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 names and to match variants to images)
  63          *             [image type] => array(
  64          *                 [variant name] => array(
  65          *                     'color' => [color string, e.g. '#ffff00'],
  66          *                     'global' => [boolean, if true, this variant is available for all images of this type],
  67          *                 ),
  68          *             )
  69          *         ),
  70          *         // List of image files and their options
  71          *         'images' => array(
  72          *             [image type] => array(
  73          *                 [file path string],
  74          *                 [file path string] => array(
  75          *                     'name' => [image name string, defaults to file name],
  76          *                     'variants' => [array of variant name strings, variants available for this image],
  77          *                 ),
  78          *             )
  79          *         ),
  80          *     )
  81          * @endcode
  82          * @throws MWException
  83          */
  84         public function __construct( $options = array(), $localBasePath = null ) {
  85                 $this->localBasePath = self::extractLocalBasePath( $options, $localBasePath );
  86
  87                 if ( !isset( $options['prefix'] ) || !$options['prefix'] ) {
  88                         throw new MWException(
  89                                 "Required 'prefix' option not given or empty."
  90                         );
  91                 }
  92
  93                 foreach ( $options as $member => $option ) {
  94                         switch ( $member ) {
  95                                 case 'images':
  96                                         if ( !is_array( $option ) ) {
  97                                                 throw new MWException(
  98                                                         "Invalid collated file path list error. '$option' given, array expected."
  99                                                 );
 100                                         }
 101                                         foreach ( $option as $key => $value ) {
 102                                                 if ( !is_string( $key ) ) {
 103                                                         throw new MWException(
 104                                                                 "Invalid collated file path list key error. '$key' given, string expected."
 105                                                         );
 106                                                 }
 107                                                 $this->{$member}[$key] = (array)$value;
 108                                         }
 109                                         break;
 110
 111                                 case 'variants':
 112                                         if ( !is_array( $option ) ) {
 113                                                 throw new MWException(
 114                                                         "Invalid variant list error. '$option' given, array expected."
 115                                                 );
 116                                         }
 117                                         $this->{$member} = $option;
 118                                         break;
 119
 120                                 case 'prefix':
 121                                         $this->{$member} = (string)$option;
 122                                         break;
 123                         }
 124                 }
 125         }
 126
 127         /**
 128          * Get CSS class prefix used by this module.
 129          * @return string
 130          */
 131         public function getPrefix() {
 132                 return $this->prefix;
 133         }
 134
 135         /**
 136          * Get a ResourceLoaderImage object for given image.
 137          * @param string $name Image name
 138          * @return ResourceLoaderImage|null
 139          */
 140         public function getImage( $name ) {
 141                 $images = $this->getImages();
 142                 return isset( $images[$name] ) ? $images[$name] : null;
 143         }
 144
 145         /**
 146          * Get ResourceLoaderImage objects for all images.
 147          * @return ResourceLoaderImage[] Array keyed by image name
 148          */
 149         public function getImages() {
 150                 if ( !isset( $this->imageObjects ) ) {
 151                         $this->imageObjects = array();
 152
 153                         foreach ( $this->images as $type => $list ) {
 154                                 foreach ( $list as $name => $options ) {
 155                                         $imageDesc = is_string( $options ) ? $options : $options['image'];
 156
 157                                         $allowedVariants = array_merge(
 158                                                 isset( $options['variants'] ) ? $options['variants'] : array(),
 159                                                 $this->getGlobalVariants( $type )
 160                                         );
 161                                         if ( isset( $this->variants[$type] ) ) {
 162                                                 $variantConfig = array_intersect_key(
 163                                                         $this->variants[$type],
 164                                                         array_fill_keys( $allowedVariants, true )
 165                                                 );
 166                                         } else {
 167                                                 $variantConfig = array();
 168                                         }
 169
 170                                         $image = new ResourceLoaderImage( $name, $this->getName(), $imageDesc, $this->localBasePath, $variantConfig );
 171                                         $this->imageObjects[ $image->getName() ] = $image;
 172                                 }
 173                         }
 174                 }
 175
 176                 return $this->imageObjects;
 177         }
 178
 179         /**
 180          * Get list of variants in this module that are 'global' for given type of images, i.e., available
 181          * for every image of given type regardless of image options.
 182          * @param string $type Image type
 183          * @return string[]
 184          */
 185         public function getGlobalVariants( $type ) {
 186                 if ( !isset( $this->globalVariants[$type] ) ) {
 187                         $this->globalVariants[$type] = array();
 188
 189                         if ( isset( $this->variants[$type] ) ) {
 190                                 foreach ( $this->variants[$type] as $name => $config ) {
 191                                         if ( isset( $config['global'] ) && $config['global'] ) {
 192                                                 $this->globalVariants[$type][] = $name;
 193                                         }
 194                                 }
 195                         }
 196                 }
 197
 198                 return $this->globalVariants[$type];
 199         }
 200
 201         /**
 202          * Get the type of given image.
 203          * @param string $imageName Image name
 204          * @return string
 205          */
 206         public function getImageType( $imageName ) {
 207                 foreach ( $this->images as $type => $list ) {
 208                         foreach ( $list as $key => $value ) {
 209                                 $file = is_int( $key ) ? $value : $key;
 210                                 $options = is_array( $value ) ? $value : array();
 211                                 $name = isset( $options['name'] ) ? $options['name'] : pathinfo( $file, PATHINFO_FILENAME );
 212                                 if ( $name === $imageName ) {
 213                                         return $type;
 214                                 }
 215                         }
 216                 }
 217         }
 218
 219         /**
 220          * @param ResourceLoaderContext $context
 221          * @return array
 222          */
 223         public function getStyles( ResourceLoaderContext $context ) {
 224                 // Build CSS rules
 225                 $rules = array();
 226                 $script = $context->getResourceLoader()->getLoadScript( $this->getSource() );
 227                 $prefix = $this->getPrefix();
 228
 229                 foreach ( $this->getImages() as $name => $image ) {
 230                         $type = $this->getImageType( $name );
 231
 232                         $declarations = $this->getCssDeclarations(
 233                                 $image->getDataUri( $context, null, 'original' ),
 234                                 $image->getUrl( $context, $script, null, 'rasterized' )
 235                         );
 236                         $declarations = implode( "\n\t", $declarations );
 237                         $rules[] = ".$prefix-$type-$name {\n\t$declarations\n}";
 238
 239                         // TODO: Get variant configurations from $context->getSkin()
 240                         foreach ( $image->getVariants() as $variant ) {
 241                                 $declarations = $this->getCssDeclarations(
 242                                         $image->getDataUri( $context, $variant, 'original' ),
 243                                         $image->getUrl( $context, $script, $variant, 'rasterized' )
 244                                 );
 245                                 $declarations = implode( "\n\t", $declarations );
 246                                 $rules[] = ".$prefix-$type-$name-$variant {\n\t$declarations\n}";
 247                         }
 248                 }
 249
 250                 $style = implode( "\n", $rules );
 251                 if ( $this->getFlip( $context ) ) {
 252                         $style = CSSJanus::transform( $style, true, false );
 253                 }
 254                 return array( 'all' => $style );
 255         }
 256
 257         /**
 258          * @param string $primary Primary URI
 259          * @param string $fallback Fallback URI
 260          * @return string[] CSS declarations to use given URIs as background-image
 261          */
 262         protected function getCssDeclarations( $primary, $fallback ) {
 263                 // SVG support using a transparent gradient to guarantee cross-browser
 264                 // compatibility (browsers able to understand gradient syntax support also SVG).
 265                 // http://pauginer.tumblr.com/post/36614680636/invisible-gradient-technique
 266                 return array(
 267                         "background-image: url($fallback);",
 268                         "background-image: -webkit-linear-gradient(transparent, transparent), url($primary);",
 269                         "background-image: linear-gradient(transparent, transparent), url($primary);",
 270                 );
 271         }
 272
 273         /**
 274          * @return bool
 275          */
 276         public function supportsURLLoading() {
 277                 return false;
 278         }
 279
 280         /**
 281          * Extract a local base path from module definition information.
 282          *
 283          * @param array $options Module definition
 284          * @param string $localBasePath Path to use if not provided in module definition. Defaults
 285          *     to $IP
 286          * @return string Local base path
 287          */
 288         public static function extractLocalBasePath( $options, $localBasePath = null ) {
 289                 global $IP;
 290
 291                 if ( $localBasePath === null ) {
 292                         $localBasePath = $IP;
 293                 }
 294
 295                 if ( array_key_exists( 'localBasePath', $options ) ) {
 296                         $localBasePath = (string)$options['localBasePath'];
 297                 }
 298
 299                 return $localBasePath;
 300         }
 301 }