| | left | center | right
]
[
| | 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
{
protected $length;
protected $percentage;
public function HTMLPurifier_AttrDef_CSS_BackgroundPosition() {
$this->length = new HTMLPurifier_AttrDef_CSS_Length();
$this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage();
}
public function validate($string, $config, &$context) {
$string = $this->parseCDATA($string);
$bits = explode(' ', $string);
$keywords = array();
$keywords['h'] = false; // left, right
$keywords['v'] = false; // top, bottom
$keywords['c'] = false; // center
$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];
$keywords[$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[] = $keywords['h'];
elseif (count($measures)) $ret[] = array_shift($measures);
elseif ($keywords['c']) {
$ret[] = $keywords['c'];
$keywords['c'] = false; // prevent re-use: center = center center
}
if ($keywords['v']) $ret[] = $keywords['v'];
elseif (count($measures)) $ret[] = array_shift($measures);
elseif ($keywords['c']) $ret[] = $keywords['c'];
if (empty($ret)) return false;
return implode(' ', $ret);
}
}