Merge branch 'dev' into patch-1

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2019 Hakim El Hattab, http://hakim.se, and reveal.js contributors
+Copyright (C) 2020 Hakim El Hattab, http://hakim.se, and reveal.js contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

css/reveal.css

@@ -3,7 +3,7 @@
  * http://revealjs.com
  * MIT licensed
  *
- * Copyright (C) 2019 Hakim El Hattab, http://hakim.se
+ * Copyright (C) 2020 Hakim El Hattab, http://hakim.se
  */
 /*********************************************
  * GLOBAL STYLES
@@ -77,29 +77,29 @@ body {
     text-decoration: line-through; }
 
 .reveal .slides section .fragment.fade-up {
-  -webkit-transform: translate(0, 20%);
+  -webkit-transform: translate(0, 40px);
-          transform: translate(0, 20%); }
+          transform: translate(0, 40px); }
   .reveal .slides section .fragment.fade-up.visible {
     -webkit-transform: translate(0, 0);
             transform: translate(0, 0); }
 
 .reveal .slides section .fragment.fade-down {
-  -webkit-transform: translate(0, -20%);
+  -webkit-transform: translate(0, -40px);
-          transform: translate(0, -20%); }
+          transform: translate(0, -40px); }
   .reveal .slides section .fragment.fade-down.visible {
     -webkit-transform: translate(0, 0);
             transform: translate(0, 0); }
 
 .reveal .slides section .fragment.fade-right {
-  -webkit-transform: translate(-20%, 0);
+  -webkit-transform: translate(-40px, 0);
-          transform: translate(-20%, 0); }
+          transform: translate(-40px, 0); }
   .reveal .slides section .fragment.fade-right.visible {
     -webkit-transform: translate(0, 0);
             transform: translate(0, 0); }
 
 .reveal .slides section .fragment.fade-left {
-  -webkit-transform: translate(20%, 0);
+  -webkit-transform: translate(40px, 0);
-          transform: translate(20%, 0); }
+          transform: translate(40px, 0); }
   .reveal .slides section .fragment.fade-left.visible {
     -webkit-transform: translate(0, 0);
             transform: translate(0, 0); }
@@ -227,7 +227,7 @@ body {
   bottom: 12px;
   right: 12px;
   left: auto;
-  z-index: 1;
+  z-index: 11;
   color: #000;
   pointer-events: none;
   font-size: 10px; }
@@ -312,7 +312,8 @@ body {
               transform: rotate(90deg); }
   .reveal .controls .navigate-down {
     right: 3.2em;
-    bottom: 0;
+    bottom: -1.4em;
+    padding-bottom: 1.4em;
     -webkit-transform: translateY(10px);
             transform: translateY(10px); }
     .reveal .controls .navigate-down .controls-arrow {
@@ -395,18 +396,18 @@ body {
     right: auto; }
   .reveal .controls[data-controls-layout="edges"] .navigate-left {
     top: 50%;
-    left: 8px;
+    left: 0.8em;
     margin-top: -1.8em; }
   .reveal .controls[data-controls-layout="edges"] .navigate-right {
     top: 50%;
-    right: 8px;
+    right: 0.8em;
     margin-top: -1.8em; }
   .reveal .controls[data-controls-layout="edges"] .navigate-up {
-    top: 8px;
+    top: 0.8em;
     left: 50%;
     margin-left: -1.8em; }
   .reveal .controls[data-controls-layout="edges"] .navigate-down {
-    bottom: 8px;
+    bottom: -0.3em;
     left: 50%;
     margin-left: -1.8em; } }
 
@@ -1453,9 +1454,16 @@ body {
   text-align: right;
   vertical-align: top; }
 
-.reveal .hljs[data-line-numbers]:not([data-line-numbers=""]) tr:not(.highlight-line) {
+.reveal .hljs.has-highlights tr:not(.highlight-line) {
   opacity: 0.4; }
 
+.reveal .hljs:not(:first-child).fragment {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  box-sizing: border-box; }
+
 /*********************************************
  * ROLLING LINKS
  *********************************************/

css/reveal.scss

@@ -3,7 +3,7 @@
  * http://revealjs.com
  * MIT licensed
  *
- * Copyright (C) 2019 Hakim El Hattab, http://hakim.se
+ * Copyright (C) 2020 Hakim El Hattab, http://hakim.se
  */
 
 
@@ -102,7 +102,7 @@ body {
 }
 
 .reveal .slides section .fragment.fade-up {
-	transform: translate(0, 20%);
+	transform: translate(0, 40px);
 
 	&.visible {
 		transform: translate(0, 0);
@@ -110,7 +110,7 @@ body {
 }
 
 .reveal .slides section .fragment.fade-down {
-	transform: translate(0, -20%);
+	transform: translate(0, -40px);
 
 	&.visible {
 		transform: translate(0, 0);
@@ -118,7 +118,7 @@ body {
 }
 
 .reveal .slides section .fragment.fade-right {
-	transform: translate(-20%, 0);
+	transform: translate(-40px, 0);
 
 	&.visible {
 		transform: translate(0, 0);
@@ -126,7 +126,7 @@ body {
 }
 
 .reveal .slides section .fragment.fade-left {
-	transform: translate(20%, 0);
+	transform: translate(40px, 0);
 
 	&.visible {
 		transform: translate(0, 0);
@@ -263,7 +263,7 @@ $controlsArrowAngleActive: 36deg;
 	bottom: $spacing;
 	right: $spacing;
 	left: auto;
-	z-index: 1;
+	z-index: 11;
 	color: #000;
 	pointer-events: none;
 	font-size: 10px;
@@ -355,7 +355,8 @@ $controlsArrowAngleActive: 36deg;
 
 	.navigate-down {
 		right: $controlArrowSpacing + $controlArrowSize/2;
-		bottom: 0;
+		bottom: -$controlArrowSpacing;
+		padding-bottom: $controlArrowSpacing;
 		transform: translateY( 10px );
 
 		.controls-arrow {
@@ -452,7 +453,7 @@ $controlsArrowAngleActive: 36deg;
 // Edge aligned controls layout
 @media screen and (min-width: 500px) {
 
-	$spacing: 8px;
+	$spacing: 0.8em;
 
 	.reveal .controls[data-controls-layout="edges"] {
 		& {
@@ -489,7 +490,7 @@ $controlsArrowAngleActive: 36deg;
 		}
 
 		.navigate-down {
-			bottom: $spacing;
+			bottom: $spacing - $controlArrowSpacing + 0.3em;
 			left: 50%;
 			margin-left: -$controlArrowSize/2;
 		}
@@ -1590,10 +1591,18 @@ $controlsArrowAngleActive: 36deg;
 	vertical-align: top;
 }
 
-.reveal .hljs[data-line-numbers]:not([data-line-numbers=""]) tr:not(.highlight-line) {
+.reveal .hljs.has-highlights tr:not(.highlight-line) {
 	opacity: 0.4;
 }
 
+.reveal .hljs:not(:first-child).fragment {
+	position: absolute;
+	top: 0;
+	left: 0;
+	width: 100%;
+	box-sizing: border-box;
+}
+
 
 /*********************************************
  * ROLLING LINKS

css/theme/README.md

@@ -4,7 +4,7 @@ Themes are written using Sass to keep things modular and reduce the need for rep
 
 ## Creating a Theme
 
-To create your own theme, start by duplicating a ```.scss``` file in [/css/theme/source](https://github.com/hakimel/reveal.js/blob/master/css/theme/source). It will be automatically compiled by Grunt from Sass to CSS (see the [Gruntfile](https://github.com/hakimel/reveal.js/blob/master/Gruntfile.js)) when you run `npm run build -- css-themes`.
+To create your own theme, start by duplicating a ```.scss``` file in [/css/theme/source](https://github.com/hakimel/reveal.js/blob/master/css/theme/source). It will be automatically compiled by Grunt from Sass to CSS (see the [Gruntfile](https://github.com/hakimel/reveal.js/blob/master/gruntfile.js)) when you run `npm run build -- css-themes`.
 
 Each theme file does four things in the following order:
 

demo.html

@@ -241,7 +241,7 @@
 
 				<section>
 					<h2>Pretty Code</h2>
-					<pre><code class="hljs" data-trim data-line-numbers="4,8-11">
+					<pre><code class="hljs" data-trim data-line-numbers="4|9|4,8-11">
 import React, { useState } from 'react';
 
 function Example() {
@@ -412,7 +412,7 @@ Reveal.addEventListener( 'customevent', function() {
 				dependencies: [
 					{ src: 'plugin/markdown/marked.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
 					{ src: 'plugin/markdown/markdown.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
-					{ src: 'plugin/highlight/highlight.js', async: true },
+					{ src: 'plugin/highlight/highlight.js' },
 					{ src: 'plugin/search/search.js', async: true },
 					{ src: 'plugin/zoom-js/zoom.js', async: true },
 					{ src: 'plugin/notes/notes.js', async: true }

gruntfile.js

@@ -19,7 +19,7 @@ module.exports = grunt => {
 				' * http://revealjs.com\n' +
 				' * MIT licensed\n' +
 				' *\n' +
-				' * Copyright (C) 2019 Hakim El Hattab, http://hakim.se\n' +
+				' * Copyright (C) 2020 Hakim El Hattab, http://hakim.se\n' +
 				' */'
 		},
 

index.html

@@ -37,11 +37,12 @@
 			// - https://github.com/hakimel/reveal.js#configuration
 			// - https://github.com/hakimel/reveal.js#dependencies
 			Reveal.initialize({
+				hash: true,
 				dependencies: [
 					{ src: 'plugin/markdown/marked.js' },
 					{ src: 'plugin/markdown/markdown.js' },
-					{ src: 'plugin/notes/notes.js', async: true },
+					{ src: 'plugin/highlight/highlight.js' },
-					{ src: 'plugin/highlight/highlight.js', async: true }
+					{ src: 'plugin/notes/notes.js', async: true }
 				]
 			});
 		</script>

js/reveal.js

@@ -3,7 +3,7 @@
  * http://revealjs.com
  * MIT licensed
  *
- * Copyright (C) 2019 Hakim El Hattab, http://hakim.se
+ * Copyright (C) 2020 Hakim El Hattab, http://hakim.se
  */
 (function( root, factory ) {
 	if( typeof define === 'function' && define.amd ) {
@@ -270,6 +270,11 @@
 			// Number of slides away from the current that are visible
 			viewDistance: 3,
 
+			// Number of slides away from the current that are visible on mobile
+			// devices. It is advisable to set this to a lower number than
+			// viewDistance in order to save resources.
+			mobileViewDistance: 2,
+
 			// The display mode that will be used to show slides
 			display: 'block',
 
@@ -447,7 +452,8 @@
 	 */
 	function checkCapabilities() {
 
-		isMobileDevice = /(iphone|ipod|ipad|android)/gi.test( UA );
+		isMobileDevice = /(iphone|ipod|ipad|android)/gi.test( UA ) ||
+							( navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1 ); // iPadOS
 		isChrome = /chrome/i.test( UA ) && !/edge/i.test( UA );
 
 		var testElement = document.createElement( 'div' );
@@ -1217,6 +1223,8 @@
 		if( data.backgroundColor ) element.style.backgroundColor = data.backgroundColor;
 		if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition );
 
+		if( slide.hasAttribute( 'data-preload' ) ) element.setAttribute( 'data-preload', '' );
+
 		// Background image options are set on the content wrapper
 		if( data.backgroundSize ) contentElement.style.backgroundSize = data.backgroundSize;
 		if( data.backgroundRepeat ) contentElement.style.backgroundRepeat = data.backgroundRepeat;
@@ -1276,7 +1284,11 @@
 
 					// Check if the requested method can be found
 					if( data.method && typeof Reveal[data.method] === 'function' ) {
-						Reveal[data.method].apply( Reveal, data.args );
+						var result = Reveal[data.method].apply( Reveal, data.args );
+
+						// Dispatch a postMessage event with the returned value from
+						// our method invocation for getter functions
+						dispatchPostMessage( 'callback', { method: data.method, result: result } );
 					}
 				}
 			}, false );
@@ -1447,8 +1459,8 @@
 			keyboardShortcuts['↓  ,  J'] = 'Navigate down';
 		}
 
-		keyboardShortcuts['Home  ,  ⌘/CTRL ←'] = 'First slide';
+		keyboardShortcuts['Home  ,  Shift ←']        = 'First slide';
-		keyboardShortcuts['End  ,  ⌘/CTRL →']  = 'Last slide';
+		keyboardShortcuts['End  ,  Shift →']         = 'Last slide';
 		keyboardShortcuts['B  ,  .']                       = 'Pause';
 		keyboardShortcuts['F']                             = 'Fullscreen';
 		keyboardShortcuts['ESC, O']                        = 'Slide overview';
@@ -1981,8 +1993,25 @@
 
 		// If we're in an iframe, post each reveal.js event to the
 		// parent window. Used by the notes plugin
+		dispatchPostMessage( type );
+
+	}
+
+	/**
+	 * Dispatched a postMessage of the given type from our window.
+	 */
+	function dispatchPostMessage( type, data ) {
+
 		if( config.postMessageEvents && window.parent !== window.self ) {
-			window.parent.postMessage( JSON.stringify({ namespace: 'reveal', eventName: type, state: getState() }), '*' );
+			var message = {
+				namespace: 'reveal',
+				eventName: type,
+				state: getState()
+			};
+
+			extend( message, data );
+
+			window.parent.postMessage( JSON.stringify( message ), '*' );
 		}
 
 	}
@@ -2243,10 +2272,12 @@
 					transformSlides( { layout: '' } );
 				}
 				else {
-					// Prefer zoom for scaling up so that content remains crisp.
+					// Zoom Scaling
-					// Don't use zoom to scale down since that can lead to shifts
+					// Content remains crisp no matter how much we scale. Side
-					// in text layout/line breaks.
+					// effects are minor differences in text layout and iframe
-					if( scale > 1 && features.zoom ) {
+					// viewports changing size. A 200x200 iframe viewport in a
+					// 2x zoomed presentation ends up having a 400x400 viewport.
+					if( scale > 1 && features.zoom && window.devicePixelRatio < 2 ) {
 						dom.slides.style.zoom = scale;
 						dom.slides.style.left = '';
 						dom.slides.style.top = '';
@@ -2254,7 +2285,10 @@
 						dom.slides.style.right = '';
 						transformSlides( { layout: '' } );
 					}
-					// Apply scale transform as a fallback
+					// Transform Scaling
+					// Content layout remains the exact same when scaled up.
+					// Side effect is content becoming blurred, especially with
+					// high scale values on ldpi screens.
 					else {
 						dom.slides.style.zoom = '';
 						dom.slides.style.left = '50%';
@@ -3039,11 +3073,11 @@
 		syncBackground( slide );
 		syncFragments( slide );
 
+		loadSlide( slide );
+
 		updateBackground();
 		updateNotes();
 
-		loadSlide( slide );
-
 	}
 
 	/**
@@ -3255,9 +3289,10 @@
 			// be visible
 			var viewDistance = isOverview() ? 10 : config.viewDistance;
 
-			// Limit view distance on weaker devices
+			// Shorten the view distance on devices that typically have
+			// less resources
 			if( isMobileDevice ) {
-				viewDistance = isOverview() ? 6 : 2;
+				viewDistance = isOverview() ? 6 : config.mobileViewDistance;
 			}
 
 			// All slides need to be visible when exporting to PDF
@@ -3309,7 +3344,7 @@
 			}
 
 			// Flag if there are ANY vertical slides, anywhere in the deck
-			if( dom.wrapper.querySelectorAll( '.slides>section>section' ).length ) {
+			if( hasVerticalSlides() ) {
 				dom.wrapper.classList.add( 'has-vertical-slides' );
 			}
 			else {
@@ -3317,7 +3352,7 @@
 			}
 
 			// Flag if there are ANY horizontal slides, anywhere in the deck
-			if( dom.wrapper.querySelectorAll( '.slides>section' ).length > 1 ) {
+			if( hasHorizontalSlides() ) {
 				dom.wrapper.classList.add( 'has-horizontal-slides' );
 			}
 			else {
@@ -3599,7 +3634,7 @@
 		// Stop content inside of previous backgrounds
 		if( previousBackground ) {
 
-			stopEmbeddedContent( previousBackground );
+			stopEmbeddedContent( previousBackground, { unloadIframes: !shouldPreload( previousBackground ) } );
 
 		}
 
@@ -3778,6 +3813,7 @@
 			background.style.display = 'block';
 
 			var backgroundContent = slide.slideBackgroundContentElement;
+			var backgroundIframe = slide.getAttribute( 'data-background-iframe' );
 
 			// If the background contains media, load it
 			if( background.hasAttribute( 'data-loaded' ) === false ) {
@@ -3786,8 +3822,7 @@
 				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' ),
+					backgroundVideoMuted = slide.hasAttribute( 'data-background-video-muted' );
-					backgroundIframe = slide.getAttribute( 'data-background-iframe' );
 
 				// Images
 				if( backgroundImage ) {
@@ -3827,15 +3862,9 @@
 					iframe.setAttribute( 'allowfullscreen', '' );
 					iframe.setAttribute( 'mozallowfullscreen', '' );
 					iframe.setAttribute( 'webkitallowfullscreen', '' );
+					iframe.setAttribute( 'allow', 'autoplay' );
 
-					// 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%';
@@ -3846,6 +3875,19 @@
 				}
 			}
 
+			// Start loading preloadable iframes
+			var backgroundIframeElement = backgroundContent.querySelector( 'iframe[data-src]' );
+			if( backgroundIframeElement ) {
+
+				// Check if this iframe is eligible to be preloaded
+				if( shouldPreload( background ) && !/autoplay=(1|true|yes)/gi.test( backgroundIframe ) ) {
+					if( backgroundIframeElement.getAttribute( 'src' ) !== backgroundIframe ) {
+						backgroundIframeElement.setAttribute( 'src', backgroundIframe );
+					}
+				}
+
+			}
+
 		}
 
 	}
@@ -3865,6 +3907,11 @@
 		var background = getSlideBackground( slide );
 		if( background ) {
 			background.style.display = 'none';
+
+			// Unload any background iframes
+			toArray( background.querySelectorAll( 'iframe[src]' ) ).forEach( function( element ) {
+				element.removeAttribute( 'src' );
+			} );
 		}
 
 		// Reset lazy-loaded media elements with src attributes
@@ -4429,7 +4476,44 @@
 	 */
 	function getSlides() {
 
-		return toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' ));
+		return toArray( dom.wrapper.querySelectorAll( SLIDES_SELECTOR + ':not(.stack)' ) );
+
+	}
+
+	/**
+	 * Returns a list of all horizontal slides in the deck. Each
+	 * vertical stack is included as one horizontal slide in the
+	 * resulting array.
+	 */
+	function getHorizontalSlides() {
+
+		return toArray( dom.wrapper.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
+
+	}
+
+	/**
+	 * Returns all vertical slides that exist within this deck.
+	 */
+	function getVerticalSlides() {
+
+		return toArray( dom.wrapper.querySelectorAll( '.slides>section>section' ) );
+
+	}
+
+	/**
+	 * Returns true if there are at least two horizontal slides.
+	 */
+	function hasHorizontalSlides() {
+
+		return getHorizontalSlides().length > 1;
+	}
+
+	/**
+	 * Returns true if there are at least two vertical slides.
+	 */
+	function hasVerticalSlides() {
+
+		return getVerticalSlides().length > 1;
 
 	}
 
@@ -4667,6 +4751,8 @@
 
 			if( fragments.length ) {
 
+				var maxIndex = 0;
+
 				if( typeof index !== 'number' ) {
 					var currentFragment = sortFragments( currentSlide.querySelectorAll( '.fragment.visible' ) ).pop();
 					if( currentFragment ) {
@@ -4680,6 +4766,8 @@
 						i = parseInt( el.getAttribute( 'data-fragment-index' ), 10 );
 					}
 
+					maxIndex = Math.max( maxIndex, i );
+
 					// Visible fragments
 					if( i <= index ) {
 						if( !el.classList.contains( 'visible' ) ) changedFragments.shown.push( el );
@@ -4703,6 +4791,13 @@
 
 				} );
 
+				// Write the current fragment index to the slide <section>.
+				// This can be used by end users to apply styles based on
+				// the current fragment index.
+				index = typeof index === 'number' ? index : -1;
+				index = Math.max( Math.min( index, maxIndex ), -1 );
+				currentSlide.setAttribute( 'data-fragment', index );
+
 			}
 
 		}
@@ -5116,8 +5211,8 @@
 
 		// Whitelist specific modified + keycode combinations
 		var prevSlideShortcut = event.shiftKey && event.keyCode === 32;
-		var firstSlideShortcut = ( event.metaKey || event.ctrlKey ) && keyCode === 37;
+		var firstSlideShortcut = event.shiftKey && keyCode === 37;
-		var lastSlideShortcut = ( event.metaKey || event.ctrlKey ) && keyCode === 39;
+		var lastSlideShortcut = event.shiftKey && keyCode === 39;
 
 		// Prevent all other events when a modifier is pressed
 		var unusedModifier = 	!prevSlideShortcut && !firstSlideShortcut && !lastSlideShortcut &&
@@ -5144,6 +5239,10 @@
 			return false;
 		}
 
+		// Use linear navigation if we're configured to OR if
+		// the presentation is one-dimensional
+		var useLinearMode = config.navigationMode === 'linear' || !hasHorizontalSlides() || !hasVerticalSlides();
+
 		var triggered = false;
 
 		// 1. User defined key bindings
@@ -5216,7 +5315,7 @@
 				if( firstSlideShortcut ) {
 					slide( 0 );
 				}
-				else if( !isOverview() && config.navigationMode === 'linear' ) {
+				else if( !isOverview() && useLinearMode ) {
 					navigatePrev();
 				}
 				else {
@@ -5228,7 +5327,7 @@
 				if( lastSlideShortcut ) {
 					slide( Number.MAX_VALUE );
 				}
-				else if( !isOverview() && config.navigationMode === 'linear' ) {
+				else if( !isOverview() && useLinearMode ) {
 					navigateNext();
 				}
 				else {
@@ -5237,7 +5336,7 @@
 			}
 			// K, UP
 			else if( keyCode === 75 || keyCode === 38 ) {
-				if( !isOverview() && config.navigationMode === 'linear' ) {
+				if( !isOverview() && useLinearMode ) {
 					navigatePrev();
 				}
 				else {
@@ -5246,7 +5345,7 @@
 			}
 			// J, DOWN
 			else if( keyCode === 74 || keyCode === 40 ) {
-				if( !isOverview() && config.navigationMode === 'linear' ) {
+				if( !isOverview() && useLinearMode ) {
 					navigateNext();
 				}
 				else {
@@ -5356,20 +5455,50 @@
 
 				if( deltaX > touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
 					touch.captured = true;
+					if( config.navigationMode === 'linear' ) {
+						if( config.rtl ) {
+							navigateNext();
+						}
+						else {
+							navigatePrev();
+						}
+					}
+					else {
 						navigateLeft();
 					}
+				}
 				else if( deltaX < -touch.threshold && Math.abs( deltaX ) > Math.abs( deltaY ) ) {
 					touch.captured = true;
+					if( config.navigationMode === 'linear' ) {
+						if( config.rtl ) {
+							navigatePrev();
+						}
+						else {
+							navigateNext();
+						}
+					}
+					else {
 						navigateRight();
 					}
+				}
 				else if( deltaY > touch.threshold ) {
 					touch.captured = true;
+					if( config.navigationMode === 'linear' ) {
+						navigatePrev();
+					}
+					else {
 						navigateUp();
 					}
+				}
 				else if( deltaY < -touch.threshold ) {
 					touch.captured = true;
+					if( config.navigationMode === 'linear' ) {
+						navigateNext();
+					}
+					else {
 						navigateDown();
 					}
+				}
 
 				// If we're embedded, only block touch events if they have
 				// triggered an action
@@ -5905,6 +6034,15 @@
 		// Returns the speaker notes string for a slide, or null
 		getSlideNotes: getSlideNotes,
 
+		// Returns an array with all horizontal/vertical slides in the deck
+		getHorizontalSlides: getHorizontalSlides,
+		getVerticalSlides: getVerticalSlides,
+
+		// Checks if the presentation contains two or more
+		// horizontal/vertical slides
+		hasHorizontalSlides: hasHorizontalSlides,
+		hasVerticalSlides: hasVerticalSlides,
+
 		// Returns the previous slide element, may be null
 		getPreviousSlide: function() {
 			return previousSlide;

package-lock.json

@@ -44,18 +44,18 @@
       "dev": true
     },
     "agent-base": {
-      "version": "4.2.1",
+      "version": "4.3.0",
-      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.2.1.tgz",
+      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.3.0.tgz",
-      "integrity": "sha512-JVwXMr9nHYTUXsBFKUqhJwvlcYU/blreOEUkhNR2eXZIvwd+c+o5V4MgDPKWnMS/56awN3TRzIP+KoPn+roQtg==",
+      "integrity": "sha512-salcGninV0nPrwpGNn4VTXBb1SOuXQBiqbrNXoeizJsHrsL6ERFM2Ne3JUSBWRE6aeNJI2ROP/WEEIDUiDe3cg==",
       "dev": true,
       "requires": {
         "es6-promisify": "^5.0.0"
       }
     },
     "ajv": {
-      "version": "6.9.2",
+      "version": "6.10.2",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.9.2.tgz",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.2.tgz",
-      "integrity": "sha512-4UFy0/LgDo7Oa/+wOAlj44tp9K78u38E5/359eSrqEp1Z5PdVfimCcs7SluXMP755RUQu6d2b4AvF0R1C9RZjg==",
+      "integrity": "sha512-TXtUUEYHuaTEbLZWIKUr5pmBuhDLy+8KYtPYdcV8qC+pOZL+NKqYwvWSRrVXHn+ZmRRAu8vJTAznH7Oag6RVRw==",
       "dev": true,
       "requires": {
         "fast-deep-equal": "^2.0.1",
@@ -275,9 +275,9 @@
       "dev": true
     },
     "aws4": {
-      "version": "1.8.0",
+      "version": "1.9.0",
-      "resolved": "https://registry.npmjs.org/aws4/-/aws4-1.8.0.tgz",
+      "resolved": "https://registry.npmjs.org/aws4/-/aws4-1.9.0.tgz",
-      "integrity": "sha512-ReZxvNHIOv88FlT7rxcXIIC0fPt4KZqZbOlivyWtXLt8ESx84zd3kMC6iK5jVeS2qt+g7ftS7ye4fi06X5rtRQ==",
+      "integrity": "sha512-Uvq6hVe90D0B2WEnUqtdgY1bATGz3mw33nH9Y+dmA+w5DHvUmBgkr5rM/KCHpCsiFNRUfokW/szpPPgMK2hm4A==",
       "dev": true
     },
     "backo2": {
@@ -712,9 +712,9 @@
       "dev": true
     },
     "combined-stream": {
-      "version": "1.0.7",
+      "version": "1.0.8",
-      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.7.tgz",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
-      "integrity": "sha512-brWl9y6vOB1xYPZcpZde3N9zDByXTosAeMDo4p1wzo6UMOX4vumB+TP1RZ76sfE6Md68Q0NJSrE/gbezd4Ul+w==",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
       "dev": true,
       "requires": {
         "delayed-stream": "~1.0.0"
@@ -1263,9 +1263,9 @@
       }
     },
     "es6-promise": {
-      "version": "4.2.6",
+      "version": "4.2.8",
-      "resolved": "https://registry.npmjs.org/es6-promise/-/es6-promise-4.2.6.tgz",
+      "resolved": "https://registry.npmjs.org/es6-promise/-/es6-promise-4.2.8.tgz",
-      "integrity": "sha512-aRVgGdnmW2OiySVPUC9e6m+plolMAJKjZnQlCwNSuK5yQ0JN61DZSO1X1Ufd1foqWRAlig0rhduTCHe7sVtK5Q==",
+      "integrity": "sha512-HJDGx5daxeIvxdBxvG2cb9g4tEvwIk3i8+nhX0yGrYmZUzbkdg8QbDevheDB8gd0//uPj4c1EQua8Q+MViT0/w==",
       "dev": true
     },
     "es6-promisify": {
@@ -1615,9 +1615,9 @@
       }
     },
     "extend": {
-      "version": "3.0.0",
+      "version": "3.0.2",
-      "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.2.tgz",
-      "integrity": "sha1-WkdDU7nzNT3dgXbf03uRyDpG8dQ=",
+      "integrity": "sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==",
       "dev": true
     },
     "extend-shallow": {
@@ -1737,15 +1737,15 @@
           "dev": true
         },
         "process-nextick-args": {
-          "version": "2.0.0",
+          "version": "2.0.1",
-          "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-2.0.0.tgz",
+          "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-2.0.1.tgz",
-          "integrity": "sha512-MtEC1TqN0EU5nephaJ4rAtThHtC86dNN9qCuEhtshvpVBkAW5ZO7BASN9REnF9eoXGcRub+pFuKEpOHE+HbEMw==",
+          "integrity": "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag==",
           "dev": true
         },
         "readable-stream": {
-          "version": "2.3.6",
+          "version": "2.3.7",
-          "resolved": "http://registry.npmjs.org/readable-stream/-/readable-stream-2.3.6.tgz",
+          "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.3.7.tgz",
-          "integrity": "sha512-tQtKA9WIAhBF3+VLAseyMqZeBjW0AHJoxOtYqSUZNJxauErmLbVm2FW1y+J/YA9dUrAC39ITejlZWhVIwawkKw==",
+          "integrity": "sha512-Ebho8K4jIbHAxnuxi7o42OrZgF/ZTNcsZj6nRKyUmkhLFq8CHItp/fy6hQZuZmP/n3yZ9VBUbp4zz/mX8hmYPw==",
           "dev": true,
           "requires": {
             "core-util-is": "~1.0.0",
@@ -1781,9 +1781,9 @@
       "dev": true
     },
     "fast-json-stable-stringify": {
-      "version": "2.0.0",
+      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz",
-      "integrity": "sha1-1RQsDK7msRifh9OnYREGT4bIu/I=",
+      "integrity": "sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw==",
       "dev": true
     },
     "faye-websocket": {
@@ -1988,9 +1988,9 @@
       "dev": true
     },
     "fstream": {
-      "version": "1.0.11",
+      "version": "1.0.12",
-      "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.11.tgz",
+      "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.12.tgz",
-      "integrity": "sha1-XB+x8RdHcRTwYyoOtLcbPLD9MXE=",
+      "integrity": "sha512-WvJ193OHa0GHPEL+AycEJgxvBEwyfRkN1vhjca23OaPVMCaLCXTd5qAu82AjTcgP1UJmytkOKb63Ypde7raDIg==",
       "dev": true,
       "requires": {
         "graceful-fs": "^4.1.2",
@@ -2305,9 +2305,9 @@
           }
         },
         "lodash": {
-          "version": "4.17.11",
+          "version": "4.17.15",
-          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.11.tgz",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-          "integrity": "sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==",
+          "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
           "dev": true
         }
       }
@@ -2790,12 +2790,12 @@
       "dev": true
     },
     "https-proxy-agent": {
-      "version": "2.2.1",
+      "version": "2.2.4",
-      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz",
+      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.4.tgz",
-      "integrity": "sha512-HPCTS1LW51bcyMYbxUIOO4HEOlQ1/1qRaFWcyxvwaqUS9TY88aoEuHUY33kuAh1YhVVaDQhLZsnPd+XNARWZlQ==",
+      "integrity": "sha512-OmvfoQ53WLjtA9HeYP9RNrWMJzzAz1JGaSFr1nijg0PVR1JaD/xbJq1mdEIIlxGpXp9eSe/O2LgU9DJmTPd0Eg==",
       "dev": true,
       "requires": {
-        "agent-base": "^4.1.0",
+        "agent-base": "^4.3.0",
         "debug": "^3.1.0"
       },
       "dependencies": {
@@ -3120,9 +3120,9 @@
       "dev": true
     },
     "js-yaml": {
-      "version": "3.13.0",
+      "version": "3.13.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.0.tgz",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-      "integrity": "sha512-pZZoSxcCYco+DIKBTimr67J6Hy+EYGZDY/HCWC+iAEA9h1ByhMXAIVUXMcMFpOCxQ/xjXmPI2MkDL5HRm5eFrQ==",
+      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
       "dev": true,
       "requires": {
         "argparse": "^1.0.7",
@@ -3276,21 +3276,9 @@
       }
     },
     "lodash": {
-      "version": "4.17.11",
+      "version": "4.17.15",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.11.tgz",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-      "integrity": "sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==",
+      "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
-      "dev": true
-    },
-    "lodash.assign": {
-      "version": "4.2.0",
-      "resolved": "https://registry.npmjs.org/lodash.assign/-/lodash.assign-4.2.0.tgz",
-      "integrity": "sha1-DZnzzNem0mHRm9rrkkUAXShYCOc=",
-      "dev": true
-    },
-    "lodash.clonedeep": {
-      "version": "4.5.0",
-      "resolved": "https://registry.npmjs.org/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz",
-      "integrity": "sha1-4j8/nE+Pvd6HJSnBBxhXoIblzO8=",
       "dev": true
     },
     "lodash.isfinite": {
@@ -3299,12 +3287,6 @@
       "integrity": "sha1-+4m2WpqAKBgz8LdHizpRBPiY67M=",
       "dev": true
     },
-    "lodash.mergewith": {
-      "version": "4.6.1",
-      "resolved": "https://registry.npmjs.org/lodash.mergewith/-/lodash.mergewith-4.6.1.tgz",
-      "integrity": "sha512-eWw5r+PYICtEBgrBE5hhlT6aAa75f411bgDz/ZL2KZqYV03USvucsxcHUIlGTDTECs1eunpI7HOV7U+WLDvNdQ==",
-      "dev": true
-    },
     "loud-rejection": {
       "version": "1.6.0",
       "resolved": "https://registry.npmjs.org/loud-rejection/-/loud-rejection-1.6.0.tgz",
@@ -3431,18 +3413,18 @@
       "dev": true
     },
     "mime-db": {
-      "version": "1.38.0",
+      "version": "1.43.0",
-      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.38.0.tgz",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.43.0.tgz",
-      "integrity": "sha512-bqVioMFFzc2awcdJZIzR3HjZFX20QhilVS7hytkKrv7xFAn8bM1gzc/FOX2awLISvWe0PV8ptFKcon+wZ5qYkg==",
+      "integrity": "sha512-+5dsGEEovYbT8UY9yD7eE4XTc4UwJ1jBYlgaQQF38ENsKR3wj/8q8RFZrF9WIZpB2V1ArTVFUva8sAul1NzRzQ==",
       "dev": true
     },
     "mime-types": {
-      "version": "2.1.22",
+      "version": "2.1.26",
-      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.22.tgz",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.26.tgz",
-      "integrity": "sha512-aGl6TZGnhm/li6F7yx82bJiBZwgiEa4Hf6CNr8YO+r5UHr53tSTYZb102zyU50DOWWKeOv0uQLRL0/9EiKWCog==",
+      "integrity": "sha512-01paPWYgLrkqAyrlDorC1uDwl2p3qZT7yl806vW7DvDoxwXi46jsjFbg+WdwotBIk6/MbEhO/dh5aZ5sNj/dWQ==",
       "dev": true,
       "requires": {
-        "mime-db": "~1.38.0"
+        "mime-db": "1.43.0"
       }
     },
     "minimatch": {
@@ -3461,9 +3443,9 @@
       "dev": true
     },
     "mixin-deep": {
-      "version": "1.3.1",
+      "version": "1.3.2",
-      "resolved": "https://registry.npmjs.org/mixin-deep/-/mixin-deep-1.3.1.tgz",
+      "resolved": "https://registry.npmjs.org/mixin-deep/-/mixin-deep-1.3.2.tgz",
-      "integrity": "sha512-8ZItLHeEgaqEvd5lYBXfm4EZSFCX29Jb9K+lAHhDKzReKBQKj3R+7NOF6tjqYi9t4oI8VUfaWITJQm86wnXGNQ==",
+      "integrity": "sha512-WRoDn//mXBiJ1H40rqa3vH0toePwSsGb45iInWlTySa+Uu4k3tYUSxa2v1KqAiLtvlrSzaExqS1gtk96A9zvEA==",
       "dev": true,
       "requires": {
         "for-in": "^1.0.2",
@@ -3559,9 +3541,9 @@
       "dev": true
     },
     "nan": {
-      "version": "2.12.1",
+      "version": "2.14.0",
-      "resolved": "https://registry.npmjs.org/nan/-/nan-2.12.1.tgz",
+      "resolved": "https://registry.npmjs.org/nan/-/nan-2.14.0.tgz",
-      "integrity": "sha512-JY7V6lRkStKcKTvHO5NVSQRv+RV+FIL5pvDoLiAtSL9pKlC5x9PKQcZDsq7m4FO4d57mkhC6Z+QhAh3Jdk5JFw==",
+      "integrity": "sha512-INOFj37C7k3AfaNTtX8RhsTw7qRy7eLET14cROi9+5HAVbbHuIWUHEauBv5qT4Av2tWasiTY1Jw6puUNqRJXQg==",
       "dev": true
     },
     "nanomatch": {
@@ -3609,45 +3591,6 @@
         "which": "1"
       },
       "dependencies": {
-        "balanced-match": {
-          "version": "1.0.0",
-          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
-          "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c=",
-          "dev": true
-        },
-        "brace-expansion": {
-          "version": "1.1.11",
-          "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-          "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
-          "dev": true,
-          "requires": {
-            "balanced-match": "^1.0.0",
-            "concat-map": "0.0.1"
-          }
-        },
-        "glob": {
-          "version": "7.1.3",
-          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
-          "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
-          "dev": true,
-          "requires": {
-            "fs.realpath": "^1.0.0",
-            "inflight": "^1.0.4",
-            "inherits": "2",
-            "minimatch": "^3.0.4",
-            "once": "^1.3.0",
-            "path-is-absolute": "^1.0.0"
-          }
-        },
-        "minimatch": {
-          "version": "3.0.4",
-          "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-          "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
-          "dev": true,
-          "requires": {
-            "brace-expansion": "^1.1.7"
-          }
-        },
         "semver": {
           "version": "5.3.0",
           "resolved": "https://registry.npmjs.org/semver/-/semver-5.3.0.tgz",
@@ -3673,9 +3616,9 @@
       }
     },
     "node-sass": {
-      "version": "4.11.0",
+      "version": "4.13.0",
-      "resolved": "https://registry.npmjs.org/node-sass/-/node-sass-4.11.0.tgz",
+      "resolved": "https://registry.npmjs.org/node-sass/-/node-sass-4.13.0.tgz",
-      "integrity": "sha512-bHUdHTphgQJZaF1LASx0kAviPH7sGlcyNhWade4eVIpFp6tsn7SV8xNMTbsQFpEV9VXpnwTTnNYlfsZXgGgmkA==",
+      "integrity": "sha512-W1XBrvoJ1dy7VsvTAS5q1V45lREbTlZQqFbiHb3R3OTTCma0XBtuG6xZ6Z4506nR4lmHPTqVRwxT6KgtWC97CA==",
       "dev": true,
       "requires": {
         "async-foreach": "^0.1.3",
@@ -3685,12 +3628,10 @@
         "get-stdin": "^4.0.1",
         "glob": "^7.0.3",
         "in-publish": "^2.0.0",
-        "lodash.assign": "^4.2.0",
+        "lodash": "^4.17.15",
-        "lodash.clonedeep": "^4.3.2",
-        "lodash.mergewith": "^4.6.0",
         "meow": "^3.7.0",
         "mkdirp": "^0.5.1",
-        "nan": "^2.10.0",
+        "nan": "^2.13.2",
         "node-gyp": "^3.8.0",
         "npmlog": "^4.0.0",
         "request": "^2.88.0",
@@ -3699,44 +3640,11 @@
         "true-case-path": "^1.0.2"
       },
       "dependencies": {
-        "balanced-match": {
+        "lodash": {
-          "version": "1.0.0",
+          "version": "4.17.15",
-          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-          "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c=",
+          "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
           "dev": true
-        },
-        "brace-expansion": {
-          "version": "1.1.11",
-          "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-          "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
-          "dev": true,
-          "requires": {
-            "balanced-match": "^1.0.0",
-            "concat-map": "0.0.1"
-          }
-        },
-        "glob": {
-          "version": "7.1.3",
-          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
-          "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
-          "dev": true,
-          "requires": {
-            "fs.realpath": "^1.0.0",
-            "inflight": "^1.0.4",
-            "inherits": "2",
-            "minimatch": "^3.0.4",
-            "once": "^1.3.0",
-            "path-is-absolute": "^1.0.0"
-          }
-        },
-        "minimatch": {
-          "version": "3.0.4",
-          "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-          "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
-          "dev": true,
-          "requires": {
-            "brace-expansion": "^1.1.7"
-          }
         }
       }
     },
@@ -4153,9 +4061,9 @@
           }
         },
         "lodash": {
-          "version": "4.17.11",
+          "version": "4.17.15",
-          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.11.tgz",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-          "integrity": "sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==",
+          "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
           "dev": true
         }
       }
@@ -4229,9 +4137,9 @@
       "dev": true
     },
     "psl": {
-      "version": "1.1.31",
+      "version": "1.7.0",
-      "resolved": "https://registry.npmjs.org/psl/-/psl-1.1.31.tgz",
+      "resolved": "https://registry.npmjs.org/psl/-/psl-1.7.0.tgz",
-      "integrity": "sha512-/6pt4+C+T+wZUieKR620OpzN/LlnNKuWjy1iFLQ/UG35JqHlR/89MP1d96dUfkf6Dne3TuLQzOYEYshJ+Hx8mw==",
+      "integrity": "sha512-5NsSEDv8zY70ScRnOTn7bK7eanl2MvFrOrS/R6x+dBt5g1ghnj9Zv90kO8GwT8gxcu2ANyFprnFYB85IogIJOQ==",
       "dev": true
     },
     "punycode": {
@@ -4241,9 +4149,9 @@
       "dev": true
     },
     "puppeteer": {
-      "version": "1.12.2",
+      "version": "1.20.0",
-      "resolved": "https://registry.npmjs.org/puppeteer/-/puppeteer-1.12.2.tgz",
+      "resolved": "https://registry.npmjs.org/puppeteer/-/puppeteer-1.20.0.tgz",
-      "integrity": "sha512-xWSyCeD6EazGlfnQweMpM+Hs6X6PhUYhNTHKFj/axNZDq4OmrVERf70isBf7HsnFgB3zOC1+23/8+wCAZYg+Pg==",
+      "integrity": "sha512-bt48RDBy2eIwZPrkgbcwHtb51mj2nKvHOPMaSH2IsWiv7lOG9k9zhaRzpDZafrk05ajMc3cu+lSQYYOfH2DkVQ==",
       "dev": true,
       "requires": {
         "debug": "^4.1.0",
@@ -4266,9 +4174,9 @@
           }
         },
         "mime": {
-          "version": "2.4.0",
+          "version": "2.4.4",
-          "resolved": "https://registry.npmjs.org/mime/-/mime-2.4.0.tgz",
+          "resolved": "https://registry.npmjs.org/mime/-/mime-2.4.4.tgz",
-          "integrity": "sha512-ikBcWwyqXQSHKtciCcctu9YfPbFYZ4+gbHEmE0Q8jzcTYQg5dHCr3g2wwAZjPoJfQVXZq6KXAjpXOTf5/cjT7w==",
+          "integrity": "sha512-LRxmNwziLPT828z+4YkNzloCFC2YM4wrB99k+AV5ZbEyfGNWfG8SO1FUXLmLDBSo89NrJZ4DIWeLjy1CHGhMGA==",
           "dev": true
         }
       }
@@ -4572,47 +4480,6 @@
         "lodash": "^4.0.0",
         "scss-tokenizer": "^0.2.3",
         "yargs": "^7.0.0"
-      },
-      "dependencies": {
-        "balanced-match": {
-          "version": "1.0.0",
-          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
-          "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c=",
-          "dev": true
-        },
-        "brace-expansion": {
-          "version": "1.1.11",
-          "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-          "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
-          "dev": true,
-          "requires": {
-            "balanced-match": "^1.0.0",
-            "concat-map": "0.0.1"
-          }
-        },
-        "glob": {
-          "version": "7.1.3",
-          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
-          "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
-          "dev": true,
-          "requires": {
-            "fs.realpath": "^1.0.0",
-            "inflight": "^1.0.4",
-            "inherits": "2",
-            "minimatch": "^3.0.4",
-            "once": "^1.3.0",
-            "path-is-absolute": "^1.0.0"
-          }
-        },
-        "minimatch": {
-          "version": "3.0.4",
-          "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-          "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
-          "dev": true,
-          "requires": {
-            "brace-expansion": "^1.1.7"
-          }
-        }
       }
     },
     "scss-tokenizer": {
@@ -4773,9 +4640,9 @@
       "dev": true
     },
     "set-value": {
-      "version": "2.0.0",
+      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/set-value/-/set-value-2.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/set-value/-/set-value-2.0.1.tgz",
-      "integrity": "sha512-hw0yxk9GT/Hr5yJEYnHNKYXkIA8mVJgd9ditYZCe16ZczcaELYYcfvaXesNACk2O8O0nTiPQcQhGUQj8JLzeeg==",
+      "integrity": "sha512-JxHc1weCN68wRY0fhCoXpyK55m/XPHafOmK4UWD7m2CI14GMcFypt4w/0+NV5f/ZMby2F6S2wwA7fgynh9gWSw==",
       "dev": true,
       "requires": {
         "extend-shallow": "^2.0.1",
@@ -5248,13 +5115,13 @@
       "dev": true
     },
     "tar": {
-      "version": "2.2.1",
+      "version": "2.2.2",
-      "resolved": "https://registry.npmjs.org/tar/-/tar-2.2.1.tgz",
+      "resolved": "https://registry.npmjs.org/tar/-/tar-2.2.2.tgz",
-      "integrity": "sha1-jk0qJWwOIYXGsYrWlK7JaLg8sdE=",
+      "integrity": "sha512-FCEhQ/4rE1zYv9rYXJw/msRqsnmlje5jHP6huWeBZ704jUTy02c5AZyWujpMR1ax6mVw9NyJMfuK2CMDWVIfgA==",
       "dev": true,
       "requires": {
         "block-stream": "*",
-        "fstream": "^1.0.2",
+        "fstream": "^1.0.12",
         "inherits": "2"
       }
     },
@@ -5379,26 +5246,10 @@
         "glob": "^7.1.2"
       },
       "dependencies": {
-        "balanced-match": {
-          "version": "1.0.0",
-          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.0.tgz",
-          "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c=",
-          "dev": true
-        },
-        "brace-expansion": {
-          "version": "1.1.11",
-          "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-          "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
-          "dev": true,
-          "requires": {
-            "balanced-match": "^1.0.0",
-            "concat-map": "0.0.1"
-          }
-        },
         "glob": {
-          "version": "7.1.3",
+          "version": "7.1.6",
-          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.6.tgz",
-          "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
+          "integrity": "sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==",
           "dev": true,
           "requires": {
             "fs.realpath": "^1.0.0",
@@ -5488,38 +5339,15 @@
       }
     },
     "union-value": {
-      "version": "1.0.0",
+      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/union-value/-/union-value-1.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/union-value/-/union-value-1.0.1.tgz",
-      "integrity": "sha1-XHHDTLW61dzr4+oM0IIHulqhrqQ=",
+      "integrity": "sha512-tJfXmxMeWYnczCVs7XAEvIV7ieppALdyepWMkHkwciRpZraG/xwT+s2JN8+pr1+8jCRf80FFzvr+MpQeeoF4Xg==",
       "dev": true,
       "requires": {
         "arr-union": "^3.1.0",
         "get-value": "^2.0.6",
         "is-extendable": "^0.1.1",
-        "set-value": "^0.4.3"
+        "set-value": "^2.0.1"
-      },
-      "dependencies": {
-        "extend-shallow": {
-          "version": "2.0.1",
-          "resolved": "https://registry.npmjs.org/extend-shallow/-/extend-shallow-2.0.1.tgz",
-          "integrity": "sha1-Ua99YUrZqfYQ6huvu5idaxxWiQ8=",
-          "dev": true,
-          "requires": {
-            "is-extendable": "^0.1.0"
-          }
-        },
-        "set-value": {
-          "version": "0.4.3",
-          "resolved": "https://registry.npmjs.org/set-value/-/set-value-0.4.3.tgz",
-          "integrity": "sha1-fbCPnT0i3H945Trzw79GZuzfzPE=",
-          "dev": true,
-          "requires": {
-            "extend-shallow": "^2.0.1",
-            "is-extendable": "^0.1.1",
-            "is-plain-object": "^2.0.1",
-            "to-object-path": "^0.3.0"
-          }
-        }
       }
     },
     "unpipe": {
@@ -5649,9 +5477,9 @@
       "dev": true
     },
     "uuid": {
-      "version": "3.3.2",
+      "version": "3.3.3",
-      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.2.tgz",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.3.tgz",
-      "integrity": "sha512-yXJmeNaw3DnnKAOKJE51sL/ZaYfWJRl1pK9dr19YFCu0ObS231AB1/LbqTKRAQ5kw8A90rA6fr4riOUpTZvQZA==",
+      "integrity": "sha512-pW0No1RGHgzlpHJO1nsVrHKpOEIxkGg1xB+v0ZmdNH5OAeAwzAVrCnI2/6Mtx+Uys6iaylxa+D3g4j63IKKjSQ==",
       "dev": true
     },
     "v8flags": {

package.json

@@ -36,7 +36,7 @@
     "grunt-sass": "^3.0.2",
     "grunt-zip": "~0.17.1",
     "load-grunt-tasks": "^4.0.0",
-    "node-sass": "^4.11.0",
+    "node-sass": "^4.13.0",
     "mustache": "^2.3.0",
     "socket.io": "^2.2.0"
   },

plugin/notes/notes.html

@@ -539,12 +539,17 @@
 
 					callRevealApi( 'getSlidesAttributes', [], function ( slideAttributes ) {
 						callRevealApi( 'getConfig', [], function ( config ) {
+							var totalTime = config.totalTime;
+							var minTimePerSlide = config.minimumTimePerSlide || 0;
 							var defaultTiming = config.defaultTiming;
-							if (defaultTiming == null) {
+							if ((defaultTiming == null) && (totalTime == null)) {
 								callback(null);
 								return;
 							}
-
+							// Setting totalTime overrides defaultTiming
+							if (totalTime) {
+								defaultTiming = 0;
+							}
 							var timings = [];
 							for ( var i in slideAttributes ) {
 								var slide = slideAttributes[ i ];
@@ -559,7 +564,22 @@
 								}
 								timings.push(timing);
 							}
-
+							if ( totalTime ) {
+								// After we've allocated time to individual slides, we summarize it and
+								// subtract it from the total time
+								var remainingTime = totalTime - timings.reduce( function(a, b) { return a + b; }, 0 );
+								// The remaining time is divided by the number of slides that have 0 seconds
+								// allocated at the moment, giving the average time-per-slide on the remaining slides
+								var remainingSlides = (timings.filter( function(x) { return x == 0 }) ).length
+								var timePerSlide = Math.round( remainingTime / remainingSlides, 0 )
+								// And now we replace every zero-value timing with that average
+								timings = timings.map( function(x) { return (x==0 ? timePerSlide : x) } );
+							}
+							var slidesUnderMinimum = timings.filter( function(x) { return (x < minTimePerSlide) } ).length
+							if ( slidesUnderMinimum ) {
+								message = "The pacing time for " + slidesUnderMinimum + " slide(s) is under the configured minimum of " + minTimePerSlide + " seconds. Check the data-timing attribute on individual slides, or consider increasing the totalTime or minimumTimePerSlide configuration options (or removing some slides).";
+								alert(message);
+							}
 							callback( timings );
 						} );
 					} );

test/test-iframe-backgrounds.html

@@ -0,0 +1,104 @@
+<!doctype html>
+<html lang="en">
+
+	<head>
+		<meta charset="utf-8">
+
+		<title>reveal.js - Test Iframe Backgrounds</title>
+
+		<link rel="stylesheet" href="../css/reveal.css">
+		<link rel="stylesheet" href="qunit-2.5.0.css">
+	</head>
+
+	<body style="overflow: auto;">
+
+		<div id="qunit"></div>
+		<div id="qunit-fixture"></div>
+
+		<div class="reveal" style="display: none;">
+
+			<div class="slides">
+
+				<section data-background-iframe="#1">1</section>
+				<section data-background-iframe="#2">2</section>
+				<section data-background-iframe="#3" data-preload>3</section>
+				<section data-background-iframe="#4">4</section>
+				<section data-background-iframe="#5">5</section>
+				<section data-background-iframe="#6">6</section>
+
+			</div>
+
+		</div>
+
+		<script src="../js/reveal.js"></script>
+		<script src="qunit-2.5.0.js"></script>
+
+		<script>
+
+
+			Reveal.addEventListener( 'ready', function() {
+
+				function getIframe( index ) {
+					return document.querySelectorAll( '.slide-background' )[index].querySelector( 'iframe' );
+				}
+
+				QUnit.module( 'Iframe' );
+
+				QUnit.test( 'Using default settings', function( assert ) {
+
+					Reveal.slide(0);
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), false, 'not preloaded when within viewDistance' );
+
+					Reveal.slide(1);
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), true, 'loaded when slide becomes visible' );
+
+					Reveal.slide(0);
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), false, 'unloaded when slide becomes invisible' );
+
+				});
+
+				QUnit.test( 'Using data-preload', function( assert ) {
+
+					Reveal.slide(1);
+					assert.strictEqual( getIframe(2).hasAttribute( 'src' ), true, 'preloaded within viewDistance' );
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), true, 'loaded when slide becomes visible' );
+
+					Reveal.slide(0);
+					assert.strictEqual( getIframe(3).hasAttribute( 'src' ), false, 'unloads outside of viewDistance' );
+
+				});
+
+				QUnit.test( 'Using preloadIframes: true', function( assert ) {
+
+					Reveal.configure({ preloadIframes: true });
+
+					Reveal.slide(1);
+					assert.strictEqual( getIframe(0).hasAttribute( 'src' ), true, 'preloaded within viewDistance' );
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), true, 'preloaded within viewDistance' );
+					assert.strictEqual( getIframe(2).hasAttribute( 'src' ), true, 'preloaded within viewDistance' );
+
+				});
+
+				QUnit.test( 'Using preloadIframes: false', function( assert ) {
+
+					Reveal.configure({ preloadIframes: false });
+
+					Reveal.slide(0);
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), false, 'not preloaded within viewDistance' );
+					assert.strictEqual( getIframe(2).hasAttribute( 'src' ), false, 'not preloaded within viewDistance' );
+
+					Reveal.slide(1);
+					assert.strictEqual( getIframe(1).hasAttribute( 'src' ), true, 'loaded when slide becomes visible' );
+
+
+				});
+
+			} );
+
+			Reveal.initialize({
+				viewDistance: 3
+			});
+		</script>
+
+	</body>
+</html>

test/test.js

@@ -250,6 +250,22 @@ Reveal.addEventListener( 'ready', function() {
 		assert.deepEqual( Reveal.getIndices(), { h: 2, v: 0, f: 1 }, 'Reveal.slide( 2, 0, 1 )' );
 	});
 
+	QUnit.test( 'data-fragment is set on slide <section>', function( assert ) {
+		Reveal.slide( 2, 0, -1 );
+		assert.deepEqual( Reveal.getCurrentSlide().getAttribute( 'data-fragment' ), '-1' );
+
+		Reveal.slide( 2, 0, 2 );
+		assert.deepEqual( Reveal.getCurrentSlide().getAttribute( 'data-fragment' ), '2' );
+
+		Reveal.slide( 2, 0, 0 );
+		assert.deepEqual( Reveal.getCurrentSlide().getAttribute( 'data-fragment' ), '0' );
+
+		var fragmentSlide = Reveal.getCurrentSlide();
+
+		Reveal.slide( 3, 0 );
+		assert.deepEqual( fragmentSlide.getAttribute( 'data-fragment' ), '0', 'data-fragment persists when jumping to another slide' );
+	});
+
 	QUnit.test( 'Hiding all fragments', function( assert ) {
 		var fragmentSlide = document.querySelector( '#fragment-slides>section:nth-child(1)' );