;; $Id: dbnavig.dsl,v 1.3 2001/07/05 12:08:42 nwalsh Exp $

;;

;; This file is part of the Modular DocBook Stylesheet distribution.

;; See ../README or http://nwalsh.com/docbook/dsssl/

;;

;; The header of a chunk has this form:

;;

;; +-----------------------------------------+

;; |               nav-banner                |

;; +------------+---------------+------------|

;; |  prevlink  |  nav-context  |  nextlink  |

;; +-----------------------------------------+

(define (nav-banner? elemnode)

  ;; This node has a banner if:

  ;; 1. There's an inherited dbhtml PI value for "banner-text" and that

  ;;    value is not the empty string, or

  ;; 2. The element is not the root element

  (let ((banner (inherited-dbhtml-value elemnode "banner-text")))

    (or (and banner (not (string=? banner "")))

	(not (node-list=? elemnode (sgml-root-element))))))

(define (nav-banner elemnode)

  (let* ((rootelem       (sgml-root-element))

	 (info           (info-element rootelem))

	 (subtitle-child (select-elements (children rootelem)

					  (normalize "subtitle")))

	 (subtitle-info  (select-elements (children info)

					  (normalize "subtitle")))

	 (subtitle       (if (node-list-empty? subtitle-info)

			     subtitle-child

			     subtitle-info))

	 (banner-text    (inherited-dbhtml-value elemnode "banner-text"))

	 (banner-href    (inherited-dbhtml-value elemnode "banner-href"))

	 (banner         (if (and banner-text (not (string=? banner-text "")))

			     (literal banner-text)

			     (make sequence

			       (element-title-sosofo rootelem)

			       (if (node-list-empty? subtitle)

				   (empty-sosofo)

				   (make sequence

				     (literal ": ")

				     (with-mode subtitle-mode

				       (process-node-list subtitle))))))))

    (make sequence

      (if banner-href

	  (make element gi: "A"

		attributes: (list (list "HREF" banner-href))

		banner)

	  banner))))

(define (nav-context? elemnode)

  ;; Print a context header if

  ;; 1. There's an inherited dbhtml PI value for "context-text" and that

  ;;    value is not the empty string, or

  ;; 2. The chunk is a top level section and the parent component 

  ;;    isn't the same as the root element (which appears in the nav-banner).

  ;;

  (let* ((context-text (inherited-dbhtml-value elemnode "context-text"))

	 (rootelem     (sgml-root-element))

	 (component    (ancestor-member elemnode

					(append (book-element-list)

						(division-element-list)

						(component-element-list))))

	 (gencontext   (and (or (equal? (gi elemnode) (normalize "sect1"))

				(equal? (gi elemnode) (normalize "section")))

			    (not (node-list=? component rootelem)))))

    (or gencontext

	(and context-text (not (string=? context-text ""))))))

(define (nav-context elemnode)

  ;; Print the context string for elemnode.  If there's an inherited

  ;; dbhtml value for 'context-text', use that.  Otherwise, use the

  ;; title of the parent component...

  (let* ((context-href  (inherited-dbhtml-value elemnode "context-href")))

    (if (nav-context? elemnode)

	(if context-href

	    (make element gi: "A"

		  attributes: (list (list "HREF" context-href))

		  (nav-context-sosofo elemnode))

	    (nav-context-sosofo elemnode))

	(empty-sosofo))))

(define (nav-context-sosofo elemnode)

  (let* ((component     (ancestor-member elemnode

					 (append (book-element-list)

						 (division-element-list)

						 (component-element-list))))

	 (context-text  (inherited-dbhtml-value elemnode "context-text")))

    (if (and context-text (not (string=? context-text "")))

	(literal context-text)

	(if (equal? (element-label component) "")

	    (make sequence

	      (element-title-sosofo component))

	    (make sequence

	      ;; Special case.  This is a bit of a hack.

	      ;; I need to revisit this aspect of 

	      ;; appendixes. 

	      (if (and (equal? (gi component) (normalize "appendix"))

		       (or (equal? (gi elemnode) (normalize "sect1"))

			   (equal? (gi elemnode) (normalize "section")))

		       (equal? (gi (parent component)) (normalize "article")))

		  (empty-sosofo)

		  (literal (gentext-element-name-space (gi component))))

	      (element-label-sosofo component)

	      (literal (gentext-label-title-sep (gi component)))

	      (element-title-sosofo component))))))

;; The footer of a chunk has this form:

;;

;; +----------------------------------------+

;; |  prevlink  |   nav-home   |  nextlink  |

;; +------------+--------------+------------|

;; |  p. title  |    nav-up    |  n. title  |

;; +-----------------------------------------+

(define (nav-home? elemnode)

  (not (node-list=? elemnode (sgml-root-element))))

(define (nav-home elemnode)

  (sgml-root-element))

(define (nav-home-link elemnode)

  (let ((home      (nav-home elemnode))

	(home-text (inherited-dbhtml-value elemnode "home-text")))

    (if (node-list=? elemnode home)

	(make entity-ref name: "nbsp")

	(make element gi: "A"

	      attributes: (list

			   (list "HREF" 

				 (href-to home))

			   (list "ACCESSKEY" "H"))

	      (if home-text

		  (literal home-text)

		  (gentext-nav-home home))))))

;; nav-up is displayed in the bottom center of the footer-navigation

;; table.  The definition below will show "Up" for nested components

;; (the component wrapping a section, the division wrapping a component

;; etc.).  It can be abused for other things, such as an index...

;;

(define (nav-up? elemnode)

  (let ((up      (parent elemnode))

	(up-text (inherited-dbhtml-value elemnode "up-text")))

    (if (and up-text (not (string=? up-text "")))

	#t

	(if (or (node-list-empty? up)

		(node-list=? up (sgml-root-element))

		(equal? (gi up) (normalize "bookinfo"))

		(equal? (gi up) (normalize "docinfo"))

		(equal? (gi up) (normalize "setinfo")))

	    #f

	    #t))))

(define (nav-up elemnode)

  (let* ((up      (parent elemnode))

	 (up-href (inherited-dbhtml-value elemnode "up-href"))

	 (uplink? (not (or (node-list-empty? up)

			   (node-list=? up (sgml-root-element)))))

	 (href    (if up-href

		      up-href

		      (if uplink?

			  (href-to up)

			  #f))))

    (if href

	(make element gi: "A"

	      attributes: (list

			   (list "HREF" href)

			   (list "ACCESSKEY" "U"))

	      (nav-up-sosofo elemnode))

	(nav-up-sosofo elemnode))))

(define (nav-up-sosofo elemnode)

  (let* ((up      (parent elemnode))

	 (up-text (inherited-dbhtml-value elemnode "up-text")))

    (if (and up-text (not (string=? up-text "")))

	(literal up-text)

	(if (or (node-list-empty? up)

		(node-list=? up (sgml-root-element)))

	    (make entity-ref name: "nbsp")

	    (gentext-nav-up up)))))

(define (nav-footer elemnode)

  (empty-sosofo))

;; ======================================================================

(define (header-navigation nd #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element nd)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element nd)

		    (list-ref navlist 1)))

	 (prevm (if (null? navlist)

		    (prev-major-component-chunk-element nd)

		    (list-ref navlist 2)))

	 (nextm (if (null? navlist)

		    (next-major-component-chunk-element nd)

		    (list-ref navlist 3)))

	 (rnavlist (list prev next prevm nextm)))

    (make sequence

      ($html-body-start$)

      (if %header-navigation%

	  (cond 

	   ((equal? (gi nd) (normalize "set"))

	    (set-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "book"))

	    (book-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "part"))

	    (part-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "preface"))

	    (preface-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "chapter"))

	    (chapter-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "article"))

	    (article-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "appendix"))

	    (appendix-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "reference"))

	    (reference-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "refentry"))

	    (refentry-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "glossary"))

	    (glossary-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "bibliography"))

	    (bibliography-header-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "index"))

	    (index-header-navigation nd rnavlist))

	   ;; LegalNotice only happens when %generate-legalnotice-link% is #t

	   ((equal? (gi nd) (normalize "legalnotice"))

	    (default-header-navigation nd

	      (empty-node-list) (empty-node-list)

	      (empty-node-list) (empty-node-list)))

	   ((member (gi nd) (section-element-list))

	    (section-header-navigation nd rnavlist))

	   (else (default-header-navigation nd prev next prevm nextm)))

	  (empty-sosofo))

      ($user-header-navigation$ prev next prevm nextm)

      ($html-body-content-start$))))

(define (footer-navigation nd #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element nd)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element nd)

		    (list-ref navlist 1)))

	 (prevm (if (null? navlist)

		    (prev-major-component-chunk-element nd)

		    (list-ref navlist 2)))

	 (nextm (if (null? navlist)

		    (next-major-component-chunk-element nd)

		    (list-ref navlist 3)))

	 (rnavlist (list prev next prevm nextm)))

    (make sequence

      (make-endnotes)

      ($html-body-content-end$)

      ($user-footer-navigation$ prev next prevm nextm)

      (if %footer-navigation%

	  (cond 

	   ((equal? (gi nd) (normalize "set"))          

	    (set-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "book"))

	    (book-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "part"))

	    (part-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "preface"))

	    (preface-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "chapter"))

	    (chapter-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "article"))

	    (article-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "appendix"))

	    (appendix-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "reference"))

	    (reference-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "refentry"))

	    (refentry-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "glossary"))

	    (glossary-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "bibliography"))

	    (bibliography-footer-navigation nd rnavlist))

	   ((equal? (gi nd) (normalize "index"))

	    (index-footer-navigation nd rnavlist))

	   ;; LegalNotice only happens when %generate-legalnotice-link% is #t

	   ((equal? (gi nd) (normalize "legalnotice"))  

	    (default-footer-navigation nd

	      (empty-node-list) (empty-node-list)

	      (empty-node-list) (empty-node-list)))

	   ((member (gi nd) (section-element-list))

	    (section-footer-navigation nd rnavlist))

	   (else (default-footer-navigation nd prev next prevm nextm)))

	  (empty-sosofo))

      (nav-footer nd)

      ($html-body-end$))))

(define (set-header-navigation elemnode #!optional (navlist '()))

  (empty-sosofo))

(define (book-header-navigation elemnode #!optional (navlist '()))

  (empty-sosofo))

(define (part-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (preface-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (chapter-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (appendix-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (article-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (if (node-list=? elemnode (sgml-root-element))

	(empty-sosofo)

	(default-header-navigation elemnode prev next prevsib nextsib))))

(define (glossary-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (bibliography-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (index-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (reference-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (refentry-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (section-header-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-header-navigation elemnode prev next prevsib nextsib)))

(define (set-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (book-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (part-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (preface-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (chapter-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (appendix-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (article-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (glossary-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (bibliography-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (index-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (reference-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (refentry-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

(define (section-footer-navigation elemnode #!optional (navlist '()))

  (let* ((prev  (if (null? navlist)

		    (prev-chunk-element elemnode)

		    (list-ref navlist 0)))

	 (next  (if (null? navlist)

		    (next-chunk-element elemnode)

		    (list-ref navlist 1)))

	 (prevsib (if (null? navlist)

		    (prev-major-component-chunk-element elemnode)

		    (list-ref navlist 2)))

	 (nextsib (if (null? navlist)

		    (next-major-component-chunk-element elemnode)

		    (list-ref navlist 3))))

    (default-footer-navigation elemnode prev next prevsib nextsib)))

;; ----------------------------------------------------------------------

(define (default-header-nav-tbl-ff elemnode prev next prevsib nextsib)

  (let* ((r1? (nav-banner? elemnode))

	 (r1-sosofo (make element gi: "TR"

			  (make element gi: "TH"

				attributes: (list

					     (list "COLSPAN" "5")

					     (list "ALIGN" "center")

					     (list "VALIGN" "bottom"))

				(nav-banner elemnode))))

	 (r2? (or (not (node-list-empty? prev))

		  (not (node-list-empty? next))

		  (not (node-list-empty? prevsib))

		  (not (node-list-empty? nextsib))

		  (nav-context? elemnode)))

	 (r2-sosofo (make element gi: "TR"

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "left")

					     (list "VALIGN" "top"))

				(if (node-list-empty? prev)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF"

							     (href-to

							      prev))

						       (list "ACCESSKEY"

							     "P"))

					  (gentext-nav-prev prev))))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "left")

					     (list "VALIGN" "top"))

				(if (node-list-empty? prevsib)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF"

							     (href-to

							      prevsib)))

					  (gentext-nav-prev-sibling prevsib))))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "60%")

					     (list "ALIGN" "center")

					     (list "VALIGN" "bottom"))

				(nav-context elemnode))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "right")

					     (list "VALIGN" "top"))

				(if (node-list-empty? nextsib)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF" 

							     (href-to

							      nextsib)))

					  (gentext-nav-next-sibling nextsib))))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "right")

					     (list "VALIGN" "top"))

				(if (node-list-empty? next)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF" 

							     (href-to

							      next))

						       (list "ACCESSKEY"

							     "N"))

					  (gentext-nav-next next)))))))

    (if (or r1? r2?)

	(make element gi: "DIV"

	      attributes: '(("CLASS" "NAVHEADER"))

	  (make element gi: "TABLE"

		attributes: (list

			     (list "SUMMARY" "Header navigation table")

			     (list "WIDTH" %gentext-nav-tblwidth%)

			     (list "BORDER" "0")

			     (list "CELLPADDING" "0")

			     (list "CELLSPACING" "0"))

		(if r1? r1-sosofo (empty-sosofo))

		(if r2? r2-sosofo (empty-sosofo)))

	  (make empty-element gi: "HR"

		attributes: (list

			     (list "ALIGN" "LEFT")

			     (list "WIDTH" %gentext-nav-tblwidth%))))

	(empty-sosofo))))

(define (default-header-nav-tbl-noff elemnode prev next prevsib nextsib)

  (let* ((r1? (nav-banner? elemnode))

	 (r1-sosofo (make element gi: "TR"

			  (make element gi: "TH"

				attributes: (list

					     (list "COLSPAN" "3")

					     (list "ALIGN" "center"))

				(nav-banner elemnode))))

	 (r2? (or (not (node-list-empty? prev))

		  (not (node-list-empty? next))

		  (nav-context? elemnode)))

	 (r2-sosofo (make element gi: "TR"

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "left")

					     (list "VALIGN" "bottom"))

				(if (node-list-empty? prev)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF" 

							     (href-to 

							      prev))

						       (list "ACCESSKEY"

							     "P"))

					  (gentext-nav-prev prev))))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "80%")

					     (list "ALIGN" "center")

					     (list "VALIGN" "bottom"))

				(nav-context elemnode))

			  (make element gi: "TD"

				attributes: (list

					     (list "WIDTH" "10%")

					     (list "ALIGN" "right")

					     (list "VALIGN" "bottom"))

				(if (node-list-empty? next)

				    (make entity-ref name: "nbsp")

				    (make element gi: "A"

					  attributes: (list

						       (list "HREF" 

							     (href-to

							      next))

						       (list "ACCESSKEY"

							     "N"))

					  (gentext-nav-next next)))))))

    (if (or r1? r2?)

	(make element gi: "DIV"

	      attributes: '(("CLASS" "NAVHEADER"))

	  (make element gi: "TABLE"

		attributes: (list

			     (list "SUMMARY" "Header navigation table")

			     (list "WIDTH" %gentext-nav-tblwidth%)

			     (list "BORDER" "0")

			     (list "CELLPADDING" "0")

			     (list "CELLSPACING" "0"))

		(if r1? r1-sosofo (empty-sosofo))

		(if r2? r2-sosofo (empty-sosofo)))

	  (make empty-element gi: "HR"

		attributes: (list

			     (list "ALIGN" "LEFT")

			     (list "WIDTH" %gentext-nav-tblwidth%))))

	(empty-sosofo))))

(define (default-header-nav-notbl-ff elemnode prev next prevsib nextsib)

  (make element gi: "DIV"

	attributes: '(("CLASS" "NAVHEADER"))

	(if (nav-banner? elemnode)

	    (make element gi: "H1"

		  (nav-banner elemnode))

	    (empty-sosofo))

	(if (and (node-list-empty? prev)

		 (node-list-empty? prevsib)

		 (node-list-empty? nextsib)

		 (node-list-empty? next))

	    (empty-sosofo)

	    (make element gi: "P"

		  (if (node-list-empty? next)

		      (empty-sosofo)

		      (make sequence 

			(make element gi: "A"

			      attributes: (list

					   (list "HREF" (href-to next))

					   (list "ACCESSKEY" "N"))

			      (gentext-nav-next next))))

		  (if (node-list-empty? prev)

		      (empty-sosofo)

		      (make sequence

			(if (node-list-empty? next)

			    (empty-sosofo)

			    (literal ", "))

			(make element gi: "A"

			      attributes: (list

					   (list "HREF" (href-to prev))

					   (list "ACCESSKEY" "P"))

			      (gentext-nav-prev prev))))

		  (if (node-list-empty? nextsib)

		      (empty-sosofo)

		      (make sequence 

			(if (and (node-list-empty? next)

				 (node-list-empty? prev))

			    (empty-sosofo)

			    (literal ", "))

			(make element gi: "A"

			      attributes: (list

					   (list "HREF" (href-to nextsib)))

			      (gentext-nav-next-sibling nextsib))))

		  (if (node-list-empty? prevsib)

		      (empty-sosofo)

		      (make sequence 

			(if (and (node-list-empty? next)