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: protected $length;
48: protected $percentage;
49:
50: public function __construct() {
51: $this->length = new HTMLPurifier_AttrDef_CSS_Length();
52: $this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage();
53: }
54:
55: public function validate($string, $config, $context) {
56: $string = $this->parseCDATA($string);
57: $bits = explode(' ', $string);
58:
59: $keywords = array();
60: $keywords['h'] = false; // left, right
61: $keywords['v'] = false; // top, bottom
62: $keywords['ch'] = false; // center (first word)
63: $keywords['cv'] = false; // center (second word)
64: $measures = array();
65:
66: $i = 0;
67:
68: $lookup = array(
69: 'top' => 'v',
70: 'bottom' => 'v',
71: 'left' => 'h',
72: 'right' => 'h',
73: 'center' => 'c'
74: );
75:
76: foreach ($bits as $bit) {
77: if ($bit === '') continue;
78:
79: // test for keyword
80: $lbit = ctype_lower($bit) ? $bit : strtolower($bit);
81: if (isset($lookup[$lbit])) {
82: $status = $lookup[$lbit];
83: if ($status == 'c') {
84: if ($i == 0) {
85: $status = 'ch';
86: } else {
87: $status = 'cv';
88: }
89: }
90: $keywords[$status] = $lbit;
91: $i++;
92: }
93:
94: // test for length
95: $r = $this->length->validate($bit, $config, $context);
96: if ($r !== false) {
97: $measures[] = $r;
98: $i++;
99: }
100:
101: // test for percentage
102: $r = $this->percentage->validate($bit, $config, $context);
103: if ($r !== false) {
104: $measures[] = $r;
105: $i++;
106: }
107:
108: }
109:
110: if (!$i) return false; // no valid values were caught
111:
112: $ret = array();
113:
114: // first keyword
115: if ($keywords['h']) $ret[] = $keywords['h'];
116: elseif ($keywords['ch']) {
117: $ret[] = $keywords['ch'];
118: $keywords['cv'] = false; // prevent re-use: center = center center
119: }
120: elseif (count($measures)) $ret[] = array_shift($measures);
121:
122: if ($keywords['v']) $ret[] = $keywords['v'];
123: elseif ($keywords['cv']) $ret[] = $keywords['cv'];
124: elseif (count($measures)) $ret[] = array_shift($measures);
125:
126: if (empty($ret)) return false;
127: return implode(' ', $ret);
128:
129: }
130:
131: }
132:
133: // vim: et sw=4 sts=4
134: