<?xml version="1.0" encoding="UTF-8"?>
<!--

 Copyright (C) 2006-2007 Yevgen Muntyan <muntyan@tamu.edu>

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Library General Public
 License as published by the Free Software Foundation; either
 version 2 of the License, or (at your option) any later version.

 This library 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
 Library General Public License for more details.

 You should have received a copy of the GNU Library General Public
 License along with this library; if not, write to the
 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.

-->
<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">

<start>
  <element name="style-scheme">
    <attribute name="id">
      <data type="string">
        <param name="pattern">([a-zA-Z0-9_]|-)+</param>
      </data>
    </attribute>

    <choice>
      <attribute name="name"/>
      <attribute name="_name"/>
    </choice>

    <optional>
      <attribute name="parent-scheme"/>
    </optional>

    <attribute name="version">
      <value>1.0</value>
    </attribute>

    <optional>
      <oneOrMore>
        <element name="author">
          <text/>
        </element>
      </oneOrMore>        
    </optional>

    <optional>
      <choice>
        <element name="description">
          <text/>
        </element>
        <element name="_description">
          <text/>
        </element>
      </choice>
    </optional>

    <optional>
      <oneOrMore>
          <element name="color">
              <attribute name="name">
                <data type="string">
                  <param name="pattern">([a-zA-Z0-9_]|-)+</param>
                </data>
              </attribute>
              <attribute name="value">
                <data type="string">
                  <param name="pattern">#.*</param>
                </data>
              </attribute>
          </element>
      </oneOrMore>
    </optional>

    <optional>
      <oneOrMore>
          <element name="style">
              <attribute name="name"/>

              <optional>
                <choice>
                  <attribute name="use-style"/>
                  <ref name="style-elements"/>
                </choice>
              </optional>
          </element>
      </oneOrMore>
    </optional>
  </element>
</start>

<define name="boolean-value">
  <choice>
    <value>true</value>
    <value>false</value>
  </choice>
</define>

<define name="style-elements">
  <optional>
    <attribute name="foreground"/>
  </optional>
  <optional>
    <attribute name="background"/>
  </optional>
  <optional>
    <attribute name="line-background"/>
  </optional>
  <optional>
    <attribute name="bold">
      <ref name="boolean-value"/>
    </attribute>
  </optional>
  <optional>
    <attribute name="italic">
      <ref name="boolean-value"/>
    </attribute>
  </optional>
  <optional>
    <attribute name="underline">
      <ref name="boolean-value"/>
    </attribute>
  </optional>
  <optional>
    <attribute name="strikethrough">
      <ref name="boolean-value"/>
    </attribute>
  </optional>
</define>

</grammar>
