lca2020-pay-it-forward/js/reveal.js

649 lines
19 KiB
JavaScript

/**
* Copyright (C) 2011 Hakim El Hattab, http://hakim.se
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*
* #############################################################################
*
*
* Reveal.js is an easy to use HTML based slideshow enhanced by
* sexy CSS 3D transforms.
*
* Slides are given unique hash based URL's so that they can be
* opened directly.
*
* Public facing methods:
* - Reveal.initialize( { ... options ... } );
* - Reveal.navigateTo( indexh, indexv );
* - Reveal.navigateLeft();
* - Reveal.navigateRight();
* - Reveal.navigateUp();
* - Reveal.navigateDown();
*
*
* version 0.1:
* - First release
*
* version 0.2:
* - Refactored code and added inline documentation
* - Slides now have unique URL's
* - A basic API to invoke navigation was added
*
* version 0.3:
* - Added licensing terms
* - Fixed broken links on touch devices
*
* version 1.0:
* - Added controls
* - Added initialization options
* - Reveal views in fragments
* - Revamped, darker, theme
* - Tweaked markup styles (a, em, strong, b, i, blockquote, q, pre, ul, ol)
* - Support for themes at initialization (default/linear/concave)
* - Code highlighting via highlight.js
*
* version 1.1:
* - Optional progress bar UI element
* - Slide overview available via SPACE
* - Added 'transition' option for specifying transition styles
* - Added 'theme' option for specifying UI styles
* - Slides that contain nested-slides are given the 'stack' class
*
* version 1.2:
* - Big changes to DOM structure:
* - Previous #main wrapper is now called #reveal
* - Slides were moved one level deeper, into #reveal .slides
* - Controls and progress bar were moved into #reveal
* - All CSS is now much more explicit, rooted at #reveal, to prevent conflicts
*
*
* @author Hakim El Hattab | http://hakim.se
* @version 1.2
*/
var Reveal = (function(){
var HORIZONTAL_SLIDES_SELECTOR = '#reveal .slides>section',
VERTICAL_SLIDES_SELECTOR = '#reveal .slides>section.present>section',
// The horizontal and verical index of the currently active slide
indexh = 0,
indexv = 0,
// Configurations options, including;
// > {Boolean} controls
// > {Boolean} progress
// > {String} theme
// > {String} transition
// > {Boolean} rollingLinks
config = {},
// Cached references to DOM elements
dom = {},
// Detect support for CSS 3D transforms
supports3DTransforms = document.body.style['perspectiveProperty'] !== undefined ||
document.body.style['WebkitPerspective'] !== undefined ||
document.body.style['MozPerspective'] !== undefined ||
document.body.style['msTransform'] !== undefined;
/**
* Starts up the slideshow by applying configuration
* options and binding various events.
*/
function initialize( options ) {
// Cache references to DOM elements
dom.wrapper = document.querySelector( '#reveal' );
dom.progress = document.querySelector( '#reveal .progress' );
dom.progressbar = document.querySelector( '#reveal .progress span' );
dom.controls = document.querySelector( '#reveal .controls' );
dom.controlsLeft = document.querySelector( '#reveal .controls .left' );
dom.controlsRight = document.querySelector( '#reveal .controls .right' );
dom.controlsUp = document.querySelector( '#reveal .controls .up' );
dom.controlsDown = document.querySelector( '#reveal .controls .down' );
// Bind all view events
document.addEventListener('keydown', onDocumentKeyDown, false);
document.addEventListener('touchstart', onDocumentTouchStart, false);
window.addEventListener('hashchange', onWindowHashChange, false);
dom.controlsLeft.addEventListener('click', preventAndForward( navigateLeft ), false);
dom.controlsRight.addEventListener('click', preventAndForward( navigateRight ), false);
dom.controlsUp.addEventListener('click', preventAndForward( navigateUp ), false);
dom.controlsDown.addEventListener('click', preventAndForward( navigateDown ), false);
// Fall back on default options
config.rollingLinks = options.rollingLinks === undefined ? true : options.rollingLinks;
config.controls = options.controls === undefined ? false : options.controls;
config.progress = options.progress === undefined ? false : options.progress;
config.transition = options.transition === undefined ? 'default' : options.transition;
config.theme = options.theme === undefined ? 'default' : options.theme;
// Fall back on the 2D transform theme 'linear'
if( supports3DTransforms === false ) {
config.transition = 'linear';
}
if( config.controls ) {
dom.controls.style.display = 'block';
}
if( config.progress ) {
dom.progress.style.display = 'block';
}
if( config.transition !== 'default' ) {
dom.wrapper.classList.add( config.transition );
}
if( config.theme !== 'default' ) {
dom.wrapper.classList.add( config.theme );
}
if( config.rollingLinks ) {
// Add some 3D magic to our anchors
linkify();
}
// Read the initial hash
readURL();
}
/**
* Prevents an events defaults behavior calls the
* specified delegate.
*
* @param {Function} delegate The method to call
* after the wrapper has been executed
*/
function preventAndForward( delegate ) {
return function( event ) {
event.preventDefault();
delegate.call();
}
}
/**
* Handler for the document level 'keydown' event.
*
* @param {Object} event
*/
function onDocumentKeyDown( event ) {
// FFT: Use document.querySelector( ':focus' ) === null
// instead of checking contentEditable?
if( event.target.contentEditable === 'inherit' ) {
if( event.keyCode >= 37 && event.keyCode <= 40 ) {
switch( event.keyCode ) {
case 37: navigateLeft(); break; // left
case 39: navigateRight(); break; // right
case 38: navigateUp(); break; // up
case 40: navigateDown(); break; // down
}
slide();
event.preventDefault();
}
// Space bar
else if ( event.keyCode === 32 && supports3DTransforms ) {
if( overviewIsActive() ) {
deactivateOverview();
}
else {
activateOverview();
}
}
}
}
/**
* Handler for the document level 'touchstart' event.
*
* This enables very basic tap interaction for touch
* devices. Added mainly for performance testing of 3D
* transforms on iOS but was so happily surprised with
* how smoothly it runs so I left it in here. Apple +1
*
* @param {Object} event
*/
function onDocumentTouchStart( event ) {
// We're only interested in one point taps
if (event.touches.length === 1) {
// Never prevent taps on anchors and images
if( event.target.tagName.toLowerCase() === 'a' || event.target.tagName.toLowerCase() === 'img' ) {
return;
}
event.preventDefault();
var point = {
x: event.touches[0].clientX,
y: event.touches[0].clientY
};
// Define the extent of the areas that may be tapped
// to navigate
var wt = window.innerWidth * 0.3;
var ht = window.innerHeight * 0.3;
if( point.x < wt ) {
navigateLeft();
}
else if( point.x > window.innerWidth - wt ) {
navigateRight();
}
else if( point.y < ht ) {
navigateUp();
}
else if( point.y > window.innerHeight - ht ) {
navigateDown();
}
slide();
}
}
/**
* Handler for the window level 'hashchange' event.
*
* @param {Object} event
*/
function onWindowHashChange( event ) {
readURL();
}
/**
* Wrap all links in 3D goodness.
*/
function linkify() {
if( supports3DTransforms ) {
var nodes = document.querySelectorAll( '#reveal .slides section a:not(.image)' );
for( var i = 0, len = nodes.length; i < len; i++ ) {
var node = nodes[i];
if( node.textContent && ( !node.className || !node.className.match( /roll/g ) ) ) {
node.className += ' roll';
node.innerHTML = '<span data-title="'+ node.text +'">' + node.innerHTML + '</span>';
}
};
}
}
/**
* Displays the overview of slides (quick nav) by
* scaling down and arranging all slide elements.
*
* Experimental feature, might be dropped if perf
* can't be improved.
*/
function activateOverview() {
dom.wrapper.classList.add( 'overview' );
var horizontalSlides = Array.prototype.slice.call( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );
for( var i = 0, len1 = horizontalSlides.length; i < len1; i++ ) {
var hslide = horizontalSlides[i],
htransform = 'translateZ(-2500px) translate(' + ( ( i - indexh ) * 105 ) + '%, 0%)';
hslide.setAttribute( 'data-index-h', i );
hslide.style.display = 'block';
hslide.style.WebkitTransform = htransform;
hslide.style.MozTransform = htransform;
hslide.style.msTransform = htransform;
hslide.style.OTransform = htransform;
hslide.style.transform = htransform;
if( !hslide.classList.contains( 'stack' ) ) {
// Navigate to this slide on click
hslide.addEventListener( 'click', onOverviewSlideClicked, true );
}
var verticalSlides = Array.prototype.slice.call( hslide.querySelectorAll( 'section' ) );
for( var j = 0, len2 = verticalSlides.length; j < len2; j++ ) {
var vslide = verticalSlides[j],
vtransform = 'translate(0%, ' + ( ( j - indexv ) * 105 ) + '%)';
vslide.setAttribute( 'data-index-h', i );
vslide.setAttribute( 'data-index-v', j );
vslide.style.display = 'block';
vslide.style.WebkitTransform = vtransform;
vslide.style.MozTransform = vtransform;
vslide.style.msTransform = vtransform;
vslide.style.OTransform = vtransform;
vslide.style.transform = vtransform;
// Navigate to this slide on click
vslide.addEventListener( 'click', onOverviewSlideClicked, true );
}
}
}
/**
* Exits the slide overview and enters the currently
* active slide.
*/
function deactivateOverview() {
dom.wrapper.classList.remove( 'overview' );
var slides = Array.prototype.slice.call( document.querySelectorAll( '#reveal .slides section' ) );
for( var i = 0, len = slides.length; i < len; i++ ) {
var element = slides[i];
// Resets all transforms to use the external styles
element.style.WebkitTransform = '';
element.style.MozTransform = '';
element.style.msTransform = '';
element.style.OTransform = '';
element.style.transform = '';
element.removeEventListener( 'click', onOverviewSlideClicked );
}
slide();
}
/**
* Checks if the overview is currently active.
*
* @return {Boolean} true if the overview is active,
* false otherwise
*/
function overviewIsActive() {
return dom.wrapper.classList.contains( 'overview' );
}
/**
* Invoked when a slide is and we're in the overview.
*/
function onOverviewSlideClicked( event ) {
// TODO There's a bug here where the event listeners are not
// removed after deactivating the overview.
if( overviewIsActive() ) {
event.preventDefault();
deactivateOverview();
indexh = this.getAttribute( 'data-index-h' );
indexv = this.getAttribute( 'data-index-v' );
slide();
}
}
/**
* Updates one dimension of slides by showing the slide
* with the specified index.
*
* @param {String} selector A CSS selector that will fetch
* the group of slides we are working with
* @param {Number} index The index of the slide that should be
* shown
*
* @return {Number} The index of the slide that is now shown,
* might differ from the passed in index if it was out of
* bounds.
*/
function updateSlides( selector, index ) {
// Select all slides and convert the NodeList result to
// an array
var slides = Array.prototype.slice.call( document.querySelectorAll( selector ) );
if( slides.length ) {
// Enforce max and minimum index bounds
index = Math.max(Math.min(index, slides.length - 1), 0);
slides[index].setAttribute('class', 'present');
for( var i = 0; i < slides.length; i++ ) {
var slide = slides[i];
// Optimization; hide all slides that are three or more steps
// away from the present slide
if( overviewIsActive() === false ) {
slide.style.display = Math.abs( index - i ) > 3 ? 'none' : 'block';
}
if( i < index ) {
// Any element previous to index is given the 'past' class
slide.setAttribute('class', 'past');
}
else if( i > index ) {
// Any element subsequent to index is given the 'future' class
slide.setAttribute('class', 'future');
}
// If this element contains vertical slides
if( slide.querySelector( 'section' ) ) {
slide.classList.add( 'stack' );
}
}
}
else {
// Since there are no slides we can't be anywhere beyond the
// zeroth index
index = 0;
}
return index;
}
/**
* Updates the visual slides to represent the currently
* set indices.
*/
function slide() {
indexh = updateSlides( HORIZONTAL_SLIDES_SELECTOR, indexh );
indexv = updateSlides( VERTICAL_SLIDES_SELECTOR, indexv );
// Update progress if enabled
if( config.progress ) {
dom.progressbar.style.width = ( indexh / ( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ).length - 1 ) ) * window.innerWidth + 'px';
}
// Close the overview if it's active
if( overviewIsActive() ) {
activateOverview();
}
updateControls();
writeURL();
}
/**
* Updates the state and link pointers of the controls.
*/
function updateControls() {
var routes = availableRoutes();
// Remove the 'enabled' class from all directions
[ dom.controlsLeft, dom.controlsRight, dom.controlsUp, dom.controlsDown ].forEach( function( node ) {
node.classList.remove( 'enabled' );
} )
if( routes.left ) dom.controlsLeft.classList.add( 'enabled' );
if( routes.right ) dom.controlsRight.classList.add( 'enabled' );
if( routes.up ) dom.controlsUp.classList.add( 'enabled' );
if( routes.down ) dom.controlsDown.classList.add( 'enabled' );
}
/**
* Determine what available routes there are for navigation.
*
* @return {Object} containing four booleans: left/right/up/down
*/
function availableRoutes() {
var horizontalSlides = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR );
var verticalSlides = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR );
return {
left: indexh > 0,
right: indexh < horizontalSlides.length - 1,
up: indexv > 0,
down: indexv < verticalSlides.length - 1
};
}
/**
* Reads the current URL (hash) and navigates accordingly.
*/
function readURL() {
// Break the hash down to separate components
var bits = window.location.hash.slice(2).split('/');
// Read the index components of the hash
indexh = bits[0] ? parseInt( bits[0] ) : 0;
indexv = bits[1] ? parseInt( bits[1] ) : 0;
navigateTo( indexh, indexv );
}
/**
* Updates the page URL (hash) to reflect the current
* state.
*/
function writeURL() {
var url = '/';
// Only include the minimum possible number of components in
// the URL
if( indexh > 0 || indexv > 0 ) url += indexh;
if( indexv > 0 ) url += '/' + indexv;
window.location.hash = url;
}
/**
* Navigate to the next slide fragment.
*
* @return {Boolean} true if there was a next fragment,
* false otherwise
*/
function nextFragment() {
// Vertical slides:
if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
if( verticalFragments.length ) {
verticalFragments[0].classList.add( 'visible' );
return true;
}
}
// Horizontal slides:
else {
var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment:not(.visible)' );
if( horizontalFragments.length ) {
horizontalFragments[0].classList.add( 'visible' );
return true;
}
}
return false;
}
/**
* Navigate to the previous slide fragment.
*
* @return {Boolean} true if there was a previous fragment,
* false otherwise
*/
function previousFragment() {
// Vertical slides:
if( document.querySelector( VERTICAL_SLIDES_SELECTOR + '.present' ) ) {
var verticalFragments = document.querySelectorAll( VERTICAL_SLIDES_SELECTOR + '.present .fragment.visible' );
if( verticalFragments.length ) {
verticalFragments[ verticalFragments.length - 1 ].classList.remove( 'visible' );
return true;
}
}
// Horizontal slides:
else {
var horizontalFragments = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR + '.present .fragment.visible' );
if( horizontalFragments.length ) {
horizontalFragments[ horizontalFragments.length - 1 ].classList.remove( 'visible' );
return true;
}
}
return false;
}
/**
* Triggers a navigation to the specified indices.
*
* @param {Number} h The horizontal index of the slide to show
* @param {Number} v The vertical index of the slide to show
*/
function navigateTo( h, v ) {
indexh = h === undefined ? indexh : h;
indexv = v === undefined ? indexv : v;
slide();
}
function navigateLeft() {
// Prioritize hiding fragments
if( overviewIsActive() || previousFragment() === false ) {
indexh --;
indexv = 0;
slide();
}
}
function navigateRight() {
// Prioritize revealing fragments
if( overviewIsActive() || nextFragment() === false ) {
indexh ++;
indexv = 0;
slide();
}
}
function navigateUp() {
// Prioritize hiding fragments
if( overviewIsActive() || previousFragment() === false ) {
indexv --;
slide();
}
}
function navigateDown() {
// Prioritize revealing fragments
if( overviewIsActive() || nextFragment() === false ) {
indexv ++;
slide();
}
}
// Expose some methods publicly
return {
initialize: initialize,
navigateTo: navigateTo,
navigateLeft: navigateLeft,
navigateRight: navigateRight,
navigateUp: navigateUp,
navigateDown: navigateDown
};
})();