Merge branch 'dev' into patch-1

css/reveal.css

@@ -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

@@ -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

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 }

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

@@ -1217,6 +1217,8 @@
 		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 +1278,11 @@
 
 					// 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 +1453,8 @@
 			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 +1987,25 @@
 
 		// 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 +2266,12 @@
 					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 +2279,10 @@
 						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 +3067,11 @@
 		syncBackground( slide );
 		syncFragments( slide );
 
+		loadSlide( slide );
+
 		updateBackground();
 		updateNotes();
 
-		loadSlide( slide );
-
 	}
 
 	/**
@@ -3309,7 +3337,7 @@
 			}
 
 			// 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 +3345,7 @@
 			}
 
 			// 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 +3627,7 @@
 		// Stop content inside of previous backgrounds
 		if( previousBackground ) {
 
-			stopEmbeddedContent( previousBackground );
+			stopEmbeddedContent( previousBackground, { unloadIframes: !shouldPreload( previousBackground ) } );
 
 		}
 
@@ -3778,6 +3806,7 @@
 			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 +3815,7 @@
 				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 ) {
@@ -3828,14 +3856,7 @@
 					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%';
@@ -3846,6 +3867,19 @@
 				}
 			}
 
+			// 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 +3899,11 @@
 		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 +4468,44 @@
 	 */
 	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;
 
 	}
 
@@ -5116,8 +5192,8 @@
 
 		// 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 +5220,10 @@
 			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 +5296,7 @@
 				if( firstSlideShortcut ) {
 					slide( 0 );
 				}
-				else if( !isOverview() && config.navigationMode === 'linear' ) {
+				else if( !isOverview() && useLinearMode ) {
 					navigatePrev();
 				}
 				else {
@@ -5228,7 +5308,7 @@
 				if( lastSlideShortcut ) {
 					slide( Number.MAX_VALUE );
 				}
-				else if( !isOverview() && config.navigationMode === 'linear' ) {
+				else if( !isOverview() && useLinearMode ) {
 					navigateNext();
 				}
 				else {
@@ -5237,7 +5317,7 @@
 			}
 			// K, UP
 			else if( keyCode === 75 || keyCode === 38 ) {
-				if( !isOverview() && config.navigationMode === 'linear' ) {
+				if( !isOverview() && useLinearMode ) {
 					navigatePrev();
 				}
 				else {
@@ -5246,7 +5326,7 @@
 			}
 			// J, DOWN
 			else if( keyCode === 74 || keyCode === 40 ) {
-				if( !isOverview() && config.navigationMode === 'linear' ) {
+				if( !isOverview() && useLinearMode ) {
 					navigateNext();
 				}
 				else {
@@ -5356,20 +5436,50 @@
 
 				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 +6015,15 @@
 		// 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

@@ -53,9 +53,9 @@
       }
     },
     "ajv": {
-      "version": "6.9.2",
+      "version": "6.10.1",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.9.2.tgz",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.1.tgz",
-      "integrity": "sha512-4UFy0/LgDo7Oa/+wOAlj44tp9K78u38E5/359eSrqEp1Z5PdVfimCcs7SluXMP755RUQu6d2b4AvF0R1C9RZjg==",
+      "integrity": "sha512-w1YQaVGNC6t2UCPjEawK/vo/dG8OOrVtUmhBT1uJJYxbl5kU2Tj3v6LGqBcsysN1yhuCStJCCA3GqdvKY8sqXQ==",
       "dev": true,
       "requires": {
         "fast-deep-equal": "^2.0.1",
@@ -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"
@@ -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",
@@ -3281,30 +3281,12 @@
       "integrity": "sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==",
       "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": {
       "version": "3.3.2",
       "resolved": "https://registry.npmjs.org/lodash.isfinite/-/lodash.isfinite-3.3.2.tgz",
       "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": "1.40.0",
-      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.38.0.tgz",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.40.0.tgz",
-      "integrity": "sha512-bqVioMFFzc2awcdJZIzR3HjZFX20QhilVS7hytkKrv7xFAn8bM1gzc/FOX2awLISvWe0PV8ptFKcon+wZ5qYkg==",
+      "integrity": "sha512-jYdeOMPy9vnxEqFRRo6ZvTZ8d9oPb+k18PKoYNYUe2stVEBPPwsln/qWzdbmaIvnhZ9v2P+CuecK+fpUfsV2mA==",
       "dev": true
     },
     "mime-types": {
-      "version": "2.1.22",
+      "version": "2.1.24",
-      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.22.tgz",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.24.tgz",
-      "integrity": "sha512-aGl6TZGnhm/li6F7yx82bJiBZwgiEa4Hf6CNr8YO+r5UHr53tSTYZb102zyU50DOWWKeOv0uQLRL0/9EiKWCog==",
+      "integrity": "sha512-WaFHS3MCl5fapm3oLxU4eYDw77IQM2ACcxQ9RIxfaC3ooc6PFuBMGZZsYpvoXS5D5QTWPieo1jjLdAm3TBP3cQ==",
       "dev": true,
       "requires": {
-        "mime-db": "~1.38.0"
+        "mime-db": "1.40.0"
       }
     },
     "minimatch": {
@@ -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": "4.12.0",
-      "resolved": "https://registry.npmjs.org/node-sass/-/node-sass-4.11.0.tgz",
+      "resolved": "https://registry.npmjs.org/node-sass/-/node-sass-4.12.0.tgz",
-      "integrity": "sha512-bHUdHTphgQJZaF1LASx0kAviPH7sGlcyNhWade4eVIpFp6tsn7SV8xNMTbsQFpEV9VXpnwTTnNYlfsZXgGgmkA==",
+      "integrity": "sha512-A1Iv4oN+Iel6EPv77/HddXErL2a+gZ4uBeZUy+a8O35CFYTXhgA8MgLCWBtwpGZdCvTvQ9d+bQxX/QC36GDPpQ==",
       "dev": true,
       "requires": {
         "async-foreach": "^0.1.3",
@@ -3685,59 +3628,16 @@
         "get-stdin": "^4.0.1",
         "glob": "^7.0.3",
         "in-publish": "^2.0.0",
-        "lodash.assign": "^4.2.0",
+        "lodash": "^4.17.11",
-        "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",
         "sass-graph": "^2.2.4",
         "stdout-stream": "^1.4.0",
         "true-case-path": "^1.0.2"
-      },
-      "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",
-          "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"
-          }
-        }
       }
     },
     "nopt": {
@@ -4229,9 +4129,9 @@
       "dev": true
     },
     "psl": {
-      "version": "1.1.31",
+      "version": "1.2.0",
-      "resolved": "https://registry.npmjs.org/psl/-/psl-1.1.31.tgz",
+      "resolved": "https://registry.npmjs.org/psl/-/psl-1.2.0.tgz",
-      "integrity": "sha512-/6pt4+C+T+wZUieKR620OpzN/LlnNKuWjy1iFLQ/UG35JqHlR/89MP1d96dUfkf6Dne3TuLQzOYEYshJ+Hx8mw==",
+      "integrity": "sha512-GEn74ZffufCmkDDLNcl3uuyF/aSD6exEyh1v/ZSdAomB82t6G9hzJVRx0jBmLDW+VfZqks3aScmMw9DszwUalA==",
       "dev": true
     },
     "punycode": {
@@ -4572,47 +4472,6 @@
         "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": {
@@ -5248,13 +5107,13 @@
       "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 +5238,10 @@
         "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": "7.1.4",
-          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.4.tgz",
-          "integrity": "sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==",
+          "integrity": "sha512-hkLPepehmnKk41pUGm3sYxoFs/umurYfYJCerbXEyFIWcAzvpipAgVkBqqT9RBKMGjnq6kMuyYwha6csxbiM1A==",
           "dev": true,
           "requires": {
             "fs.realpath": "^1.0.0",

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": "^4.12.0",
     "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>