[Summary view]

   1  <?php
   2  
   3  /* W3C says:

   4      [ // adjective and number must be in correct order, even if

   5        // you could switch them without introducing ambiguity.

   6        // some browsers support that syntax

   7          [

   8              <percentage> | <length> | left | center | right

   9          ]

  10          [

  11              <percentage> | <length> | top | center | bottom

  12          ]?

  13      ] |

  14      [ // this signifies that the vertical and horizontal adjectives

  15        // can be arbitrarily ordered, however, there can only be two,

  16        // one of each, or none at all

  17          [

  18              left | center | right

  19          ] ||

  20          [

  21              top | center | bottom

  22          ]

  23      ]

  24      top, left = 0%

  25      center, (none) = 50%

  26      bottom, right = 100%

  27  */
  28  
  29  /* QuirksMode says:

  30      keyword + length/percentage must be ordered correctly, as per W3C

  31  

  32      Internet Explorer and Opera, however, support arbitrary ordering. We

  33      should fix it up.

  34  

  35      Minor issue though, not strictly necessary.

  36  */
  37  
  38  // control freaks may appreciate the ability to convert these to

  39  // percentages or something, but it's not necessary

  40  
  41  /**

  42   * Validates the value of background-position.

  43   */
  44  class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef
  45  {
  46  
  47      /**

  48       * @type HTMLPurifier_AttrDef_CSS_Length

  49       */
  50      protected $length;
  51  
  52      /**

  53       * @type HTMLPurifier_AttrDef_CSS_Percentage

  54       */
  55      protected $percentage;
  56  
  57      public function __construct()
  58      {
  59          $this->length = new HTMLPurifier_AttrDef_CSS_Length();
  60          $this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage();
  61      }
  62  
  63      /**

  64       * @param string $string

  65       * @param HTMLPurifier_Config $config

  66       * @param HTMLPurifier_Context $context

  67       * @return bool|string

  68       */
  69      public function validate($string, $config, $context)
  70      {
  71          $string = $this->parseCDATA($string);
  72          $bits = explode(' ', $string);
  73  
  74          $keywords = array();
  75          $keywords['h'] = false; // left, right

  76          $keywords['v'] = false; // top, bottom

  77          $keywords['ch'] = false; // center (first word)

  78          $keywords['cv'] = false; // center (second word)

  79          $measures = array();
  80  
  81          $i = 0;
  82  
  83          $lookup = array(
  84              'top' => 'v',
  85              'bottom' => 'v',
  86              'left' => 'h',
  87              'right' => 'h',
  88              'center' => 'c'
  89          );
  90  
  91          foreach ($bits as $bit) {
  92              if ($bit === '') {
  93                  continue;
  94              }
  95  
  96              // test for keyword

  97              $lbit = ctype_lower($bit) ? $bit : strtolower($bit);
  98              if (isset($lookup[$lbit])) {
  99                  $status = $lookup[$lbit];
 100                  if ($status == 'c') {
 101                      if ($i == 0) {
 102                          $status = 'ch';
 103                      } else {
 104                          $status = 'cv';
 105                      }
 106                  }
 107                  $keywords[$status] = $lbit;
 108                  $i++;
 109              }
 110  
 111              // test for length

 112              $r = $this->length->validate($bit, $config, $context);
 113              if ($r !== false) {
 114                  $measures[] = $r;
 115                  $i++;
 116              }
 117  
 118              // test for percentage

 119              $r = $this->percentage->validate($bit, $config, $context);
 120              if ($r !== false) {
 121                  $measures[] = $r;
 122                  $i++;
 123              }
 124          }
 125  
 126          if (!$i) {
 127              return false;
 128          } // no valid values were caught

 129  
 130          $ret = array();
 131  
 132          // first keyword

 133          if ($keywords['h']) {
 134              $ret[] = $keywords['h'];
 135          } elseif ($keywords['ch']) {
 136              $ret[] = $keywords['ch'];
 137              $keywords['cv'] = false; // prevent re-use: center = center center

 138          } elseif (count($measures)) {
 139              $ret[] = array_shift($measures);
 140          }
 141  
 142          if ($keywords['v']) {
 143              $ret[] = $keywords['v'];
 144          } elseif ($keywords['cv']) {
 145              $ret[] = $keywords['cv'];
 146          } elseif (count($measures)) {
 147              $ret[] = array_shift($measures);
 148          }
 149  
 150          if (empty($ret)) {
 151              return false;
 152          }
 153          return implode(' ', $ret);
 154      }
 155  }
 156  
 157  // vim: et sw=4 sts=4