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See Release Notes

  • Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
  • Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.
<?php
/**
 * RTLCSS.
 *
 * @package   MoodleHQ\RTLCSS
 * @copyright 2016 Frédéric Massart - FMCorz.net
 * @license   https://opensource.org/licenses/MIT MIT
 */

namespace MoodleHQ\RTLCSS;

use Sabberworm\CSS\CSSList\CSSList;
use Sabberworm\CSS\CSSList\Document;
use Sabberworm\CSS\OutputFormat;
use Sabberworm\CSS\Parser;
use Sabberworm\CSS\Rule\Rule;
use Sabberworm\CSS\RuleSet\RuleSet;
use Sabberworm\CSS\Settings;
use Sabberworm\CSS\Value\CSSFunction;
use Sabberworm\CSS\Value\CSSString;
use Sabberworm\CSS\Value\PrimitiveValue;
use Sabberworm\CSS\Value\RuleValueList;
use Sabberworm\CSS\Value\Size;
use Sabberworm\CSS\Value\ValueList;

/**
 * RTLCSS Class.
 *
 * @package   MoodleHQ\RTLCSS
 * @copyright 2016 Frédéric Massart - FMCorz.net
 * @license   https://opensource.org/licenses/MIT MIT
 */
class RTLCSS {

    protected $tree;
    protected $shouldAddCss = [];
    protected $shouldIgnore = false;
    protected $shouldRemove = false;

    public function __construct(Document $tree) {
        $this->tree = $tree;
    }

    protected function compare($what, $to, $ignoreCase) {
        if ($ignoreCase) {
            return strtolower($what) === strtolower($to);
        }
        return $what === $to;
    }

    protected function complement($value) {
        if ($value instanceof Size) {
            $value->setSize(100 - $value->getSize());

        } else if ($value instanceof CSSFunction) {
            $arguments = implode($value->getListSeparator(), $value->getArguments());
            $arguments = "100% - ($arguments)";
            $value->setListComponents([$arguments]);
        }
    }

    public function flip() {
        $this->processBlock($this->tree);
        return $this->tree;
    }

    protected function negate($value) {
        if ($value instanceof ValueList) {
            foreach ($value->getListComponents() as $part) {
                $this->negate($part);
            }
        } else if ($value instanceof Size) {
            if ($value->getSize() != 0) {
                $value->setSize(-$value->getSize());
            }
        }
    }

    protected function parseComments(array $comments) {
        $startRule = '^(\s|\*)*!?rtl:';
        foreach ($comments as $comment) {
            $content = $comment->getComment();
            if (preg_match('/' . $startRule . 'ignore/', $content)) {
                $this->shouldIgnore = 1;
            } else if (preg_match('/' . $startRule . 'begin:ignore/', $content)) {
                $this->shouldIgnore = true;
            } else if (preg_match('/' . $startRule . 'end:ignore/', $content)) {
                $this->shouldIgnore = false;
            } else if (preg_match('/' . $startRule . 'remove/', $content)) {
                $this->shouldRemove = 1;
            } else if (preg_match('/' . $startRule . 'begin:remove/', $content)) {
                $this->shouldRemove = true;
            } else if (preg_match('/' . $startRule . 'end:remove/', $content)) {
                $this->shouldRemove = false;
            } else if (preg_match('/' . $startRule . 'raw:/', $content)) {
                $this->shouldAddCss[] = preg_replace('/' . $startRule . 'raw:/', '', $content);
            }
        }
    }

    protected function processBackground(Rule $rule) {
        $value = $rule->getValue();

        // TODO Fix upstream library as it does not parse this well, commas don't take precedence.
        // There can be multiple sets of properties per rule.
        $hasItems = false;
        $items = [$value];
        if ($value instanceof RuleValueList && $value->getListSeparator() == ',') {
            $hasItems = true;
            $items = $value->getListComponents();
        }

        // Foreach set.
        foreach ($items as $itemKey => $item) {

            // There can be multiple values in the same set.
            $hasValues = false;
            $parts = [$item];
            if ($item instanceof RuleValueList) {
                $hasValues = true;
                $parts = $value->getListComponents();
            }

            $requiresPositionalArgument = false;
            $hasPositionalArgument = false;
            foreach ($parts as $key => $part) {
                $part = $parts[$key];

                if (!is_object($part)) {
                    $flipped = $this->swapLeftRight($part);

                    // Positional arguments can have a size following.
                    $hasPositionalArgument = $parts[$key] != $flipped;
                    $requiresPositionalArgument = true;

                    $parts[$key] = $flipped;
                    continue;

                } else if ($part instanceof CSSFunction && strpos($part->getName(), 'gradient') !== false) {
                    // TODO Fix this.

                } else if ($part instanceof Size && ($part->getUnit() === '%' || !$part->getUnit())) {

                    // Is this a value we're interested in?
                    if (!$requiresPositionalArgument || $hasPositionalArgument) {
                        $this->complement($part);
                        $part->setUnit('%');
                        // We only need to change one value.
                        break;
                    }

                }

                $hasPositionalArgument = false;
            }

            if ($hasValues) {
                $item->setListComponents($parts);
            } else {
                $items[$itemKey] = $parts[$key];
            }
        }

        if ($hasItems) {
            $value->setListComponents($items);
        } else {
            $rule->setValue($items[0]);
        }
    }

    protected function processBlock($block) {
        $contents = [];

        foreach ($block->getContents() as $node) {
            $this->parseComments($node->getComments());

            if ($toAdd = $this->shouldAddCss()) {
                foreach ($toAdd as $add) {
                    $parser = new Parser($add);
                    $contents[] = $parser->parse();
                }
            }

            if ($this->shouldRemoveNext()) {
                continue;

            } else if (!$this->shouldIgnoreNext()) {
                if ($node instanceof CSSList) {
                    $this->processBlock($node);
                }
                if ($node instanceof RuleSet) {
                    $this->processDeclaration($node);
                }
            }

            $contents[] = $node;
        }

        $block->setContents($contents);
    }

    protected function processDeclaration($node) {
        $rules = [];

        foreach ($node->getRules() as $key => $rule) {
            $this->parseComments($rule->getComments());

            if ($toAdd = $this->shouldAddCss()) {
                foreach ($toAdd as $add) {
                    $parser = new Parser('.wrapper{' . $add . '}');
                    $tree = $parser->parse();
                    $contents = $tree->getContents();
                    foreach ($contents[0]->getRules() as $newRule) {
                        $rules[] = $newRule;
                    }
                }
            }

            if ($this->shouldRemoveNext()) {
                continue;

            } else if (!$this->shouldIgnoreNext()) {
                $this->processRule($rule);
            }

            $rules[] = $rule;
        }

        $node->setRules($rules);
    }

    protected function processRule($rule) {
        $property = $rule->getRule();
        $value = $rule->getValue();

        if (preg_match('/direction$/im', $property)) {
            $rule->setValue($this->swapLtrRtl($value));

        } else if (preg_match('/left/im', $property)) {
            $rule->setRule(str_replace('left', 'right', $property));

        } else if (preg_match('/right/im', $property)) {
            $rule->setRule(str_replace('right', 'left', $property));

        } else if (preg_match('/transition(-property)?$/i', $property)) {
            $rule->setValue($this->swapLeftRight($value));

        } else if (preg_match('/float|clear|text-align/i', $property)) {
            $rule->setValue($this->swapLeftRight($value));

        } else if (preg_match('/^(margin|padding|border-(color|style|width))$/i', $property)) {

            if ($value instanceof RuleValueList) {
                $values = $value->getListComponents();
                $count = count($values);
                if ($count == 4) {
                    $right = $values[3];
                    $values[3] = $values[1];
                    $values[1] = $right;
                }
                $value->setListComponents($values);
            }

        } else if (preg_match('/border-radius/i', $property)) {
            if ($value instanceof RuleValueList) {

                // Border radius can contain two lists separated by a slash.
                $groups = $value->getListComponents();
                if ($value->getListSeparator() !== '/') {
                    $groups = [$value];
                }
                foreach ($groups as $group) {
> if ($group instanceof RuleValueList) {
$values = $group->getListComponents(); switch (count($values)) { case 2: $group->setListComponents(array_reverse($values)); break; case 3: $group->setListComponents([$values[1], $values[0], $values[1], $values[2]]); break; case 4: $group->setListComponents([$values[1], $values[0], $values[3], $values[2]]); break; } } }
> }
} else if (preg_match('/shadow/i', $property)) { // TODO Fix upstream, each shadow should be in a RuleValueList. if ($value instanceof RuleValueList) { // negate($value->getListComponents()[0]); } } else if (preg_match('/transform-origin/i', $property)) { $this->processTransformOrigin($rule); } else if (preg_match('/^(?!text\-).*?transform$/i', $property)) { // TODO Parse function parameters first. } else if (preg_match('/background(-position(-x)?|-image)?$/i', $property)) { $this->processBackground($rule); } else if (preg_match('/cursor/i', $property)) { $hasList = false; $parts = [$value]; if ($value instanceof RuleValueList) { $hastList = true; $parts = $value->getListComponents(); } foreach ($parts as $key => $part) { if (!is_object($part)) { $parts[$key] = preg_replace_callback('/\b(ne|nw|se|sw|nesw|nwse)-resize/', function($matches) { return str_replace($matches[1], str_replace(['e', 'w', '*'], ['*', 'e', 'w'], $matches[1]), $matches[0]); }, $part); } } if ($hasList) { $value->setListComponents($parts); } else { $rule->setValue($parts[0]); } } } protected function processTransformOrigin(Rule $rule) { $value = $rule->getValue(); $foundLeftOrRight = false; // Search for left or right. $parts = [$value]; if ($value instanceof RuleValueList) { $parts = $value->getListComponents(); $isInList = true; } foreach ($parts as $key => $part) { if (!is_object($part) && preg_match('/left|right/i', $part)) { $foundLeftOrRight = true; $parts[$key] = $this->swapLeftRight($part); } } if ($foundLeftOrRight) { // We need to reconstruct the value because left/right are not represented by an object. $list = new RuleValueList(' '); $list->setListComponents($parts); $rule->setValue($list); } else { $value = $parts[0]; // The first value may be referencing top or bottom (y instead of x).
< if (!is_object($value) && preg_match('/top|bottom/i', $value)) {
> if (!is_object($value) && preg_match('/top|bottom/i', $value) && count($parts)>1) {
$value = $parts[1]; } // Flip the value. if ($value instanceof Size) { if ($value->getSize() == 0) { $value->setSize(100); $value->setUnit('%'); } else if ($value->getUnit() === '%') { $this->complement($value); } } else if ($value instanceof CSSFunction && strpos($value->getName(), 'calc') !== false) { // TODO Fix upstream calc parsing. $this->complement($value); } } } protected function shouldAddCss() { if (!empty($this->shouldAddCss)) { $css = $this->shouldAddCss; $this->shouldAddCss = []; return $css; } return []; } protected function shouldIgnoreNext() { if ($this->shouldIgnore) { if (is_int($this->shouldIgnore)) { $this->shouldIgnore--; } return true; } return false; } protected function shouldRemoveNext() { if ($this->shouldRemove) { if (is_int($this->shouldRemove)) { $this->shouldRemove--; } return true; } return false; } protected function swap($value, $a, $b, $options = ['scope' => '*', 'ignoreCase' => true]) { $expr = preg_quote($a) . '|' . preg_quote($b); if (!empty($options['greedy'])) { $expr = '\\b(' . $expr . ')\\b'; } $flags = !empty($options['ignoreCase']) ? 'im' : 'm'; $expr = "/$expr/$flags"; return preg_replace_callback($expr, function($matches) use ($a, $b, $options) { return $this->compare($matches[0], $a, !empty($options['ignoreCase'])) ? $b : $a; }, $value); } protected function swapLeftRight($value) { return $this->swap($value, 'left', 'right'); } protected function swapLtrRtl($value) { return $this->swap($value, 'ltr', 'rtl'); } }