<?php

/**

 * "Inline" diff renderer.

 *

 * This class renders diffs in the Wiki-style "inline" format.

 *

 * $Horde: framework/Text_Diff/Diff/Renderer/inline.php,v 1.16 2006/01/08 00:06:57 jan Exp $

 *

 * @author  Ciprian Popovici

 * @package Text_Diff

 */

class Text_Diff_Renderer_inline extends Text_Diff_Renderer {

    /**

     * Number of leading context "lines" to preserve.

     */

    var $_leading_context_lines = 10000;

    /**

     * Number of trailing context "lines" to preserve.

     */

    var $_trailing_context_lines = 10000;

    /**

     * Prefix for inserted text.

     */

    var $_ins_prefix = '<ins>';

    /**

     * Suffix for inserted text.

     */

    var $_ins_suffix = '</ins>';

    /**

     * Prefix for deleted text.

     */

    var $_del_prefix = '<del>';

    /**

     * Suffix for deleted text.

     */

    var $_del_suffix = '</del>';

    /**

     * Header for each change block.

     */

    var $_block_header = '';

    /**

     * What are we currently splitting on? Used to recurse to show word-level

     * changes.

     */

    var $_split_level = 'words';

    function _blockHeader($xbeg, $xlen, $ybeg, $ylen)

    {

        return $this->_block_header;

    }

    function _startBlock($header)

    {

        return $header;

    }

    function _lines($lines, $prefix = ' ', $encode = true)

    {

        if ($encode) {

            array_walk($lines, array(&$this, '_encode'));

        }

        if ($this->_split_level == 'words') {

            return implode('', $lines);

        } else {

            return implode("\n", $lines) . "\n";

        }

    }

    function _added($lines)

    {

        array_walk($lines, array(&$this, '_encode'));

        $lines[0] = $this->_ins_prefix . $lines[0];

        $lines[count($lines) - 1] .= $this->_ins_suffix;

        return $this->_lines($lines, ' ', false);

    }

    function _deleted($lines, $words = false)

    {

        array_walk($lines, array(&$this, '_encode'));

        $lines[0] = $this->_del_prefix . $lines[0];

        $lines[count($lines) - 1] .= $this->_del_suffix;

        return $this->_lines($lines, ' ', false);

    }

    function _context($lines)

    {

        return "<!-- Start context -->\n<tr><td></td><td class=\"diff-context\">".$this->_lines($lines).'</td></tr>'."\n<!-- End context -->\n\n";

    }

    function _changed($orig, $final)

    {

        /* If we've already split on words, don't try to do so again - just

         * display. */

        if ($this->_split_level == 'words') {

            $prefix = '';

            while ($orig[0] !== false && $final[0] !== false &&

                   substr($orig[0], 0, 1) == ' ' &&

                   substr($final[0], 0, 1) == ' ') {

                $prefix .= substr($orig[0], 0, 1);

                $orig[0] = substr($orig[0], 1);

                $final[0] = substr($final[0], 1);

            }

            return $prefix . $this->_deleted($orig) . $this->_added($final);

        }

        $text1 = implode("\n", $orig);

        $text2 = implode("\n", $final);

        /* Non-printing newline marker. */

        $nl = "\0";

        /* We want to split on word boundaries, but we need to

         * preserve whitespace as well. Therefore we split on words,

         * but include all blocks of whitespace in the wordlist. */

        $diff = &new Text_Diff($this->_splitOnWords($text1, $nl),

                               $this->_splitOnWords($text2, $nl));

        /* Get the diff in inline format. */

        $renderer = &new Text_Diff_Renderer_inline(array_merge($this->getParams(),

                                                               array('split_level' => 'words')));

        /* Run the diff and get the output. */

        return str_replace($nl, "\n", $renderer->render($diff)) . "\n";

    }

    function _splitOnWords($string, $newlineEscape = "\n")

    {

        $words = array();

        $length = strlen($string);

        $pos = 0;

        while ($pos < $length) {

            // Eat a word with any preceding whitespace.

            $spaces = strspn(substr($string, $pos), " \n");

            $nextpos = strcspn(substr($string, $pos + $spaces), " \n");

            $words[] = str_replace("\n", $newlineEscape, substr($string, $pos, $spaces + $nextpos));

            $pos += $spaces + $nextpos;

        }

        return $words;

    }

    function _encode(&$string)

    {

        $string = htmlspecialchars($string);

    }

}