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                         title: mw.msg( 'gallery-slideshow-toggle' )
 135                 } ).on( 'click', this.toggleThumbnails.bind( this ) );
 136
 137                 interfaceElements = new OO.ui.PanelLayout( {
 138                         expanded: false,
 139                         classes: [ 'mw-gallery-slideshow-buttons' ],
 140                         $content: $( '<div>' ).append(
 141                                 prev.$element,
 142                                 toggle.$element,
 143                                 next.$element
 144                         )
 145                 } );
 146                 this.$interface = interfaceElements.$element;
 147
 148                 // Containers for the current image, caption etc.
 149                 this.$img = $( '<img>' );
 150                 this.$imgLink = $( '<a>' ).append( this.$img );
 151                 this.$imgCaption = $( '<p>' ).attr( 'class', 'mw-gallery-slideshow-caption' );
 152                 this.$imgContainer = $( '<div>' )
 153                         .attr( 'class', 'mw-gallery-slideshow-img-container' )
 154                         .append( this.$imgLink );
 155
 156                 carouselStack = new OO.ui.StackLayout( {
 157                         continuous: true,
 158                         expanded: false,
 159                         items: [
 160                                 interfaceElements,
 161                                 new OO.ui.PanelLayout( {
 162                                         expanded: false,
 163                                         $content: this.$imgContainer
 164                                 } ),
 165                                 new OO.ui.PanelLayout( {
 166                                         expanded: false,
 167                                         $content: this.$imgCaption
 168                                 } )
 169                         ]
 170                 } );
 171                 this.$carousel.append( carouselStack.$element );
 172
 173                 // Append below the caption or as the first element in the gallery
 174                 if ( this.$galleryCaption.length !== 0 ) {
 175                         this.$galleryCaption.after( this.$carousel );
 176                 } else {
 177                         this.$gallery.prepend( this.$carousel );
 178                 }
 179         };
 180
 181         /**
 182          * Sets the {@link #imageWidth} and {@link #imageHeight} properties
 183          * based on the size of the window. Also flushes the
 184          * {@link #imageInfoCache} as we'll now need URLs for a different
 185          * size.
 186          */
 187         mw.GallerySlideshow.prototype.setSizeRequirement = function () {
 188                 var w, h;
 189
 190                 if ( this.$container !== undefined ) {
 191                         w = this.$container.width() * 0.9;
 192                         h = ( this.$container.height() - this.getChromeHeight() ) * 0.9;
 193                 } else {
 194                         w = this.$imgContainer.width();
 195                         h = Math.min( $( window ).height() * ( 3 / 4 ), this.$imgContainer.width() ) - this.getChromeHeight();
 196                 }
 197
 198                 // Only update and flush the cache if the size changed
 199                 if ( w !== this.imageWidth || h !== this.imageHeight ) {
 200                         this.imageWidth = w;
 201                         this.imageHeight = h;
 202                         this.imageInfoCache = {};
 203                         this.setImageSize();
 204                 }
 205         };
 206
 207         /**
 208          * Gets the height of the interface elements and the
 209          * gallery's caption.
 210          */
 211         mw.GallerySlideshow.prototype.getChromeHeight = function () {
 212                 return this.$interface.outerHeight() + this.$galleryCaption.outerHeight();
 213         };
 214
 215         /**
 216          * Sets the height and width of {@link #$img} based on the
 217          * proportion of the image and the values generated by
 218          * {@link #setSizeRequirement}.
 219          *
 220          * @return {boolean} Whether or not the image was sized.
 221          */
 222         mw.GallerySlideshow.prototype.setImageSize = function () {
 223                 if ( this.$img === undefined || this.$thumbnail === undefined ) {
 224                         return false;
 225                 }
 226
 227                 // Reset height and width
 228                 this.$img
 229                         .removeAttr( 'width' )
 230                         .removeAttr( 'height' );
 231
 232                 // Stretch image to take up the required size
 233                 if ( this.$thumbnail.width() > this.$thumbnail.height() ) {
 234                         this.$img.attr( 'width', this.imageWidth + 'px' );
 235                 } else {
 236                         this.$img.attr( 'height', this.imageHeight + 'px' );
 237                 }
 238
 239                 // Make the image smaller in case the current image
 240                 // size is larger than the original file size.
 241                 this.getImageInfo( this.$thumbnail ).done( function ( info ) {
 242                         // NOTE: There will be a jump when resizing the window
 243                         // because the cache is cleared and this a new network request.
 244                         if (
 245                                 info.thumbwidth < this.$img.width() ||
 246                                 info.thumbheight < this.$img.height()
 247                         ) {
 248                                 this.$img.attr( 'width', info.thumbwidth + 'px' );
 249                                 this.$img.attr( 'height', info.thumbheight + 'px' );
 250                         }
 251                 }.bind( this ) );
 252
 253                 return true;
 254         };
 255
 256         /**
 257          * Displays the image set as {@link #$currentImage} in the carousel.
 258          */
 259         mw.GallerySlideshow.prototype.showCurrentImage = function () {
 260                 var imageLi = this.getCurrentImage(),
 261                         caption = imageLi.find( '.gallerytext' );
 262
 263                 // Highlight current thumbnail
 264                 this.$gallery
 265                         .find( '.gallerybox.slideshow-current' )
 266                         .removeClass( 'slideshow-current' );
 267                 imageLi.addClass( 'slideshow-current' );
 268
 269                 // Show thumbnail stretched to the right size while the image loads
 270                 this.$thumbnail = imageLi.find( 'img' );
 271                 this.$img.attr( 'src', this.$thumbnail.attr( 'src' ) );
 272                 this.$img.attr( 'alt', this.$thumbnail.attr( 'alt' ) );
 273                 this.$imgLink.attr( 'href', imageLi.find( 'a' ).eq( 0 ).attr( 'href' ) );
 274                 this.setImageSize();
 275
 276                 // Copy caption
 277                 this.$imgCaption
 278                         .empty()
 279                         .append( caption.clone() );
 280
 281                 // Load image at the required size
 282                 this.loadImage( this.$thumbnail ).done( function ( info, $img ) {
 283                         // Show this image to the user only if its still the current one
 284                         if ( this.$thumbnail.attr( 'src' ) === $img.attr( 'src' ) ) {
 285                                 this.$img.attr( 'src', info.thumburl );
 286                                 this.setImageSize();
 287
 288                                 // Keep the next image ready
 289                                 this.loadImage( this.getNextImage().find( 'img' ) );
 290                         }
 291                 }.bind( this ) );
 292         };
 293
 294         /**
 295          * Loads the full image given the `<img>` element of the thumbnail.
 296          *
 297          * @param {Object} $img
 298          * @return {jQuery.Promise} Resolves with the images URL and original
 299          *      element once the image has loaded.
 300          */
 301         mw.GallerySlideshow.prototype.loadImage = function ( $img ) {
 302                 var img, d = $.Deferred();
 303
 304                 this.getImageInfo( $img ).done( function ( info ) {
 305                         img = new Image();
 306                         img.src = info.thumburl;
 307                         img.onload = function () {
 308                                 d.resolve( info, $img );
 309                         };
 310                         img.onerror = function () {
 311                                 d.reject();
 312                         };
 313                 } ).fail( function () {
 314                         d.reject();
 315                 } );
 316
 317                 return d.promise();
 318         };
 319
 320         /**
 321          * Gets the image's info given an `<img>` element.
 322          *
 323          * @param {Object} $img
 324          * @return {jQuery.Promise} Resolves with the image's info.
 325          */
 326         mw.GallerySlideshow.prototype.getImageInfo = function ( $img ) {
 327                 var api, title, params,
 328                         imageSrc = $img.attr( 'src' );
 329
 330                 // Reject promise if there is no thumbnail image
 331                 if ( $img[ 0 ] === undefined ) {
 332                         return $.Deferred().reject();
 333                 }
 334
 335                 if ( this.imageInfoCache[ imageSrc ] === undefined ) {
 336                         api = new mw.Api();
 337                         // TODO: This supports only gallery of images
 338                         title = mw.Title.newFromImg( $img );
 339                         params = {
 340                                 action: 'query',
 341                                 formatversion: 2,
 342                                 titles: title.toString(),
 343                                 prop: 'imageinfo',
 344                                 iiprop: 'url'
 345                         };
 346
 347                         // Check which dimension we need to request, based on
 348                         // image and container proportions.
 349                         if ( this.getDimensionToRequest( $img ) === 'height' ) {
 350                                 params.iiurlheight = this.imageHeight;
 351                         } else {
 352                                 params.iiurlwidth = this.imageWidth;
 353                         }
 354
 355                         this.imageInfoCache[ imageSrc ] = api.get( params ).then( function ( data ) {
 356                                 if ( OO.getProp( data, 'query', 'pages', 0, 'imageinfo', 0, 'thumburl' ) !== undefined ) {
 357                                         return data.query.pages[ 0 ].imageinfo[ 0 ];
 358                                 } else {
 359                                         return $.Deferred().reject();
 360                                 }
 361                         } );
 362                 }
 363
 364                 return this.imageInfoCache[ imageSrc ];
 365         };
 366
 367         /**
 368          * Given an image, the method checks whether to use the height
 369          * or the width to request the larger image.
 370          *
 371          * @param {jQuery} $img
 372          * @return {string}
 373          */
 374         mw.GallerySlideshow.prototype.getDimensionToRequest = function ( $img ) {
 375                 var ratio = $img.width() / $img.height();
 376
 377                 if ( this.imageHeight * ratio <= this.imageWidth ) {
 378                         return 'height';
 379                 } else {
 380                         return 'width';
 381                 }
 382         };
 383
 384         /**
 385          * Toggles visibility of the thumbnails.
 386          *
 387          * @param {boolean} show Optional argument to control the state
 388          */
 389         mw.GallerySlideshow.prototype.toggleThumbnails = function ( show ) {
 390                 this.$galleryBox.toggle( show );
 391                 this.$carousel.toggleClass( 'mw-gallery-slideshow-thumbnails-toggled', show );
 392         };
 393
 394         /**
 395          * Getter method for {@link #$currentImage}
 396          *
 397          * @return {jQuery}
 398          */
 399         mw.GallerySlideshow.prototype.getCurrentImage = function () {
 400                 this.$currentImage = this.$currentImage || this.$galleryBox.eq( 0 );
 401                 return this.$currentImage;
 402         };
 403
 404         /**
 405          * Gets the image after the current one. Returns the first image if
 406          * the current one is the last.
 407          *
 408          * @return {jQuery}
 409          */
 410         mw.GallerySlideshow.prototype.getNextImage = function () {
 411                 // Not the last image in the gallery
 412                 if ( this.$currentImage.next( '.gallerybox' )[ 0 ] !== undefined ) {
 413                         return this.$currentImage.next( '.gallerybox' );
 414                 } else {
 415                         return this.$galleryBox.eq( 0 );
 416                 }
 417         };
 418
 419         /**
 420          * Gets the image before the current one. Returns the last image if
 421          * the current one is the first.
 422          *
 423          * @return {jQuery}
 424          */
 425         mw.GallerySlideshow.prototype.getPrevImage = function () {
 426                 // Not the first image in the gallery
 427                 if ( this.$currentImage.prev( '.gallerybox' )[ 0 ] !== undefined ) {
 428                         return this.$currentImage.prev( '.gallerybox' );
 429                 } else {
 430                         return this.$galleryBox.last();
 431                 }
 432         };
 433
 434         /**
 435          * Sets the {@link #$currentImage} to the next one and shows
 436          * it in the carousel
 437          */
 438         mw.GallerySlideshow.prototype.nextImage = function () {
 439                 this.$currentImage = this.getNextImage();
 440                 this.showCurrentImage();
 441         };
 442
 443         /**
 444          * Sets the {@link #$currentImage} to the previous one and shows
 445          * it in the carousel
 446          */
 447         mw.GallerySlideshow.prototype.prevImage = function () {
 448                 this.$currentImage = this.getPrevImage();
 449                 this.showCurrentImage();
 450         };
 451
 452         // Bootstrap all slideshow galleries
 453         mw.hook( 'wikipage.content' ).add( function ( $content ) {
 454                 $content.find( '.mw-gallery-slideshow' ).each( function () {
 455                         // eslint-disable-next-line no-new
 456                         new mw.GallerySlideshow( this );
 457                 } );
 458         } );
 459 }( mediaWiki, jQuery, OO ) );