slides.js

/*
 Google HTML5 slides template

 Authors: Luke Mahé (code)
 Marcin Wichary (code and design)

 Dominic Mazzoni (browser compatibility)
 Charles Chen (ChromeVox support)

 URL: http://code.google.com/p/html5slides/
 */

var PERMANENT_URL_PREFIX = '';

var SLIDE_CLASSES = ['far-past', 'past', 'current', 'next', 'far-next'];

var PM_TOUCH_SENSITIVITY = 15;

var curSlide;

/* ---------------------------------------------------------------------- */
/* classList polyfill by Eli Grey 
 * (http://purl.eligrey.com/github/classList.js/blob/master/classList.js) */

if (typeof document !== "undefined" && !("classList" in document.createElement("a"))) {

	(function (view) {

		var
			classListProp = "classList"
			, protoProp = "prototype"
			, elemCtrProto = (view.HTMLElement || view.Element)[protoProp]
			, objCtr = Object
		strTrim = String[protoProp].trim || function () {
			return this.replace(/^\s+|\s+$/g, "");
		}
			, arrIndexOf = Array[protoProp].indexOf || function (item) {
			for (var i = 0, len = this.length; i < len; i++) {
				if (i in this && this[i] === item) {
					return i;
				}
			}
			return -1;
		}
			// Vendors: please allow content code to instantiate DOMExceptions
			, DOMEx = function (type, message) {
			this.name = type;
			this.code = DOMException[type];
			this.message = message;
		}
			, checkTokenAndGetIndex = function (classList, token) {
			if (token === "") {
				throw new DOMEx(
					"SYNTAX_ERR"
					, "An invalid or illegal string was specified"
				);
			}
			if (/\s/.test(token)) {
				throw new DOMEx(
					"INVALID_CHARACTER_ERR"
					, "String contains an invalid character"
				);
			}
			return arrIndexOf.call(classList, token);
		}
			, ClassList = function (elem) {
			var
				trimmedClasses = strTrim.call(elem.className)
				, classes = trimmedClasses ? trimmedClasses.split(/\s+/) : []
				;
			for (var i = 0, len = classes.length; i < len; i++) {
				this.push(classes[i]);
			}
			this._updateClassName = function () {
				elem.className = this.toString();
			};
		}
			, classListProto = ClassList[protoProp] = []
			, classListGetter = function () {
			return new ClassList(this);
		}
		;
// Most DOMException implementations don't allow calling DOMException's toString()
// on non-DOMExceptions. Error's toString() is sufficient here.
		DOMEx[protoProp] = Error[protoProp];
		classListProto.item = function (i) {
			return this[i] || null;
		};
		classListProto.contains = function (token) {
			token += "";
			return checkTokenAndGetIndex(this, token) !== -1;
		};
		classListProto.add = function (token) {
			token += "";
			if (checkTokenAndGetIndex(this, token) === -1) {
				this.push(token);
				this._updateClassName();
			}
		};
		classListProto.remove = function (token) {
			token += "";
			var index = checkTokenAndGetIndex(this, token);
			if (index !== -1) {
				this.splice(index, 1);
				this._updateClassName();
			}
		};
		classListProto.toggle = function (token) {
			token += "";
			if (checkTokenAndGetIndex(this, token) === -1) {
				this.add(token);
			} else {
				this.remove(token);
			}
		};
		classListProto.toString = function () {
			return this.join(" ");
		};

		if (objCtr.defineProperty) {
			var classListPropDesc = {
				get: classListGetter
				, enumerable: true
				, configurable: true
			};
			try {
				objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
			} catch (ex) { // IE 8 doesn't support enumerable:true
				if (ex.number === -0x7FF5EC54) {
					classListPropDesc.enumerable = false;
					objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
				}
			}
		} else if (objCtr[protoProp].__defineGetter__) {
			elemCtrProto.__defineGetter__(classListProp, classListGetter);
		}

	}(self));

}
/* ---------------------------------------------------------------------- */

/* Slide movement */

function getSlideEl(no) {
	if ((no < 0) || (no >= slideEls.length)) {
		return null;
	} else {
		return slideEls[no];
	}
};

function updateSlideClass(slideNo, className) {
	var el = getSlideEl(slideNo);

	if (!el) {
		return;
	}

	if (className) {
		el.classList.add(className);
	}

	for (var i in SLIDE_CLASSES) {
		if (className != SLIDE_CLASSES[i]) {
			el.classList.remove(SLIDE_CLASSES[i]);
		}
	}
};

function updateSlides() {
	for (var i = 0; i < slideEls.length; i++) {
		switch (i) {
			case curSlide - 2:
				updateSlideClass(i, 'far-past');
				break;
			case curSlide - 1:
				updateSlideClass(i, 'past');
				break;
			case curSlide:
				updateSlideClass(i, 'current');
				break;
			case curSlide + 1:
				updateSlideClass(i, 'next');
				break;
			case curSlide + 2:
				updateSlideClass(i, 'far-next');
				break;
			default:
				updateSlideClass(i);
				break;
		}
	}

	triggerLeaveEvent(curSlide - 1);
	triggerEnterEvent(curSlide);

	window.setTimeout(function() {
		// Hide after the slide
		disableSlideFrames(curSlide - 2);
	}, 301);

	enableSlideFrames(curSlide - 1);
	enableSlideFrames(curSlide + 2);

	if (isChromeVoxActive()) {
		speakAndSyncToNode(slideEls[curSlide]);
	}

	updateHash();
};

function buildNextItem() {
	var toBuild  = slideEls[curSlide].querySelectorAll('.to-build');

	if (!toBuild.length) {
		return false;
	}

	toBuild[0].classList.remove('to-build', '');

	if (isChromeVoxActive()) {
		speakAndSyncToNode(toBuild[0]);
	}

	return true;
};

function prevSlide() {
	if (curSlide > 0) {
		curSlide--;

		updateSlides();
	}
};

function nextSlide() {
	if (buildNextItem()) {
		return;
	}

	if (curSlide < slideEls.length - 1) {
		curSlide++;

		updateSlides();
	}
};

/* Slide events */

function triggerEnterEvent(no) {
	var el = getSlideEl(no);
	if (!el) {
		return;
	}

	var onEnter = el.getAttribute('onslideenter');
	if (onEnter) {
		new Function(onEnter).call(el);
	}

	var evt = document.createEvent('Event');
	evt.initEvent('slideenter', true, true);
	evt.slideNumber = no + 1; // Make it readable

	el.dispatchEvent(evt);
};

function triggerLeaveEvent(no) {
	var el = getSlideEl(no);
	if (!el) {
		return;
	}

	var onLeave = el.getAttribute('onslideleave');
	if (onLeave) {
		new Function(onLeave).call(el);
	}

	var evt = document.createEvent('Event');
	evt.initEvent('slideleave', true, true);
	evt.slideNumber = no + 1; // Make it readable

	el.dispatchEvent(evt);
};

/* Touch events */

function handleTouchStart(event) {
	if (event.touches.length == 1) {
		touchDX = 0;
		touchDY = 0;

		touchStartX = event.touches[0].pageX;
		touchStartY = event.touches[0].pageY;

		document.body.addEventListener('touchmove', handleTouchMove, true);
		document.body.addEventListener('touchend', handleTouchEnd, true);
	}
};

function handleTouchMove(event) {
	if (event.touches.length > 1) {
		cancelTouch();
	} else {
		touchDX = event.touches[0].pageX - touchStartX;
		touchDY = event.touches[0].pageY - touchStartY;
	}
};

function handleTouchEnd(event) {
	var dx = Math.abs(touchDX);
	var dy = Math.abs(touchDY);

	if ((dx > PM_TOUCH_SENSITIVITY) && (dy < (dx * 2 / 3))) {
		if (touchDX > 0) {
			prevSlide();
		} else {
			nextSlide();
		}
	}

	cancelTouch();
};

function cancelTouch() {
	document.body.removeEventListener('touchmove', handleTouchMove, true);
	document.body.removeEventListener('touchend', handleTouchEnd, true);
};

/* Preloading frames */

function disableSlideFrames(no) {
	var el = getSlideEl(no);
	if (!el) {
		return;
	}

	var frames = el.getElementsByTagName('iframe');
	for (var i = 0, frame; frame = frames[i]; i++) {
		disableFrame(frame);
	}
};

function enableSlideFrames(no) {
	var el = getSlideEl(no);
	if (!el) {
		return;
	}

	var frames = el.getElementsByTagName('iframe');
	for (var i = 0, frame; frame = frames[i]; i++) {
		enableFrame(frame);
	}
};

function disableFrame(frame) {
	frame.src = 'about:blank';
};

function enableFrame(frame) {
	var src = frame._src;

	if (frame.src != src && src != 'about:blank') {
		frame.src = src;
	}
};

function setupFrames() {
	var frames = document.querySelectorAll('iframe');
	for (var i = 0, frame; frame = frames[i]; i++) {
		frame._src = frame.src;
		disableFrame(frame);
	}

	enableSlideFrames(curSlide);
	enableSlideFrames(curSlide + 1);
	enableSlideFrames(curSlide + 2);
};

function setupInteraction() {
	/* Clicking and tapping */

	var el = document.createElement('div');
	el.className = 'slide-area';
	el.id = 'prev-slide-area';
	el.addEventListener('click', prevSlide, false);
	document.querySelector('section.slides').appendChild(el);

	var el = document.createElement('div');
	el.className = 'slide-area';
	el.id = 'next-slide-area';
	el.addEventListener('click', nextSlide, false);
	document.querySelector('section.slides').appendChild(el);

	/* Swiping */

	document.body.addEventListener('touchstart', handleTouchStart, false);
}

/* ChromeVox support */

function isChromeVoxActive() {
	if (typeof(cvox) == 'undefined') {
		return false;
	} else {
		return true;
	}
};

function speakAndSyncToNode(node) {
	if (!isChromeVoxActive()) {
		return;
	}

	cvox.ChromeVox.navigationManager.switchToStrategy(
		cvox.ChromeVoxNavigationManager.STRATEGIES.LINEARDOM, 0, true);
	cvox.ChromeVox.navigationManager.syncToNode(node);
	cvox.ChromeVoxUserCommands.finishNavCommand('');
	var target = node;
	while (target.firstChild) {
		target = target.firstChild;
	}
	cvox.ChromeVox.navigationManager.syncToNode(target);
};

function speakNextItem() {
	if (!isChromeVoxActive()) {
		return;
	}

	cvox.ChromeVox.navigationManager.switchToStrategy(
		cvox.ChromeVoxNavigationManager.STRATEGIES.LINEARDOM, 0, true);
	cvox.ChromeVox.navigationManager.next(true);
	if (!cvox.DomUtil.isDescendantOfNode(
		cvox.ChromeVox.navigationManager.getCurrentNode(), slideEls[curSlide])){
		var target = slideEls[curSlide];
		while (target.firstChild) {
			target = target.firstChild;
		}
		cvox.ChromeVox.navigationManager.syncToNode(target);
		cvox.ChromeVox.navigationManager.next(true);
	}
	cvox.ChromeVoxUserCommands.finishNavCommand('');
};

function speakPrevItem() {
	if (!isChromeVoxActive()) {
		return;
	}

	cvox.ChromeVox.navigationManager.switchToStrategy(
		cvox.ChromeVoxNavigationManager.STRATEGIES.LINEARDOM, 0, true);
	cvox.ChromeVox.navigationManager.previous(true);
	if (!cvox.DomUtil.isDescendantOfNode(
		cvox.ChromeVox.navigationManager.getCurrentNode(), slideEls[curSlide])){
		var target = slideEls[curSlide];
		while (target.lastChild){
			target = target.lastChild;
		}
		cvox.ChromeVox.navigationManager.syncToNode(target);
		cvox.ChromeVox.navigationManager.previous(true);
	}
	cvox.ChromeVoxUserCommands.finishNavCommand('');
};

/* Hash functions */

function getCurSlideFromHash() {
	var slideNo = parseInt(location.hash.substr(1));

	if (slideNo) {
		curSlide = slideNo - 1;
	} else {
		curSlide = 0;
	}
};

function updateHash() {
	location.replace('#' + (curSlide + 1));
};

/* Event listeners */

function handleBodyKeyDown(event) {
	switch (event.keyCode) {
		case 39: // right arrow
		case 13: // Enter
		case 32: // space
		case 34: // PgDn
			nextSlide();
			event.preventDefault();
			break;

		case 37: // left arrow
		case 8: // Backspace
		case 33: // PgUp
			prevSlide();
			event.preventDefault();
			break;

		case 40: // down arrow
			if (isChromeVoxActive()) {
				speakNextItem();
			} else {
				nextSlide();
			}
			event.preventDefault();
			break;

		case 38: // up arrow
			if (isChromeVoxActive()) {
				speakPrevItem();
			} else {
				prevSlide();
			}
			event.preventDefault();
			break;
	}
};

function addEventListeners() {
	document.addEventListener('keydown', handleBodyKeyDown, false);
};

/* Initialization */

function addPrettify() {
	var els = document.querySelectorAll('pre');
	for (var i = 0, el; el = els[i]; i++) {
		if (!el.classList.contains('noprettyprint')) {
			el.classList.add('prettyprint');
		}
	}

	var el = document.createElement('script');
	el.type = 'text/javascript';
	el.src = PERMANENT_URL_PREFIX + 'prettify.js';
	el.onload = function() {
		prettyPrint();
	}
	document.body.appendChild(el);
};

function addFontStyle() {
	var el = document.createElement('link');
	el.rel = 'stylesheet';
	el.type = 'text/css';
	el.href = 'http://fonts.googleapis.com/css?family=' +
		'Oswald:400,700|Open+Sans:300,300italic,700,700italic';

	document.body.appendChild(el);
};

function addGeneralStyle() {
	var el = document.createElement('link');
	el.rel = 'stylesheet';
	el.type = 'text/css';
	el.href = PERMANENT_URL_PREFIX + 'styles.css';
	document.body.appendChild(el);

	var el = document.createElement('meta');
	el.name = 'viewport';
	el.content = 'width=1100,height=750';
	document.querySelector('head').appendChild(el);

	var el = document.createElement('meta');
	el.name = 'apple-mobile-web-app-capable';
	el.content = 'yes';
	document.querySelector('head').appendChild(el);
};

function makeBuildLists() {
	for (var i = curSlide, slide; slide = slideEls[i]; i++) {
		var items = slide.querySelectorAll('.build > *');
		for (var j = 0, item; item = items[j]; j++) {
			if (item.classList) {
				item.classList.add('to-build');
			}
		}
	}
};

function handleDomLoaded() {
	slideEls = document.querySelectorAll('section.slides > article');

	setupFrames();

	addFontStyle();
	addGeneralStyle();
	addPrettify();
	addEventListeners();

	updateSlides();

	setupInteraction();
	makeBuildLists();

	document.body.classList.add('loaded');
};

function initialize() {
	getCurSlideFromHash();

	if (window['_DEBUG']) {
		PERMANENT_URL_PREFIX = '../';
	}

	if (window['_DCL']) {
		handleDomLoaded();
	} else {
		document.addEventListener('DOMContentLoaded', handleDomLoaded, false);
	}
}

// If ?debug exists then load the script relative instead of absolute
if (!window['_DEBUG'] && document.location.href.indexOf('?debug') !== -1) {
	document.addEventListener('DOMContentLoaded', function() {
		// Avoid missing the DomContentLoaded event
		window['_DCL'] = true
	}, false);

	window['_DEBUG'] = true;
	var script = document.createElement('script');
	script.type = 'text/javascript';
	script.src = '../slides.js';
	var s = document.getElementsByTagName('script')[0];
	s.parentNode.insertBefore(script, s);

	// Remove this script
	s.parentNode.removeChild(s);
} else {
	initialize();
}