File indexing completed on 2024-12-22 05:36:18

 <?php
 
 /* W3C says:
     [ // adjective and number must be in correct order, even if
       // you could switch them without introducing ambiguity.
       // some browsers support that syntax
         [
             <percentage> | <length> | left | center | right
         ]
         [
             <percentage> | <length> | top | center | bottom
         ]?
     ] |
     [ // this signifies that the vertical and horizontal adjectives
       // can be arbitrarily ordered, however, there can only be two,
       // one of each, or none at all
         [
             left | center | right
         ] ||
         [
             top | center | bottom
         ]
     ]
     top, left = 0%
     center, (none) = 50%
     bottom, right = 100%
 */
 
 /* QuirksMode says:
     keyword + length/percentage must be ordered correctly, as per W3C
 
     Internet Explorer and Opera, however, support arbitrary ordering. We
     should fix it up.
 
     Minor issue though, not strictly necessary.
 */
 
 // control freaks may appreciate the ability to convert these to
 // percentages or something, but it's not necessary
 
 /**
  * Validates the value of background-position.
  */
 class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef
 {
 
     /**
      * @type HTMLPurifier_AttrDef_CSS_Length
      */
     protected $length;
 
     /**
      * @type HTMLPurifier_AttrDef_CSS_Percentage
      */
     protected $percentage;
 
     public function __construct()
     {
         $this->length = new HTMLPurifier_AttrDef_CSS_Length();
         $this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage();
     }
 
     /**
      * @param string $string
      * @param HTMLPurifier_Config $config
      * @param HTMLPurifier_Context $context
      * @return bool|string
      */
     public function validate($string, $config, $context)
     {
         $string = $this->parseCDATA($string);
         $bits = explode(' ', $string);
 
         $keywords = array();
         $keywords['h'] = false; // left, right
         $keywords['v'] = false; // top, bottom
         $keywords['ch'] = false; // center (first word)
         $keywords['cv'] = false; // center (second word)
         $measures = array();
 
         $i = 0;
 
         $lookup = array(
             'top' => 'v',
             'bottom' => 'v',
             'left' => 'h',
             'right' => 'h',
             'center' => 'c'
         );
 
         foreach ($bits as $bit) {
             if ($bit === '') {
                 continue;
             }
 
             // test for keyword
             $lbit = ctype_lower($bit) ? $bit : strtolower($bit);
             if (isset($lookup[$lbit])) {
                 $status = $lookup[$lbit];
                 if ($status == 'c') {
                     if ($i == 0) {
                         $status = 'ch';
                     } else {
                         $status = 'cv';
                     }
                 }
                 $keywords[$status] = $lbit;
                 $i++;
             }
 
             // test for length
             $r = $this->length->validate($bit, $config, $context);
             if ($r !== false) {
                 $measures[] = $r;
                 $i++;
             }
 
             // test for percentage
             $r = $this->percentage->validate($bit, $config, $context);
             if ($r !== false) {
                 $measures[] = $r;
                 $i++;
             }
         }
 
         if (!$i) {
             return false;
         } // no valid values were caught
 
         $ret = array();
 
         // first keyword
         if ($keywords['h']) {
             $ret[] = $keywords['h'];
         } elseif ($keywords['ch']) {
             $ret[] = $keywords['ch'];
             $keywords['cv'] = false; // prevent re-use: center = center center
         } elseif (count($measures)) {
             $ret[] = array_shift($measures);
         }
 
         if ($keywords['v']) {
             $ret[] = $keywords['v'];
         } elseif ($keywords['cv']) {
             $ret[] = $keywords['cv'];
         } elseif (count($measures)) {
             $ret[] = array_shift($measures);
         }
 
         if (empty($ret)) {
             return false;
         }
         return implode(' ', $ret);
     }
 }
 
 // vim: et sw=4 sts=4