (list
;   '("\\(<[^>]*>\\)+" . font-lock-comment-face)
;   '("[Hh][Rr][Ee][Ff]=\"\\([^\"]*\\)\"" 1 font-lock-string-face t)
;   '("[Ss][Rr][Cc]=\"\\([^\"]*\\)\"" 1 font-lock-string-face t))
;  "Patterns to highlight in HTML buffers.")

;; By Ulrik Dickow <dickow@nbi.dk>.
;;
;; Originally aimed at Emacs 19.29.  Later on disabled syntactic fontification
;; and reordered regexps completely, to be compatible with XEmacs (it doesn't
;; understand OVERRIDE=`keep').
;;
;; We make an effort on handling nested tags intelligently.

;; font-lock compatibility with XEmacs/Lucid and older Emacsen (<19.29).
;;
(if (string-match "XEmacs\\|Lucid" (emacs-version))
    ;; XEmacs/Lucid
    ;; Make needed faces if the user hasn't already done so.
    ;; Respect X resources (`make-face' uses them when they exist).
    (let ((change-it
	   (function (lambda (face)
		       (or (if (fboundp 'facep)
			       (facep face)
			     (memq face (face-list)))
			   (make-face face))
		       (not (face-differs-from-default-p face))))))
      (if (funcall change-it 'html-helper-bold-face)
	  (copy-face 'bold 'html-helper-bold-face))
      (if (funcall change-it 'html-helper-italic-face)
	  (copy-face 'italic 'html-helper-italic-face))
      (if (funcall change-it 'html-helper-underline-face)
	  (set-face-underline-p 'html-helper-underline-face t))
      (if (funcall change-it 'font-lock-variable-name-face)
	  (set-face-foreground 'font-lock-variable-name-face "salmon"))
      (if (funcall change-it 'font-lock-reference-face)
	  (set-face-foreground 'font-lock-reference-face "violet")))
  ;; Emacs (any version)
  ;;
  ;; Note that Emacs evaluates the face entries in `font-lock-keywords',
  ;; while XEmacs doesn't.  So XEmacs doesn't use the following *variables*,
  ;; but instead the faces with the same names as the variables.
  (defvar html-helper-bold-face 'bold
    "Face used as bold.  Typically `bold'.")
  (defvar html-helper-italic-face 'italic
    "Face used as italic.  Typically `italic'.")
  (defvar html-helper-underline-face 'underline
    "Face used as underline.  Typically `underline'.")
  ;;
  (if (string-lessp "19.28.89" emacs-version)
      () ; Emacs 19.29 and later
    ;; Emacs 19.28 and older
    ;; Define face variables that don't exist until Emacs 19.29.
    (defvar font-lock-variable-name-face 'font-lock-doc-string-face
      "Face to use for variable names -- and some HTML keywords.")
    (defvar font-lock-reference-face 'underline ; Ugly at line breaks
      "Face to use for references -- including HTML hyperlink texts.")))

(defvar html-font-lock-keywords
  (let (;; Titles and H1's, like function defs.
	;;   We allow for HTML 3.0 attributes, like `<h1 align=center>'.
	(tword "\\(h1\\|title\\)\\([ \t\n]+[^>]+\\)?")
	;; Names of tags to boldify.
	(bword "\\(b\\|h[2-4]\\|strong\\)\\([ \t\n]+[^>]+\\)?")
	;; Names of tags to italify.
	(iword "\\(address\\|cite\\|em\\|i\\|var\\)\\([ \t\n]+[^>]+\\)?")
	;; Regexp to match shortest sequence that surely isn't a bold end.
	;; We simplify a bit by extending "</strong>" to "</str.*".
	;; Do similarly for non-italic and non-title ends.
	(not-bend (concat "\\([^<]\\|<\\([^/]\\|/\\([^bhs]\\|"
			  "b[^>]\\|"
			  "h\\([^2-4]\\|[2-4][^>]\\)\\|"
			  "s\\([^t]\\|t[^r]\\)\\)\\)\\)"))
	(not-iend (concat "\\([^<]\\|<\\([^/]\\|/\\([^aceiv]\\|"
			  "a\\([^d]\\|d[^d]\\)\\|"
			  "c\\([^i]\\|i[^t]\\)\\|"
			  "e\\([^m]\\|m[^>]\\)\\|"
			  "i[^>]\\|"
			  "v\\([^a]\\|a[^r]\\)\\)\\)\\)"))
	(not-tend (concat "\\([^<]\\|<\\([^/]\\|/\\([^ht]\\|"
			  "h[^1]\\|t\\([^i]\\|i[^t]\\)\\)\\)\\)")))
    (list ; Avoid use of `keep', since XEmacs will treat it the same as `t'.
     ;; First fontify the text of a HREF anchor.  It may be overridden later.
     ;; Anchors in headings will be made bold, for instance.
     '("<a\\s-+href[^>]*>\\([^>]+\\)</a>"
       1 font-lock-reference-face t)
     ;; Tag pairs like <b>...</b> etc.
     ;; Cunning repeated fontification to handle common cases of overlap.
     ;; Bold complex --- possibly with arbitrary other non-bold stuff inside.
     (list (concat "<" bword ">\\(" not-bend "*\\)</\\1>")
	   3 'html-helper-bold-face t)
     ;; Italic complex --- possibly with arbitrary non-italic kept inside.
     (list (concat "<" iword ">\\(" not-iend "*\\)</\\1>")
	   3 'html-helper-italic-face t)
     ;; Bold simple --- first fontify bold regions with no tags inside.
     (list (concat "<" bword ">\\("  "[^<]"  "*\\)</\\1>")
	   3 'html-helper-bold-face t)
     ;; Any tag, general rule, just after bold/italic stuff.
     '("\\(<[^>]*>\\)" 1 font-lock-type-face t)
     ;; Titles and level 1 headings (anchors do sometimes appear in h1's)
     (list (concat "<" tword ">\\(" not-tend "*\\)</\\1>")
	   3 'font-lock-function-name-face t)
     ;; Underline is rarely used. Only handle it when no tags inside.
     '("<u>\\([^<]*\\)</u>" 1 html-helper-underline-face t)
     ;; Forms, anchors & images (also fontify strings inside)
     '("\\(<\\(form\\|i\\(mg\\|nput\\)\\)\\>[^>]*>\\)"
       1 font-lock-variable-name-face t)
     '("</a>" 0 font-lock-keyword-face t)
     '("\\(<a\\b[^>]*>\\)" 1 font-lock-keyword-face t)
     '("=[ \t\n]*\\(\"[^\"]+\"\\)" 1 font-lock-string-face t)
     ;; Large-scale structure keywords (like "program" in Fortran).
     ;;   "<html>" "</html>" "<body>" "</body>" "<head>" "</head>" "</form>"
     '("</?\\(body\\|form\\|h\\(ead\\|tml\\)\\)>"
       0 font-lock-variable-name-face t)
     ;; HTML special characters
     '("&[^;\n]*;" 0 font-lock-string-face t)
     ;; SGML things like <!DOCTYPE ...> with possible <!ENTITY...> inside.
     '("\\(<![a-z]+\\>[^<>]*\\(<[^>]*>[^<>]*\\)*>\\)"
       1 font-lock-comment-face t)
     ;; Comments: <!-- ... -->. They traditionally override anything else.
     ;; It's complicated 'cause we won't allow "-->" inside a comment, and
     ;; font-lock colours the *longest* possible match of the regexp.
     '("\\(<!--\\([^-]\\|-[^-]\\|--[^>]\\)*-->\\)"
       1 font-lock-comment-face t)))
    "Additional expressions to highlight in HTML mode.")

(put 'html-mode 'font-lock-defaults '(html-font-lock-keywords))
(put 'html3-mode 'font-lock-defaults '(html-font-lock-keywords))

;;}}}

;;{{{ patterns for hilit19

;; Define some useful highlighting patterns for the hilit19 package.
;; These will activate only if hilit19 has already been loaded.
;; Thanks to <dickow@nbi.dk> for some pattern suggestions

(if (featurep 'hilit19)
    (hilit-set-mode-patterns
     'html-helper-mode
     '(("<!--" "-->" comment)
       ("<![a-z]+\\>[^<>]*\\(<[^>]*>[^<>]*\\)*>" nil comment) ;<!DOCTYPE ...>
       ("<title>" "</title>" defun)
       ("<h[1-6]>" "</h[1-6]>" bold) ;only colour inside tag
       ("<a\\b" ">" define)
       ("</a>" nil define)
       ("<img\\b" ">" include)
       ("<option\\|</?select\\|<input\\|</?form\\|</?textarea" ">" include)
       ;; First <i> highlighting just handles unnested tags, then do nesting
       ("<i>[^<]*</i>" nil italic)
       ("<b>" "</b>" bold)
       ("<i>" "</i>" italic)
       ("<u>" "</u>" underline)
       ("&[^;\n]*;" nil string)
       ("<" ">" keyword))
     nil 'case-insensitive)
  nil)

;;}}}

;;{{{ timestamps

(defun html-helper-update-timestamp ()
  "Basic function for updating timestamps.
It finds the timestamp in the buffer by looking for
`html-helper-timestamp-start', deletes all text up to
`html-helper-timestamp-end', and runs `html-helper-timestamp-hook' which
will should insert an appropriate timestamp in the buffer."
  (save-excursion
    (goto-char (point-max))
    (if (not (search-backward html-helper-timestamp-start nil t))
	(message "timestamp delimiter start was not found")
      (let ((ts-start (+ (point) (length html-helper-timestamp-start)))
	    (ts-end (if (search-forward html-helper-timestamp-end nil t)
			(- (point) (length html-helper-timestamp-end))
		      nil)))
	(if (not ts-end)
	    (message "timestamp delimiter end was not found. Type C-c C-t to insert one.")
	  (delete-region ts-start ts-end)
	  (goto-char ts-start)
	  (run-hooks 'html-helper-timestamp-hook)))))
  nil)

(defun html-helper-return-created-string ()
  "Return a \"Created:\" string."
  (let ((time (current-time-string)))
    (concat "<!-- Created: "
	    (substring time 0 20)
	    (nth 1 (current-time-zone))
	    " "
	    (substring time -4)
	    " -->\n")))

(defun html-helper-default-insert-timestamp ()
  "Default timestamp insertion function."
  (let ((time (current-time-string)))
    (insert "Last modified: "
	    (substring time 0 20)
	    (nth 1 (current-time-zone))
	    " "
	    (substring time -4)
	    "\n")))

(defun html-helper-insert-timestamp-delimiter-at-point ()
  "Simple function that inserts timestamp delimiters at point.
Useful for adding timestamps to existing buffers."
  (interactive)
  (insert html-helper-timestamp-start)
  (insert html-helper-timestamp-end))

;;}}}

(defun mail-address-at-point (pos &optional buffer)
  "Return a list (NAME ADDRESS) of the address at POS in BUFFER."
  (or buffer (setq buffer (current-buffer)))
  (let (beg end)
    (save-excursion
      (set-buffer buffer)
      (save-excursion
	(goto-char pos)
	(or (re-search-forward "[\n,]" nil t)
	    (error "Can't find address at position"))
	(backward-char)
	(setq end (point))
	(or (re-search-backward "[\n,:]" nil t)
	    (error "Can't find address at position"))
	(forward-char)
	(re-search-forward "[ \t]*" nil t)
	(setq beg (point))
	(mail-extract-address-components (buffer-substring beg end))))))

(defun html-insert-mailto-reference-from-click ()
  "Insert a mailto: reference for the clicked-on e-mail address."
  (interactive)
  (let (event)
    (message "Click on a mail address:")
    (save-excursion
      (setq event (next-command-event))
      (or (mouse-event-p event)
	  (error "Aborted.")))
    (let ((lis (mail-address-at-point (event-closest-point event)
				      (event-buffer event))))
      (insert "<a href=\"mailto:" (car (cdr lis)) "\">"
	      (or (car lis) (car (cdr lis))) "</a>"))))

(defun html-quote-region (begin end)
  "\"Quote\" any characters in the region that have special HTML meanings.
This converts <'s, >'s, and &'s into the HTML commands necessary to
get those characters to appear literally in the output."
  (interactive "r")
  (save-excursion
    (goto-char begin)
    (while (search-forward "&" end t)
      (forward-char -1)
      (delete-char 1)
      (insert "&amp;"))
    (goto-char begin)
    (while (search-forward "<" end t)
      (forward-char -1)
      (delete-char 1)
      (insert "&lt;"))
    (goto-char begin)
    (while (search-forward ">" end t)
      (forward-char -1)
      (delete-char 1)
      (insert "&gt;"))))

;;{{{ html-helper-insert-new-buffer-strings

(tempo-define-template "html-skeleton" html-helper-new-buffer-template
		       nil
		       "Insert a skeleton for a HTML document")

(defun html-helper-insert-new-buffer-strings ()
  "Insert `html-helper-new-buffer-strings'."
  (tempo-template-html-skeleton))

;;}}}

;;;###autoload
(autoload 'html-mode "psgml-html" "HTML mode." t)

;;;###autoload
(autoload 'html3-mode "psgml-html" "HTML3 mode." t)

(defvar sgml-html-menu
  (cons "HTML"
	(append '(["View in Netscape" sgml-html-netscape-file
		   (buffer-file-name
		    (current-buffer))]
		  ["View in W3" w3-preview-this-buffer t]
		  "---"
		  ["HTML-Quote Region" html-quote-region t]
		  "---")
		(cdr sgml-main-menu))))

(defun sgml-html-netscape-file ()
  "Preview the file for the current buffer in Netscape."
  (interactive)
  (highlight-headers-follow-url-netscape
   (concat "file:" (buffer-file-name (current-buffer)))))

(define-derived-mode html3-mode html-mode "HTML3"
  (setq sgml-declaration             (expand-file-name "html3.decl"
						       sgml-data-directory)
	sgml-default-doctype-name    "html-3"
	sgml-shortag                 nil  ))

