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
  43         /**
  44          * Constructs a new module from an options array.
  45          *
  46          * @param array $options List of options; if not given or empty, an empty module will be
  47          *     constructed
  48          * @param string $localBasePath Base path to prepend to all local paths in $options. Defaults
  49          *     to $IP
  50          *
  51          * Below is a description for the $options array:
  52          * @par Construction options:
  53          * @code
  54          *     array(
  55          *         // Base path to prepend to all local paths in $options. Defaults to $IP
  56          *         'localBasePath' => [base path],
  57          *         // CSS class prefix to use in all style rules
  58          *         'prefix' => [CSS class prefix],
  59          *         // List of variants that may be used for the image files
  60          *         'variants' => array(
  61          *             // ([image type] is a string, used in generated CSS class names and to match variants to images)
  62          *             [image type] => array(
  63          *                 [variant name] => array(
  64          *                     'color' => [color string, e.g. '#ffff00'],
  65          *                     'global' => [boolean, if true, this variant is available for all images of this type],
  66          *                 ),
  67          *             )
  68          *         ),
  69          *         // List of image files and their options
  70          *         'images' => array(
  71          *             [image type] => array(
  72          *                 [file path string],
  73          *                 [file path string] => array(
  74          *                     'name' => [image name string, defaults to file name],
  75          *                     'variants' => [array of variant name strings, variants available for this image],
  76          *                 ),
  77          *             )
  78          *         ),
  79          *     )
  80          * @endcode
  81          * @throws MWException
  82          */
  83         public function __construct( $options = array(), $localBasePath = null ) {
  84                 $this->localBasePath = self::extractLocalBasePath( $options, $localBasePath );
  85
  86                 if ( !isset( $options['prefix'] ) || !$options['prefix'] ) {
  87                         throw new MWException(
  88                                 "Required 'prefix' option not given or empty."
  89                         );
  90                 }
  91
  92                 foreach ( $options as $member => $option ) {
  93                         switch ( $member ) {
  94                                 case 'images':
  95                                         if ( !is_array( $option ) ) {
  96                                                 throw new MWException(
  97                                                         "Invalid collated file path list error. '$option' given, array expected."
  98                                                 );
  99                                         }
 100                                         foreach ( $option as $key => $value ) {
 101                                                 if ( !is_string( $key ) ) {
 102                                                         throw new MWException(
 103                                                                 "Invalid collated file path list key error. '$key' given, string expected."
 104                                                         );
 105                                                 }
 106                                                 $this->{$member}[$key] = (array)$value;
 107                                         }
 108                                         break;
 109
 110                                 case 'variants':
 111                                         if ( !is_array( $option ) ) {
 112                                                 throw new MWException(
 113                                                         "Invalid variant list error. '$option' given, array expected."
 114                                                 );
 115                                         }
 116                                         $this->{$member} = $option;
 117                                         break;
 118
 119                                 case 'prefix':
 120                                         $this->{$member} = (string)$option;
 121                                         break;
 122                         }
 123                 }
 124         }
 125
 126         /**
 127          * Get CSS class prefix used by this module.
 128          * @return string
 129          */
 130         public function getPrefix() {
 131                 return $this->prefix;
 132         }
 133
 134         /**
 135          * Get a ResourceLoaderImage object for given image.
 136          * @param string $name Image name
 137          * @return ResourceLoaderImage|null
 138          */
 139         public function getImage( $name ) {
 140                 $images = $this->getImages();
 141                 return isset( $images[$name] ) ? $images[$name] : null;
 142         }
 143
 144         /**
 145          * Get ResourceLoaderImage objects for all images.
 146          * @return ResourceLoaderImage[] Array keyed by image name
 147          */
 148         public function getImages() {
 149                 if ( !isset( $this->imageObjects ) ) {
 150                         $this->imageObjects = array();
 151
 152                         foreach ( $this->images as $type => $list ) {
 153                                 foreach ( $list as $name => $options ) {
 154                                         $imageDesc = is_string( $options ) ? $options : $options['image'];
 155
 156                                         $allowedVariants = array_merge(
 157                                                 isset( $options['variants'] ) ? $options['variants'] : array(),
 158                                                 $this->getGlobalVariants( $type )
 159                                         );
 160                                         $variantConfig = array_intersect_key(
 161                                                 $this->variants[$type],
 162                                                 array_fill_keys( $allowedVariants, true )
 163                                         );
 164
 165                                         $image = new ResourceLoaderImage( $name, $this->getName(), $imageDesc, $this->localBasePath, $variantConfig );
 166                                         $this->imageObjects[ $image->getName() ] = $image;
 167                                 }
 168                         }
 169                 }
 170
 171                 return $this->imageObjects;
 172         }
 173
 174         /**
 175          * Get list of variants in this module that are 'global' for given type of images, i.e., available
 176          * for every image of given type regardless of image options.
 177          * @param string $type Image type
 178          * @return string[]
 179          */
 180         public function getGlobalVariants( $type ) {
 181                 if ( !isset( $this->globalVariants[$type] ) ) {
 182                         $this->globalVariants[$type] = array();
 183
 184                         foreach ( $this->variants[$type] as $name => $config ) {
 185                                 if ( isset( $config['global'] ) && $config['global'] ) {
 186                                         $this->globalVariants[$type][] = $name;
 187                                 }
 188                         }
 189                 }
 190
 191                 return $this->globalVariants[$type];
 192         }
 193
 194         /**
 195          * Get the type of given image.
 196          * @param string $imageName Image name
 197          * @return string
 198          */
 199         public function getImageType( $imageName ) {
 200                 foreach ( $this->images as $type => $list ) {
 201                         foreach ( $list as $key => $value ) {
 202                                 $file = is_int( $key ) ? $value : $key;
 203                                 $options = is_array( $value ) ? $value : array();
 204                                 $name = isset( $options['name'] ) ? $options['name'] : pathinfo( $file, PATHINFO_FILENAME );
 205                                 if ( $name === $imageName ) {
 206                                         return $type;
 207                                 }
 208                         }
 209                 }
 210         }
 211
 212         /**
 213          * @param ResourceLoaderContext $context
 214          * @return array
 215          */
 216         public function getStyles( ResourceLoaderContext $context ) {
 217                 // Build CSS rules
 218                 $rules = array();
 219                 $script = $context->getResourceLoader()->getLoadScript( $this->getSource() );
 220                 $prefix = $this->getPrefix();
 221
 222                 foreach ( $this->getImages() as $name => $image ) {
 223                         $type = $this->getImageType( $name );
 224
 225                         $declarations = $this->getCssDeclarations(
 226                                 $image->getDataUri( $context, null, 'original' ),
 227                                 $image->getUrl( $context, $script, null, 'rasterized' )
 228                         );
 229                         $declarations = implode( "\n\t", $declarations );
 230                         $rules[] = ".$prefix-$type-$name {\n\t$declarations\n}";
 231
 232                         // TODO: Get variant configurations from $context->getSkin()
 233                         foreach ( $image->getVariants() as $variant ) {
 234                                 $declarations = $this->getCssDeclarations(
 235                                         $image->getDataUri( $context, $variant, 'original' ),
 236                                         $image->getUrl( $context, $script, $variant, 'rasterized' )
 237                                 );
 238                                 $declarations = implode( "\n\t", $declarations );
 239                                 $rules[] = ".$prefix-$type-$name-$variant {\n\t$declarations\n}";
 240                         }
 241                 }
 242
 243                 $style = implode( "\n", $rules );
 244                 if ( $this->getFlip( $context ) ) {
 245                         $style = CSSJanus::transform( $style, true, false );
 246                 }
 247                 return array( 'all' => $style );
 248         }
 249
 250         /**
 251          * @param string $primary Primary URI
 252          * @param string $fallback Fallback URI
 253          * @return string[] CSS declarations to use given URIs as background-image
 254          */
 255         protected function getCssDeclarations( $primary, $fallback ) {
 256                 // SVG support using a transparent gradient to guarantee cross-browser
 257                 // compatibility (browsers able to understand gradient syntax support also SVG).
 258                 // http://pauginer.tumblr.com/post/36614680636/invisible-gradient-technique
 259                 return array(
 260                         "background-image: url($fallback);",
 261                         "background-image: -webkit-linear-gradient(transparent, transparent), url($primary);",
 262                         "background-image: linear-gradient(transparent, transparent), url($primary);",
 263                 );
 264         }
 265
 266         /**
 267          * @return bool
 268          */
 269         public function supportsURLLoading() {
 270                 return false;
 271         }
 272
 273         /**
 274          * Extract a local base path from module definition information.
 275          *
 276          * @param array $options Module definition
 277          * @param string $localBasePath Path to use if not provided in module definition. Defaults
 278          *     to $IP
 279          * @return string Local base path
 280          */
 281         public static function extractLocalBasePath( $options, $localBasePath = null ) {
 282                 global $IP;
 283
 284                 if ( $localBasePath === null ) {
 285                         $localBasePath = $IP;
 286                 }
 287
 288                 if ( array_key_exists( 'localBasePath', $options ) ) {
 289                         $localBasePath = (string)$options['localBasePath'];
 290                 }
 291
 292                 return $localBasePath;
 293         }
 294 }