| 1 | /** |
| 2 | * Handles the display of reveal.js' overlay elements used |
| 3 | * to preview iframes, images & videos. |
| 4 | */ |
| 5 | export default class Overlay { |
| 6 | |
| 7 | constructor( Reveal ) { |
| 8 | |
| 9 | this.Reveal = Reveal; |
| 10 | |
| 11 | this.onSlidesClicked = this.onSlidesClicked.bind( this ); |
| 12 | |
| 13 | this.iframeTriggerSelector = null; |
| 14 | this.mediaTriggerSelector = '[data-preview-image], [data-preview-video]'; |
| 15 | |
| 16 | this.stateProps = ['previewIframe', 'previewImage', 'previewVideo', 'previewFit']; |
| 17 | this.state = {}; |
| 18 | |
| 19 | } |
| 20 | |
| 21 | update() { |
| 22 | |
| 23 | // Enable link previews globally |
| 24 | if( this.Reveal.getConfig().previewLinks ) { |
| 25 | this.iframeTriggerSelector = 'a[href]:not([data-preview-link=false]), [data-preview-link]:not(a):not([data-preview-link=false])'; |
| 26 | } |
| 27 | // Enable link previews for individual elements |
| 28 | else { |
| 29 | this.iframeTriggerSelector = '[data-preview-link]:not([data-preview-link=false])'; |
| 30 | } |
| 31 | |
| 32 | const hasLinkPreviews = this.Reveal.getSlidesElement().querySelectorAll( this.iframeTriggerSelector ).length > 0; |
| 33 | const hasMediaPreviews = this.Reveal.getSlidesElement().querySelectorAll( this.mediaTriggerSelector ).length > 0; |
| 34 | |
| 35 | // Only add the listener when there are previewable elements in the slides |
| 36 | if( hasLinkPreviews || hasMediaPreviews ) { |
| 37 | this.Reveal.getSlidesElement().addEventListener( 'click', this.onSlidesClicked, false ); |
| 38 | } |
| 39 | else { |
| 40 | this.Reveal.getSlidesElement().removeEventListener( 'click', this.onSlidesClicked, false ); |
| 41 | } |
| 42 | |
| 43 | } |
| 44 | |
| 45 | createOverlay( className ) { |
| 46 | |
| 47 | this.dom = document.createElement( 'div' ); |
| 48 | this.dom.classList.add( 'r-overlay' ); |
| 49 | this.dom.classList.add( className ); |
| 50 | |
| 51 | this.viewport = document.createElement( 'div' ); |
| 52 | this.viewport.classList.add( 'r-overlay-viewport' ); |
| 53 | |
| 54 | this.dom.appendChild( this.viewport ); |
| 55 | this.Reveal.getRevealElement().appendChild( this.dom ); |
| 56 | |
| 57 | } |
| 58 | |
| 59 | /** |
| 60 | * Opens a lightbox that previews the target URL. |
| 61 | * |
| 62 | * @param {string} url - url for lightbox iframe src |
| 63 | */ |
| 64 | previewIframe( url ) { |
| 65 | |
| 66 | this.close(); |
| 67 | |
| 68 | this.state = { previewIframe: url }; |
| 69 | |
| 70 | this.createOverlay( 'r-overlay-preview' ); |
| 71 | this.dom.dataset.state = 'loading'; |
| 72 | |
| 73 | this.viewport.innerHTML = |
| 74 | `<header class="r-overlay-header"> |
| 75 | <a class="r-overlay-header-button r-overlay-external" href="${url}" target="_blank"><span class="icon"></span></a> |
| 76 | <button class="r-overlay-header-button r-overlay-close"><span class="icon"></span></button> |
| 77 | </header> |
| 78 | <div class="r-overlay-spinner"></div> |
| 79 | <div class="r-overlay-content"> |
| 80 | <iframe src="${url}"></iframe> |
| 81 | <small class="r-overlay-content-inner"> |
| 82 | <span class="r-overlay-error x-frame-error">Unable to load iframe. This is likely due to the site's policy (x-frame-options).</span> |
| 83 | </small> |
| 84 | </div>`; |
| 85 | |
| 86 | this.dom.querySelector( 'iframe' ).addEventListener( 'load', event => { |
| 87 | this.dom.dataset.state = 'loaded'; |
| 88 | }, false ); |
| 89 | |
| 90 | this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', event => { |
| 91 | this.close(); |
| 92 | event.preventDefault(); |
| 93 | }, false ); |
| 94 | |
| 95 | this.dom.querySelector( '.r-overlay-external' ).addEventListener( 'click', event => { |
| 96 | this.close(); |
| 97 | }, false ); |
| 98 | |
| 99 | this.Reveal.dispatchEvent({ type: 'previewiframe', data: { url } }); |
| 100 | |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Opens a lightbox window that provides a larger view of the |
| 105 | * given image/video. |
| 106 | * |
| 107 | * @param {string} url - url to the image/video to preview |
| 108 | * @param {image|video} mediaType |
| 109 | * @param {string} [fitMode] - the fit mode to use for the preview |
| 110 | */ |
| 111 | previewMedia( url, mediaType, fitMode ) { |
| 112 | |
| 113 | if( mediaType !== 'image' && mediaType !== 'video' ) { |
| 114 | console.warn( 'Please specify a valid media type to preview (image|video)' ); |
| 115 | return; |
| 116 | } |
| 117 | |
| 118 | this.close(); |
| 119 | |
| 120 | fitMode = fitMode || 'scale-down'; |
| 121 | |
| 122 | this.createOverlay( 'r-overlay-preview' ); |
| 123 | this.dom.dataset.state = 'loading'; |
| 124 | this.dom.dataset.previewFit = fitMode; |
| 125 | |
| 126 | this.viewport.innerHTML = |
| 127 | `<header class="r-overlay-header"> |
| 128 | <button class="r-overlay-header-button r-overlay-close">Esc <span class="icon"></span></button> |
| 129 | </header> |
| 130 | <div class="r-overlay-spinner"></div> |
| 131 | <div class="r-overlay-content"></div>`; |
| 132 | |
| 133 | const contentElement = this.dom.querySelector( '.r-overlay-content' ); |
| 134 | |
| 135 | if( mediaType === 'image' ) { |
| 136 | |
| 137 | this.state = { previewImage: url, previewFit: fitMode } |
| 138 | |
| 139 | const img = document.createElement( 'img', {} ); |
| 140 | img.src = url; |
| 141 | contentElement.appendChild( img ); |
| 142 | |
| 143 | img.addEventListener( 'load', () => { |
| 144 | this.dom.dataset.state = 'loaded'; |
| 145 | }, false ); |
| 146 | |
| 147 | img.addEventListener( 'error', () => { |
| 148 | this.dom.dataset.state = 'error'; |
| 149 | contentElement.innerHTML = |
| 150 | `<span class="r-overlay-error">Unable to load image.</span>` |
| 151 | }, false ); |
| 152 | |
| 153 | // Hide image overlays when clicking outside the overlay |
| 154 | this.dom.style.cursor = 'zoom-out'; |
| 155 | this.dom.addEventListener( 'click', ( event ) => { |
| 156 | this.close(); |
| 157 | }, false ); |
| 158 | |
| 159 | this.Reveal.dispatchEvent({ type: 'previewimage', data: { url } }); |
| 160 | |
| 161 | } |
| 162 | else if( mediaType === 'video' ) { |
| 163 | |
| 164 | this.state = { previewVideo: url, previewFit: fitMode } |
| 165 | |
| 166 | const video = document.createElement( 'video' ); |
| 167 | video.autoplay = this.dom.dataset.previewAutoplay === 'false' ? false : true; |
| 168 | video.controls = this.dom.dataset.previewControls === 'false' ? false : true; |
| 169 | video.loop = this.dom.dataset.previewLoop === 'true' ? true : false; |
| 170 | video.muted = this.dom.dataset.previewMuted === 'true' ? true : false; |
| 171 | video.playsInline = true; |
| 172 | video.src = url; |
| 173 | contentElement.appendChild( video ); |
| 174 | |
| 175 | video.addEventListener( 'loadeddata', () => { |
| 176 | this.dom.dataset.state = 'loaded'; |
| 177 | }, false ); |
| 178 | |
| 179 | video.addEventListener( 'error', () => { |
| 180 | this.dom.dataset.state = 'error'; |
| 181 | contentElement.innerHTML = |
| 182 | `<span class="r-overlay-error">Unable to load video.</span>`; |
| 183 | }, false ); |
| 184 | |
| 185 | this.Reveal.dispatchEvent({ type: 'previewvideo', data: { url } }); |
| 186 | |
| 187 | } |
| 188 | else { |
| 189 | throw new Error( 'Please specify a valid media type to preview' ); |
| 190 | } |
| 191 | |
| 192 | this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', ( event ) => { |
| 193 | this.close(); |
| 194 | event.preventDefault(); |
| 195 | }, false ); |
| 196 | |
| 197 | } |
| 198 | |
| 199 | previewImage( url, fitMode ) { |
| 200 | |
| 201 | this.previewMedia( url, 'image', fitMode ); |
| 202 | |
| 203 | } |
| 204 | |
| 205 | previewVideo( url, fitMode ) { |
| 206 | |
| 207 | this.previewMedia( url, 'video', fitMode ); |
| 208 | |
| 209 | } |
| 210 | |
| 211 | /** |
| 212 | * Open or close help overlay window. |
| 213 | * |
| 214 | * @param {Boolean} [override] Flag which overrides the |
| 215 | * toggle logic and forcibly sets the desired state. True means |
| 216 | * help is open, false means it's closed. |
| 217 | */ |
| 218 | toggleHelp( override ) { |
| 219 | |
| 220 | if( typeof override === 'boolean' ) { |
| 221 | override ? this.showHelp() : this.close(); |
| 222 | } |
| 223 | else { |
| 224 | if( this.dom ) { |
| 225 | this.close(); |
| 226 | } |
| 227 | else { |
| 228 | this.showHelp(); |
| 229 | } |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * Opens an overlay window with help material. |
| 235 | */ |
| 236 | showHelp() { |
| 237 | |
| 238 | if( this.Reveal.getConfig().help ) { |
| 239 | |
| 240 | this.close(); |
| 241 | |
| 242 | this.createOverlay( 'r-overlay-help' ); |
| 243 | |
| 244 | let html = '<p class="title">Keyboard Shortcuts</p>'; |
| 245 | |
| 246 | let shortcuts = this.Reveal.keyboard.getShortcuts(), |
| 247 | bindings = this.Reveal.keyboard.getBindings(); |
| 248 | |
| 249 | html += '<table><th>KEY</th><th>ACTION</th>'; |
| 250 | for( let key in shortcuts ) { |
| 251 | html += `<tr><td>${key}</td><td>${shortcuts[ key ]}</td></tr>`; |
| 252 | } |
| 253 | |
| 254 | // Add custom key bindings that have associated descriptions |
| 255 | for( let binding in bindings ) { |
| 256 | if( bindings[binding].key && bindings[binding].description ) { |
| 257 | html += `<tr><td>${bindings[binding].key}</td><td>${bindings[binding].description}</td></tr>`; |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | html += '</table>'; |
| 262 | |
| 263 | this.viewport.innerHTML = ` |
| 264 | <header class="r-overlay-header"> |
| 265 | <button class="r-overlay-header-button r-overlay-close">Esc <span class="icon"></span></button> |
| 266 | </header> |
| 267 | <div class="r-overlay-content"> |
| 268 | <div class="r-overlay-help-content">${html}</div> |
| 269 | </div> |
| 270 | `; |
| 271 | |
| 272 | this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', event => { |
| 273 | this.close(); |
| 274 | event.preventDefault(); |
| 275 | }, false ); |
| 276 | |
| 277 | this.Reveal.dispatchEvent({ type: 'showhelp' }); |
| 278 | |
| 279 | } |
| 280 | |
| 281 | } |
| 282 | |
| 283 | isOpen() { |
| 284 | |
| 285 | return !!this.dom; |
| 286 | |
| 287 | } |
| 288 | |
| 289 | /** |
| 290 | * Closes any currently open overlay. |
| 291 | */ |
| 292 | close() { |
| 293 | |
| 294 | if( this.dom ) { |
| 295 | this.dom.remove(); |
| 296 | this.dom = null; |
| 297 | |
| 298 | this.state = {}; |
| 299 | |
| 300 | this.Reveal.dispatchEvent({ type: 'closeoverlay' }); |
| 301 | |
| 302 | return true; |
| 303 | } |
| 304 | |
| 305 | return false; |
| 306 | |
| 307 | } |
| 308 | |
| 309 | getState() { |
| 310 | |
| 311 | return this.state; |
| 312 | |
| 313 | } |
| 314 | |
| 315 | setState( state ) { |
| 316 | |
| 317 | // Ignore the incoming state if none of the preview related |
| 318 | // props have changed |
| 319 | if( this.stateProps.every( key => this.state[ key ] === state[ key ] ) ) { |
| 320 | return; |
| 321 | } |
| 322 | |
| 323 | if( state.previewIframe ) { |
| 324 | this.previewIframe( state.previewIframe ); |
| 325 | } |
| 326 | else if( state.previewImage ) { |
| 327 | this.previewImage( state.previewImage, state.previewFit ); |
| 328 | } |
| 329 | else if( state.previewVideo ) { |
| 330 | this.previewVideo( state.previewVideo, state.previewFit ); |
| 331 | } |
| 332 | else { |
| 333 | this.close(); |
| 334 | } |
| 335 | |
| 336 | } |
| 337 | |
| 338 | onSlidesClicked( event ) { |
| 339 | |
| 340 | const target = event.target; |
| 341 | |
| 342 | const linkTarget = target.closest( this.iframeTriggerSelector ); |
| 343 | const mediaTarget = target.closest( this.mediaTriggerSelector ); |
| 344 | |
| 345 | // Was an iframe lightbox trigger clicked? |
| 346 | if( linkTarget ) { |
| 347 | if( event.metaKey || event.shiftKey || event.altKey ) { |
| 348 | // Let the browser handle meta keys naturally so users can cmd+click |
| 349 | return; |
| 350 | } |
| 351 | const dataPreviewLink = linkTarget.getAttribute( 'data-preview-link' ); |
| 352 | const dataPreviewLinkIsUrl = typeof dataPreviewLink === 'string' && dataPreviewLink.startsWith( 'http' ); |
| 353 | let url = dataPreviewLinkIsUrl ? dataPreviewLink : linkTarget.getAttribute( 'href' ); |
| 354 | if( url ) { |
| 355 | this.previewIframe( url ); |
| 356 | event.preventDefault(); |
| 357 | } |
| 358 | } |
| 359 | // Was a media lightbox trigger clicked? |
| 360 | else if( mediaTarget ) { |
| 361 | if( mediaTarget.hasAttribute( 'data-preview-image' ) ) { |
| 362 | let url = mediaTarget.dataset.previewImage || mediaTarget.getAttribute( 'src' ); |
| 363 | if( url ) { |
| 364 | this.previewImage( url, mediaTarget.dataset.previewFit ); |
| 365 | event.preventDefault(); |
| 366 | } |
| 367 | } |
| 368 | else if( mediaTarget.hasAttribute( 'data-preview-video' ) ) { |
| 369 | let url = mediaTarget.dataset.previewVideo || mediaTarget.getAttribute( 'src' ); |
| 370 | if( !url ) { |
| 371 | let source = mediaTarget.querySelector( 'source' ); |
| 372 | if( source ) { |
| 373 | url = source.getAttribute( 'src' ); |
| 374 | } |
| 375 | } |
| 376 | if( url ) { |
| 377 | this.previewVideo( url, mediaTarget.dataset.previewFit ); |
| 378 | event.preventDefault(); |
| 379 | } |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | } |
| 384 | |
| 385 | destroy() { |
| 386 | |
| 387 | this.close(); |
| 388 | |
| 389 | } |
| 390 | |
| 391 | } |