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-rw-r--r--library/HTMLPurifier/Length.php115
1 files changed, 115 insertions, 0 deletions
diff --git a/library/HTMLPurifier/Length.php b/library/HTMLPurifier/Length.php
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+++ b/library/HTMLPurifier/Length.php
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+<?php
+
+/**
+ * Represents a measurable length, with a string numeric magnitude
+ * and a unit. This object is immutable.
+ */
+class HTMLPurifier_Length
+{
+
+ /**
+ * String numeric magnitude.
+ */
+ protected $n;
+
+ /**
+ * String unit. False is permitted if $n = 0.
+ */
+ protected $unit;
+
+ /**
+ * Whether or not this length is valid. Null if not calculated yet.
+ */
+ protected $isValid;
+
+ /**
+ * Lookup array of units recognized by CSS 2.1
+ */
+ protected static $allowedUnits = array(
+ 'em' => true, 'ex' => true, 'px' => true, 'in' => true,
+ 'cm' => true, 'mm' => true, 'pt' => true, 'pc' => true
+ );
+
+ /**
+ * @param number $n Magnitude
+ * @param string $u Unit
+ */
+ public function __construct($n = '0', $u = false) {
+ $this->n = (string) $n;
+ $this->unit = $u !== false ? (string) $u : false;
+ }
+
+ /**
+ * @param string $s Unit string, like '2em' or '3.4in'
+ * @warning Does not perform validation.
+ */
+ static public function make($s) {
+ if ($s instanceof HTMLPurifier_Length) return $s;
+ $n_length = strspn($s, '1234567890.+-');
+ $n = substr($s, 0, $n_length);
+ $unit = substr($s, $n_length);
+ if ($unit === '') $unit = false;
+ return new HTMLPurifier_Length($n, $unit);
+ }
+
+ /**
+ * Validates the number and unit.
+ */
+ protected function validate() {
+ // Special case:
+ if ($this->n === '+0' || $this->n === '-0') $this->n = '0';
+ if ($this->n === '0' && $this->unit === false) return true;
+ if (!ctype_lower($this->unit)) $this->unit = strtolower($this->unit);
+ if (!isset(HTMLPurifier_Length::$allowedUnits[$this->unit])) return false;
+ // Hack:
+ $def = new HTMLPurifier_AttrDef_CSS_Number();
+ $result = $def->validate($this->n, false, false);
+ if ($result === false) return false;
+ $this->n = $result;
+ return true;
+ }
+
+ /**
+ * Returns string representation of number.
+ */
+ public function toString() {
+ if (!$this->isValid()) return false;
+ return $this->n . $this->unit;
+ }
+
+ /**
+ * Retrieves string numeric magnitude.
+ */
+ public function getN() {return $this->n;}
+
+ /**
+ * Retrieves string unit.
+ */
+ public function getUnit() {return $this->unit;}
+
+ /**
+ * Returns true if this length unit is valid.
+ */
+ public function isValid() {
+ if ($this->isValid === null) $this->isValid = $this->validate();
+ return $this->isValid;
+ }
+
+ /**
+ * Compares two lengths, and returns 1 if greater, -1 if less and 0 if equal.
+ * @warning If both values are too large or small, this calculation will
+ * not work properly
+ */
+ public function compareTo($l) {
+ if ($l === false) return false;
+ if ($l->unit !== $this->unit) {
+ $converter = new HTMLPurifier_UnitConverter();
+ $l = $converter->convert($l, $this->unit);
+ if ($l === false) return false;
+ }
+ return $this->n - $l->n;
+ }
+
+}
+
+// vim: et sw=4 sts=4