# =========================================================
#                                                          
# (c) 2004, RenderX                                        
#                                                          
# Author: Alexander Peshkov <peshkov@renderx.com>          
#                                                          
# Permission is granted to use this document, copy and     
# modify free of charge, provided that every derived work  
# bear a reference to the present document.                
#                                                          
# This document contains a computer program written in     
# XSL Transformations Language. It is published with no    
# warranty of any kind about its usability, as a mere      
# example of XSL technology. RenderX shall not be          
# considered liable for any damage or loss of data caused  
# by use of this program.                                  
#                                                          
# =========================================================

namespace local = ""
default namespace fo = "http://www.w3.org/1999/XSL/Format"
namespace rx = "http://www.renderx.com/XSL/Extensions"

include "elements.rnc"

start = root

# ****************************************************************************************
# Element structure for top-level elements
# ****************************************************************************************
# ===============================================================
# Root element. Contains everything, generates nothing. It has an
# id, a FO namespace prefix declaration, and other namespace
# declarations if used.
# ===============================================================
root = element fo:root { root.attlist, root.content }
root.content = 
  meta-info?,
  layout-master-set,
  declarations?,
  outline?,
  page-sequence+

# ===============================================================
# Document meta information - RenderX extension
# ===============================================================
meta-info = element rx:meta-info { meta-info.attlist, meta-info.content }
meta-info.content = meta-field+ 

meta-field = element rx:meta-field { meta-field.attlist, empty }

# ===============================================================
# Color profile declarations
# ===============================================================
declarations = element fo:declarations { declarations.attlist, declarations.content }
declarations.content = color-profile+ 

color-profile = element fo:color-profile { color-profile.attlist, empty }

# ===============================================================
# Bookmarks - RenderX extension
# ===============================================================
outline = element rx:outline { outline.attlist, outline.content }
outline.content = bookmark+

bookmark = element rx:bookmark { bookmark.attlist, bookmark.content }
bookmark.content = bookmark-label, bookmark*

bookmark-label = element rx:bookmark-label { bookmark-label.attlist, bookmark-label.content }
bookmark-label.content = text

# ===============================================================
# Layout-master-set. Contains a set of page-masters.
# Content model made more strict than in the spec, to enforce
# that a page-sequence-master be always accompanied by at least
# one simple-page-master.
# ===============================================================
layout-master-set = element fo:layout-master-set { layout-master-set.attlist, layout-master-set.content }
layout-master-set.content = page-sequence-master* & simple-page-master+

# ===============================================================
# Page sequence master
# ===============================================================
page-sequence-master = 
  element fo:page-sequence-master { 
    page-sequence-master.attlist, page-sequence-master.content
  }
page-sequence-master.content = 
  (single-page-master-reference
   | repeatable-page-master-reference
   | repeatable-page-master-alternatives)+

# ===============================================================
# Sequence specifiers are predefined sequences of page masters
# that are used by page sequence master to construct a desired
# page collection.
# ===============================================================
single-page-master-reference = 
  element fo:single-page-master-reference {
    single-page-master-reference.attlist, empty
  }

repeatable-page-master-reference = 
  element fo:repeatable-page-master-reference {
    repeatable-page-master-reference.attlist, empty
  }

repeatable-page-master-alternatives = 
  element fo:repeatable-page-master-alternatives {
    repeatable-page-master-alternatives.attlist, repeatable-page-master-alternatives.content
  }
repeatable-page-master-alternatives.content = conditional-page-master-reference+

conditional-page-master-reference = 
  element fo:conditional-page-master-reference {
    conditional-page-master-reference.attlist, empty
  }

# ===============================================================
# Simple page master defines a page layout. It does not
# explicitly generate any content.
# ===============================================================
simple-page-master =
  element fo:simple-page-master {
    simple-page-master.attlist,
    simple-page-master.content
  }
simple-page-master.content =
    region-body,
    region-before?,
    region-after?,
    region-start?,
    region-end?

# ===============================================================
# Regions. The page instance is divided into subareas, whose
# properties are described by the five region-* elements. These
# elements by themselves do not generate any content.
# ===============================================================

# ===============================================================
# Body region: middle of the page.
# ===============================================================
region-body = element fo:region-body { region-body.attlist, empty }

# ===============================================================
# Side regions: page edges.
# ===============================================================

region-before = element fo:region-before { region-before.attlist, empty }
region-after = element fo:region-after { region-after.attlist, empty }
region-start = element fo:region-start { region-start.attlist, empty }
region-end = element fo:region-end { region-end.attlist, empty }

# ===============================================================
# Page sequence defines the order of choosing page masters to
# accomodate all the contents generated by its fo:flow and
# fo:static-content children, and the way of numbering them.
# ===============================================================
page-sequence = element fo:page-sequence { page-sequence.attlist, page-sequence.content }
page-sequence.content = title?, static-content*, flow

# ===============================================================
# Title. May not contain out-of-lines.
# ===============================================================
#MEMO: Spec states:
# XSL> Additionally, an fo:title is not permitted to have as a descendant an fo:block-container
# XSL> that generates an absolutely positioned area.
# We prohibit block-level descendants except for those descendats of fo:inline-container.
# This content model shared by fo:leader and fo:inline child of an fo:footnote.
title = element fo:title { title.attlist, title.content }
title.content = inlines-inline*

# ===============================================================
# Flows. They are just sequences of blocks. 'flow-name' feature
# defines linkage of the flow to a region in the page master.
# ===============================================================
# ===============================================================
# An extension element, rx:flow-section, has been added in order
# to overcome limitations on multicolumn layout imposed by XSL FO
# ===============================================================
#NOTE: We use tricks with nested grammar in order control marker/retrieve-marker 
#and outlines  appearance inside fo:static-content and fo:flow
#MEMO: We forcedly prohibit side-floats as descendants of ablsoutely positioned
# block-containers. This problem appears due to the 'half-outline' behavior of
# an absolute-container - it cannot contain outlines except for side-float and it cannot
# be nested into any other outlines.
#NOTE: 'Folint' prohibits use of side-floats in static-content that is against the spec.
static-content = element fo:static-content { static-content.attlist, static-content.content }
static-content.content = grammar {
  start = blocks+
  include "elements.rnc" {
    retrieve-marker =  retrieve-marker-real
    absolute-container = absolute-container-real
    absolute-container.content = parent absolute-container.content
    side-float = side-float-real
    float.content = parent float.content
    leader.content = parent leader.content
  }
}

flow = element fo:flow { flow.attlist, flow.content }
flow.content = grammar {
  start =marker*, (blocks | flow-section)+
  include "elements.rnc" {
    absolute-container = absolute-container-real
    #MEMO: We have two options here:
    # * use parent content model which is too strict (side-floats descendants not allowed);
    # * use current content model which is too loose (all outline descendants are allowed).
    # We prefer stricter mode.
    absolute-container.content = parent absolute-container.content
    marker = marker-real
    marker.content = parent marker.content
    side-float = side-float-real
    before-float = before-float-real
    float.content = parent float.content
    footnote = footnote-real
    footnote.content = parent footnote.content
    #NOTE: fo:leader can't have outlines and marker descendants
    leader.content = parent leader.content
  }
  # Extension element. Acts like a top-level block with multiple columns.
  flow-section = element rx:flow-section { flow-section.attlist, flow-section.content }
  flow-section.content = blocks+
}  

#MEMO: Spec prohibits use of fo:leader as a descendant of itself.
# We find this constraint somewhat abusive so we do not enforce it.
# 'Folint' also does not controll this constraint
# However following trick can be used to prevent fo:leader to appear as it's own child.
# (to make it work we have to set leader.content to be notAllowed and move
# actual content into leader.content-real in elements.rnc)
#leader.content |= grammar {
# start = leader.content-real
#  include "elements.rnc" {
#    leader = notAllowed 
#  }
#}