<?php
/**
 * File containing the ezcDocumentDocbookToHtmlSectionHandler class.
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 * @package Document
 * @version //autogen//
 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
 */

/**
 * Visit docbook sections
 *
 * Updates the docbook sections, which give us information about the depth
 * in the document, and may also be reference targets.
 *
 * Also visits title elements, which are commonly the first element in sections
 * and define section titles, which are converted to HTML header elements of
 * the respective level of indentation
 *
 * @package Document
 * @version //autogen//
 */
class ezcDocumentDocbookToHtmlSectionHandler extends ezcDocumentDocbookToHtmlBaseHandler
{
    /**
     * Current level of indentation in the docbook document.
     *
     * @var int
     */
    protected $level = 0;

    /**
     * Handle a node
     *
     * Handle / transform a given node, and return the result of the
     * conversion.
     *
     * @param ezcDocumentElementVisitorConverter $converter
     * @param DOMElement $node
     * @param mixed $root
     * @return mixed
     */
    public function handle( ezcDocumentElementVisitorConverter $converter, DOMElement $node, $root )
    {
        if ( $node->tagName === 'title' )
        {
            // Also set the document title from the first heading
            if ( $this->level === 1 )
            {
                $head = $this->getHead( $root );
                $title = $root->ownerDocument->createElement( 'title', htmlspecialchars( trim( $node->textContent ) ) );
                $head->appendChild( $title );
            }

            // Create common HTML headers
            $header = $root->ownerDocument->createElement( 'h' . min( 6, $this->level ) );
            if ( $this->level >= 6 )
            {
                $header->setAttribute( 'class', 'h' . $this->level );
            }
            $root->appendChild( $header );

            // Recurse
            $converter->visitChildren( $node, $header );
        }
        else
        {
            ++$this->level;

            // Set internal cross reference target if section has an ID assigned
            if ( $node->hasAttribute( 'ID' ) )
            {
                $target = $root->ownerDocument->createElement( 'a' );
                $target->setAttribute( 'name', $node->getAttribute( 'ID' ) );
                $root->appendChild( $target );
            }

            // Recurse
            $converter->visitChildren( $node, $root );

            // Reduce header level back to original state after recursion
            --$this->level;
        }

        return $root;
    }
}

?>