Template:HFUT-china/scrollrevealJs
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/**
* ScrollReveal * ------------ * Version : 3.3.1 * Website : scrollrevealjs.org * Repo : github.com/jlmakes/scrollreveal.js * Author : Julian Lloyd (@jlmakes) */
- (function () {
'use strict'
var sr var _requestAnimationFrame
function ScrollReveal (config) {
// Support instantiation without the `new` keyword.
if (typeof this === 'undefined' || Object.getPrototypeOf(this) !== ScrollReveal.prototype) {
return new ScrollReveal(config)
}
sr = this // Save reference to instance. sr.version = '3.3.1' sr.tools = new Tools() // *required utilities
if (sr.isSupported()) {
sr.tools.extend(sr.defaults, config || {})
_resolveContainer(sr.defaults)
sr.store = {
elements: {},
containers: []
}
sr.sequences = {}
sr.history = []
sr.uid = 0
sr.initialized = false
} else if (typeof console !== 'undefined' && console !== null) {
// Note: IE9 only supports console if devtools are open.
console.log('ScrollReveal is not supported in this browser.')
}
return sr }
/** * Configuration * ------------- * This object signature can be passed directly to the ScrollReveal constructor, * or as the second argument of the `reveal()` method. */
ScrollReveal.prototype.defaults = {
// 'bottom', 'left', 'top', 'right'
origin: 'bottom',
// Can be any valid CSS distance, e.g. '5rem', '10%', '20vw', etc. distance: '20px',
// Time in milliseconds. duration: 500, delay: 0,
// Starting angles in degrees, will transition from these values to 0 in all axes.
rotate: { x: 0, y: 0, z: 0 },
// Starting opacity value, before transitioning to the computed opacity. opacity: 0,
// Starting scale value, will transition from this value to 1 scale: 0.9,
// Accepts any valid CSS easing, e.g. 'ease', 'ease-in-out', 'linear', etc. easing: 'cubic-bezier(0.6, 0.2, 0.1, 1)',
// `` is the default reveal container. You can pass either:
// DOM Node, e.g. document.querySelector('.fooContainer')
// Selector, e.g. '.fooContainer'
container: window.document.documentElement,
// true/false to control reveal animations on mobile.
mobile: true,
// true: reveals occur every time elements become visible
// false: reveals occur once as elements become visible
reset: false,
// 'always' — delay for all reveal animations
// 'once' — delay only the first time reveals occur
// 'onload' - delay only for animations triggered by first load
useDelay: 'always',
// Change when an element is considered in the viewport. The default value
// of 0.20 means 20% of an element must be visible for its reveal to occur.
viewFactor: 0.2,
// Pixel values that alter the container boundaries.
// e.g. Set `{ top: 48 }`, if you have a 48px tall fixed toolbar.
// --
// Visual Aid: https://scrollrevealjs.org/assets/viewoffset.png
viewOffset: { top: 0, right: 0, bottom: 0, left: 0 },
// Callbacks that fire for each completed element reveal, and if
// `config.reset = true`, for each completed element reset. When creating your
// callbacks, remember they are passed the element’s DOM node that triggered
// it as the first argument.
beforeReveal: function (domEl) {},
afterReveal: function (domEl) {},
beforeReset: function (domEl) {},
afterReset: function (domEl) {}
}
/**
* Check if client supports CSS Transform and CSS Transition.
* @return {boolean}
*/
ScrollReveal.prototype.isSupported = function () {
var style = document.documentElement.style
return 'WebkitTransition' in style && 'WebkitTransform' in style ||
'transition' in style && 'transform' in style
}
/**
* Creates a reveal set, a group of elements that will animate when they
* become visible. If [interval] is provided, a new sequence is created
* that will ensure elements reveal in the order they appear in the DOM.
*
* @param {Node|NodeList|string} [target] The node, node list or selector to use for animation.
* @param {Object} [config] Override the defaults for this reveal set.
* @param {number} [interval] Time between sequenced element animations (milliseconds).
* @param {boolean} [sync] Used internally when updating reveals for async content.
*
* @return {Object} The current ScrollReveal instance.
*/
ScrollReveal.prototype.reveal = function (target, config, interval, sync) {
var container
var elements
var elem
var elemId
var sequence
var sequenceId
// No custom configuration was passed, but a sequence interval instead.
// let’s shuffle things around to make sure everything works.
if (config !== undefined && typeof config === 'number') {
interval = config
config = {}
} else if (config === undefined || config === null) {
config = {}
}
container = _resolveContainer(config)
elements = _getRevealElements(target, container)
if (!elements.length) {
console.log('ScrollReveal: reveal on "' + target + '" failed, no elements found.')
return sr
}
// Prepare a new sequence if an interval is passed.
if (interval && typeof interval === 'number') {
sequenceId = _nextUid()
sequence = sr.sequences[sequenceId] = {
id: sequenceId,
interval: interval,
elemIds: [],
active: false
}
}
// Begin main loop to configure ScrollReveal elements.
for (var i = 0; i < elements.length; i++) {
// Check if the element has already been configured and grab it from the store.
elemId = elements[i].getAttribute('data-sr-id')
if (elemId) {
elem = sr.store.elements[elemId]
} else {
// Otherwise, let’s do some basic setup.
elem = {
id: _nextUid(),
domEl: elements[i],
seen: false,
revealing: false
}
elem.domEl.setAttribute('data-sr-id', elem.id)
}
// Sequence only setup
if (sequence) {
elem.sequence = {
id: sequence.id,
index: sequence.elemIds.length
}
sequence.elemIds.push(elem.id)
}
// New or existing element, it’s time to update its configuration, styles,
// and send the updates to our store.
_configure(elem, config, container)
_style(elem)
_updateStore(elem)
// We need to make sure elements are set to visibility: visible, even when
// on mobile and `config.mobile === false`, or if unsupported.
if (sr.tools.isMobile() && !elem.config.mobile || !sr.isSupported()) {
elem.domEl.setAttribute('style', elem.styles.inline)
elem.disabled = true
} else if (!elem.revealing) {
// Otherwise, proceed normally.
elem.domEl.setAttribute('style',
elem.styles.inline +
elem.styles.transform.initial
)
}
}
// Each `reveal()` is recorded so that when calling `sync()` while working
// with asynchronously loaded content, it can re-trace your steps but with
// all your new elements now in the DOM.
// Since `reveal()` is called internally by `sync()`, we don’t want to
// record or intiialize each reveal during syncing.
if (!sync && sr.isSupported()) {
_record(target, config, interval)
// We push initialization to the event queue using setTimeout, so that we can
// give ScrollReveal room to process all reveal calls before putting things into motion.
// --
// Philip Roberts - What the heck is the event loop anyway? (JSConf EU 2014)
// https://www.youtube.com/watch?v=8aGhZQkoFbQ
if (sr.initTimeout) {
window.clearTimeout(sr.initTimeout)
}
sr.initTimeout = window.setTimeout(_init, 0)
}
return sr
}
/**
* Re-runs `reveal()` for each record stored in history, effectively capturing
* any content loaded asynchronously that matches existing reveal set targets.
* @return {Object} The current ScrollReveal instance.
*/
ScrollReveal.prototype.sync = function () {
if (sr.history.length && sr.isSupported()) {
for (var i = 0; i < sr.history.length; i++) {
var record = sr.history[i]
sr.reveal(record.target, record.config, record.interval, true)
}
_init()
} else {
console.log('ScrollReveal: sync failed, no reveals found.')
}
return sr
}
/**
* Private Methods
* ---------------
*/
function _resolveContainer (config) {
if (config && config.container) {
if (typeof config.container === 'string') {
return window.document.documentElement.querySelector(config.container)
} else if (sr.tools.isNode(config.container)) {
return config.container
} else {
console.log('ScrollReveal: invalid container "' + config.container + '" provided.')
console.log('ScrollReveal: falling back to default container.')
}
}
return sr.defaults.container
}
/**
* check to see if a node or node list was passed in as the target,
* otherwise query the container using target as a selector.
*
* @param {Node|NodeList|string} [target] client input for reveal target.
* @param {Node} [container] parent element for selector queries.
*
* @return {array} elements to be revealed.
*/
function _getRevealElements (target, container) {
if (typeof target === 'string') {
return Array.prototype.slice.call(container.querySelectorAll(target))
} else if (sr.tools.isNode(target)) {
return [target]
} else if (sr.tools.isNodeList(target)) {
return Array.prototype.slice.call(target)
}
return []
}
/**
* A consistent way of creating unique IDs.
* @returns {number}
*/
function _nextUid () {
return ++sr.uid
}
function _configure (elem, config, container) {
// If a container was passed as a part of the config object,
// let’s overwrite it with the resolved container passed in.
if (config.container) config.container = container
// If the element hasn’t already been configured, let’s use a clone of the
// defaults extended by the configuration passed as the second argument.
if (!elem.config) {
elem.config = sr.tools.extendClone(sr.defaults, config)
} else {
// Otherwise, let’s use a clone of the existing element configuration extended
// by the configuration passed as the second argument.
elem.config = sr.tools.extendClone(elem.config, config)
}
// Infer CSS Transform axis from origin string.
if (elem.config.origin === 'top' || elem.config.origin === 'bottom') {
elem.config.axis = 'Y'
} else {
elem.config.axis = 'X'
}
}
function _style (elem) {
var computed = window.getComputedStyle(elem.domEl)
if (!elem.styles) {
elem.styles = {
transition: {},
transform: {},
computed: {}
}
// Capture any existing inline styles, and add our visibility override.
// --
// See section 4.2. in the Documentation:
// https://github.com/jlmakes/scrollreveal.js#42-improve-user-experience
elem.styles.inline = elem.domEl.getAttribute('style') || ''
elem.styles.inline += '; visibility: visible; '
// grab the elements existing opacity.
elem.styles.computed.opacity = computed.opacity
// grab the elements existing transitions.
if (!computed.transition || computed.transition === 'all 0s ease 0s') {
elem.styles.computed.transition = ''
} else {
elem.styles.computed.transition = computed.transition + ', '
}
}
// Create transition styles
elem.styles.transition.instant = _generateTransition(elem, 0)
elem.styles.transition.delayed = _generateTransition(elem, elem.config.delay)
// Generate transform styles, first with the webkit prefix.
elem.styles.transform.initial = ' -webkit-transform:'
elem.styles.transform.target = ' -webkit-transform:'
_generateTransform(elem)
// And again without any prefix.
elem.styles.transform.initial += 'transform:'
elem.styles.transform.target += 'transform:'
_generateTransform(elem)
}
function _generateTransition (elem, delay) {
var config = elem.config
return '-webkit-transition: ' + elem.styles.computed.transition +
'-webkit-transform ' + config.duration / 1000 + 's ' +
config.easing + ' ' +
delay / 1000 + 's, opacity ' +
config.duration / 1000 + 's ' +
config.easing + ' ' +
delay / 1000 + 's; ' +
'transition: ' + elem.styles.computed.transition +
'transform ' + config.duration / 1000 + 's ' +
config.easing + ' ' +
delay / 1000 + 's, opacity ' +
config.duration / 1000 + 's ' +
config.easing + ' ' +
delay / 1000 + 's; '
}
function _generateTransform (elem) {
var config = elem.config
var cssDistance
var transform = elem.styles.transform
// Let’s make sure our our pixel distances are negative for top and left.
// e.g. origin = 'top' and distance = '25px' starts at `top: -25px` in CSS.
if (config.origin === 'top' || config.origin === 'left') {
cssDistance = /^-/.test(config.distance)
? config.distance.substr(1)
: '-' + config.distance
} else {
cssDistance = config.distance
}
if (parseInt(config.distance)) {
transform.initial += ' translate' + config.axis + '(' + cssDistance + ')'
transform.target += ' translate' + config.axis + '(0)'
}
if (config.scale) {
transform.initial += ' scale(' + config.scale + ')'
transform.target += ' scale(1)'
}
if (config.rotate.x) {
transform.initial += ' rotateX(' + config.rotate.x + 'deg)'
transform.target += ' rotateX(0)'
}
if (config.rotate.y) {
transform.initial += ' rotateY(' + config.rotate.y + 'deg)'
transform.target += ' rotateY(0)'
}
if (config.rotate.z) {
transform.initial += ' rotateZ(' + config.rotate.z + 'deg)'
transform.target += ' rotateZ(0)'
}
transform.initial += '; opacity: ' + config.opacity + ';'
transform.target += '; opacity: ' + elem.styles.computed.opacity + ';'
}
function _updateStore (elem) {
var container = elem.config.container
// If this element’s container isn’t already in the store, let’s add it.
if (container && sr.store.containers.indexOf(container) === -1) {
sr.store.containers.push(elem.config.container)
}
// Update the element stored with our new element.
sr.store.elements[elem.id] = elem
}
function _record (target, config, interval) {
// Save the `reveal()` arguments that triggered this `_record()` call, so we
// can re-trace our steps when calling the `sync()` method.
var record = {
target: target,
config: config,
interval: interval
}
sr.history.push(record)
}
function _init () {
if (sr.isSupported()) {
// Initial animate call triggers valid reveal animations on first load.
// Subsequent animate calls are made inside the event handler.
_animate()
// Then we loop through all container nodes in the store and bind event
// listeners to each.
for (var i = 0; i < sr.store.containers.length; i++) {
sr.store.containers[i].addEventListener('scroll', _handler)
sr.store.containers[i].addEventListener('resize', _handler)
}
// Let’s also do a one-time binding of window event listeners.
if (!sr.initialized) {
window.addEventListener('scroll', _handler)
window.addEventListener('resize', _handler)
sr.initialized = true
}
}
return sr
}
function _handler () {
_requestAnimationFrame(_animate)
}
function _setActiveSequences () {
var active
var elem
var elemId
var sequence
// Loop through all sequences
sr.tools.forOwn(sr.sequences, function (sequenceId) {
sequence = sr.sequences[sequenceId]
active = false
// For each sequenced elemenet, let’s check visibility and if
// any are visible, set it’s sequence to active.
for (var i = 0; i < sequence.elemIds.length; i++) {
elemId = sequence.elemIds[i]
elem = sr.store.elements[elemId]
if (_isElemVisible(elem) && !active) {
active = true
}
}
sequence.active = active
})
}
function _animate () {
var delayed
var elem
_setActiveSequences()
// Loop through all elements in the store
sr.tools.forOwn(sr.store.elements, function (elemId) {
elem = sr.store.elements[elemId]
delayed = _shouldUseDelay(elem)
// Let’s see if we should revealand if so,
// trigger the `beforeReveal` callback and
// determine whether or not to use delay.
if (_shouldReveal(elem)) {
elem.config.beforeReveal(elem.domEl)
if (delayed) {
elem.domEl.setAttribute('style',
elem.styles.inline +
elem.styles.transform.target +
elem.styles.transition.delayed
)
} else {
elem.domEl.setAttribute('style',
elem.styles.inline +
elem.styles.transform.target +
elem.styles.transition.instant
)
}
// Let’s queue the `afterReveal` callback
// and mark the element as seen and revealing.
_queueCallback('reveal', elem, delayed)
elem.revealing = true
elem.seen = true
if (elem.sequence) {
_queueNextInSequence(elem, delayed)
}
} else if (_shouldReset(elem)) {
//Otherwise reset our element and
// trigger the `beforeReset` callback.
elem.config.beforeReset(elem.domEl)
elem.domEl.setAttribute('style',
elem.styles.inline +
elem.styles.transform.initial +
elem.styles.transition.instant
)
// And queue the `afterReset` callback.
_queueCallback('reset', elem)
elem.revealing = false
}
})
}
function _queueNextInSequence (elem, delayed) {
var elapsed = 0
var delay = 0
var sequence = sr.sequences[elem.sequence.id]
// We’re processing a sequenced element, so let's block other elements in this sequence.
sequence.blocked = true
// Since we’re triggering animations a part of a sequence after animations on first load,
// we need to check for that condition and explicitly add the delay to our timer.
if (delayed && elem.config.useDelay === 'onload') {
delay = elem.config.delay
}
// If a sequence timer is already running, capture the elapsed time and clear it.
if (elem.sequence.timer) {
elapsed = Math.abs(elem.sequence.timer.started - new Date())
window.clearTimeout(elem.sequence.timer)
}
// Start a new timer.
elem.sequence.timer = { started: new Date() }
elem.sequence.timer.clock = window.setTimeout(function () {
// Sequence interval has passed, so unblock the sequence and re-run the handler.
sequence.blocked = false
elem.sequence.timer = null
_handler()
}, Math.abs(sequence.interval) + delay - elapsed)
}
function _queueCallback (type, elem, delayed) {
var elapsed = 0
var duration = 0
var callback = 'after'
// Check which callback we’re working with.
switch (type) {
case 'reveal':
duration = elem.config.duration
if (delayed) {
duration += elem.config.delay
}
callback += 'Reveal'
break
case 'reset':
duration = elem.config.duration
callback += 'Reset'
break
}
// If a timer is already running, capture the elapsed time and clear it.
if (elem.timer) {
elapsed = Math.abs(elem.timer.started - new Date())
window.clearTimeout(elem.timer.clock)
}
// Start a new timer.
elem.timer = { started: new Date() }
elem.timer.clock = window.setTimeout(function () {
// The timer completed, so let’s fire the callback and null the timer.
elem.config[callback](elem.domEl)
elem.timer = null
}, duration - elapsed)
}
function _shouldReveal (elem) {
if (elem.sequence) {
var sequence = sr.sequences[elem.sequence.id]
return sequence.active &&
!sequence.blocked &&
!elem.revealing &&
!elem.disabled
}
return _isElemVisible(elem) &&
!elem.revealing &&
!elem.disabled
}
function _shouldUseDelay (elem) {
var config = elem.config.useDelay
return config === 'always' ||
(config === 'onload' && !sr.initialized) ||
(config === 'once' && !elem.seen)
}
function _shouldReset (elem) {
if (elem.sequence) {
var sequence = sr.sequences[elem.sequence.id]
return !sequence.active &&
elem.config.reset &&
elem.revealing &&
!elem.disabled
}
return !_isElemVisible(elem) &&
elem.config.reset &&
elem.revealing &&
!elem.disabled
}
function _getContainer (container) {
return {
width: container.clientWidth,
height: container.clientHeight
}
}
function _getScrolled (container) {
// Return the container scroll values, plus the its offset.
if (container && container !== window.document.documentElement) {
var offset = _getOffset(container)
return {
x: container.scrollLeft + offset.left,
y: container.scrollTop + offset.top
}
} else {
// Otherwise, default to the window object’s scroll values.
return {
x: window.pageXOffset,
y: window.pageYOffset
}
}
}
function _getOffset (domEl) {
var offsetTop = 0
var offsetLeft = 0
// Grab the element’s dimensions.
var offsetHeight = domEl.offsetHeight
var offsetWidth = domEl.offsetWidth
// Now calculate the distance between the element and its parent, then
// again for the parent to its parent, and again etc... until we have the
// total distance of the element to the document’s top and left origin.
do {
if (!isNaN(domEl.offsetTop)) {
offsetTop += domEl.offsetTop
}
if (!isNaN(domEl.offsetLeft)) {
offsetLeft += domEl.offsetLeft
}
domEl = domEl.offsetParent
} while (domEl)
return {
top: offsetTop,
left: offsetLeft,
height: offsetHeight,
width: offsetWidth
}
}
function _isElemVisible (elem) {
var offset = _getOffset(elem.domEl)
var container = _getContainer(elem.config.container)
var scrolled = _getScrolled(elem.config.container)
var vF = elem.config.viewFactor
// Define the element geometry.
var elemHeight = offset.height
var elemWidth = offset.width
var elemTop = offset.top
var elemLeft = offset.left
var elemBottom = elemTop + elemHeight
var elemRight = elemLeft + elemWidth
return confirmBounds() || isPositionFixed()
function confirmBounds () {
// Define the element’s functional boundaries using its view factor.
var top = elemTop + elemHeight * vF
var left = elemLeft + elemWidth * vF
var bottom = elemBottom - elemHeight * vF
var right = elemRight - elemWidth * vF
// Define the container functional boundaries using its view offset.
var viewTop = scrolled.y + elem.config.viewOffset.top
var viewLeft = scrolled.x + elem.config.viewOffset.left
var viewBottom = scrolled.y - elem.config.viewOffset.bottom + container.height
var viewRight = scrolled.x - elem.config.viewOffset.right + container.width
return top < viewBottom &&
bottom > viewTop &&
left > viewLeft &&
right < viewRight
}
function isPositionFixed () {
return (window.getComputedStyle(elem.domEl).position === 'fixed')
}
}
/**
* Utilities
* ---------
*/
function Tools () {}
Tools.prototype.isObject = function (object) {
return object !== null && typeof object === 'object' && object.constructor === Object
}
Tools.prototype.isNode = function (object) {
return typeof window.Node === 'object'
? object instanceof window.Node
: object && typeof object === 'object' &&
typeof object.nodeType === 'number' &&
typeof object.nodeName === 'string'
}
Tools.prototype.isNodeList = function (object) {
var prototypeToString = Object.prototype.toString.call(object)
var regex = /^\[object (HTMLCollection|NodeList|Object)\]$/
return typeof window.NodeList === 'object'
? object instanceof window.NodeList
: object && typeof object === 'object' &&
regex.test(prototypeToString) &&
typeof object.length === 'number' &&
(object.length === 0 || this.isNode(object[0]))
}
Tools.prototype.forOwn = function (object, callback) {
if (!this.isObject(object)) {
throw new TypeError('Expected "object", but received "' + typeof object + '".')
} else {
for (var property in object) {
if (object.hasOwnProperty(property)) {
callback(property)
}
}
}
}
Tools.prototype.extend = function (target, source) {
this.forOwn(source, function (property) {
if (this.isObject(source[property])) {
if (!target[property] || !this.isObject(target[property])) {
target[property] = {}
}
this.extend(target[property], source[property])
} else {
target[property] = source[property]
}
}.bind(this))
return target
}
Tools.prototype.extendClone = function (target, source) {
return this.extend(this.extend({}, target), source)
}
Tools.prototype.isMobile = function () {
return /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)
}
/**
* Polyfills
* --------
*/
_requestAnimationFrame = window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function (callback) {
window.setTimeout(callback, 1000 / 60)
}
/**
* Module Wrapper
* --------------
*/
if (typeof define === 'function' && typeof define.amd === 'object' && define.amd) {
define(function () {
return ScrollReveal
})
} else if (typeof module !== 'undefined' && module.exports) {
module.exports = ScrollReveal
} else {
window.ScrollReveal = ScrollReveal
}
}())
