fa20-bt/js/reveal.js

447 lines
12 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
*
* TODO:
* - Touch/swipe interactions
* - Presentation overview via keyboard shortcut
*
* @author Hakim El Hattab | http://hakim.se
* @version 1.0
*/
var Reveal = (function(){
var HORIZONTAL_SLIDES_SELECTOR = '#main>section',
VERTICAL_SLIDES_SELECTOR = 'section.present>section',
indexh = 0,
indexv = 0,
config = {},
dom = {};
/**
* Activates the main program logic.
*/
function initialize( options ) {
// Gather references to DOM elements
dom.controls = document.querySelector( '.controls' );
dom.controlsLeft = document.querySelector( '.controls .left' );
dom.controlsRight = document.querySelector( '.controls .right' );
dom.controlsUp = document.querySelector( '.controls .up' );
dom.controlsDown = document.querySelector( '.controls .down' );
// Add event listeners
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);
// Default options
config.rollingLinks = options.rollingLinks === undefined ? true : options.rollingLinks;
config.controls = options.controls === undefined ? false : options.controls;
config.theme = options.theme === undefined ? 'default' : options.theme;
if( config.controls ) {
dom.controls.style.display = 'block';
}
if( config.theme !== 'default' ) {
document.body.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.
*/
function preventAndForward( delegate ) {
return function( event ) {
event.preventDefault();
delegate.call();
}
}
/**
* Handler for the document level 'keydown' event.
*
* @param {Object} event
*/
function onDocumentKeyDown( event ) {
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();
}
}
/**
* 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() {
var supports3DTransforms = document.body.style['webkitPerspective'] !== undefined ||
document.body.style['MozPerspective'] !== undefined ||
document.body.style['perspective'] !== undefined;
if( supports3DTransforms ) {
var nodes = document.querySelectorAll( 'section a:not(.image)' );
for( var i = 0, len = nodes.length; i < len; i++ ) {
var node = nodes[i];
if( !node.className || !node.className.match( /roll/g ) ) {
node.className += ' roll';
node.innerHTML = '<span data-title="'+ node.text +'">' + node.innerHTML + '</span>';
}
};
}
}
/**
* 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');
// Any element previous to index is given the 'past' class
slides.slice(0, index).map(function(element){
element.setAttribute('class', 'past');
});
// Any element subsequent to index is given the 'future' class
slides.slice(index + 1).map(function(element){
element.setAttribute('class', 'future');
});
}
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 );
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
* navigational 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 nexy slide fragment.
*
* @return {Boolean} true if there was a next fragment,
* false otherwise
*/
function nextFragment() {
var fragments = document.querySelectorAll( '.present .fragment:not(.visible)' );
if( fragments.length ) {
fragments[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() {
var fragments = document.querySelectorAll( '.present .fragment.visible' );
if( fragments.length ) {
fragments[ fragments.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( previousFragment() === false ) {
indexh --;
indexv = 0;
slide();
}
}
function navigateRight() {
// Prioritize revealing fragments
if( nextFragment() === false ) {
indexh ++;
indexv = 0;
slide();
}
}
function navigateUp() {
// Prioritize hiding fragments
if( previousFragment() === false ) {
indexv --;
slide();
}
}
function navigateDown() {
// Prioritize revealing fragments
if( nextFragment() === false ) {
indexv ++;
slide();
}
}
// Expose some methods publicly
return {
initialize: initialize,
navigateTo: navigateTo,
navigateLeft: navigateLeft,
navigateRight: navigateRight,
navigateUp: navigateUp,
navigateDown: navigateDown
};
})();