aboutsummaryrefslogtreecommitdiffstats
path: root/vendor/ezyang/htmlpurifier/library/HTMLPurifier/AttrDef/CSS/BackgroundPosition.php
blob: 4580ef5a91e48e817ff01896ec490330aa2bda9b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
<?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