text_frame_reflower.cls.php

来自「国外很不错的一个开源OA系统Group-Office」· PHP 代码 · 共 378 行

<?php
/**
 * DOMPDF - PHP5 HTML to PDF renderer
 *
 * File: $RCSfile: text_frame_reflower.cls.php,v $
 * Created on: 2004-06-17
 *
 * Copyright (c) 2004 - Benj Carson <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library in the file LICENSE.LGPL; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307 USA
 *
 * Alternatively, you may distribute this software under the terms of the
 * PHP License, version 3.0 or later.  A copy of this license should have
 * been distributed with this file in the file LICENSE.PHP .  If this is not
 * the case, you can obtain a copy at http://www.php.net/license/3_0.txt.
 *
 * The latest version of DOMPDF might be available at:
 * http://www.digitaljunkies.ca/dompdf
 *
 * @link http://www.digitaljunkies.ca/dompdf
 * @copyright 2004 Benj Carson
 * @author Benj Carson <[e-mail]>
 * @package dompdf
 * @version 0.5.1
 */

/* $Id: text_frame_reflower.cls.php,v 1.2 2006/07/21 10:46:20 mschering Exp $ */

/**
 * Reflows text frames.
 *
 * @access private
 * @package dompdf
 */
class Text_Frame_Reflower extends Frame_Reflower {

  protected $_block_parent; // Nearest block-level ancestor

  function __construct(Text_Frame_Decorator $frame) {
    parent::__construct($frame);
    $this->_block_parent = null;
  }

  //........................................................................

  protected function _collapse_white_space($text) {
    //$text = $this->_frame->get_text();
    if ( $this->_block_parent->get_current_line("w") == 0 )
      $text = ltrim($text, " \n\r\t");
    return preg_replace("/[\s\n]+/u", " ", $text);
  }

  //........................................................................

  protected function _line_break($text) {
    $style = $this->_frame->get_style();
    $size = $style->font_size;
    $font = $style->font_family;

    // Determine the available width
    $line_width = $this->_frame->get_containing_block("w");
    $current_line_width = $this->_block_parent->get_current_line("w");

    $available_width = $line_width - $current_line_width;

    // split the text into words
    $words = preg_split('/([\s-]+)/u', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
    $wc = count($words);

    // Account for word-spacing
    $word_spacing = $style->length_in_pt($style->word_spacing);

    // Determine the frame width including margin, padding & border
    $text_width = Font_Metrics::get_text_width($text, $font, $size, $word_spacing);
    $mbp_width =
      $style->length_in_pt( array( $style->margin_left,
                                   $style->border_left_width,
                                   $style->padding_left,
                                   $style->padding_right,
                                   $style->border_right_width,
                                   $style->margin_right), $line_width );
    $frame_width = $text_width + $mbp_width;

// Debugging:
//    pre_r("Text: '" . htmlspecialchars($text). "'");
//    pre_r("width: " .$frame_width);
//    pre_r("textwidth + delta: $text_width + $mbp_width");
//    pre_r("font-size: $size");
//    pre_r("cb[w]: " .$line_width);
//    pre_r("available width: " . $available_width);
//    pre_r("current line width: " . $current_line_width);

//     pre_r($words);

    if ( $frame_width <= $available_width )
      return false;

    // Determine the split point
    $width = 0;
    $str = "";
    reset($words);

    for ($i = 0; $i < count($words); $i += 2) {
      $word = $words[$i] . (isset($words[$i+1]) ? $words[$i+1] : "");
      $word_width = Font_Metrics::get_text_width($word, $font, $size, $word_spacing);
      if ( $width + $word_width + $mbp_width > $available_width )
        break;

      $width += $word_width;
      $str .= $word;

    }

    // The first word has overflowed.   Force it onto the line
    if ( $current_line_width == 0 && $width == 0 ) {
      $width += $word_width;
      $str .= $word;
    }

    $offset = mb_strlen($str);

// More debugging:
//     pre_var_dump($str);
//     pre_r("Width: ". $width);
//     pre_r("Offset: " . $offset);

    return $offset;

  }

  //........................................................................

  protected function _newline_break($text) {

    if ( ($i = mb_strpos($text, "\n")) === false)
      return false;

    return $i+1;

  }

  //........................................................................

  protected function _layout_line() {
    $style = $this->_frame->get_style();
    $text = $this->_frame->get_text();
    $size = $style->font_size;
    $font = $style->font_family;
    $word_spacing = $style->length_in_pt($style->word_spacing);

    // Determine the text height
    $style->height = Font_Metrics::get_font_height( $font, $size );

    $split = false;
    $add_line = false;

    // Handle white-space property:
    // http://www.w3.org/TR/CSS21/text.html#propdef-white-space

    switch ($style->white_space) {

    default:
    case "normal":
      $this->_frame->set_text( $text = $this->_collapse_white_space($text) );
      if ( $text == "" )
        break;

      $split = $this->_line_break($text);
      break;

    case "pre":
      $split = $this->_newline_break($text);
      $add_line = $split !== false;
      break;

    case "nowrap":
      $this->_frame->set_text( $text = $this->_collapse_white_space($text) );
      break;

    case "pre-wrap":
      $split = $this->_newline_break($text);

      if ( ($tmp = $this->_line_break($text)) !== false ) {
        $add_line = $split < $tmp;
        $split = min($tmp, $split);
      } else
        $add_line = true;

      break;

    case "pre-line":
      // Collapse white-space except for \n
      $this->_frame->set_text( $text = preg_replace( "/[ \t]+/u", " ", $text ) );

      if ( $text == "" )
        break;

      $split = $this->_newline_break($text);

      if ( ($tmp = $this->_line_break($text)) !== false ) {
        $add_line = $split < $tmp;
        $split = min($tmp, $split);
      } else
        $add_line = true;

      break;

    }

    // Handle degenerate case
    if ( $text === "" )
      return;

    if ( $split !== false) {

      // Handle edge cases
      if ( $split == 0 && $text == " " ) {
        $this->_frame->set_text("");
        return;
      }

      if ( $split == 0 ) {

        // Trim newlines from the beginning of the line
        //$this->_frame->set_text(ltrim($text, "\n\r"));

        $this->_block_parent->add_line();
        $this->_frame->position();

        // Layout the new line
        $this->_layout_line();

      } else if ( $split < mb_strlen($this->_frame->get_text()) ) {

        // split the line if required
        $this->_frame->split_text($split);

        // Remove any trailing newlines
        $t = $this->_frame->get_text();

        if ( $split > 1 && $t{$split-1} == "\n" )
          $this->_frame->set_text( mb_substr($t, 0, -1) );

      }

      if ( $add_line ) {
        $this->_block_parent->add_line();
        $this->_frame->position();
      }

      // Set our new width
      $width = Font_Metrics::get_text_width($this->_frame->get_text(), $font, $size, $word_spacing);
      $style->width = $width;

    } else {
      // Add the current frame to the line
      $width = Font_Metrics::get_text_width($text, $font, $size, $word_spacing);
      $style->width = $width;

    }
  }

  //........................................................................

  function reflow() {

    $this->_block_parent = $this->_frame->find_block_parent();

    $this->_frame->position();

    $this->_layout_line();

  }

  //........................................................................

  // Returns an array(0 => min, 1 => max, "min" => min, "max" => max) of the
  // minimum and maximum widths of this frame
  function get_min_max_width() {

    $style = $this->_frame->get_style();
    $this->_block_parent = $this->_frame->find_block_parent();
    $line_width = $this->_frame->get_containing_block("w");

    $str = $text = $this->_frame->get_text();
    $size = $style->font_size;
    $font = $style->font_family;

    $spacing = $style->length_in_pt($style->word_spacing);

    switch($style->white_space) {

    default:
    case "normal":
      $str = preg_replace("/[\s\n]+/u"," ", $str);
    case "pre-wrap":
    case "pre-line":

      // Find the longest word (i.e. minimum length)

      // This technique (using arrays & an anonymous function) is actually
      // faster than doing a single-pass character by character scan.  Heh,
      // yes I took the time to bench it ;)
      $words = array_flip(preg_split("/[\s-]+/u",$str, -1, PREG_SPLIT_DELIM_CAPTURE));
      array_walk($words, create_function('&$val,$str',
                                         '$val = Font_Metrics::get_text_width($str, "'.$font.'", '.$size.', '.$spacing.');'));
      arsort($words);
      $min = reset($words);
      break;

    case "pre":
      $lines = array_flip(preg_split("/\n/u", $str));
      array_walk($lines, create_function('&$val,$str',
                                         '$val = Font_Metrics::get_text_width($str, "'.$font.'", '.$size.', '.$spacing.');'));

      arsort($lines);
      $min = reset($lines);
      break;

    case "nowrap":
      $min = Font_Metrics::get_text_width($this->_collapse_white_space($str), $font, $size, $spacing);
      break;

    }

    switch ($style->white_space) {

    default:
    case "normal":
    case "nowrap":
      $str = preg_replace("/[\s\n]+/u"," ", $text);
      break;

    case "pre-line":
      $str = preg_replace( "/[ \t]+/u", " ", $text);

    case "pre-wrap":
      // Find the longest word (i.e. minimum length)
      $lines = array_flip(preg_split("/\n/", $text));
      array_walk($lines, create_function('&$val,$str',
                                         '$val = Font_Metrics::get_text_width($str, "'.$font.'", '.$size.', '.$spacing.');'));
      arsort($lines);
      reset($lines);
      $str = key($lines);
      break;

    }

    $max = Font_Metrics::get_text_width($str, $font, $size, $spacing);
    
    $delta = $style->length_in_pt(array($style->margin_left,
                                        $style->border_left_width,
                                        $style->padding_left,
                                        $style->padding_right,
                                        $style->border_right_width,
                                        $style->margin_right), $line_width);
    $min += $delta;
    $max += $delta;

    return array($min, $max, "min" => $min, "max" => $max);

  }

}