resources/src/mediawiki/page/gallery-slideshow.js

   1 /*!
   2  * mw.GallerySlideshow: Interface controls for the slideshow gallery
   3  */
   4 ( function ( mw, $, OO ) {
   5         /**
   6          * mw.GallerySlideshow encapsulates the user interface of the slideshow
   7          * galleries. An object is instantiated for each `.mw-gallery-slideshow`
   8          * element.
   9          *
  10          * @class mw.GallerySlideshow
  11          * @uses mw.Title
  12          * @uses mw.Api
  13          * @param {jQuery} gallery The `<ul>` element of the gallery.
  14          */
  15         mw.GallerySlideshow = function ( gallery ) {
  16                 // Properties
  17                 this.$gallery = $( gallery );
  18                 this.$galleryCaption = this.$gallery.find( '.gallerycaption' );
  19                 this.$galleryBox = this.$gallery.find( '.gallerybox' );
  20                 this.$currentImage = null;
  21                 this.imageInfoCache = {};
  22                 if ( this.$gallery.parent().attr( 'id' ) !== 'mw-content-text' ) {
  23                         this.$container = this.$gallery.parent();
  24                 }
  25
  26                 // Initialize
  27                 this.drawCarousel();
  28                 this.setSizeRequirement();
  29                 this.toggleThumbnails( false );
  30                 this.showCurrentImage();
  31
  32                 // Events
  33                 $( window ).on(
  34                         'resize',
  35                         OO.ui.debounce(
  36                                 this.setSizeRequirement.bind( this ),
  37                                 100
  38                         )
  39                 );
  40
  41                 // Disable thumbnails' link, instead show the image in the carousel
  42                 this.$galleryBox.on( 'click', function ( e ) {
  43                         this.$currentImage = $( e.currentTarget );
  44                         this.showCurrentImage();
  45                         return false;
  46                 }.bind( this ) );
  47         };
  48
  49         /* Properties */
  50         /**
  51          * @property {jQuery} $gallery The `<ul>` element of the gallery.
  52          */
  53
  54         /**
  55          * @property {jQuery} $galleryCaption The `<li>` that has the gallery caption.
  56          */
  57
  58         /**
  59          * @property {jQuery} $galleryBox Selection of `<li>` elements that have thumbnails.
  60          */
  61
  62         /**
  63          * @property {jQuery} $carousel The `<li>` elements that contains the carousel.
  64          */
  65
  66         /**
  67          * @property {jQuery} $interface The `<div>` elements that contains the interface buttons.
  68          */
  69
  70         /**
  71          * @property {jQuery} $img The `<img>` element that'll display the current image.
  72          */
  73
  74         /**
  75          * @property {jQuery} $imgLink The `<a>` element that links to the image's File page.
  76          */
  77
  78         /**
  79          * @property {jQuery} $imgCaption The `<p>` element that holds the image caption.
  80          */
  81
  82         /**
  83          * @property {jQuery} $imgContainer The `<div>` element that contains the image.
  84          */
  85
  86         /**
  87          * @property {jQuery} $currentImage The `<li>` element of the current image.
  88          */
  89
  90         /**
  91          * @property {jQuery} $container If the gallery contained in an element that is
  92          *      not the main content element, then it stores that element.
  93          */
  94
  95         /**
  96          * @property {Object} imageInfoCache A key value pair of thumbnail URLs and image info.
  97          */
  98
  99         /**
 100          * @property {number} imageWidth Width of the image based on viewport size
 101          */
 102
 103         /**
 104          * @property {number} imageHeight Height of the image based on viewport size
 105          *      the URLs in the required size.
 106          */
 107
 108         /* Setup */
 109         OO.initClass( mw.GallerySlideshow );
 110
 111         /* Methods */
 112         /**
 113          * Draws the carousel and the interface around it.
 114          */
 115         mw.GallerySlideshow.prototype.drawCarousel = function () {
 116                 var next, prev, toggle, interfaceElements, carouselStack;
 117
 118                 this.$carousel = $( '<li>' ).addClass( 'gallerycarousel' );
 119
 120                 // Buttons for the interface
 121                 prev = new OO.ui.ButtonWidget( {
 122                         framed: false,
 123                         icon: 'previous'
 124                 } ).on( 'click', this.prevImage.bind( this ) );
 125
 126                 next = new OO.ui.ButtonWidget( {
 127                         framed: false,
 128                         icon: 'next'
 129                 } ).on( 'click', this.nextImage.bind( this ) );
 130
 131                 toggle = new OO.ui.ButtonWidget( {
 132                         framed: false,
 133                         icon: 'imageGallery'
 134                 } ).on( 'click', this.toggleThumbnails.bind( this ) );
 135
 136                 interfaceElements = new OO.ui.PanelLayout( {
 137                         expanded: false,
 138                         classes: [ 'mw-gallery-slideshow-buttons' ],
 139                         $content: $( '<div>' ).append(
 140                                 prev.$element,
 141                                 toggle.$element,
 142                                 next.$element
 143                         )
 144                 } );
 145                 this.$interface = interfaceElements.$element;
 146
 147                 // Containers for the current image, caption etc.
 148                 this.$img = $( '<img>' );
 149                 this.$imgLink = $( '<a>' ).append( this.$img );
 150                 this.$imgCaption = $( '<p>' ).attr( 'class', 'mw-gallery-slideshow-caption' );
 151                 this.$imgContainer = $( '<div>' )
 152                         .attr( 'class', 'mw-gallery-slideshow-img-container' )
 153                         .append( this.$imgLink );
 154
 155                 carouselStack = new OO.ui.StackLayout( {
 156                         continuous: true,
 157                         expanded: false,
 158                         items: [
 159                                 interfaceElements,
 160                                 new OO.ui.PanelLayout( {
 161                                         expanded: false,
 162                                         $content: this.$imgContainer
 163                                 } ),
 164                                 new OO.ui.PanelLayout( {
 165                                         expanded: false,
 166                                         $content: this.$imgCaption
 167                                 } )
 168                         ]
 169                 } );
 170                 this.$carousel.append( carouselStack.$element );
 171
 172                 // Append below the caption or as the first element in the gallery
 173                 if ( this.$galleryCaption.length !== 0 ) {
 174                         this.$galleryCaption.after( this.$carousel );
 175                 } else {
 176                         this.$gallery.prepend( this.$carousel );
 177                 }
 178         };
 179
 180         /**
 181          * Sets the {@link #imageWidth} and {@link #imageHeight} properties
 182          * based on the size of the window. Also flushes the
 183          * {@link #imageInfoCache} as we'll now need URLs for a different
 184          * size.
 185          */
 186         mw.GallerySlideshow.prototype.setSizeRequirement = function () {
 187                 var w, h;
 188
 189                 if ( this.$container !== undefined ) {
 190                         w = this.$container.width() * 0.9;
 191                         h = ( this.$container.height() - this.getChromeHeight() ) * 0.9;
 192                 } else {
 193                         w = this.$imgContainer.width();
 194                         h = Math.min( $( window ).height() * ( 3 / 4 ), this.$imgContainer.width() ) - this.getChromeHeight();
 195                 }
 196
 197                 // Only update and flush the cache if the size changed
 198                 if ( w !== this.imageWidth || h !== this.imageHeight ) {
 199                         this.imageWidth = w;
 200                         this.imageHeight = h;
 201                         this.imageInfoCache = {};
 202                         this.setImageSize();
 203                 }
 204         };
 205
 206         /**
 207          * Gets the height of the interface elements and the
 208          * gallery's caption.
 209          */
 210         mw.GallerySlideshow.prototype.getChromeHeight = function () {
 211                 return this.$interface.outerHeight() + this.$galleryCaption.outerHeight();
 212         };
 213
 214         /**
 215          * Sets the height and width of {@link #$img} based on the
 216          * proportion of the image and the values generated by
 217          * {@link #setSizeRequirement}.
 218          *
 219          * @return {boolean} Whether or not the image was sized.
 220          */
 221         mw.GallerySlideshow.prototype.setImageSize = function () {
 222                 if ( this.$img === undefined || this.$thumbnail === undefined ) {
 223                         return false;
 224                 }
 225
 226                 // Reset height and width
 227                 this.$img
 228                         .removeAttr( 'width' )
 229                         .removeAttr( 'height' );
 230
 231                 // Stretch image to take up the required size
 232                 if ( this.$thumbnail.width() > this.$thumbnail.height() ) {
 233                         this.$img.attr( 'width', this.imageWidth + 'px' );
 234                 } else {
 235                         this.$img.attr( 'height', this.imageHeight + 'px' );
 236                 }
 237
 238                 // Make the image smaller in case the current image
 239                 // size is larger than the original file size.
 240                 this.getImageInfo( this.$thumbnail ).done( function ( info ) {
 241                         // NOTE: There will be a jump when resizing the window
 242                         // because the cache is cleared and this a new network request.
 243                         if (
 244                                 info.thumbwidth < this.$img.width() ||
 245                                 info.thumbheight < this.$img.height()
 246                         ) {
 247                                 this.$img.attr( 'width', info.thumbwidth + 'px' );
 248                                 this.$img.attr( 'height', info.thumbheight + 'px' );
 249                         }
 250                 }.bind( this ) );
 251
 252                 return true;
 253         };
 254
 255         /**
 256          * Displays the image set as {@link #$currentImage} in the carousel.
 257          */
 258         mw.GallerySlideshow.prototype.showCurrentImage = function () {
 259                 var imageLi = this.getCurrentImage(),
 260                         caption = imageLi.find( '.gallerytext' );
 261
 262                 // Highlight current thumbnail
 263                 this.$gallery
 264                         .find( '.gallerybox.slideshow-current' )
 265                         .removeClass( 'slideshow-current' );
 266                 imageLi.addClass( 'slideshow-current' );
 267
 268                 // Show thumbnail stretched to the right size while the image loads
 269                 this.$thumbnail = imageLi.find( 'img' );
 270                 this.$img.attr( 'src', this.$thumbnail.attr( 'src' ) );
 271                 this.$imgLink.attr( 'href', imageLi.find( 'a' ).eq( 0 ).attr( 'href' ) );
 272                 this.setImageSize();
 273
 274                 // Copy caption
 275                 this.$imgCaption
 276                         .empty()
 277                         .append( caption.clone() );
 278
 279                 // Load image at the required size
 280                 this.loadImage( this.$thumbnail ).done( function ( info, $img ) {
 281                         // Show this image to the user only if its still the current one
 282                         if ( this.$thumbnail.attr( 'src' ) === $img.attr( 'src' ) ) {
 283                                 this.$img.attr( 'src', info.thumburl );
 284                                 this.setImageSize();
 285
 286                                 // Keep the next image ready
 287                                 this.loadImage( this.getNextImage().find( 'img' ) );
 288                         }
 289                 }.bind( this ) );
 290         };
 291
 292         /**
 293          * Loads the full image given the `<img>` element of the thumbnail.
 294          *
 295          * @param {Object} $img
 296          * @return {jQuery.Promise} Resolves with the images URL and original
 297          *      element once the image has loaded.
 298          */
 299         mw.GallerySlideshow.prototype.loadImage = function ( $img ) {
 300                 var img, d = $.Deferred();
 301
 302                 this.getImageInfo( $img ).done( function ( info ) {
 303                         img = new Image();
 304                         img.src = info.thumburl;
 305                         img.onload = function () {
 306                                 d.resolve( info, $img );
 307                         };
 308                         img.onerror = function () {
 309                                 d.reject();
 310                         };
 311                 } ).fail( function () {
 312                         d.reject();
 313                 } );
 314
 315                 return d.promise();
 316         };
 317
 318         /**
 319          * Gets the image's info given an `<img>` element.
 320          *
 321          * @param {Object} $img
 322          * @return {jQuery.Promise} Resolves with the image's info.
 323          */
 324         mw.GallerySlideshow.prototype.getImageInfo = function ( $img ) {
 325                 var api, title, params,
 326                         imageSrc = $img.attr( 'src' );
 327
 328                 if ( this.imageInfoCache[ imageSrc ] === undefined ) {
 329                         api = new mw.Api();
 330                         // TODO: This supports only gallery of images
 331                         title = new mw.Title.newFromImg( $img );
 332                         params = {
 333                                 action: 'query',
 334                                 formatversion: 2,
 335                                 titles: title.toString(),
 336                                 prop: 'imageinfo',
 337                                 iiprop: 'url'
 338                         };
 339
 340                         // Check which dimension we need to request, based on
 341                         // image and container proportions.
 342                         if ( this.getDimensionToRequest( $img ) === 'height' ) {
 343                                 params.iiurlheight = this.imageHeight;
 344                         } else {
 345                                 params.iiurlwidth = this.imageWidth;
 346                         }
 347
 348                         this.imageInfoCache[ imageSrc ] = api.get( params ).then( function ( data ) {
 349                                 if ( OO.getProp( data, 'query', 'pages', 0, 'imageinfo', 0, 'thumburl' ) !== undefined ) {
 350                                         return data.query.pages[ 0 ].imageinfo[ 0 ];
 351                                 } else {
 352                                         return $.Deferred().reject();
 353                                 }
 354                         } );
 355                 }
 356
 357                 return this.imageInfoCache[ imageSrc ];
 358         };
 359
 360         /**
 361          * Given an image, the method checks whether to use the height
 362          * or the width to request the larger image.
 363          *
 364          * @param {jQuery} $img
 365          * @return {string}
 366          */
 367         mw.GallerySlideshow.prototype.getDimensionToRequest = function ( $img ) {
 368                 var ratio = $img.width() / $img.height();
 369
 370                 if ( this.imageHeight * ratio <= this.imageWidth ) {
 371                         return 'height';
 372                 } else {
 373                         return 'width';
 374                 }
 375         };
 376
 377         /**
 378          * Toggles visibility of the thumbnails.
 379          *
 380          * @param {boolean} show Optional argument to control the state
 381          */
 382         mw.GallerySlideshow.prototype.toggleThumbnails = function ( show ) {
 383                 this.$galleryBox.toggle( show );
 384                 this.$carousel.toggleClass( 'mw-gallery-slideshow-thumbnails-toggled', show );
 385         };
 386
 387         /**
 388          * Getter method for {@link #$currentImage}
 389          *
 390          * @return {jQuery}
 391          */
 392         mw.GallerySlideshow.prototype.getCurrentImage = function () {
 393                 this.$currentImage = this.$currentImage || this.$galleryBox.eq( 0 );
 394                 return this.$currentImage;
 395         };
 396
 397         /**
 398          * Gets the image after the current one. Returns the first image if
 399          * the current one is the last.
 400          *
 401          * @return {jQuery}
 402          */
 403         mw.GallerySlideshow.prototype.getNextImage = function () {
 404                 // Not the last image in the gallery
 405                 if ( this.$currentImage.next( '.gallerybox' )[ 0 ] !== undefined ) {
 406                         return this.$currentImage.next( '.gallerybox' );
 407                 } else {
 408                         return this.$galleryBox.eq( 0 );
 409                 }
 410         };
 411
 412         /**
 413          * Gets the image before the current one. Returns the last image if
 414          * the current one is the first.
 415          *
 416          * @return {jQuery}
 417          */
 418         mw.GallerySlideshow.prototype.getPrevImage = function () {
 419                 // Not the first image in the gallery
 420                 if ( this.$currentImage.prev( '.gallerybox' )[ 0 ] !== undefined ) {
 421                         return this.$currentImage.prev( '.gallerybox' );
 422                 } else {
 423                         return this.$galleryBox.last();
 424                 }
 425         };
 426
 427         /**
 428          * Sets the {@link #$currentImage} to the next one and shows
 429          * it in the carousel
 430          */
 431         mw.GallerySlideshow.prototype.nextImage = function () {
 432                 this.$currentImage = this.getNextImage();
 433                 this.showCurrentImage();
 434         };
 435
 436         /**
 437          * Sets the {@link #$currentImage} to the previous one and shows
 438          * it in the carousel
 439          */
 440         mw.GallerySlideshow.prototype.prevImage = function () {
 441                 this.$currentImage = this.getPrevImage();
 442                 this.showCurrentImage();
 443         };
 444
 445         // Bootstrap all slideshow galleries
 446         $( function () {
 447                 $( '.mw-gallery-slideshow' ).each( function () {
 448                         /*jshint -W031 */
 449                         new mw.GallerySlideshow( this );
 450                         /*jshint +W031 */
 451                 } );
 452         } );
 453 }( mediaWiki, jQuery, OO ) );