837 lines
32 KiB
JavaScript
837 lines
32 KiB
JavaScript
/**
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* impress.js
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*
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* impress.js is a presentation tool based on the power of CSS3 transforms and transitions
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* in modern browsers and inspired by the idea behind prezi.com.
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*
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*
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* Copyright 2011-2012 Bartek Szopka (@bartaz)
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*
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* Released under the MIT and GPL Licenses.
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*
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* ------------------------------------------------
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* author: Bartek Szopka
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* version: 0.6.0
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* url: http://bartaz.github.com/impress.js/
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* source: http://github.com/bartaz/impress.js/
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*/
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/*jshint bitwise:true, curly:true, eqeqeq:true, forin:true, latedef:true, newcap:true,
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noarg:true, noempty:true, undef:true, strict:true, browser:true */
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// You are one of those who like to know how things work inside?
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// Let me show you the cogs that make impress.js run...
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( function( document, window ) {
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"use strict";
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// HELPER FUNCTIONS
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// `pfx` is a function that takes a standard CSS property name as a parameter
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// and returns it's prefixed version valid for current browser it runs in.
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// The code is heavily inspired by Modernizr http://www.modernizr.com/
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var pfx = ( function() {
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var style = document.createElement( "dummy" ).style,
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prefixes = "Webkit Moz O ms Khtml".split( " " ),
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memory = {};
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return function( prop ) {
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if ( typeof memory[ prop ] === "undefined" ) {
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var ucProp = prop.charAt( 0 ).toUpperCase() + prop.substr( 1 ),
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props = ( prop + " " + prefixes.join( ucProp + " " ) + ucProp ).split( " " );
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memory[ prop ] = null;
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for ( var i in props ) {
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if ( style[ props[ i ] ] !== undefined ) {
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memory[ prop ] = props[ i ];
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break;
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}
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}
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}
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return memory[ prop ];
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};
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} )();
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// `arrayify` takes an array-like object and turns it into real Array
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// to make all the Array.prototype goodness available.
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var arrayify = function( a ) {
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return [].slice.call( a );
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};
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// `css` function applies the styles given in `props` object to the element
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// given as `el`. It runs all property names through `pfx` function to make
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// sure proper prefixed version of the property is used.
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var css = function( el, props ) {
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var key, pkey;
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for ( key in props ) {
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if ( props.hasOwnProperty( key ) ) {
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pkey = pfx( key );
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if ( pkey !== null ) {
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el.style[ pkey ] = props[ key ];
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}
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}
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}
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return el;
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};
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// `toNumber` takes a value given as `numeric` parameter and tries to turn
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// it into a number. If it is not possible it returns 0 (or other value
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// given as `fallback`).
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var toNumber = function( numeric, fallback ) {
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return isNaN( numeric ) ? ( fallback || 0 ) : Number( numeric );
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};
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// `byId` returns element with given `id` - you probably have guessed that ;)
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var byId = function( id ) {
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return document.getElementById( id );
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};
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// `$` returns first element for given CSS `selector` in the `context` of
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// the given element or whole document.
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var $ = function( selector, context ) {
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context = context || document;
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return context.querySelector( selector );
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};
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// `$$` return an array of elements for given CSS `selector` in the `context` of
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// the given element or whole document.
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var $$ = function( selector, context ) {
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context = context || document;
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return arrayify( context.querySelectorAll( selector ) );
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};
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// `triggerEvent` builds a custom DOM event with given `eventName` and `detail` data
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// and triggers it on element given as `el`.
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var triggerEvent = function( el, eventName, detail ) {
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var event = document.createEvent( "CustomEvent" );
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event.initCustomEvent( eventName, true, true, detail );
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el.dispatchEvent( event );
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};
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// `translate` builds a translate transform string for given data.
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var translate = function( t ) {
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return " translate3d(" + t.x + "px," + t.y + "px," + t.z + "px) ";
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};
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// `rotate` builds a rotate transform string for given data.
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// By default the rotations are in X Y Z order that can be reverted by passing `true`
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// as second parameter.
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var rotate = function( r, revert ) {
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var rX = " rotateX(" + r.x + "deg) ",
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rY = " rotateY(" + r.y + "deg) ",
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rZ = " rotateZ(" + r.z + "deg) ";
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return revert ? rZ + rY + rX : rX + rY + rZ;
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};
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// `scale` builds a scale transform string for given data.
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var scale = function( s ) {
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return " scale(" + s + ") ";
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};
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// `getElementFromHash` returns an element located by id from hash part of
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// window location.
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var getElementFromHash = function() {
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// Get id from url # by removing `#` or `#/` from the beginning,
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// so both "fallback" `#slide-id` and "enhanced" `#/slide-id` will work
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return byId( window.location.hash.replace( /^#\/?/, "" ) );
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};
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// `computeWindowScale` counts the scale factor between window size and size
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// defined for the presentation in the config.
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var computeWindowScale = function( config ) {
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var hScale = window.innerHeight / config.height,
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wScale = window.innerWidth / config.width,
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scale = hScale > wScale ? wScale : hScale;
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if ( config.maxScale && scale > config.maxScale ) {
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scale = config.maxScale;
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}
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if ( config.minScale && scale < config.minScale ) {
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scale = config.minScale;
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}
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return scale;
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};
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// CHECK SUPPORT
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var body = document.body;
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var ua = navigator.userAgent.toLowerCase();
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var impressSupported =
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// Browser should support CSS 3D transtorms
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( pfx( "perspective" ) !== null ) &&
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// Browser should support `classList` and `dataset` APIs
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( body.classList ) &&
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( body.dataset ) &&
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// But some mobile devices need to be blacklisted,
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// because their CSS 3D support or hardware is not
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// good enough to run impress.js properly, sorry...
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( ua.search( /(iphone)|(ipod)|(android)/ ) === -1 );
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if ( !impressSupported ) {
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// We can't be sure that `classList` is supported
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body.className += " impress-not-supported ";
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} else {
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body.classList.remove( "impress-not-supported" );
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body.classList.add( "impress-supported" );
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}
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// GLOBALS AND DEFAULTS
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// This is where the root elements of all impress.js instances will be kept.
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// Yes, this means you can have more than one instance on a page, but I'm not
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// sure if it makes any sense in practice ;)
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var roots = {};
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// Some default config values.
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var defaults = {
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width: 1024,
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height: 768,
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maxScale: 1,
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minScale: 0,
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perspective: 1000,
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transitionDuration: 1000
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};
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// It's just an empty function ... and a useless comment.
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var empty = function() { return false; };
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// IMPRESS.JS API
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// And that's where interesting things will start to happen.
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// It's the core `impress` function that returns the impress.js API
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// for a presentation based on the element with given id ('impress'
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// by default).
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var impress = window.impress = function( rootId ) {
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// If impress.js is not supported by the browser return a dummy API
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// it may not be a perfect solution but we return early and avoid
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// running code that may use features not implemented in the browser.
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if ( !impressSupported ) {
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return {
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init: empty,
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goto: empty,
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prev: empty,
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next: empty
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};
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}
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rootId = rootId || "impress";
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// If given root is already initialized just return the API
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if ( roots[ "impress-root-" + rootId ] ) {
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return roots[ "impress-root-" + rootId ];
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}
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// Data of all presentation steps
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var stepsData = {};
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// Element of currently active step
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var activeStep = null;
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// Current state (position, rotation and scale) of the presentation
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var currentState = null;
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// Array of step elements
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var steps = null;
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// Configuration options
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var config = null;
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// Scale factor of the browser window
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var windowScale = null;
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// Root presentation elements
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var root = byId( rootId );
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var canvas = document.createElement( "div" );
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var initialized = false;
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// STEP EVENTS
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//
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// There are currently two step events triggered by impress.js
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// `impress:stepenter` is triggered when the step is shown on the
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// screen (the transition from the previous one is finished) and
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// `impress:stepleave` is triggered when the step is left (the
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// transition to next step just starts).
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// Reference to last entered step
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var lastEntered = null;
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// `onStepEnter` is called whenever the step element is entered
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// but the event is triggered only if the step is different than
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// last entered step.
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var onStepEnter = function( step ) {
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if ( lastEntered !== step ) {
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triggerEvent( step, "impress:stepenter" );
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lastEntered = step;
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}
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};
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// `onStepLeave` is called whenever the step element is left
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// but the event is triggered only if the step is the same as
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// last entered step.
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var onStepLeave = function( step ) {
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if ( lastEntered === step ) {
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triggerEvent( step, "impress:stepleave" );
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lastEntered = null;
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}
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};
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// `initStep` initializes given step element by reading data from its
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// data attributes and setting correct styles.
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var initStep = function( el, idx ) {
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var data = el.dataset,
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step = {
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translate: {
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x: toNumber( data.x ),
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y: toNumber( data.y ),
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z: toNumber( data.z )
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},
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rotate: {
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x: toNumber( data.rotateX ),
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y: toNumber( data.rotateY ),
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z: toNumber( data.rotateZ || data.rotate )
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},
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scale: toNumber( data.scale, 1 ),
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el: el
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};
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if ( !el.id ) {
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el.id = "step-" + ( idx + 1 );
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}
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stepsData[ "impress-" + el.id ] = step;
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css( el, {
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position: "absolute",
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transform: "translate(-50%,-50%)" +
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translate( step.translate ) +
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rotate( step.rotate ) +
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scale( step.scale ),
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transformStyle: "preserve-3d"
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} );
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};
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// `init` API function that initializes (and runs) the presentation.
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var init = function() {
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if ( initialized ) { return; }
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// First we set up the viewport for mobile devices.
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// For some reason iPad goes nuts when it is not done properly.
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var meta = $( "meta[name='viewport']" ) || document.createElement( "meta" );
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meta.content = "width=device-width, minimum-scale=1, maximum-scale=1, user-scalable=no";
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if ( meta.parentNode !== document.head ) {
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meta.name = "viewport";
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document.head.appendChild( meta );
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}
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// Initialize configuration object
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var rootData = root.dataset;
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config = {
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width: toNumber( rootData.width, defaults.width ),
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height: toNumber( rootData.height, defaults.height ),
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maxScale: toNumber( rootData.maxScale, defaults.maxScale ),
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minScale: toNumber( rootData.minScale, defaults.minScale ),
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perspective: toNumber( rootData.perspective, defaults.perspective ),
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transitionDuration: toNumber(
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rootData.transitionDuration, defaults.transitionDuration
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)
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};
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windowScale = computeWindowScale( config );
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// Wrap steps with "canvas" element
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arrayify( root.childNodes ).forEach( function( el ) {
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canvas.appendChild( el );
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} );
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root.appendChild( canvas );
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// Set initial styles
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document.documentElement.style.height = "100%";
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css( body, {
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height: "100%",
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overflow: "hidden"
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} );
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var rootStyles = {
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position: "absolute",
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transformOrigin: "top left",
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transition: "all 0s ease-in-out",
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transformStyle: "preserve-3d"
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};
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css( root, rootStyles );
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css( root, {
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top: "50%",
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left: "50%",
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perspective: ( config.perspective / windowScale ) + "px",
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transform: scale( windowScale )
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} );
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css( canvas, rootStyles );
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body.classList.remove( "impress-disabled" );
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body.classList.add( "impress-enabled" );
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// Get and init steps
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steps = $$( ".step", root );
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steps.forEach( initStep );
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// Set a default initial state of the canvas
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currentState = {
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translate: { x: 0, y: 0, z: 0 },
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rotate: { x: 0, y: 0, z: 0 },
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scale: 1
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};
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initialized = true;
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triggerEvent( root, "impress:init", { api: roots[ "impress-root-" + rootId ] } );
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};
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// `getStep` is a helper function that returns a step element defined by parameter.
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// If a number is given, step with index given by the number is returned, if a string
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// is given step element with such id is returned, if DOM element is given it is returned
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// if it is a correct step element.
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var getStep = function( step ) {
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if ( typeof step === "number" ) {
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step = step < 0 ? steps[ steps.length + step ] : steps[ step ];
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} else if ( typeof step === "string" ) {
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step = byId( step );
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}
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return ( step && step.id && stepsData[ "impress-" + step.id ] ) ? step : null;
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};
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// Used to reset timeout for `impress:stepenter` event
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var stepEnterTimeout = null;
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// `goto` API function that moves to step given with `el` parameter
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// (by index, id or element), with a transition `duration` optionally
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// given as second parameter.
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var goto = function( el, duration ) {
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if ( !initialized || !( el = getStep( el ) ) ) {
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// Presentation not initialized or given element is not a step
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return false;
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}
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// Sometimes it's possible to trigger focus on first link with some keyboard action.
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// Browser in such a case tries to scroll the page to make this element visible
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// (even that body overflow is set to hidden) and it breaks our careful positioning.
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//
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// So, as a lousy (and lazy) workaround we will make the page scroll back to the top
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// whenever slide is selected
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//
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// If you are reading this and know any better way to handle it, I'll be glad to hear
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// about it!
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window.scrollTo( 0, 0 );
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var step = stepsData[ "impress-" + el.id ];
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if ( activeStep ) {
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activeStep.classList.remove( "active" );
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body.classList.remove( "impress-on-" + activeStep.id );
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}
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el.classList.add( "active" );
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body.classList.add( "impress-on-" + el.id );
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// Compute target state of the canvas based on given step
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var target = {
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rotate: {
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x: -step.rotate.x,
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y: -step.rotate.y,
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z: -step.rotate.z
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},
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translate: {
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x: -step.translate.x,
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y: -step.translate.y,
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z: -step.translate.z
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},
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scale: 1 / step.scale
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};
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// Check if the transition is zooming in or not.
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//
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// This information is used to alter the transition style:
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// when we are zooming in - we start with move and rotate transition
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// and the scaling is delayed, but when we are zooming out we start
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// with scaling down and move and rotation are delayed.
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var zoomin = target.scale >= currentState.scale;
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duration = toNumber( duration, config.transitionDuration );
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var delay = ( duration / 2 );
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// If the same step is re-selected, force computing window scaling,
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// because it is likely to be caused by window resize
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if ( el === activeStep ) {
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windowScale = computeWindowScale( config );
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}
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var targetScale = target.scale * windowScale;
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// Trigger leave of currently active element (if it's not the same step again)
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if ( activeStep && activeStep !== el ) {
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onStepLeave( activeStep );
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}
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// Now we alter transforms of `root` and `canvas` to trigger transitions.
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//
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// And here is why there are two elements: `root` and `canvas` - they are
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// being animated separately:
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// `root` is used for scaling and `canvas` for translate and rotations.
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// Transitions on them are triggered with different delays (to make
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// visually nice and 'natural' looking transitions), so we need to know
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// that both of them are finished.
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css( root, {
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// For IE 11 support we must specify perspective independent
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// of transform.
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perspective: ( config.perspective / targetScale ) + "px",
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// To keep the perspective look similar for different scales
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// we need to 'scale' the perspective, too
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transform: scale( targetScale ),
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transitionDuration: duration + "ms",
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transitionDelay: ( zoomin ? delay : 0 ) + "ms"
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} );
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css( canvas, {
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transform: rotate( target.rotate, true ) + translate( target.translate ),
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transitionDuration: duration + "ms",
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transitionDelay: ( zoomin ? 0 : delay ) + "ms"
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} );
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// Here is a tricky part...
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//
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// If there is no change in scale or no change in rotation and translation, it means
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// there was actually no delay - because there was no transition on `root` or `canvas`
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// elements. We want to trigger `impress:stepenter` event in the correct moment, so
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// here we compare the current and target values to check if delay should be taken into
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// account.
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//
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// I know that this `if` statement looks scary, but it's pretty simple when you know
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// what is going on
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// - it's simply comparing all the values.
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if ( currentState.scale === target.scale ||
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( currentState.rotate.x === target.rotate.x &&
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currentState.rotate.y === target.rotate.y &&
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currentState.rotate.z === target.rotate.z &&
|
|
currentState.translate.x === target.translate.x &&
|
|
currentState.translate.y === target.translate.y &&
|
|
currentState.translate.z === target.translate.z ) ) {
|
|
delay = 0;
|
|
}
|
|
|
|
// Store current state
|
|
currentState = target;
|
|
activeStep = el;
|
|
|
|
// And here is where we trigger `impress:stepenter` event.
|
|
// We simply set up a timeout to fire it taking transition duration
|
|
// (and possible delay) into account.
|
|
//
|
|
// I really wanted to make it in more elegant way. The `transitionend` event seemed to
|
|
// be the best way to do it, but the fact that I'm using transitions on two separate
|
|
// elements and that the `transitionend` event is only triggered when there was a
|
|
// transition (change in the values) caused some bugs and made the code really
|
|
// complicated, cause I had to handle all the conditions separately. And it still
|
|
// needed a `setTimeout` fallback for the situations when there is no transition at
|
|
// all.
|
|
// So I decided that I'd rather make the code simpler than use shiny new
|
|
// `transitionend`.
|
|
//
|
|
// If you want learn something interesting and see how it was done with `transitionend`
|
|
// go back to
|
|
// version 0.5.2 of impress.js:
|
|
// http://github.com/bartaz/impress.js/blob/0.5.2/js/impress.js
|
|
window.clearTimeout( stepEnterTimeout );
|
|
stepEnterTimeout = window.setTimeout( function() {
|
|
onStepEnter( activeStep );
|
|
}, duration + delay );
|
|
|
|
return el;
|
|
};
|
|
|
|
// `prev` API function goes to previous step (in document order)
|
|
var prev = function() {
|
|
var prev = steps.indexOf( activeStep ) - 1;
|
|
prev = prev >= 0 ? steps[ prev ] : steps[ steps.length - 1 ];
|
|
|
|
return goto( prev );
|
|
};
|
|
|
|
// `next` API function goes to next step (in document order)
|
|
var next = function() {
|
|
var next = steps.indexOf( activeStep ) + 1;
|
|
next = next < steps.length ? steps[ next ] : steps[ 0 ];
|
|
|
|
return goto( next );
|
|
};
|
|
|
|
// Adding some useful classes to step elements.
|
|
//
|
|
// All the steps that have not been shown yet are given `future` class.
|
|
// When the step is entered the `future` class is removed and the `present`
|
|
// class is given. When the step is left `present` class is replaced with
|
|
// `past` class.
|
|
//
|
|
// So every step element is always in one of three possible states:
|
|
// `future`, `present` and `past`.
|
|
//
|
|
// There classes can be used in CSS to style different types of steps.
|
|
// For example the `present` class can be used to trigger some custom
|
|
// animations when step is shown.
|
|
root.addEventListener( "impress:init", function() {
|
|
|
|
// STEP CLASSES
|
|
steps.forEach( function( step ) {
|
|
step.classList.add( "future" );
|
|
} );
|
|
|
|
root.addEventListener( "impress:stepenter", function( event ) {
|
|
event.target.classList.remove( "past" );
|
|
event.target.classList.remove( "future" );
|
|
event.target.classList.add( "present" );
|
|
}, false );
|
|
|
|
root.addEventListener( "impress:stepleave", function( event ) {
|
|
event.target.classList.remove( "present" );
|
|
event.target.classList.add( "past" );
|
|
}, false );
|
|
|
|
}, false );
|
|
|
|
// Adding hash change support.
|
|
root.addEventListener( "impress:init", function() {
|
|
|
|
// Last hash detected
|
|
var lastHash = "";
|
|
|
|
// `#/step-id` is used instead of `#step-id` to prevent default browser
|
|
// scrolling to element in hash.
|
|
//
|
|
// And it has to be set after animation finishes, because in Chrome it
|
|
// makes transtion laggy.
|
|
// BUG: http://code.google.com/p/chromium/issues/detail?id=62820
|
|
root.addEventListener( "impress:stepenter", function( event ) {
|
|
window.location.hash = lastHash = "#/" + event.target.id;
|
|
}, false );
|
|
|
|
window.addEventListener( "hashchange", function() {
|
|
|
|
// When the step is entered hash in the location is updated
|
|
// (just few lines above from here), so the hash change is
|
|
// triggered and we would call `goto` again on the same element.
|
|
//
|
|
// To avoid this we store last entered hash and compare.
|
|
if ( window.location.hash !== lastHash ) {
|
|
goto( getElementFromHash() );
|
|
}
|
|
}, false );
|
|
|
|
// START
|
|
// by selecting step defined in url or first step of the presentation
|
|
goto( getElementFromHash() || steps[ 0 ], 0 );
|
|
}, false );
|
|
|
|
body.classList.add( "impress-disabled" );
|
|
|
|
// Store and return API for given impress.js root element
|
|
return ( roots[ "impress-root-" + rootId ] = {
|
|
init: init,
|
|
goto: goto,
|
|
next: next,
|
|
prev: prev
|
|
} );
|
|
|
|
};
|
|
|
|
// Flag that can be used in JS to check if browser have passed the support test
|
|
impress.supported = impressSupported;
|
|
|
|
} )( document, window );
|
|
|
|
// NAVIGATION EVENTS
|
|
|
|
// As you can see this part is separate from the impress.js core code.
|
|
// It's because these navigation actions only need what impress.js provides with
|
|
// its simple API.
|
|
//
|
|
// In future I think about moving it to make them optional, move to separate files
|
|
// and treat more like a 'plugins'.
|
|
( function( document, window ) {
|
|
"use strict";
|
|
|
|
// Throttling function calls, by Remy Sharp
|
|
// http://remysharp.com/2010/07/21/throttling-function-calls/
|
|
var throttle = function( fn, delay ) {
|
|
var timer = null;
|
|
return function() {
|
|
var context = this, args = arguments;
|
|
clearTimeout( timer );
|
|
timer = setTimeout( function() {
|
|
fn.apply( context, args );
|
|
}, delay );
|
|
};
|
|
};
|
|
|
|
// Wait for impress.js to be initialized
|
|
document.addEventListener( "impress:init", function( event ) {
|
|
|
|
// Getting API from event data.
|
|
// So you don't event need to know what is the id of the root element
|
|
// or anything. `impress:init` event data gives you everything you
|
|
// need to control the presentation that was just initialized.
|
|
var api = event.detail.api;
|
|
|
|
// KEYBOARD NAVIGATION HANDLERS
|
|
|
|
// Prevent default keydown action when one of supported key is pressed.
|
|
document.addEventListener( "keydown", function( event ) {
|
|
if ( event.keyCode === 9 ||
|
|
( event.keyCode >= 32 && event.keyCode <= 34 ) ||
|
|
( event.keyCode >= 37 && event.keyCode <= 40 ) ) {
|
|
event.preventDefault();
|
|
}
|
|
}, false );
|
|
|
|
// Trigger impress action (next or prev) on keyup.
|
|
|
|
// Supported keys are:
|
|
// [space] - quite common in presentation software to move forward
|
|
// [up] [right] / [down] [left] - again common and natural addition,
|
|
// [pgdown] / [pgup] - often triggered by remote controllers,
|
|
// [tab] - this one is quite controversial, but the reason it ended up on
|
|
// this list is quite an interesting story... Remember that strange part
|
|
// in the impress.js code where window is scrolled to 0,0 on every presentation
|
|
// step, because sometimes browser scrolls viewport because of the focused element?
|
|
// Well, the [tab] key by default navigates around focusable elements, so clicking
|
|
// it very often caused scrolling to focused element and breaking impress.js
|
|
// positioning. I didn't want to just prevent this default action, so I used [tab]
|
|
// as another way to moving to next step... And yes, I know that for the sake of
|
|
// consistency I should add [shift+tab] as opposite action...
|
|
document.addEventListener( "keyup", function( event ) {
|
|
|
|
if ( event.shiftKey || event.altKey || event.ctrlKey || event.metaKey ) {
|
|
return;
|
|
}
|
|
|
|
if ( event.keyCode === 9 ||
|
|
( event.keyCode >= 32 && event.keyCode <= 34 ) ||
|
|
( event.keyCode >= 37 && event.keyCode <= 40 ) ) {
|
|
switch ( event.keyCode ) {
|
|
case 33: // Page up
|
|
case 37: // Left
|
|
case 38: // Up
|
|
api.prev();
|
|
break;
|
|
case 9: // Tab
|
|
case 32: // Space
|
|
case 34: // Page down
|
|
case 39: // Right
|
|
case 40: // Down
|
|
api.next();
|
|
break;
|
|
}
|
|
|
|
event.preventDefault();
|
|
}
|
|
}, false );
|
|
|
|
// Delegated handler for clicking on the links to presentation steps
|
|
document.addEventListener( "click", function( event ) {
|
|
|
|
// Event delegation with "bubbling"
|
|
// Check if event target (or any of its parents is a link)
|
|
var target = event.target;
|
|
while ( ( target.tagName !== "A" ) &&
|
|
( target !== document.documentElement ) ) {
|
|
target = target.parentNode;
|
|
}
|
|
|
|
if ( target.tagName === "A" ) {
|
|
var href = target.getAttribute( "href" );
|
|
|
|
// If it's a link to presentation step, target this step
|
|
if ( href && href[ 0 ] === "#" ) {
|
|
target = document.getElementById( href.slice( 1 ) );
|
|
}
|
|
}
|
|
|
|
if ( api.goto( target ) ) {
|
|
event.stopImmediatePropagation();
|
|
event.preventDefault();
|
|
}
|
|
}, false );
|
|
|
|
// Delegated handler for clicking on step elements
|
|
document.addEventListener( "click", function( event ) {
|
|
var target = event.target;
|
|
|
|
// Find closest step element that is not active
|
|
while ( !( target.classList.contains( "step" ) &&
|
|
!target.classList.contains( "active" ) ) &&
|
|
( target !== document.documentElement ) ) {
|
|
target = target.parentNode;
|
|
}
|
|
|
|
if ( api.goto( target ) ) {
|
|
event.preventDefault();
|
|
}
|
|
}, false );
|
|
|
|
// Touch handler to detect taps on the left and right side of the screen
|
|
// based on awesome work of @hakimel: https://github.com/hakimel/reveal.js
|
|
document.addEventListener( "touchstart", function( event ) {
|
|
if ( event.touches.length === 1 ) {
|
|
var x = event.touches[ 0 ].clientX,
|
|
width = window.innerWidth * 0.3,
|
|
result = null;
|
|
|
|
if ( x < width ) {
|
|
result = api.prev();
|
|
} else if ( x > window.innerWidth - width ) {
|
|
result = api.next();
|
|
}
|
|
|
|
if ( result ) {
|
|
event.preventDefault();
|
|
}
|
|
}
|
|
}, false );
|
|
|
|
// Rescale presentation when window is resized
|
|
window.addEventListener( "resize", throttle( function() {
|
|
|
|
// Force going to active step again, to trigger rescaling
|
|
api.goto( document.querySelector( ".step.active" ), 500 );
|
|
}, 250 ), false );
|
|
|
|
}, false );
|
|
|
|
} )( document, window );
|
|
|
|
// THAT'S ALL FOLKS!
|
|
//
|
|
// Thanks for reading it all.
|
|
// Or thanks for scrolling down and reading the last part.
|
|
//
|
|
// I've learnt a lot when building impress.js and I hope this code and comments
|
|
// will help somebody learn at least some part of it.
|