includes/resourceloader/ResourceLoaderImageModule.php

   1 <?php
   2 /**
   3  * Resource loader module for generated and embedded images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  */
  23
  24 /**
  25  * Resource loader module for generated and embedded images.
  26  *
  27  * @since 1.25
  28  */
  29 class ResourceLoaderImageModule extends ResourceLoaderModule {
  30
  31         /**
  32          * Local base path, see __construct()
  33          * @var string
  34          */
  35         protected $localBasePath = '';
  36
  37         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  38
  39         protected $images = array();
  40         protected $variants = array();
  41         protected $prefix = array();
  42         protected $targets = array( 'desktop', 'mobile' );
  43
  44         /**
  45          * Constructs a new module from an options array.
  46          *
  47          * @param array $options List of options; if not given or empty, an empty module will be
  48          *     constructed
  49          * @param string $localBasePath Base path to prepend to all local paths in $options. Defaults
  50          *     to $IP
  51          *
  52          * Below is a description for the $options array:
  53          * @par Construction options:
  54          * @code
  55          *     array(
  56          *         // Base path to prepend to all local paths in $options. Defaults to $IP
  57          *         'localBasePath' => [base path],
  58          *         // CSS class prefix to use in all style rules
  59          *         'prefix' => [CSS class prefix],
  60          *         // List of variants that may be used for the image files
  61          *         'variants' => array(
  62          *             // ([image type] is a string, used in generated CSS class
  63          *             //  names and to match variants to images)
  64          *             [image type] => array(
  65          *                 [variant name] => array(
  66          *                     'color' => [color string, e.g. '#ffff00'],
  67          *                     'global' => [boolean, if true, this variant is available
  68          *                                  for all images of this type],
  69          *                 ),
  70          *             )
  71          *         ),
  72          *         // List of image files and their options
  73          *         'images' => array(
  74          *             [image type] => array(
  75          *                 [file path string],
  76          *                 [file path string] => array(
  77          *                     'name' => [image name string, defaults to file name],
  78          *                     'variants' => [array of variant name strings, variants
  79          *                                    available for this image],
  80          *                 ),
  81          *             )
  82          *         ),
  83          *     )
  84          * @endcode
  85          * @throws MWException
  86          */
  87         public function __construct( $options = array(), $localBasePath = null ) {
  88                 $this->localBasePath = self::extractLocalBasePath( $options, $localBasePath );
  89
  90                 if ( !isset( $options['prefix'] ) || !$options['prefix'] ) {
  91                         throw new MWException(
  92                                 "Required 'prefix' option not given or empty."
  93                         );
  94                 }
  95
  96                 foreach ( $options as $member => $option ) {
  97                         switch ( $member ) {
  98                                 case 'images':
  99                                         if ( !is_array( $option ) ) {
 100                                                 throw new MWException(
 101                                                         "Invalid collated file path list error. '$option' given, array expected."
 102                                                 );
 103                                         }
 104                                         foreach ( $option as $key => $value ) {
 105                                                 if ( !is_string( $key ) ) {
 106                                                         throw new MWException(
 107                                                                 "Invalid collated file path list key error. '$key' given, string expected."
 108                                                         );
 109                                                 }
 110                                                 $this->{$member}[$key] = (array)$value;
 111                                         }
 112                                         break;
 113
 114                                 case 'variants':
 115                                         if ( !is_array( $option ) ) {
 116                                                 throw new MWException(
 117                                                         "Invalid variant list error. '$option' given, array expected."
 118                                                 );
 119                                         }
 120                                         $this->{$member} = $option;
 121                                         break;
 122
 123                                 case 'prefix':
 124                                         $this->{$member} = (string)$option;
 125                                         break;
 126                         }
 127                 }
 128         }
 129
 130         /**
 131          * Get CSS class prefix used by this module.
 132          * @return string
 133          */
 134         public function getPrefix() {
 135                 return $this->prefix;
 136         }
 137
 138         /**
 139          * Get a ResourceLoaderImage object for given image.
 140          * @param string $name Image name
 141          * @return ResourceLoaderImage|null
 142          */
 143         public function getImage( $name ) {
 144                 $images = $this->getImages();
 145                 return isset( $images[$name] ) ? $images[$name] : null;
 146         }
 147
 148         /**
 149          * Get ResourceLoaderImage objects for all images.
 150          * @return ResourceLoaderImage[] Array keyed by image name
 151          */
 152         public function getImages() {
 153                 if ( !isset( $this->imageObjects ) ) {
 154                         $this->imageObjects = array();
 155
 156                         foreach ( $this->images as $type => $list ) {
 157                                 foreach ( $list as $name => $options ) {
 158                                         $imageDesc = is_string( $options ) ? $options : $options['image'];
 159
 160                                         $allowedVariants = array_merge(
 161                                                 isset( $options['variants'] ) ? $options['variants'] : array(),
 162                                                 $this->getGlobalVariants( $type )
 163                                         );
 164                                         if ( isset( $this->variants[$type] ) ) {
 165                                                 $variantConfig = array_intersect_key(
 166                                                         $this->variants[$type],
 167                                                         array_fill_keys( $allowedVariants, true )
 168                                                 );
 169                                         } else {
 170                                                 $variantConfig = array();
 171                                         }
 172
 173                                         $image = new ResourceLoaderImage(
 174                                                 $name,
 175                                                 $this->getName(),
 176                                                 $imageDesc,
 177                                                 $this->localBasePath,
 178                                                 $variantConfig
 179                                         );
 180                                         $this->imageObjects[ $image->getName() ] = $image;
 181                                 }
 182                         }
 183                 }
 184
 185                 return $this->imageObjects;
 186         }
 187
 188         /**
 189          * Get list of variants in this module that are 'global' for given type of images, i.e., available
 190          * for every image of given type regardless of image options.
 191          * @param string $type Image type
 192          * @return string[]
 193          */
 194         public function getGlobalVariants( $type ) {
 195                 if ( !isset( $this->globalVariants[$type] ) ) {
 196                         $this->globalVariants[$type] = array();
 197
 198                         if ( isset( $this->variants[$type] ) ) {
 199                                 foreach ( $this->variants[$type] as $name => $config ) {
 200                                         if ( isset( $config['global'] ) && $config['global'] ) {
 201                                                 $this->globalVariants[$type][] = $name;
 202                                         }
 203                                 }
 204                         }
 205                 }
 206
 207                 return $this->globalVariants[$type];
 208         }
 209
 210         /**
 211          * Get the type of given image.
 212          * @param string $imageName Image name
 213          * @return string
 214          */
 215         public function getImageType( $imageName ) {
 216                 foreach ( $this->images as $type => $list ) {
 217                         foreach ( $list as $key => $value ) {
 218                                 $file = is_int( $key ) ? $value : $key;
 219                                 $options = is_array( $value ) ? $value : array();
 220                                 $name = isset( $options['name'] ) ? $options['name'] : pathinfo( $file, PATHINFO_FILENAME );
 221                                 if ( $name === $imageName ) {
 222                                         return $type;
 223                                 }
 224                         }
 225                 }
 226         }
 227
 228         /**
 229          * @param ResourceLoaderContext $context
 230          * @return array
 231          */
 232         public function getStyles( ResourceLoaderContext $context ) {
 233                 // Build CSS rules
 234                 $rules = array();
 235                 $script = $context->getResourceLoader()->getLoadScript( $this->getSource() );
 236                 $prefix = $this->getPrefix();
 237
 238                 foreach ( $this->getImages() as $name => $image ) {
 239                         $type = $this->getImageType( $name );
 240
 241                         $declarations = $this->getCssDeclarations(
 242                                 $image->getDataUri( $context, null, 'original' ),
 243                                 $image->getUrl( $context, $script, null, 'rasterized' )
 244                         );
 245                         $declarations = implode( "\n\t", $declarations );
 246                         $rules[] = ".$prefix-$type-$name {\n\t$declarations\n}";
 247
 248                         // TODO: Get variant configurations from $context->getSkin()
 249                         foreach ( $image->getVariants() as $variant ) {
 250                                 $declarations = $this->getCssDeclarations(
 251                                         $image->getDataUri( $context, $variant, 'original' ),
 252                                         $image->getUrl( $context, $script, $variant, 'rasterized' )
 253                                 );
 254                                 $declarations = implode( "\n\t", $declarations );
 255                                 $rules[] = ".$prefix-$type-$name-$variant {\n\t$declarations\n}";
 256                         }
 257                 }
 258
 259                 $style = implode( "\n", $rules );
 260                 if ( $this->getFlip( $context ) ) {
 261                         $style = CSSJanus::transform( $style, true, false );
 262                 }
 263                 return array( 'all' => $style );
 264         }
 265
 266         /**
 267          * SVG support using a transparent gradient to guarantee cross-browser
 268          * compatibility (browsers able to understand gradient syntax support also SVG).
 269          * http://pauginer.tumblr.com/post/36614680636/invisible-gradient-technique
 270          *
 271          * Keep synchronized with the .background-image-svg LESS mixin in
 272          * /resources/src/mediawiki.less/mediawiki.mixins.less.
 273          *
 274          * @param string $primary Primary URI
 275          * @param string $fallback Fallback URI
 276          * @return string[] CSS declarations to use given URIs as background-image
 277          */
 278         protected function getCssDeclarations( $primary, $fallback ) {
 279                 return array(
 280                         "background-image: url($fallback);",
 281                         "background-image: -webkit-linear-gradient(transparent, transparent), url($primary);",
 282                         "background-image: linear-gradient(transparent, transparent), url($primary);",
 283                         "background-image: -o-linear-gradient(transparent, transparent), url($fallback);",
 284                 );
 285         }
 286
 287         /**
 288          * @return bool
 289          */
 290         public function supportsURLLoading() {
 291                 return false;
 292         }
 293
 294         /**
 295          * Extract a local base path from module definition information.
 296          *
 297          * @param array $options Module definition
 298          * @param string $localBasePath Path to use if not provided in module definition. Defaults
 299          *     to $IP
 300          * @return string Local base path
 301          */
 302         public static function extractLocalBasePath( $options, $localBasePath = null ) {
 303                 global $IP;
 304
 305                 if ( $localBasePath === null ) {
 306                         $localBasePath = $IP;
 307                 }
 308
 309                 if ( array_key_exists( 'localBasePath', $options ) ) {
 310                         $localBasePath = (string)$options['localBasePath'];
 311                 }
 312
 313                 return $localBasePath;
 314         }
 315 }