Move ILoadBalancer to Rdbms namespace

[mediawiki.git] / includes / resourceloader / ResourceLoaderImageModule.php

<?php
/**
 * ResourceLoader module for generated and embedded images.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @author Trevor Parscal
 */

/**
 * ResourceLoader module for generated and embedded images.
 *
 * @since 1.25
 */
class ResourceLoaderImageModule extends ResourceLoaderModule {

        protected $definition = null;

        /**
         * Local base path, see __construct()
         * @var string
         */
        protected $localBasePath = '';

        protected $origin = self::ORIGIN_CORE_SITEWIDE;

        protected $images = [];
        protected $variants = [];
        protected $prefix = null;
        protected $selectorWithoutVariant = '.{prefix}-{name}';
        protected $selectorWithVariant = '.{prefix}-{name}-{variant}';
        protected $targets = [ 'desktop', 'mobile' ];

        /**
         * Constructs a new module from an options array.
         *
         * @param array $options List of options; if not given or empty, an empty module will be
         *     constructed
         * @param string $localBasePath Base path to prepend to all local paths in $options. Defaults
         *     to $IP
         *
         * Below is a description for the $options array:
         * @par Construction options:
         * @code
         *     [
         *         // Base path to prepend to all local paths in $options. Defaults to $IP
         *         'localBasePath' => [base path],
         *         // Path to JSON file that contains any of the settings below
         *         'data' => [file path string]
         *         // CSS class prefix to use in all style rules
         *         'prefix' => [CSS class prefix],
         *         // Alternatively: Format of CSS selector to use in all style rules
         *         'selector' => [CSS selector template, variables: {prefix} {name} {variant}],
         *         // Alternatively: When using variants
         *         'selectorWithoutVariant' => [CSS selector template, variables: {prefix} {name}],
         *         'selectorWithVariant' => [CSS selector template, variables: {prefix} {name} {variant}],
         *         // List of variants that may be used for the image files
         *         'variants' => [
         *             [theme name] => [
         *                 [variant name] => [
         *                     'color' => [color string, e.g. '#ffff00'],
         *                     'global' => [boolean, if true, this variant is available
         *                                  for all images of this type],
         *                 ],
         *                 ...
         *             ],
         *             ...
         *         ],
         *         // List of image files and their options
         *         'images' => [
         *             [theme name] => [
         *                 [icon name] => [
         *                     'file' => [file path string or array whose values are file path strings
         *                                    and whose keys are 'default', 'ltr', 'rtl', a single
         *                                    language code like 'en', or a list of language codes like
         *                                    'en,de,ar'],
         *                     'variants' => [array of variant name strings, variants
         *                                    available for this image],
         *                 ],
         *                 ...
         *             ],
         *             ...
         *         ],
         *     ]
         * @endcode
         * @throws InvalidArgumentException
         */
        public function __construct( $options = [], $localBasePath = null ) {
                $this->localBasePath = self::extractLocalBasePath( $options, $localBasePath );

                $this->definition = $options;
        }

        /**
         * Parse definition and external JSON data, if referenced.
         */
        protected function loadFromDefinition() {
                if ( $this->definition === null ) {
                        return;
                }

                $options = $this->definition;
                $this->definition = null;

                if ( isset( $options['data'] ) ) {
                        $dataPath = $this->localBasePath . '/' . $options['data'];
                        $data = json_decode( file_get_contents( $dataPath ), true );
                        $options = array_merge( $data, $options );
                }

                // Accepted combinations:
                // * prefix
                // * selector
                // * selectorWithoutVariant + selectorWithVariant
                // * prefix + selector
                // * prefix + selectorWithoutVariant + selectorWithVariant

                $prefix = isset( $options['prefix'] ) && $options['prefix'];
                $selector = isset( $options['selector'] ) && $options['selector'];
                $selectorWithoutVariant = isset( $options['selectorWithoutVariant'] )
                        && $options['selectorWithoutVariant'];
                $selectorWithVariant = isset( $options['selectorWithVariant'] )
                        && $options['selectorWithVariant'];

                if ( $selectorWithoutVariant && !$selectorWithVariant ) {
                        throw new InvalidArgumentException(
                                "Given 'selectorWithoutVariant' but no 'selectorWithVariant'."
                        );
                }
                if ( $selectorWithVariant && !$selectorWithoutVariant ) {
                        throw new InvalidArgumentException(
                                "Given 'selectorWithVariant' but no 'selectorWithoutVariant'."
                        );
                }
                if ( $selector && $selectorWithVariant ) {
                        throw new InvalidArgumentException(
                                "Incompatible 'selector' and 'selectorWithVariant'+'selectorWithoutVariant' given."
                        );
                }
                if ( !$prefix && !$selector && !$selectorWithVariant ) {
                        throw new InvalidArgumentException(
                                "None of 'prefix', 'selector' or 'selectorWithVariant'+'selectorWithoutVariant' given."
                        );
                }

                foreach ( $options as $member => $option ) {
                        switch ( $member ) {
                                case 'images':
                                case 'variants':
                                        if ( !is_array( $option ) ) {
                                                throw new InvalidArgumentException(
                                                        "Invalid list error. '$option' given, array expected."
                                                );
                                        }
                                        if ( !isset( $option['default'] ) ) {
                                                // Backwards compatibility
                                                $option = [ 'default' => $option ];
                                        }
                                        foreach ( $option as $skin => $data ) {
                                                if ( !is_array( $option ) ) {
                                                        throw new InvalidArgumentException(
                                                                "Invalid list error. '$option' given, array expected."
                                                        );
                                                }
                                        }
                                        $this->{$member} = $option;
                                        break;

                                case 'prefix':
                                case 'selectorWithoutVariant':
                                case 'selectorWithVariant':
                                        $this->{$member} = (string)$option;
                                        break;

                                case 'selector':
                                        $this->selectorWithoutVariant = $this->selectorWithVariant = (string)$option;
                        }
                }
        }

        /**
         * Get CSS class prefix used by this module.
         * @return string
         */
        public function getPrefix() {
                $this->loadFromDefinition();
                return $this->prefix;
        }

        /**
         * Get CSS selector templates used by this module.
         * @return string
         */
        public function getSelectors() {
                $this->loadFromDefinition();
                return [
                        'selectorWithoutVariant' => $this->selectorWithoutVariant,
                        'selectorWithVariant' => $this->selectorWithVariant,
                ];
        }

        /**
         * Get a ResourceLoaderImage object for given image.
         * @param string $name Image name
         * @param ResourceLoaderContext $context
         * @return ResourceLoaderImage|null
         */
        public function getImage( $name, ResourceLoaderContext $context ) {
                $this->loadFromDefinition();
                $images = $this->getImages( $context );
                return isset( $images[$name] ) ? $images[$name] : null;
        }

        /**
         * Get ResourceLoaderImage objects for all images.
         * @param ResourceLoaderContext $context
         * @return ResourceLoaderImage[] Array keyed by image name
         */
        public function getImages( ResourceLoaderContext $context ) {
                $skin = $context->getSkin();
                if ( !isset( $this->imageObjects ) ) {
                        $this->loadFromDefinition();
                        $this->imageObjects = [];
                }
                if ( !isset( $this->imageObjects[$skin] ) ) {
                        $this->imageObjects[$skin] = [];
                        if ( !isset( $this->images[$skin] ) ) {
                                $this->images[$skin] = isset( $this->images['default'] ) ?
                                        $this->images['default'] :
                                        [];
                        }
                        foreach ( $this->images[$skin] as $name => $options ) {
                                $fileDescriptor = is_string( $options ) ? $options : $options['file'];

                                $allowedVariants = array_merge(
                                        is_array( $options ) && isset( $options['variants'] ) ? $options['variants'] : [],
                                        $this->getGlobalVariants( $context )
                                );
                                if ( isset( $this->variants[$skin] ) ) {
                                        $variantConfig = array_intersect_key(
                                                $this->variants[$skin],
                                                array_fill_keys( $allowedVariants, true )
                                        );
                                } else {
                                        $variantConfig = [];
                                }

                                $image = new ResourceLoaderImage(
                                        $name,
                                        $this->getName(),
                                        $fileDescriptor,
                                        $this->localBasePath,
                                        $variantConfig
                                );
                                $this->imageObjects[$skin][$image->getName()] = $image;
                        }
                }

                return $this->imageObjects[$skin];
        }

        /**
         * Get list of variants in this module that are 'global', i.e., available
         * for every image regardless of image options.
         * @param ResourceLoaderContext $context
         * @return string[]
         */
        public function getGlobalVariants( ResourceLoaderContext $context ) {
                $skin = $context->getSkin();
                if ( !isset( $this->globalVariants ) ) {
                        $this->loadFromDefinition();
                        $this->globalVariants = [];
                }
                if ( !isset( $this->globalVariants[$skin] ) ) {
                        $this->globalVariants[$skin] = [];
                        if ( !isset( $this->variants[$skin] ) ) {
                                $this->variants[$skin] = isset( $this->variants['default'] ) ?
                                        $this->variants['default'] :
                                        [];
                        }
                        foreach ( $this->variants[$skin] as $name => $config ) {
                                if ( isset( $config['global'] ) && $config['global'] ) {
                                        $this->globalVariants[$skin][] = $name;
                                }
                        }
                }

                return $this->globalVariants[$skin];
        }

        /**
         * @param ResourceLoaderContext $context
         * @return array
         */
        public function getStyles( ResourceLoaderContext $context ) {
                $this->loadFromDefinition();

                // Build CSS rules
                $rules = [];
                $script = $context->getResourceLoader()->getLoadScript( $this->getSource() );
                $selectors = $this->getSelectors();

                foreach ( $this->getImages( $context ) as $name => $image ) {
                        $declarations = $this->getCssDeclarations(
                                $image->getDataUri( $context, null, 'original' ),
                                $image->getUrl( $context, $script, null, 'rasterized' )
                        );
                        $declarations = implode( "\n\t", $declarations );
                        $selector = strtr(
                                $selectors['selectorWithoutVariant'],
                                [
                                        '{prefix}' => $this->getPrefix(),
                                        '{name}' => $name,
                                        '{variant}' => '',
                                ]
                        );
                        $rules[] = "$selector {\n\t$declarations\n}";

                        foreach ( $image->getVariants() as $variant ) {
                                $declarations = $this->getCssDeclarations(
                                        $image->getDataUri( $context, $variant, 'original' ),
                                        $image->getUrl( $context, $script, $variant, 'rasterized' )
                                );
                                $declarations = implode( "\n\t", $declarations );
                                $selector = strtr(
                                        $selectors['selectorWithVariant'],
                                        [
                                                '{prefix}' => $this->getPrefix(),
                                                '{name}' => $name,
                                                '{variant}' => $variant,
                                        ]
                                );
                                $rules[] = "$selector {\n\t$declarations\n}";
                        }
                }

                $style = implode( "\n", $rules );
                return [ 'all' => $style ];
        }

        /**
         * SVG support using a transparent gradient to guarantee cross-browser
         * compatibility (browsers able to understand gradient syntax support also SVG).
         * http://pauginer.tumblr.com/post/36614680636/invisible-gradient-technique
         *
         * Keep synchronized with the .background-image-svg LESS mixin in
         * /resources/src/mediawiki.less/mediawiki.mixins.less.
         *
         * @param string $primary Primary URI
         * @param string $fallback Fallback URI
         * @return string[] CSS declarations to use given URIs as background-image
         */
        protected function getCssDeclarations( $primary, $fallback ) {
                return [
                        "background-image: url($fallback);",
                        "background-image: linear-gradient(transparent, transparent), url($primary);",
                        // Do not serve SVG to Opera 12, bad rendering with border-radius or background-size (T87504)
                        "background-image: -o-linear-gradient(transparent, transparent), url($fallback);",
                ];
        }

        /**
         * @return bool
         */
        public function supportsURLLoading() {
                return false;
        }

        /**
         * Get the definition summary for this module.
         *
         * @param ResourceLoaderContext $context
         * @return array
         */
        public function getDefinitionSummary( ResourceLoaderContext $context ) {
                $this->loadFromDefinition();
                $summary = parent::getDefinitionSummary( $context );

                $options = [];
                foreach ( [
                        'localBasePath',
                        'images',
                        'variants',
                        'prefix',
                        'selectorWithoutVariant',
                        'selectorWithVariant',
                ] as $member ) {
                        $options[$member] = $this->{$member};
                };

                $summary[] = [
                        'options' => $options,
                        'fileHashes' => $this->getFileHashes( $context ),
                ];
                return $summary;
        }

        /**
         * Helper method for getDefinitionSummary.
         */
        protected function getFileHashes( ResourceLoaderContext $context ) {
                $this->loadFromDefinition();
                $files = [];
                foreach ( $this->getImages( $context ) as $name => $image ) {
                        $files[] = $image->getPath( $context );
                }
                $files = array_values( array_unique( $files ) );
                return array_map( [ __CLASS__, 'safeFileHash' ], $files );
        }

        /**
         * Extract a local base path from module definition information.
         *
         * @param array $options Module definition
         * @param string $localBasePath Path to use if not provided in module definition. Defaults
         *     to $IP
         * @return string Local base path
         */
        public static function extractLocalBasePath( $options, $localBasePath = null ) {
                global $IP;

                if ( $localBasePath === null ) {
                        $localBasePath = $IP;
                }

                if ( array_key_exists( 'localBasePath', $options ) ) {
                        $localBasePath = (string)$options['localBasePath'];
                }

                return $localBasePath;
        }

        /**
         * @return string
         */
        public function getType() {
                return self::LOAD_STYLES;
        }
}