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-rw-r--r--lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php254
1 files changed, 0 insertions, 254 deletions
diff --git a/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php b/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php
deleted file mode 100644
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--- a/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php
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-<?php
-
-/**
- * Class for converting between different unit-lengths as specified by
- * CSS.
- */
-class HTMLPurifier_UnitConverter
-{
-
- const ENGLISH = 1;
- const METRIC = 2;
- const DIGITAL = 3;
-
- /**
- * Units information array. Units are grouped into measuring systems
- * (English, Metric), and are assigned an integer representing
- * the conversion factor between that unit and the smallest unit in
- * the system. Numeric indexes are actually magical constants that
- * encode conversion data from one system to the next, with a O(n^2)
- * constraint on memory (this is generally not a problem, since
- * the number of measuring systems is small.)
- */
- protected static $units = array(
- self::ENGLISH => array(
- 'px' => 3, // This is as per CSS 2.1 and Firefox. Your mileage may vary
- 'pt' => 4,
- 'pc' => 48,
- 'in' => 288,
- self::METRIC => array('pt', '0.352777778', 'mm'),
- ),
- self::METRIC => array(
- 'mm' => 1,
- 'cm' => 10,
- self::ENGLISH => array('mm', '2.83464567', 'pt'),
- ),
- );
-
- /**
- * Minimum bcmath precision for output.
- */
- protected $outputPrecision;
-
- /**
- * Bcmath precision for internal calculations.
- */
- protected $internalPrecision;
-
- /**
- * Whether or not BCMath is available
- */
- private $bcmath;
-
- public function __construct($output_precision = 4, $internal_precision = 10, $force_no_bcmath = false) {
- $this->outputPrecision = $output_precision;
- $this->internalPrecision = $internal_precision;
- $this->bcmath = !$force_no_bcmath && function_exists('bcmul');
- }
-
- /**
- * Converts a length object of one unit into another unit.
- * @param HTMLPurifier_Length $length
- * Instance of HTMLPurifier_Length to convert. You must validate()
- * it before passing it here!
- * @param string $to_unit
- * Unit to convert to.
- * @note
- * About precision: This conversion function pays very special
- * attention to the incoming precision of values and attempts
- * to maintain a number of significant figure. Results are
- * fairly accurate up to nine digits. Some caveats:
- * - If a number is zero-padded as a result of this significant
- * figure tracking, the zeroes will be eliminated.
- * - If a number contains less than four sigfigs ($outputPrecision)
- * and this causes some decimals to be excluded, those
- * decimals will be added on.
- */
- public function convert($length, $to_unit) {
-
- if (!$length->isValid()) return false;
-
- $n = $length->getN();
- $unit = $length->getUnit();
-
- if ($n === '0' || $unit === false) {
- return new HTMLPurifier_Length('0', false);
- }
-
- $state = $dest_state = false;
- foreach (self::$units as $k => $x) {
- if (isset($x[$unit])) $state = $k;
- if (isset($x[$to_unit])) $dest_state = $k;
- }
- if (!$state || !$dest_state) return false;
-
- // Some calculations about the initial precision of the number;
- // this will be useful when we need to do final rounding.
- $sigfigs = $this->getSigFigs($n);
- if ($sigfigs < $this->outputPrecision) $sigfigs = $this->outputPrecision;
-
- // BCMath's internal precision deals only with decimals. Use
- // our default if the initial number has no decimals, or increase
- // it by how ever many decimals, thus, the number of guard digits
- // will always be greater than or equal to internalPrecision.
- $log = (int) floor(log(abs($n), 10));
- $cp = ($log < 0) ? $this->internalPrecision - $log : $this->internalPrecision; // internal precision
-
- for ($i = 0; $i < 2; $i++) {
-
- // Determine what unit IN THIS SYSTEM we need to convert to
- if ($dest_state === $state) {
- // Simple conversion
- $dest_unit = $to_unit;
- } else {
- // Convert to the smallest unit, pending a system shift
- $dest_unit = self::$units[$state][$dest_state][0];
- }
-
- // Do the conversion if necessary
- if ($dest_unit !== $unit) {
- $factor = $this->div(self::$units[$state][$unit], self::$units[$state][$dest_unit], $cp);
- $n = $this->mul($n, $factor, $cp);
- $unit = $dest_unit;
- }
-
- // Output was zero, so bail out early. Shouldn't ever happen.
- if ($n === '') {
- $n = '0';
- $unit = $to_unit;
- break;
- }
-
- // It was a simple conversion, so bail out
- if ($dest_state === $state) {
- break;
- }
-
- if ($i !== 0) {
- // Conversion failed! Apparently, the system we forwarded
- // to didn't have this unit. This should never happen!
- return false;
- }
-
- // Pre-condition: $i == 0
-
- // Perform conversion to next system of units
- $n = $this->mul($n, self::$units[$state][$dest_state][1], $cp);
- $unit = self::$units[$state][$dest_state][2];
- $state = $dest_state;
-
- // One more loop around to convert the unit in the new system.
-
- }
-
- // Post-condition: $unit == $to_unit
- if ($unit !== $to_unit) return false;
-
- // Useful for debugging:
- //echo "<pre>n";
- //echo "$n\nsigfigs = $sigfigs\nnew_log = $new_log\nlog = $log\nrp = $rp\n</pre>\n";
-
- $n = $this->round($n, $sigfigs);
- if (strpos($n, '.') !== false) $n = rtrim($n, '0');
- $n = rtrim($n, '.');
-
- return new HTMLPurifier_Length($n, $unit);
- }
-
- /**
- * Returns the number of significant figures in a string number.
- * @param string $n Decimal number
- * @return int number of sigfigs
- */
- public function getSigFigs($n) {
- $n = ltrim($n, '0+-');
- $dp = strpos($n, '.'); // decimal position
- if ($dp === false) {
- $sigfigs = strlen(rtrim($n, '0'));
- } else {
- $sigfigs = strlen(ltrim($n, '0.')); // eliminate extra decimal character
- if ($dp !== 0) $sigfigs--;
- }
- return $sigfigs;
- }
-
- /**
- * Adds two numbers, using arbitrary precision when available.
- */
- private function add($s1, $s2, $scale) {
- if ($this->bcmath) return bcadd($s1, $s2, $scale);
- else return $this->scale($s1 + $s2, $scale);
- }
-
- /**
- * Multiples two numbers, using arbitrary precision when available.
- */
- private function mul($s1, $s2, $scale) {
- if ($this->bcmath) return bcmul($s1, $s2, $scale);
- else return $this->scale($s1 * $s2, $scale);
- }
-
- /**
- * Divides two numbers, using arbitrary precision when available.
- */
- private function div($s1, $s2, $scale) {
- if ($this->bcmath) return bcdiv($s1, $s2, $scale);
- else return $this->scale($s1 / $s2, $scale);
- }
-
- /**
- * Rounds a number according to the number of sigfigs it should have,
- * using arbitrary precision when available.
- */
- private function round($n, $sigfigs) {
- $new_log = (int) floor(log(abs($n), 10)); // Number of digits left of decimal - 1
- $rp = $sigfigs - $new_log - 1; // Number of decimal places needed
- $neg = $n < 0 ? '-' : ''; // Negative sign
- if ($this->bcmath) {
- if ($rp >= 0) {
- $n = bcadd($n, $neg . '0.' . str_repeat('0', $rp) . '5', $rp + 1);
- $n = bcdiv($n, '1', $rp);
- } else {
- // This algorithm partially depends on the standardized
- // form of numbers that comes out of bcmath.
- $n = bcadd($n, $neg . '5' . str_repeat('0', $new_log - $sigfigs), 0);
- $n = substr($n, 0, $sigfigs + strlen($neg)) . str_repeat('0', $new_log - $sigfigs + 1);
- }
- return $n;
- } else {
- return $this->scale(round($n, $sigfigs - $new_log - 1), $rp + 1);
- }
- }
-
- /**
- * Scales a float to $scale digits right of decimal point, like BCMath.
- */
- private function scale($r, $scale) {
- if ($scale < 0) {
- // The f sprintf type doesn't support negative numbers, so we
- // need to cludge things manually. First get the string.
- $r = sprintf('%.0f', (float) $r);
- // Due to floating point precision loss, $r will more than likely
- // look something like 4652999999999.9234. We grab one more digit
- // than we need to precise from $r and then use that to round
- // appropriately.
- $precise = (string) round(substr($r, 0, strlen($r) + $scale), -1);
- // Now we return it, truncating the zero that was rounded off.
- return substr($precise, 0, -1) . str_repeat('0', -$scale + 1);
- }
- return sprintf('%.' . $scale . 'f', (float) $r);
- }
-
-}
-
-// vim: et sw=4 sts=4