+
+
+
+ MuT | Python-Workshop
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
',
+ '',
+ '',
+ 'Unable to load iframe. This is likely due to the site\'s policy (x-frame-options).',
+ '',
+ '
'
+ ].join('');
+
+ dom.overlay.querySelector( 'iframe' ).addEventListener( 'load', function( event ) {
+ dom.overlay.classList.add( 'loaded' );
+ }, false );
+
+ dom.overlay.querySelector( '.close' ).addEventListener( 'click', function( event ) {
+ closeOverlay();
+ event.preventDefault();
+ }, false );
+
+ dom.overlay.querySelector( '.external' ).addEventListener( 'click', function( event ) {
+ closeOverlay();
+ }, false );
+
+ setTimeout( function() {
+ dom.overlay.classList.add( 'visible' );
+ }, 1 );
+
+ }
+
+ /**
+ * Open or close help overlay window.
+ *
+ * @param {Boolean} [override] Flag which overrides the
+ * toggle logic and forcibly sets the desired state. True means
+ * help is open, false means it's closed.
+ */
+ function toggleHelp( override ){
+
+ if( typeof override === 'boolean' ) {
+ override ? showHelp() : closeOverlay();
+ }
+ else {
+ if( dom.overlay ) {
+ closeOverlay();
+ }
+ else {
+ showHelp();
+ }
+ }
+ }
+
+ /**
+ * Opens an overlay window with help material.
+ */
+ function showHelp() {
+
+ if( config.help ) {
+
+ closeOverlay();
+
+ dom.overlay = document.createElement( 'div' );
+ dom.overlay.classList.add( 'overlay' );
+ dom.overlay.classList.add( 'overlay-help' );
+ dom.wrapper.appendChild( dom.overlay );
+
+ var html = 'Keyboard Shortcuts
';
+
+ html += '| KEY | ACTION | ';
+ for( var key in keyboardShortcuts ) {
+ html += '| ' + key + ' | ' + keyboardShortcuts[ key ] + ' |
';
+ }
+
+ html += '
';
+
+ dom.overlay.innerHTML = [
+ '',
+ ''
+ ].join('');
+
+ dom.overlay.querySelector( '.close' ).addEventListener( 'click', function( event ) {
+ closeOverlay();
+ event.preventDefault();
+ }, false );
+
+ setTimeout( function() {
+ dom.overlay.classList.add( 'visible' );
+ }, 1 );
+
+ }
+
+ }
+
+ /**
+ * Closes any currently open overlay.
+ */
+ function closeOverlay() {
+
+ if( dom.overlay ) {
+ dom.overlay.parentNode.removeChild( dom.overlay );
+ dom.overlay = null;
+ }
+
+ }
+
+ /**
+ * Applies JavaScript-controlled layout rules to the
+ * presentation.
+ */
+ function layout() {
+
+ if( dom.wrapper && !isPrintingPDF() ) {
+
+ var size = getComputedSlideSize();
+
+ // Layout the contents of the slides
+ layoutSlideContents( config.width, config.height );
+
+ dom.slides.style.width = size.width + 'px';
+ dom.slides.style.height = size.height + 'px';
+
+ // Determine scale of content to fit within available space
+ scale = Math.min( size.presentationWidth / size.width, size.presentationHeight / size.height );
+
+ // Respect max/min scale settings
+ scale = Math.max( scale, config.minScale );
+ scale = Math.min( scale, config.maxScale );
+
+ // Don't apply any scaling styles if scale is 1
+ if( scale === 1 ) {
+ dom.slides.style.zoom = '';
+ dom.slides.style.left = '';
+ dom.slides.style.top = '';
+ dom.slides.style.bottom = '';
+ dom.slides.style.right = '';
+ transformSlides( { layout: '' } );
+ }
+ else {
+ // Prefer zoom for scaling up so that content remains crisp.
+ // Don't use zoom to scale down since that can lead to shifts
+ // in text layout/line breaks.
+ if( scale > 1 && features.zoom ) {
+ dom.slides.style.zoom = scale;
+ dom.slides.style.left = '';
+ dom.slides.style.top = '';
+ dom.slides.style.bottom = '';
+ dom.slides.style.right = '';
+ transformSlides( { layout: '' } );
+ }
+ // Apply scale transform as a fallback
+ else {
+ dom.slides.style.zoom = '';
+ dom.slides.style.left = '50%';
+ dom.slides.style.top = '50%';
+ dom.slides.style.bottom = 'auto';
+ dom.slides.style.right = 'auto';
+ transformSlides( { layout: 'translate(-50%, -50%) scale('+ scale +')' } );
+ }
+ }
+
+ // Select all slides, vertical and horizontal
+ var slides = toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) );
+
+ for( var i = 0, len = slides.length; i < len; i++ ) {
+ var slide = slides[ i ];
+
+ // Don't bother updating invisible slides
+ if( slide.style.display === 'none' ) {
+ continue;
+ }
+
+ if( config.center || slide.classList.contains( 'center' ) ) {
+ // Vertical stacks are not centred since their section
+ // children will be
+ if( slide.classList.contains( 'stack' ) ) {
+ slide.style.top = 0;
+ }
+ else {
+ slide.style.top = Math.max( ( size.height - slide.scrollHeight ) / 2, 0 ) + 'px';
+ }
+ }
+ else {
+ slide.style.top = '';
+ }
+
+ }
+
+ updateProgress();
+ updateParallax();
+
+ if( isOverview() ) {
+ updateOverview();
+ }
+
+ }
+
+ }
+
+ /**
+ * Applies layout logic to the contents of all slides in
+ * the presentation.
+ *
+ * @param {string|number} width
+ * @param {string|number} height
+ */
+ function layoutSlideContents( width, height ) {
+
+ // Handle sizing of elements with the 'stretch' class
+ toArray( dom.slides.querySelectorAll( 'section > .stretch' ) ).forEach( function( element ) {
+
+ // Determine how much vertical space we can use
+ var remainingHeight = getRemainingHeight( element, height );
+
+ // Consider the aspect ratio of media elements
+ if( /(img|video)/gi.test( element.nodeName ) ) {
+ var nw = element.naturalWidth || element.videoWidth,
+ nh = element.naturalHeight || element.videoHeight;
+
+ var es = Math.min( width / nw, remainingHeight / nh );
+
+ element.style.width = ( nw * es ) + 'px';
+ element.style.height = ( nh * es ) + 'px';
+
+ }
+ else {
+ element.style.width = width + 'px';
+ element.style.height = remainingHeight + 'px';
+ }
+
+ } );
+
+ }
+
+ /**
+ * Calculates the computed pixel size of our slides. These
+ * values are based on the width and height configuration
+ * options.
+ *
+ * @param {number} [presentationWidth=dom.wrapper.offsetWidth]
+ * @param {number} [presentationHeight=dom.wrapper.offsetHeight]
+ */
+ function getComputedSlideSize( presentationWidth, presentationHeight ) {
+
+ var size = {
+ // Slide size
+ width: config.width,
+ height: config.height,
+
+ // Presentation size
+ presentationWidth: presentationWidth || dom.wrapper.offsetWidth,
+ presentationHeight: presentationHeight || dom.wrapper.offsetHeight
+ };
+
+ // Reduce available space by margin
+ size.presentationWidth -= ( size.presentationWidth * config.margin );
+ size.presentationHeight -= ( size.presentationHeight * config.margin );
+
+ // Slide width may be a percentage of available width
+ if( typeof size.width === 'string' && /%$/.test( size.width ) ) {
+ size.width = parseInt( size.width, 10 ) / 100 * size.presentationWidth;
+ }
+
+ // Slide height may be a percentage of available height
+ if( typeof size.height === 'string' && /%$/.test( size.height ) ) {
+ size.height = parseInt( size.height, 10 ) / 100 * size.presentationHeight;
+ }
+
+ return size;
+
+ }
+
+ /**
+ * Stores the vertical index of a stack so that the same
+ * vertical slide can be selected when navigating to and
+ * from the stack.
+ *
+ * @param {HTMLElement} stack The vertical stack element
+ * @param {string|number} [v=0] Index to memorize
+ */
+ function setPreviousVerticalIndex( stack, v ) {
+
+ if( typeof stack === 'object' && typeof stack.setAttribute === 'function' ) {
+ stack.setAttribute( 'data-previous-indexv', v || 0 );
+ }
+
+ }
+
+ /**
+ * Retrieves the vertical index which was stored using
+ * #setPreviousVerticalIndex() or 0 if no previous index
+ * exists.
+ *
+ * @param {HTMLElement} stack The vertical stack element
+ */
+ function getPreviousVerticalIndex( stack ) {
+
+ if( typeof stack === 'object' && typeof stack.setAttribute === 'function' && stack.classList.contains( 'stack' ) ) {
+ // Prefer manually defined start-indexv
+ var attributeName = stack.hasAttribute( 'data-start-indexv' ) ? 'data-start-indexv' : 'data-previous-indexv';
+
+ return parseInt( stack.getAttribute( attributeName ) || 0, 10 );
+ }
+
+ return 0;
+
+ }
+
+ /**
+ * Displays the overview of slides (quick nav) by scaling
+ * down and arranging all slide elements.
+ */
+ function activateOverview() {
+
+ // Only proceed if enabled in config
+ if( config.overview && !isOverview() ) {
+
+ overview = true;
+
+ dom.wrapper.classList.add( 'overview' );
+ dom.wrapper.classList.remove( 'overview-deactivating' );
+
+ if( features.overviewTransitions ) {
+ setTimeout( function() {
+ dom.wrapper.classList.add( 'overview-animated' );
+ }, 1 );
+ }
+
+ // Don't auto-slide while in overview mode
+ cancelAutoSlide();
+
+ // Move the backgrounds element into the slide container to
+ // that the same scaling is applied
+ dom.slides.appendChild( dom.background );
+
+ // Clicking on an overview slide navigates to it
+ toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
+ if( !slide.classList.contains( 'stack' ) ) {
+ slide.addEventListener( 'click', onOverviewSlideClicked, true );
+ }
+ } );
+
+ // Calculate slide sizes
+ var margin = 70;
+ var slideSize = getComputedSlideSize();
+ overviewSlideWidth = slideSize.width + margin;
+ overviewSlideHeight = slideSize.height + margin;
+
+ // Reverse in RTL mode
+ if( config.rtl ) {
+ overviewSlideWidth = -overviewSlideWidth;
+ }
+
+ updateSlidesVisibility();
+ layoutOverview();
+ updateOverview();
+
+ layout();
+
+ // Notify observers of the overview showing
+ dispatchEvent( 'overviewshown', {
+ 'indexh': indexh,
+ 'indexv': indexv,
+ 'currentSlide': currentSlide
+ } );
+
+ }
+
+ }
+
+ /**
+ * Uses CSS transforms to position all slides in a grid for
+ * display inside of the overview mode.
+ */
+ function layoutOverview() {
+
+ // Layout slides
+ toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ).forEach( function( hslide, h ) {
+ hslide.setAttribute( 'data-index-h', h );
+ transformElement( hslide, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' );
+
+ if( hslide.classList.contains( 'stack' ) ) {
+
+ toArray( hslide.querySelectorAll( 'section' ) ).forEach( function( vslide, v ) {
+ vslide.setAttribute( 'data-index-h', h );
+ vslide.setAttribute( 'data-index-v', v );
+
+ transformElement( vslide, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' );
+ } );
+
+ }
+ } );
+
+ // Layout slide backgrounds
+ toArray( dom.background.childNodes ).forEach( function( hbackground, h ) {
+ transformElement( hbackground, 'translate3d(' + ( h * overviewSlideWidth ) + 'px, 0, 0)' );
+
+ toArray( hbackground.querySelectorAll( '.slide-background' ) ).forEach( function( vbackground, v ) {
+ transformElement( vbackground, 'translate3d(0, ' + ( v * overviewSlideHeight ) + 'px, 0)' );
+ } );
+ } );
+
+ }
+
+ /**
+ * Moves the overview viewport to the current slides.
+ * Called each time the current slide changes.
+ */
+ function updateOverview() {
+
+ var vmin = Math.min( window.innerWidth, window.innerHeight );
+ var scale = Math.max( vmin / 5, 150 ) / vmin;
+
+ transformSlides( {
+ overview: [
+ 'scale('+ scale +')',
+ 'translateX('+ ( -indexh * overviewSlideWidth ) +'px)',
+ 'translateY('+ ( -indexv * overviewSlideHeight ) +'px)'
+ ].join( ' ' )
+ } );
+
+ }
+
+ /**
+ * Exits the slide overview and enters the currently
+ * active slide.
+ */
+ function deactivateOverview() {
+
+ // Only proceed if enabled in config
+ if( config.overview ) {
+
+ overview = false;
+
+ dom.wrapper.classList.remove( 'overview' );
+ dom.wrapper.classList.remove( 'overview-animated' );
+
+ // Temporarily add a class so that transitions can do different things
+ // depending on whether they are exiting/entering overview, or just
+ // moving from slide to slide
+ dom.wrapper.classList.add( 'overview-deactivating' );
+
+ setTimeout( function () {
+ dom.wrapper.classList.remove( 'overview-deactivating' );
+ }, 1 );
+
+ // Move the background element back out
+ dom.wrapper.appendChild( dom.background );
+
+ // Clean up changes made to slides
+ toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR ) ).forEach( function( slide ) {
+ transformElement( slide, '' );
+
+ slide.removeEventListener( 'click', onOverviewSlideClicked, true );
+ } );
+
+ // Clean up changes made to backgrounds
+ toArray( dom.background.querySelectorAll( '.slide-background' ) ).forEach( function( background ) {
+ transformElement( background, '' );
+ } );
+
+ transformSlides( { overview: '' } );
+
+ slide( indexh, indexv );
+
+ layout();
+
+ cueAutoSlide();
+
+ // Notify observers of the overview hiding
+ dispatchEvent( 'overviewhidden', {
+ 'indexh': indexh,
+ 'indexv': indexv,
+ 'currentSlide': currentSlide
+ } );
+
+ }
+ }
+
+ /**
+ * Toggles the slide overview mode on and off.
+ *
+ * @param {Boolean} [override] Flag which overrides the
+ * toggle logic and forcibly sets the desired state. True means
+ * overview is open, false means it's closed.
+ */
+ function toggleOverview( override ) {
+
+ if( typeof override === 'boolean' ) {
+ override ? activateOverview() : deactivateOverview();
+ }
+ else {
+ isOverview() ? deactivateOverview() : activateOverview();
+ }
+
+ }
+
+ /**
+ * Checks if the overview is currently active.
+ *
+ * @return {Boolean} true if the overview is active,
+ * false otherwise
+ */
+ function isOverview() {
+
+ return overview;
+
+ }
+
+ /**
+ * Checks if the current or specified slide is vertical
+ * (nested within another slide).
+ *
+ * @param {HTMLElement} [slide=currentSlide] The slide to check
+ * orientation of
+ * @return {Boolean}
+ */
+ function isVerticalSlide( slide ) {
+
+ // Prefer slide argument, otherwise use current slide
+ slide = slide ? slide : currentSlide;
+
+ return slide && slide.parentNode && !!slide.parentNode.nodeName.match( /section/i );
+
+ }
+
+ /**
+ * Handling the fullscreen functionality via the fullscreen API
+ *
+ * @see http://fullscreen.spec.whatwg.org/
+ * @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
+ */
+ function enterFullscreen() {
+
+ var element = document.documentElement;
+
+ // Check which implementation is available
+ var requestMethod = element.requestFullscreen ||
+ element.webkitRequestFullscreen ||
+ element.webkitRequestFullScreen ||
+ element.mozRequestFullScreen ||
+ element.msRequestFullscreen;
+
+ if( requestMethod ) {
+ requestMethod.apply( element );
+ }
+
+ }
+
+ /**
+ * Enters the paused mode which fades everything on screen to
+ * black.
+ */
+ function pause() {
+
+ if( config.pause ) {
+ var wasPaused = dom.wrapper.classList.contains( 'paused' );
+
+ cancelAutoSlide();
+ dom.wrapper.classList.add( 'paused' );
+
+ if( wasPaused === false ) {
+ dispatchEvent( 'paused' );
+ }
+ }
+
+ }
+
+ /**
+ * Exits from the paused mode.
+ */
+ function resume() {
+
+ var wasPaused = dom.wrapper.classList.contains( 'paused' );
+ dom.wrapper.classList.remove( 'paused' );
+
+ cueAutoSlide();
+
+ if( wasPaused ) {
+ dispatchEvent( 'resumed' );
+ }
+
+ }
+
+ /**
+ * Toggles the paused mode on and off.
+ */
+ function togglePause( override ) {
+
+ if( typeof override === 'boolean' ) {
+ override ? pause() : resume();
+ }
+ else {
+ isPaused() ? resume() : pause();
+ }
+
+ }
+
+ /**
+ * Checks if we are currently in the paused mode.
+ *
+ * @return {Boolean}
+ */
+ function isPaused() {
+
+ return dom.wrapper.classList.contains( 'paused' );
+
+ }
+
+ /**
+ * Toggles the auto slide mode on and off.
+ *
+ * @param {Boolean} [override] Flag which sets the desired state.
+ * True means autoplay starts, false means it stops.
+ */
+
+ function toggleAutoSlide( override ) {
+
+ if( typeof override === 'boolean' ) {
+ override ? resumeAutoSlide() : pauseAutoSlide();
+ }
+
+ else {
+ autoSlidePaused ? resumeAutoSlide() : pauseAutoSlide();
+ }
+
+ }
+
+ /**
+ * Checks if the auto slide mode is currently on.
+ *
+ * @return {Boolean}
+ */
+ function isAutoSliding() {
+
+ return !!( autoSlide && !autoSlidePaused );
+
+ }
+
+ /**
+ * Steps from the current point in the presentation to the
+ * slide which matches the specified horizontal and vertical
+ * indices.
+ *
+ * @param {number} [h=indexh] Horizontal index of the target slide
+ * @param {number} [v=indexv] Vertical index of the target slide
+ * @param {number} [f] Index of a fragment within the
+ * target slide to activate
+ * @param {number} [o] Origin for use in multimaster environments
+ */
+ function slide( h, v, f, o ) {
+
+ // Remember where we were at before
+ previousSlide = currentSlide;
+
+ // Query all horizontal slides in the deck
+ var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
+
+ // Abort if there are no slides
+ if( horizontalSlides.length === 0 ) return;
+
+ // If no vertical index is specified and the upcoming slide is a
+ // stack, resume at its previous vertical index
+ if( v === undefined && !isOverview() ) {
+ v = getPreviousVerticalIndex( horizontalSlides[ h ] );
+ }
+
+ // If we were on a vertical stack, remember what vertical index
+ // it was on so we can resume at the same position when returning
+ if( previousSlide && previousSlide.parentNode && previousSlide.parentNode.classList.contains( 'stack' ) ) {
+ setPreviousVerticalIndex( previousSlide.parentNode, indexv );
+ }
+
+ // Remember the state before this slide
+ var stateBefore = state.concat();
+
+ // Reset the state array
+ state.length = 0;
+
+ var indexhBefore = indexh || 0,
+ indexvBefore = indexv || 0;
+
+ // Activate and transition to the new slide
+ indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, h === undefined ? indexh : h );
+ indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, v === undefined ? indexv : v );
+
+ // Update the visibility of slides now that the indices have changed
+ updateSlidesVisibility();
+
+ layout();
+
+ // Apply the new state
+ stateLoop: for( var i = 0, len = state.length; i < len; i++ ) {
+ // Check if this state existed on the previous slide. If it
+ // did, we will avoid adding it repeatedly
+ for( var j = 0; j < stateBefore.length; j++ ) {
+ if( stateBefore[j] === state[i] ) {
+ stateBefore.splice( j, 1 );
+ continue stateLoop;
+ }
+ }
+
+ document.documentElement.classList.add( state[i] );
+
+ // Dispatch custom event matching the state's name
+ dispatchEvent( state[i] );
+ }
+
+ // Clean up the remains of the previous state
+ while( stateBefore.length ) {
+ document.documentElement.classList.remove( stateBefore.pop() );
+ }
+
+ // Update the overview if it's currently active
+ if( isOverview() ) {
+ updateOverview();
+ }
+
+ // Find the current horizontal slide and any possible vertical slides
+ // within it
+ var currentHorizontalSlide = horizontalSlides[ indexh ],
+ currentVerticalSlides = currentHorizontalSlide.querySelectorAll( 'section' );
+
+ // Store references to the previous and current slides
+ currentSlide = currentVerticalSlides[ indexv ] || currentHorizontalSlide;
+
+ // Show fragment, if specified
+ if( typeof f !== 'undefined' ) {
+ navigateFragment( f );
+ }
+
+ // Dispatch an event if the slide changed
+ var slideChanged = ( indexh !== indexhBefore || indexv !== indexvBefore );
+ if( slideChanged ) {
+ dispatchEvent( 'slidechanged', {
+ 'indexh': indexh,
+ 'indexv': indexv,
+ 'previousSlide': previousSlide,
+ 'currentSlide': currentSlide,
+ 'origin': o
+ } );
+ }
+ else {
+ // Ensure that the previous slide is never the same as the current
+ previousSlide = null;
+ }
+
+ // Solves an edge case where the previous slide maintains the
+ // 'present' class when navigating between adjacent vertical
+ // stacks
+ if( previousSlide ) {
+ previousSlide.classList.remove( 'present' );
+ previousSlide.setAttribute( 'aria-hidden', 'true' );
+
+ // Reset all slides upon navigate to home
+ // Issue: #285
+ if ( dom.wrapper.querySelector( HOME_SLIDE_SELECTOR ).classList.contains( 'present' ) ) {
+ // Launch async task
+ setTimeout( function () {
+ var slides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.stack') ), i;
+ for( i in slides ) {
+ if( slides[i] ) {
+ // Reset stack
+ setPreviousVerticalIndex( slides[i], 0 );
+ }
+ }
+ }, 0 );
+ }
+ }
+
+ // Handle embedded content
+ if( slideChanged || !previousSlide ) {
+ stopEmbeddedContent( previousSlide );
+ startEmbeddedContent( currentSlide );
+ }
+
+ // Announce the current slide contents, for screen readers
+ dom.statusDiv.textContent = getStatusText( currentSlide );
+
+ updateControls();
+ updateProgress();
+ updateBackground();
+ updateParallax();
+ updateSlideNumber();
+ updateNotes();
+
+ // Update the URL hash
+ writeURL();
+
+ cueAutoSlide();
+
+ }
+
+ /**
+ * Syncs the presentation with the current DOM. Useful
+ * when new slides or control elements are added or when
+ * the configuration has changed.
+ */
+ function sync() {
+
+ // Subscribe to input
+ removeEventListeners();
+ addEventListeners();
+
+ // Force a layout to make sure the current config is accounted for
+ layout();
+
+ // Reflect the current autoSlide value
+ autoSlide = config.autoSlide;
+
+ // Start auto-sliding if it's enabled
+ cueAutoSlide();
+
+ // Re-create the slide backgrounds
+ createBackgrounds();
+
+ // Write the current hash to the URL
+ writeURL();
+
+ sortAllFragments();
+
+ updateControls();
+ updateProgress();
+ updateSlideNumber();
+ updateSlidesVisibility();
+ updateBackground( true );
+ updateNotesVisibility();
+ updateNotes();
+
+ formatEmbeddedContent();
+
+ // Start or stop embedded content depending on global config
+ if( config.autoPlayMedia === false ) {
+ stopEmbeddedContent( currentSlide, { unloadIframes: false } );
+ }
+ else {
+ startEmbeddedContent( currentSlide );
+ }
+
+ if( isOverview() ) {
+ layoutOverview();
+ }
+
+ }
+
+ /**
+ * Resets all vertical slides so that only the first
+ * is visible.
+ */
+ function resetVerticalSlides() {
+
+ var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+ horizontalSlides.forEach( function( horizontalSlide ) {
+
+ var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
+ verticalSlides.forEach( function( verticalSlide, y ) {
+
+ if( y > 0 ) {
+ verticalSlide.classList.remove( 'present' );
+ verticalSlide.classList.remove( 'past' );
+ verticalSlide.classList.add( 'future' );
+ verticalSlide.setAttribute( 'aria-hidden', 'true' );
+ }
+
+ } );
+
+ } );
+
+ }
+
+ /**
+ * Sorts and formats all of fragments in the
+ * presentation.
+ */
+ function sortAllFragments() {
+
+ var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+ horizontalSlides.forEach( function( horizontalSlide ) {
+
+ var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
+ verticalSlides.forEach( function( verticalSlide, y ) {
+
+ sortFragments( verticalSlide.querySelectorAll( '.fragment' ) );
+
+ } );
+
+ if( verticalSlides.length === 0 ) sortFragments( horizontalSlide.querySelectorAll( '.fragment' ) );
+
+ } );
+
+ }
+
+ /**
+ * Randomly shuffles all slides in the deck.
+ */
+ function shuffle() {
+
+ var slides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+
+ slides.forEach( function( slide ) {
+
+ // Insert this slide next to another random slide. This may
+ // cause the slide to insert before itself but that's fine.
+ dom.slides.insertBefore( slide, slides[ Math.floor( Math.random() * slides.length ) ] );
+
+ } );
+
+ }
+
+ /**
+ * Updates one dimension of slides by showing the slide
+ * with the specified index.
+ *
+ * @param {string} selector A CSS selector that will fetch
+ * the group of slides we are working with
+ * @param {number} index The index of the slide that should be
+ * shown
+ *
+ * @return {number} The index of the slide that is now shown,
+ * might differ from the passed in index if it was out of
+ * bounds.
+ */
+ function updateSlides( selector, index ) {
+
+ // Select all slides and convert the NodeList result to
+ // an array
+ var slides = toArray( dom.wrapper.querySelectorAll( selector ) ),
+ slidesLength = slides.length;
+
+ var printMode = isPrintingPDF();
+
+ if( slidesLength ) {
+
+ // Should the index loop?
+ if( config.loop ) {
+ index %= slidesLength;
+
+ if( index < 0 ) {
+ index = slidesLength + index;
+ }
+ }
+
+ // Enforce max and minimum index bounds
+ index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
+
+ for( var i = 0; i < slidesLength; i++ ) {
+ var element = slides[i];
+
+ var reverse = config.rtl && !isVerticalSlide( element );
+
+ element.classList.remove( 'past' );
+ element.classList.remove( 'present' );
+ element.classList.remove( 'future' );
+
+ // http://www.w3.org/html/wg/drafts/html/master/editing.html#the-hidden-attribute
+ element.setAttribute( 'hidden', '' );
+ element.setAttribute( 'aria-hidden', 'true' );
+
+ // If this element contains vertical slides
+ if( element.querySelector( 'section' ) ) {
+ element.classList.add( 'stack' );
+ }
+
+ // If we're printing static slides, all slides are "present"
+ if( printMode ) {
+ element.classList.add( 'present' );
+ continue;
+ }
+
+ if( i < index ) {
+ // Any element previous to index is given the 'past' class
+ element.classList.add( reverse ? 'future' : 'past' );
+
+ if( config.fragments ) {
+ var pastFragments = toArray( element.querySelectorAll( '.fragment' ) );
+
+ // Show all fragments on prior slides
+ while( pastFragments.length ) {
+ var pastFragment = pastFragments.pop();
+ pastFragment.classList.add( 'visible' );
+ pastFragment.classList.remove( 'current-fragment' );
+ }
+ }
+ }
+ else if( i > index ) {
+ // Any element subsequent to index is given the 'future' class
+ element.classList.add( reverse ? 'past' : 'future' );
+
+ if( config.fragments ) {
+ var futureFragments = toArray( element.querySelectorAll( '.fragment.visible' ) );
+
+ // No fragments in future slides should be visible ahead of time
+ while( futureFragments.length ) {
+ var futureFragment = futureFragments.pop();
+ futureFragment.classList.remove( 'visible' );
+ futureFragment.classList.remove( 'current-fragment' );
+ }
+ }
+ }
+ }
+
+ // Mark the current slide as present
+ slides[index].classList.add( 'present' );
+ slides[index].removeAttribute( 'hidden' );
+ slides[index].removeAttribute( 'aria-hidden' );
+
+ // If this slide has a state associated with it, add it
+ // onto the current state of the deck
+ var slideState = slides[index].getAttribute( 'data-state' );
+ if( slideState ) {
+ state = state.concat( slideState.split( ' ' ) );
+ }
+
+ }
+ else {
+ // Since there are no slides we can't be anywhere beyond the
+ // zeroth index
+ index = 0;
+ }
+
+ return index;
+
+ }
+
+ /**
+ * Optimization method; hide all slides that are far away
+ * from the present slide.
+ */
+ function updateSlidesVisibility() {
+
+ // Select all slides and convert the NodeList result to
+ // an array
+ var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) ),
+ horizontalSlidesLength = horizontalSlides.length,
+ distanceX,
+ distanceY;
+
+ if( horizontalSlidesLength && typeof indexh !== 'undefined' ) {
+
+ // The number of steps away from the present slide that will
+ // be visible
+ var viewDistance = isOverview() ? 10 : config.viewDistance;
+
+ // Limit view distance on weaker devices
+ if( isMobileDevice ) {
+ viewDistance = isOverview() ? 6 : 2;
+ }
+
+ // All slides need to be visible when exporting to PDF
+ if( isPrintingPDF() ) {
+ viewDistance = Number.MAX_VALUE;
+ }
+
+ for( var x = 0; x < horizontalSlidesLength; x++ ) {
+ var horizontalSlide = horizontalSlides[x];
+
+ var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) ),
+ verticalSlidesLength = verticalSlides.length;
+
+ // Determine how far away this slide is from the present
+ distanceX = Math.abs( ( indexh || 0 ) - x ) || 0;
+
+ // If the presentation is looped, distance should measure
+ // 1 between the first and last slides
+ if( config.loop ) {
+ distanceX = Math.abs( ( ( indexh || 0 ) - x ) % ( horizontalSlidesLength - viewDistance ) ) || 0;
+ }
+
+ // Show the horizontal slide if it's within the view distance
+ if( distanceX < viewDistance ) {
+ loadSlide( horizontalSlide );
+ }
+ else {
+ unloadSlide( horizontalSlide );
+ }
+
+ if( verticalSlidesLength ) {
+
+ var oy = getPreviousVerticalIndex( horizontalSlide );
+
+ for( var y = 0; y < verticalSlidesLength; y++ ) {
+ var verticalSlide = verticalSlides[y];
+
+ distanceY = x === ( indexh || 0 ) ? Math.abs( ( indexv || 0 ) - y ) : Math.abs( y - oy );
+
+ if( distanceX + distanceY < viewDistance ) {
+ loadSlide( verticalSlide );
+ }
+ else {
+ unloadSlide( verticalSlide );
+ }
+ }
+
+ }
+ }
+
+ // Flag if there are ANY vertical slides, anywhere in the deck
+ if( dom.wrapper.querySelectorAll( '.slides>section>section' ).length ) {
+ dom.wrapper.classList.add( 'has-vertical-slides' );
+ }
+ else {
+ dom.wrapper.classList.remove( 'has-vertical-slides' );
+ }
+
+ // Flag if there are ANY horizontal slides, anywhere in the deck
+ if( dom.wrapper.querySelectorAll( '.slides>section' ).length > 1 ) {
+ dom.wrapper.classList.add( 'has-horizontal-slides' );
+ }
+ else {
+ dom.wrapper.classList.remove( 'has-horizontal-slides' );
+ }
+
+ }
+
+ }
+
+ /**
+ * Pick up notes from the current slide and display them
+ * to the viewer.
+ *
+ * @see {@link config.showNotes}
+ */
+ function updateNotes() {
+
+ if( config.showNotes && dom.speakerNotes && currentSlide && !isPrintingPDF() ) {
+
+ dom.speakerNotes.innerHTML = getSlideNotes() || 'No notes on this slide.';
+
+ }
+
+ }
+
+ /**
+ * Updates the visibility of the speaker notes sidebar that
+ * is used to share annotated slides. The notes sidebar is
+ * only visible if showNotes is true and there are notes on
+ * one or more slides in the deck.
+ */
+ function updateNotesVisibility() {
+
+ if( config.showNotes && hasNotes() ) {
+ dom.wrapper.classList.add( 'show-notes' );
+ }
+ else {
+ dom.wrapper.classList.remove( 'show-notes' );
+ }
+
+ }
+
+ /**
+ * Checks if there are speaker notes for ANY slide in the
+ * presentation.
+ */
+ function hasNotes() {
+
+ return dom.slides.querySelectorAll( '[data-notes], aside.notes' ).length > 0;
+
+ }
+
+ /**
+ * Updates the progress bar to reflect the current slide.
+ */
+ function updateProgress() {
+
+ // Update progress if enabled
+ if( config.progress && dom.progressbar ) {
+
+ dom.progressbar.style.width = getProgress() * dom.wrapper.offsetWidth + 'px';
+
+ }
+
+ }
+
+ /**
+ * Updates the slide number div to reflect the current slide.
+ *
+ * The following slide number formats are available:
+ * "h.v": horizontal . vertical slide number (default)
+ * "h/v": horizontal / vertical slide number
+ * "c": flattened slide number
+ * "c/t": flattened slide number / total slides
+ */
+ function updateSlideNumber() {
+
+ // Update slide number if enabled
+ if( config.slideNumber && dom.slideNumber ) {
+
+ var value = [];
+ var format = 'h.v';
+
+ // Check if a custom number format is available
+ if( typeof config.slideNumber === 'string' ) {
+ format = config.slideNumber;
+ }
+
+ switch( format ) {
+ case 'c':
+ value.push( getSlidePastCount() + 1 );
+ break;
+ case 'c/t':
+ value.push( getSlidePastCount() + 1, '/', getTotalSlides() );
+ break;
+ case 'h/v':
+ value.push( indexh + 1 );
+ if( isVerticalSlide() ) value.push( '/', indexv + 1 );
+ break;
+ default:
+ value.push( indexh + 1 );
+ if( isVerticalSlide() ) value.push( '.', indexv + 1 );
+ }
+
+ dom.slideNumber.innerHTML = formatSlideNumber( value[0], value[1], value[2] );
+ }
+
+ }
+
+ /**
+ * Applies HTML formatting to a slide number before it's
+ * written to the DOM.
+ *
+ * @param {number} a Current slide
+ * @param {string} delimiter Character to separate slide numbers
+ * @param {(number|*)} b Total slides
+ * @return {string} HTML string fragment
+ */
+ function formatSlideNumber( a, delimiter, b ) {
+
+ if( typeof b === 'number' && !isNaN( b ) ) {
+ return ''+ a +'' +
+ ''+ delimiter +'' +
+ ''+ b +'';
+ }
+ else {
+ return ''+ a +'';
+ }
+
+ }
+
+ /**
+ * Updates the state of all control/navigation arrows.
+ */
+ function updateControls() {
+
+ var routes = availableRoutes();
+ var fragments = availableFragments();
+
+ // Remove the 'enabled' class from all directions
+ dom.controlsLeft.concat( dom.controlsRight )
+ .concat( dom.controlsUp )
+ .concat( dom.controlsDown )
+ .concat( dom.controlsPrev )
+ .concat( dom.controlsNext ).forEach( function( node ) {
+ node.classList.remove( 'enabled' );
+ node.classList.remove( 'fragmented' );
+
+ // Set 'disabled' attribute on all directions
+ node.setAttribute( 'disabled', 'disabled' );
+ } );
+
+ // Add the 'enabled' class to the available routes; remove 'disabled' attribute to enable buttons
+ if( routes.left ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( routes.right ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( routes.up ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( routes.down ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+
+ // Prev/next buttons
+ if( routes.left || routes.up ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( routes.right || routes.down ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'enabled' ); el.removeAttribute( 'disabled' ); } );
+
+ // Highlight fragment directions
+ if( currentSlide ) {
+
+ // Always apply fragment decorator to prev/next buttons
+ if( fragments.prev ) dom.controlsPrev.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( fragments.next ) dom.controlsNext.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+
+ // Apply fragment decorators to directional buttons based on
+ // what slide axis they are in
+ if( isVerticalSlide( currentSlide ) ) {
+ if( fragments.prev ) dom.controlsUp.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( fragments.next ) dom.controlsDown.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ }
+ else {
+ if( fragments.prev ) dom.controlsLeft.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ if( fragments.next ) dom.controlsRight.forEach( function( el ) { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
+ }
+
+ }
+
+ if( config.controlsTutorial ) {
+
+ // Highlight control arrows with an animation to ensure
+ // that the viewer knows how to navigate
+ if( !hasNavigatedDown && routes.down ) {
+ dom.controlsDownArrow.classList.add( 'highlight' );
+ }
+ else {
+ dom.controlsDownArrow.classList.remove( 'highlight' );
+
+ if( !hasNavigatedRight && routes.right && indexv === 0 ) {
+ dom.controlsRightArrow.classList.add( 'highlight' );
+ }
+ else {
+ dom.controlsRightArrow.classList.remove( 'highlight' );
+ }
+ }
+
+ }
+
+ }
+
+ /**
+ * Updates the background elements to reflect the current
+ * slide.
+ *
+ * @param {boolean} includeAll If true, the backgrounds of
+ * all vertical slides (not just the present) will be updated.
+ */
+ function updateBackground( includeAll ) {
+
+ var currentBackground = null;
+
+ // Reverse past/future classes when in RTL mode
+ var horizontalPast = config.rtl ? 'future' : 'past',
+ horizontalFuture = config.rtl ? 'past' : 'future';
+
+ // Update the classes of all backgrounds to match the
+ // states of their slides (past/present/future)
+ toArray( dom.background.childNodes ).forEach( function( backgroundh, h ) {
+
+ backgroundh.classList.remove( 'past' );
+ backgroundh.classList.remove( 'present' );
+ backgroundh.classList.remove( 'future' );
+
+ if( h < indexh ) {
+ backgroundh.classList.add( horizontalPast );
+ }
+ else if ( h > indexh ) {
+ backgroundh.classList.add( horizontalFuture );
+ }
+ else {
+ backgroundh.classList.add( 'present' );
+
+ // Store a reference to the current background element
+ currentBackground = backgroundh;
+ }
+
+ if( includeAll || h === indexh ) {
+ toArray( backgroundh.querySelectorAll( '.slide-background' ) ).forEach( function( backgroundv, v ) {
+
+ backgroundv.classList.remove( 'past' );
+ backgroundv.classList.remove( 'present' );
+ backgroundv.classList.remove( 'future' );
+
+ if( v < indexv ) {
+ backgroundv.classList.add( 'past' );
+ }
+ else if ( v > indexv ) {
+ backgroundv.classList.add( 'future' );
+ }
+ else {
+ backgroundv.classList.add( 'present' );
+
+ // Only if this is the present horizontal and vertical slide
+ if( h === indexh ) currentBackground = backgroundv;
+ }
+
+ } );
+ }
+
+ } );
+
+ // Stop content inside of previous backgrounds
+ if( previousBackground ) {
+
+ stopEmbeddedContent( previousBackground );
+
+ }
+
+ // Start content in the current background
+ if( currentBackground ) {
+
+ startEmbeddedContent( currentBackground );
+
+ var backgroundImageURL = currentBackground.style.backgroundImage || '';
+
+ // Restart GIFs (doesn't work in Firefox)
+ if( /\.gif/i.test( backgroundImageURL ) ) {
+ currentBackground.style.backgroundImage = '';
+ window.getComputedStyle( currentBackground ).opacity;
+ currentBackground.style.backgroundImage = backgroundImageURL;
+ }
+
+ // Don't transition between identical backgrounds. This
+ // prevents unwanted flicker.
+ var previousBackgroundHash = previousBackground ? previousBackground.getAttribute( 'data-background-hash' ) : null;
+ var currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' );
+ if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== previousBackground ) {
+ dom.background.classList.add( 'no-transition' );
+ }
+
+ previousBackground = currentBackground;
+
+ }
+
+ // If there's a background brightness flag for this slide,
+ // bubble it to the .reveal container
+ if( currentSlide ) {
+ [ 'has-light-background', 'has-dark-background' ].forEach( function( classToBubble ) {
+ if( currentSlide.classList.contains( classToBubble ) ) {
+ dom.wrapper.classList.add( classToBubble );
+ }
+ else {
+ dom.wrapper.classList.remove( classToBubble );
+ }
+ } );
+ }
+
+ // Allow the first background to apply without transition
+ setTimeout( function() {
+ dom.background.classList.remove( 'no-transition' );
+ }, 1 );
+
+ }
+
+ /**
+ * Updates the position of the parallax background based
+ * on the current slide index.
+ */
+ function updateParallax() {
+
+ if( config.parallaxBackgroundImage ) {
+
+ var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
+ verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
+
+ var backgroundSize = dom.background.style.backgroundSize.split( ' ' ),
+ backgroundWidth, backgroundHeight;
+
+ if( backgroundSize.length === 1 ) {
+ backgroundWidth = backgroundHeight = parseInt( backgroundSize[0], 10 );
+ }
+ else {
+ backgroundWidth = parseInt( backgroundSize[0], 10 );
+ backgroundHeight = parseInt( backgroundSize[1], 10 );
+ }
+
+ var slideWidth = dom.background.offsetWidth,
+ horizontalSlideCount = horizontalSlides.length,
+ horizontalOffsetMultiplier,
+ horizontalOffset;
+
+ if( typeof config.parallaxBackgroundHorizontal === 'number' ) {
+ horizontalOffsetMultiplier = config.parallaxBackgroundHorizontal;
+ }
+ else {
+ horizontalOffsetMultiplier = horizontalSlideCount > 1 ? ( backgroundWidth - slideWidth ) / ( horizontalSlideCount-1 ) : 0;
+ }
+
+ horizontalOffset = horizontalOffsetMultiplier * indexh * -1;
+
+ var slideHeight = dom.background.offsetHeight,
+ verticalSlideCount = verticalSlides.length,
+ verticalOffsetMultiplier,
+ verticalOffset;
+
+ if( typeof config.parallaxBackgroundVertical === 'number' ) {
+ verticalOffsetMultiplier = config.parallaxBackgroundVertical;
+ }
+ else {
+ verticalOffsetMultiplier = ( backgroundHeight - slideHeight ) / ( verticalSlideCount-1 );
+ }
+
+ verticalOffset = verticalSlideCount > 0 ? verticalOffsetMultiplier * indexv : 0;
+
+ dom.background.style.backgroundPosition = horizontalOffset + 'px ' + -verticalOffset + 'px';
+
+ }
+
+ }
+
+ /**
+ * Called when the given slide is within the configured view
+ * distance. Shows the slide element and loads any content
+ * that is set to load lazily (data-src).
+ *
+ * @param {HTMLElement} slide Slide to show
+ */
+ function loadSlide( slide, options ) {
+
+ options = options || {};
+
+ // Show the slide element
+ slide.style.display = config.display;
+
+ // Media elements with data-src attributes
+ toArray( slide.querySelectorAll( 'img[data-src], video[data-src], audio[data-src]' ) ).forEach( function( element ) {
+ element.setAttribute( 'src', element.getAttribute( 'data-src' ) );
+ element.setAttribute( 'data-lazy-loaded', '' );
+ element.removeAttribute( 'data-src' );
+ } );
+
+ // Media elements with children
+ toArray( slide.querySelectorAll( 'video, audio' ) ).forEach( function( media ) {
+ var sources = 0;
+
+ toArray( media.querySelectorAll( 'source[data-src]' ) ).forEach( function( source ) {
+ source.setAttribute( 'src', source.getAttribute( 'data-src' ) );
+ source.removeAttribute( 'data-src' );
+ source.setAttribute( 'data-lazy-loaded', '' );
+ sources += 1;
+ } );
+
+ // If we rewrote sources for this video/audio element, we need
+ // to manually tell it to load from its new origin
+ if( sources > 0 ) {
+ media.load();
+ }
+ } );
+
+
+ // Show the corresponding background element
+ var indices = getIndices( slide );
+ var background = getSlideBackground( indices.h, indices.v );
+ if( background ) {
+ background.style.display = 'block';
+
+ // If the background contains media, load it
+ if( background.hasAttribute( 'data-loaded' ) === false ) {
+ background.setAttribute( 'data-loaded', 'true' );
+
+ var backgroundImage = slide.getAttribute( 'data-background-image' ),
+ backgroundVideo = slide.getAttribute( 'data-background-video' ),
+ backgroundVideoLoop = slide.hasAttribute( 'data-background-video-loop' ),
+ backgroundVideoMuted = slide.hasAttribute( 'data-background-video-muted' ),
+ backgroundIframe = slide.getAttribute( 'data-background-iframe' );
+
+ // Images
+ if( backgroundImage ) {
+ background.style.backgroundImage = 'url('+ backgroundImage +')';
+ }
+ // Videos
+ else if ( backgroundVideo && !isSpeakerNotes() ) {
+ var video = document.createElement( 'video' );
+
+ if( backgroundVideoLoop ) {
+ video.setAttribute( 'loop', '' );
+ }
+
+ if( backgroundVideoMuted ) {
+ video.muted = true;
+ }
+
+ // Inline video playback works (at least in Mobile Safari) as
+ // long as the video is muted and the `playsinline` attribute is
+ // present
+ if( isMobileDevice ) {
+ video.muted = true;
+ video.autoplay = true;
+ video.setAttribute( 'playsinline', '' );
+ }
+
+ // Support comma separated lists of video sources
+ backgroundVideo.split( ',' ).forEach( function( source ) {
+ video.innerHTML += '';
+ } );
+
+ background.appendChild( video );
+ }
+ // Iframes
+ else if( backgroundIframe && options.excludeIframes !== true ) {
+ var iframe = document.createElement( 'iframe' );
+ iframe.setAttribute( 'allowfullscreen', '' );
+ iframe.setAttribute( 'mozallowfullscreen', '' );
+ iframe.setAttribute( 'webkitallowfullscreen', '' );
+
+ // Only load autoplaying content when the slide is shown to
+ // avoid having it play in the background
+ if( /autoplay=(1|true|yes)/gi.test( backgroundIframe ) ) {
+ iframe.setAttribute( 'data-src', backgroundIframe );
+ }
+ else {
+ iframe.setAttribute( 'src', backgroundIframe );
+ }
+
+ iframe.style.width = '100%';
+ iframe.style.height = '100%';
+ iframe.style.maxHeight = '100%';
+ iframe.style.maxWidth = '100%';
+
+ background.appendChild( iframe );
+ }
+ }
+
+ }
+
+ }
+
+ /**
+ * Unloads and hides the given slide. This is called when the
+ * slide is moved outside of the configured view distance.
+ *
+ * @param {HTMLElement} slide
+ */
+ function unloadSlide( slide ) {
+
+ // Hide the slide element
+ slide.style.display = 'none';
+
+ // Hide the corresponding background element
+ var indices = getIndices( slide );
+ var background = getSlideBackground( indices.h, indices.v );
+ if( background ) {
+ background.style.display = 'none';
+ }
+
+ // Reset lazy-loaded media elements with src attributes
+ toArray( slide.querySelectorAll( 'video[data-lazy-loaded][src], audio[data-lazy-loaded][src]' ) ).forEach( function( element ) {
+ element.setAttribute( 'data-src', element.getAttribute( 'src' ) );
+ element.removeAttribute( 'src' );
+ } );
+
+ // Reset lazy-loaded media elements with children
+ toArray( slide.querySelectorAll( 'video[data-lazy-loaded] source[src], audio source[src]' ) ).forEach( function( source ) {
+ source.setAttribute( 'data-src', source.getAttribute( 'src' ) );
+ source.removeAttribute( 'src' );
+ } );
+
+ }
+
+ /**
+ * Determine what available routes there are for navigation.
+ *
+ * @return {{left: boolean, right: boolean, up: boolean, down: boolean}}
+ */
+ function availableRoutes() {
+
+ var horizontalSlides = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ),
+ verticalSlides = dom.wrapper.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
+
+ var routes = {
+ left: indexh > 0 || config.loop,
+ right: indexh < horizontalSlides.length - 1 || config.loop,
+ up: indexv > 0,
+ down: indexv < verticalSlides.length - 1
+ };
+
+ // reverse horizontal controls for rtl
+ if( config.rtl ) {
+ var left = routes.left;
+ routes.left = routes.right;
+ routes.right = left;
+ }
+
+ return routes;
+
+ }
+
+ /**
+ * Returns an object describing the available fragment
+ * directions.
+ *
+ * @return {{prev: boolean, next: boolean}}
+ */
+ function availableFragments() {
+
+ if( currentSlide && config.fragments ) {
+ var fragments = currentSlide.querySelectorAll( '.fragment' );
+ var hiddenFragments = currentSlide.querySelectorAll( '.fragment:not(.visible)' );
+
+ return {
+ prev: fragments.length - hiddenFragments.length > 0,
+ next: !!hiddenFragments.length
+ };
+ }
+ else {
+ return { prev: false, next: false };
+ }
+
+ }
+
+ /**
+ * Enforces origin-specific format rules for embedded media.
+ */
+ function formatEmbeddedContent() {
+
+ var _appendParamToIframeSource = function( sourceAttribute, sourceURL, param ) {
+ toArray( dom.slides.querySelectorAll( 'iframe['+ sourceAttribute +'*="'+ sourceURL +'"]' ) ).forEach( function( el ) {
+ var src = el.getAttribute( sourceAttribute );
+ if( src && src.indexOf( param ) === -1 ) {
+ el.setAttribute( sourceAttribute, src + ( !/\?/.test( src ) ? '?' : '&' ) + param );
+ }
+ });
+ };
+
+ // YouTube frames must include "?enablejsapi=1"
+ _appendParamToIframeSource( 'src', 'youtube.com/embed/', 'enablejsapi=1' );
+ _appendParamToIframeSource( 'data-src', 'youtube.com/embed/', 'enablejsapi=1' );
+
+ // Vimeo frames must include "?api=1"
+ _appendParamToIframeSource( 'src', 'player.vimeo.com/', 'api=1' );
+ _appendParamToIframeSource( 'data-src', 'player.vimeo.com/', 'api=1' );
+
+ // Always show media controls on mobile devices
+ if( isMobileDevice ) {
+ toArray( dom.slides.querySelectorAll( 'video, audio' ) ).forEach( function( el ) {
+ el.controls = true;
+ } );
+ }
+
+ }
+
+ /**
+ * Start playback of any embedded content inside of
+ * the given element.
+ *
+ * @param {HTMLElement} element
+ */
+ function startEmbeddedContent( element ) {
+
+ if( element && !isSpeakerNotes() ) {
+
+ // Restart GIFs
+ toArray( element.querySelectorAll( 'img[src$=".gif"]' ) ).forEach( function( el ) {
+ // Setting the same unchanged source like this was confirmed
+ // to work in Chrome, FF & Safari
+ el.setAttribute( 'src', el.getAttribute( 'src' ) );
+ } );
+
+ // HTML5 media elements
+ toArray( element.querySelectorAll( 'video, audio' ) ).forEach( function( el ) {
+ if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
+ return;
+ }
+
+ // Prefer an explicit global autoplay setting
+ var autoplay = config.autoPlayMedia;
+
+ // If no global setting is available, fall back on the element's
+ // own autoplay setting
+ if( typeof autoplay !== 'boolean' ) {
+ autoplay = el.hasAttribute( 'data-autoplay' ) || !!closestParent( el, '.slide-background' );
+ }
+
+ if( autoplay && typeof el.play === 'function' ) {
+
+ if( el.readyState > 1 ) {
+ startEmbeddedMedia( { target: el } );
+ }
+ else {
+ el.removeEventListener( 'loadeddata', startEmbeddedMedia ); // remove first to avoid dupes
+ el.addEventListener( 'loadeddata', startEmbeddedMedia );
+ }
+
+ }
+ } );
+
+ // Normal iframes
+ toArray( element.querySelectorAll( 'iframe[src]' ) ).forEach( function( el ) {
+ if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
+ return;
+ }
+
+ startEmbeddedIframe( { target: el } );
+ } );
+
+ // Lazy loading iframes
+ toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( function( el ) {
+ if( closestParent( el, '.fragment' ) && !closestParent( el, '.fragment.visible' ) ) {
+ return;
+ }
+
+ if( el.getAttribute( 'src' ) !== el.getAttribute( 'data-src' ) ) {
+ el.removeEventListener( 'load', startEmbeddedIframe ); // remove first to avoid dupes
+ el.addEventListener( 'load', startEmbeddedIframe );
+ el.setAttribute( 'src', el.getAttribute( 'data-src' ) );
+ }
+ } );
+
+ }
+
+ }
+
+ /**
+ * Starts playing an embedded video/audio element after
+ * it has finished loading.
+ *
+ * @param {object} event
+ */
+ function startEmbeddedMedia( event ) {
+
+ var isAttachedToDOM = !!closestParent( event.target, 'html' ),
+ isVisible = !!closestParent( event.target, '.present' );
+
+ if( isAttachedToDOM && isVisible ) {
+ event.target.currentTime = 0;
+ event.target.play();
+ }
+
+ event.target.removeEventListener( 'loadeddata', startEmbeddedMedia );
+
+ }
+
+ /**
+ * "Starts" the content of an embedded iframe using the
+ * postMessage API.
+ *
+ * @param {object} event
+ */
+ function startEmbeddedIframe( event ) {
+
+ var iframe = event.target;
+
+ if( iframe && iframe.contentWindow ) {
+
+ var isAttachedToDOM = !!closestParent( event.target, 'html' ),
+ isVisible = !!closestParent( event.target, '.present' );
+
+ if( isAttachedToDOM && isVisible ) {
+
+ // Prefer an explicit global autoplay setting
+ var autoplay = config.autoPlayMedia;
+
+ // If no global setting is available, fall back on the element's
+ // own autoplay setting
+ if( typeof autoplay !== 'boolean' ) {
+ autoplay = iframe.hasAttribute( 'data-autoplay' ) || !!closestParent( iframe, '.slide-background' );
+ }
+
+ // YouTube postMessage API
+ if( /youtube\.com\/embed\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) {
+ iframe.contentWindow.postMessage( '{"event":"command","func":"playVideo","args":""}', '*' );
+ }
+ // Vimeo postMessage API
+ else if( /player\.vimeo\.com\//.test( iframe.getAttribute( 'src' ) ) && autoplay ) {
+ iframe.contentWindow.postMessage( '{"method":"play"}', '*' );
+ }
+ // Generic postMessage API
+ else {
+ iframe.contentWindow.postMessage( 'slide:start', '*' );
+ }
+
+ }
+
+ }
+
+ }
+
+ /**
+ * Stop playback of any embedded content inside of
+ * the targeted slide.
+ *
+ * @param {HTMLElement} element
+ */
+ function stopEmbeddedContent( element, options ) {
+
+ options = extend( {
+ // Defaults
+ unloadIframes: true
+ }, options || {} );
+
+ if( element && element.parentNode ) {
+ // HTML5 media elements
+ toArray( element.querySelectorAll( 'video, audio' ) ).forEach( function( el ) {
+ if( !el.hasAttribute( 'data-ignore' ) && typeof el.pause === 'function' ) {
+ el.setAttribute('data-paused-by-reveal', '');
+ el.pause();
+ }
+ } );
+
+ // Generic postMessage API for non-lazy loaded iframes
+ toArray( element.querySelectorAll( 'iframe' ) ).forEach( function( el ) {
+ if( el.contentWindow ) el.contentWindow.postMessage( 'slide:stop', '*' );
+ el.removeEventListener( 'load', startEmbeddedIframe );
+ });
+
+ // YouTube postMessage API
+ toArray( element.querySelectorAll( 'iframe[src*="youtube.com/embed/"]' ) ).forEach( function( el ) {
+ if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
+ el.contentWindow.postMessage( '{"event":"command","func":"pauseVideo","args":""}', '*' );
+ }
+ });
+
+ // Vimeo postMessage API
+ toArray( element.querySelectorAll( 'iframe[src*="player.vimeo.com/"]' ) ).forEach( function( el ) {
+ if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
+ el.contentWindow.postMessage( '{"method":"pause"}', '*' );
+ }
+ });
+
+ if( options.unloadIframes === true ) {
+ // Unload lazy-loaded iframes
+ toArray( element.querySelectorAll( 'iframe[data-src]' ) ).forEach( function( el ) {
+ // Only removing the src doesn't actually unload the frame
+ // in all browsers (Firefox) so we set it to blank first
+ el.setAttribute( 'src', 'about:blank' );
+ el.removeAttribute( 'src' );
+ } );
+ }
+ }
+
+ }
+
+ /**
+ * Returns the number of past slides. This can be used as a global
+ * flattened index for slides.
+ *
+ * @return {number} Past slide count
+ */
+ function getSlidePastCount() {
+
+ var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+
+ // The number of past slides
+ var pastCount = 0;
+
+ // Step through all slides and count the past ones
+ mainLoop: for( var i = 0; i < horizontalSlides.length; i++ ) {
+
+ var horizontalSlide = horizontalSlides[i];
+ var verticalSlides = toArray( horizontalSlide.querySelectorAll( 'section' ) );
+
+ for( var j = 0; j < verticalSlides.length; j++ ) {
+
+ // Stop as soon as we arrive at the present
+ if( verticalSlides[j].classList.contains( 'present' ) ) {
+ break mainLoop;
+ }
+
+ pastCount++;
+
+ }
+
+ // Stop as soon as we arrive at the present
+ if( horizontalSlide.classList.contains( 'present' ) ) {
+ break;
+ }
+
+ // Don't count the wrapping section for vertical slides
+ if( horizontalSlide.classList.contains( 'stack' ) === false ) {
+ pastCount++;
+ }
+
+ }
+
+ return pastCount;
+
+ }
+
+ /**
+ * Returns a value ranging from 0-1 that represents
+ * how far into the presentation we have navigated.
+ *
+ * @return {number}
+ */
+ function getProgress() {
+
+ // The number of past and total slides
+ var totalCount = getTotalSlides();
+ var pastCount = getSlidePastCount();
+
+ if( currentSlide ) {
+
+ var allFragments = currentSlide.querySelectorAll( '.fragment' );
+
+ // If there are fragments in the current slide those should be
+ // accounted for in the progress.
+ if( allFragments.length > 0 ) {
+ var visibleFragments = currentSlide.querySelectorAll( '.fragment.visible' );
+
+ // This value represents how big a portion of the slide progress
+ // that is made up by its fragments (0-1)
+ var fragmentWeight = 0.9;
+
+ // Add fragment progress to the past slide count
+ pastCount += ( visibleFragments.length / allFragments.length ) * fragmentWeight;
+ }
+
+ }
+
+ return pastCount / ( totalCount - 1 );
+
+ }
+
+ /**
+ * Checks if this presentation is running inside of the
+ * speaker notes window.
+ *
+ * @return {boolean}
+ */
+ function isSpeakerNotes() {
+
+ return !!window.location.search.match( /receiver/gi );
+
+ }
+
+ /**
+ * Reads the current URL (hash) and navigates accordingly.
+ */
+ function readURL() {
+
+ var hash = window.location.hash;
+
+ // Attempt to parse the hash as either an index or name
+ var bits = hash.slice( 2 ).split( '/' ),
+ name = hash.replace( /#|\//gi, '' );
+
+ // If the first bit is invalid and there is a name we can
+ // assume that this is a named link
+ if( isNaN( parseInt( bits[0], 10 ) ) && name.length ) {
+ var element;
+
+ // Ensure the named link is a valid HTML ID attribute
+ if( /^[a-zA-Z][\w:.-]*$/.test( name ) ) {
+ // Find the slide with the specified ID
+ element = document.getElementById( name );
+ }
+
+ if( element ) {
+ // Find the position of the named slide and navigate to it
+ var indices = Reveal.getIndices( element );
+ slide( indices.h, indices.v );
+ }
+ // If the slide doesn't exist, navigate to the current slide
+ else {
+ slide( indexh || 0, indexv || 0 );
+ }
+ }
+ else {
+ // Read the index components of the hash
+ var h = parseInt( bits[0], 10 ) || 0,
+ v = parseInt( bits[1], 10 ) || 0;
+
+ if( h !== indexh || v !== indexv ) {
+ slide( h, v );
+ }
+ }
+
+ }
+
+ /**
+ * Updates the page URL (hash) to reflect the current
+ * state.
+ *
+ * @param {number} delay The time in ms to wait before
+ * writing the hash
+ */
+ function writeURL( delay ) {
+
+ if( config.history ) {
+
+ // Make sure there's never more than one timeout running
+ clearTimeout( writeURLTimeout );
+
+ // If a delay is specified, timeout this call
+ if( typeof delay === 'number' ) {
+ writeURLTimeout = setTimeout( writeURL, delay );
+ }
+ else if( currentSlide ) {
+ var url = '/';
+
+ // Attempt to create a named link based on the slide's ID
+ var id = currentSlide.getAttribute( 'id' );
+ if( id ) {
+ id = id.replace( /[^a-zA-Z0-9\-\_\:\.]/g, '' );
+ }
+
+ // If the current slide has an ID, use that as a named link
+ if( typeof id === 'string' && id.length ) {
+ url = '/' + id;
+ }
+ // Otherwise use the /h/v index
+ else {
+ if( indexh > 0 || indexv > 0 ) url += indexh;
+ if( indexv > 0 ) url += '/' + indexv;
+ }
+
+ window.location.hash = url;
+ }
+ }
+
+ }
+ /**
+ * Retrieves the h/v location and fragment of the current,
+ * or specified, slide.
+ *
+ * @param {HTMLElement} [slide] If specified, the returned
+ * index will be for this slide rather than the currently
+ * active one
+ *
+ * @return {{h: number, v: number, f: number}}
+ */
+ function getIndices( slide ) {
+
+ // By default, return the current indices
+ var h = indexh,
+ v = indexv,
+ f;
+
+ // If a slide is specified, return the indices of that slide
+ if( slide ) {
+ var isVertical = isVerticalSlide( slide );
+ var slideh = isVertical ? slide.parentNode : slide;
+
+ // Select all horizontal slides
+ var horizontalSlides = toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+
+ // Now that we know which the horizontal slide is, get its index
+ h = Math.max( horizontalSlides.indexOf( slideh ), 0 );
+
+ // Assume we're not vertical
+ v = undefined;
+
+ // If this is a vertical slide, grab the vertical index
+ if( isVertical ) {
+ v = Math.max( toArray( slide.parentNode.querySelectorAll( 'section' ) ).indexOf( slide ), 0 );
+ }
+ }
+
+ if( !slide && currentSlide ) {
+ var hasFragments = currentSlide.querySelectorAll( '.fragment' ).length > 0;
+ if( hasFragments ) {
+ var currentFragment = currentSlide.querySelector( '.current-fragment' );
+ if( currentFragment && currentFragment.hasAttribute( 'data-fragment-index' ) ) {
+ f = parseInt( currentFragment.getAttribute( 'data-fragment-index' ), 10 );
+ }
+ else {
+ f = currentSlide.querySelectorAll( '.fragment.visible' ).length - 1;
+ }
+ }
+ }
+
+ return { h: h, v: v, f: f };
+
+ }
+
+ /**
+ * Retrieves all slides in this presentation.
+ */
+ function getSlides() {
+
+ return toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' ));
+
+ }
+
+ /**
+ * Retrieves the total number of slides in this presentation.
+ *
+ * @return {number}
+ */
+ function getTotalSlides() {
+
+ return getSlides().length;
+
+ }
+
+ /**
+ * Returns the slide element matching the specified index.
+ *
+ * @return {HTMLElement}
+ */
+ function getSlide( x, y ) {
+
+ var horizontalSlide = dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR )[ x ];
+ var verticalSlides = horizontalSlide && horizontalSlide.querySelectorAll( 'section' );
+
+ if( verticalSlides && verticalSlides.length && typeof y === 'number' ) {
+ return verticalSlides ? verticalSlides[ y ] : undefined;
+ }
+
+ return horizontalSlide;
+
+ }
+
+ /**
+ * Returns the background element for the given slide.
+ * All slides, even the ones with no background properties
+ * defined, have a background element so as long as the
+ * index is valid an element will be returned.
+ *
+ * @param {number} x Horizontal background index
+ * @param {number} y Vertical background index
+ * @return {(HTMLElement[]|*)}
+ */
+ function getSlideBackground( x, y ) {
+
+ var slide = getSlide( x, y );
+ if( slide ) {
+ return slide.slideBackgroundElement;
+ }
+
+ return undefined;
+
+ }
+
+ /**
+ * Retrieves the speaker notes from a slide. Notes can be
+ * defined in two ways:
+ * 1. As a data-notes attribute on the slide
+ * 2. As an