<?php
  /**
   * DOMPDF - PHP5 HTML to PDF renderer
   *
   * File: $RCSfile: text_renderer.cls.php,v $
   * Created on: 2004-06-01
   *
   * Copyright (c) 2004 - Benj Carson <benjcarson@digitaljunkies.ca>
   *
   * 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.dompdf.com/
   *
   * @link http://www.dompdf.com/
   * @copyright 2004 Benj Carson
   * @author Benj Carson <benjcarson@digitaljunkies.ca>
   * @contributor Helmut Tischer <htischer@weihenstephan.org>
   * @package dompdf
  
   *
   * Changes
   * @contributor Helmut Tischer <htischer@weihenstephan.org>
   * @version dompdf_trunk_with_helmut_mods.20090528
   * - fix text decoration positions according to font metrics
   * @version 20090610
   * - better accuracy on using different renderer as cpdf, added comments
   */
  
  /* $Id: text_renderer.cls.php 357 2011-01-30 20:56:46Z fabien.menager $ */
  /**
   * Renders text frames
   *
   * @access private
   * @package dompdf
   */
  class Text_Renderer extends Abstract_Renderer {
    
    const DECO_THICKNESS = 0.02;     // Thickness of underline. Screen: 0.08, print: better less, e.g. 0.04
  
    //Tweaking if $base and $descent are not accurate.
    //Check method_exists( $this->_canvas, "get_cpdf" )
    //- For cpdf these can and must stay 0, because font metrics are used directly.
    //- For other renderers, if different values are wanted, separate the parameter sets.
    //  But $size and $size-$height seem to be accurate enough
    const UNDERLINE_OFFSET = 0.0;    // Relative to bottom of text, as fraction of height.
    const OVERLINE_OFFSET = 0.0;    // Relative to top of text
    const LINETHROUGH_OFFSET = 0.0; // Relative to centre of text.
    const DECO_EXTENSION = 0.0;     // How far to extend lines past either end, in pt
      
    //........................................................................
  
    function render(Frame $frame) {
      $text = $frame->get_text();
      if ( trim($text) === "" )
        return;
        
      $style = $frame->get_style();
      list($x, $y) = $frame->get_position();
      $cb = $frame->get_containing_block();
  
      if ( ($ml = $style->margin_left) === "auto" || $ml === "none" )
        $ml = 0;
  
      if ( ($pl = $style->padding_left) === "auto" || $pl === "none" )
        $pl = 0;
  
      if ( ($bl = $style->border_left_width) === "auto" || $bl === "none" )
        $bl = 0;
  
      $x += $style->length_in_pt( array($ml, $pl, $bl), $cb["w"] );
  
      $font = $style->font_family;
      $size = $frame_font_size = $style->font_size;
      $height = $style->height;    
      $word_spacing = $frame->get_text_spacing() + $style->length_in_pt($style->word_spacing);
      $char_spacing = $style->length_in_pt($style->letter_spacing);
      $width = $style->width;
  
      /*$text = str_replace(
        array("{PAGE_NUM}"),
        array($this->_canvas->get_page_number()), 
        $text
      );*/
      
      $this->_canvas->text($x, $y, $text,
                           $font, $size,
                           $style->color, $word_spacing, $char_spacing);
      
      $line = $frame->get_containing_line();
      
      // FIXME Instead of using the tallest frame to position,
      // the decoration, the text should be well placed
      if ( false && $line["tallest_frame"] ) {
        $base_frame = $line["tallest_frame"];
        $style = $base_frame->get_style();
        $size = $style->font_size;
        $height = $line["h"] * ($size / $style->line_height);
      }
      
      if ( method_exists( $this->_canvas, "get_cpdf" ) ) {
        $cpdf = $this->_canvas->get_cpdf();
        $fontBBox = $cpdf->fonts[$style->font_family]['FontBBox'];
        $base = (($fontBBox[3]*$size)/1000) * 0.90;
        $descent = ($fontBBox[1]*$size)/1000;
        //print '<pre>Text_Renderer cpdf:'.$base.' '.$descent.' '.$size.'</pre>';
      } else {
        //Descent is font part below baseline, typically negative. $height is about full height of font box.
        //$descent = -$size/6; is less accurate, depends on font family.
        // @todo Could we get font info for PDFlib adapter and others ?
        $base = $size*1.08;
        $descent = $size-$height;
        //print '<pre>Text_Renderer other than cpdf:'.$base.' '.$descent.' '.$size.'</pre>';
      }
      
      // Handle text decoration:
      // http://www.w3.org/TR/CSS21/text.html#propdef-text-decoration
      
      // Draw all applicable text-decorations.  Start with the root and work our way down.
      $p = $frame;
      $stack = array();
      while ( $p = $p->get_parent() )
        $stack[] = $p;
      
      while ( count($stack) > 0 ) {
        $f = array_pop($stack);
  
        if ( ($text_deco = $f->get_style()->text_decoration) === "none" )
          continue;
          
        $deco_y = $y; //$line["y"];
        $color = $f->get_style()->color;
  
        switch ($text_deco) {
  
        default:
          continue;
  
        case "underline":
          $deco_y += $base - $descent + $size * (self::UNDERLINE_OFFSET - self::DECO_THICKNESS/2);
          break;
  
        case "overline":
          $deco_y += $size * (self::OVERLINE_OFFSET + self::DECO_THICKNESS/2);
          break;
  
        case "line-through":
          $deco_y += $base * 0.7 + $size * self::LINETHROUGH_OFFSET;
          break;
        }
  
        $dx = 0;
        $x1 = $x - self::DECO_EXTENSION;
        $x2 = $x + $width + $dx + self::DECO_EXTENSION;
        $this->_canvas->line($x1, $deco_y, $x2, $deco_y, $color, $size * self::DECO_THICKNESS);
  
      }
      
      if (DEBUG_LAYOUT && DEBUG_LAYOUT_LINES) {
        $text_width = Font_Metrics::get_text_width($text, $font, $frame_font_size);
        $this->_debug_layout(array($x, $y, $text_width+($line["wc"]-1)*$word_spacing, $frame_font_size), "orange", array(0.5, 0.5));
      }
    }
  }