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jquery-scrollLock.js
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jquery-scrollLock.js
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/*!
* Scroll Lock v3.1.3
* https://github.com/MohammadYounes/jquery-scrollLock
*
* Copyright (c) 2017 Mohammad Younes
* Licensed under GPL 3.
*/
;(function (factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define(['jquery'], factory)
} else {
// Browser globals
factory(jQuery)
}
}(function ($) {
'use strict'
var keys = { space: 32, pageup: 33, pagedown: 34, end: 35, home: 36, up: 38, down: 40 }
var processScrollEvent = function (event, $element) {
var scrollTop = $element.scrollTop(),
scrollHeight = $element.prop('scrollHeight'),
clientHeight = $element.prop('clientHeight'),
delta = event.originalEvent.wheelDelta || (-1 * event.originalEvent.detail) || (-1 * event.originalEvent.deltaY),
deltaY = 0
if (event.type === 'wheel') {
var ratio = $element.height() / $(window).height()
deltaY = event.originalEvent.deltaY * ratio
} else if (this.options.touch && event.type === 'touchmove') {
delta = event.originalEvent.changedTouches[0].clientY - this.startClientY
}
var top, prevent
prevent = (top = delta > 0 && scrollTop + deltaY <= 0) || delta < 0 && scrollTop + deltaY >= scrollHeight - clientHeight
return {prevent: prevent, top: top, scrollTop: scrollTop, deltaY: deltaY }
}
var processKeyboardEvent = function (event, $element) {
var scrollTop = $element.scrollTop(),
result = {top: false, bottom: false}
result.top = scrollTop === 0 && (event.keyCode === keys.pageup || event.keyCode === keys.home || event.keyCode === keys.up)
if (!result.top) {
var scrollHeight = $element.prop('scrollHeight'),
clientHeight = $element.prop('clientHeight')
result.bottom = scrollHeight === scrollTop + clientHeight && (event.keyCode === keys.space || event.keyCode === keys.pagedown || event.keyCode === keys.end || event.keyCode === keys.down)
}
return result
}
var ScrollLock = function ($element, options) {
this.$element = $element
this.options = $.extend({}, ScrollLock.DEFAULTS, this.$element.data(), options)
this.enabled = true
this.startClientY = 0
if (this.options.unblock) {
this.$element.on(ScrollLock.CORE.wheelEventName + ScrollLock.NAMESPACE, this.options.unblock, $.proxy(ScrollLock.CORE.unblockHandler, this))
}
this.$element.on(ScrollLock.CORE.wheelEventName + ScrollLock.NAMESPACE, this.options.selector, $.proxy(ScrollLock.CORE.handler, this))
if (this.options.touch) {
this.$element.on('touchstart' + ScrollLock.NAMESPACE, this.options.selector, $.proxy(ScrollLock.CORE.touchHandler, this))
this.$element.on('touchmove' + ScrollLock.NAMESPACE, this.options.selector, $.proxy(ScrollLock.CORE.handler, this))
if (this.options.unblock) {
this.$element.on('touchmove' + ScrollLock.NAMESPACE, this.options.unblock, $.proxy(ScrollLock.CORE.unblockHandler, this))
}
}
if (this.options.keyboard) {
this.$element.attr('tabindex', this.options.keyboard.tabindex || 0)
this.$element.on('keydown' + ScrollLock.NAMESPACE, this.options.selector, $.proxy(ScrollLock.CORE.keyboardHandler, this))
if (this.options.unblock) {
this.$element.on('keydown' + ScrollLock.NAMESPACE, this.options.unblock, $.proxy(ScrollLock.CORE.unblockHandler, this))
}
}
}
ScrollLock.NAME = 'ScrollLock'
ScrollLock.VERSION = '3.1.2'
ScrollLock.NAMESPACE = '.scrollLock'
ScrollLock.ANIMATION_NAMESPACE = ScrollLock.NAMESPACE + '.effect'
ScrollLock.DEFAULTS = {
strict: false,
strictFn: function ($element) {
return $element.prop('scrollHeight') > $element.prop('clientHeight')
},
selector: false,
animation: false,
touch: 'ontouchstart' in window,
keyboard: false,
unblock: false
}
ScrollLock.CORE = {
wheelEventName: 'onwheel' in document.createElement('div') ? 'wheel' : // Modern browsers support "wheel"
document.onmousewheel !== undefined ? 'mousewheel' : // Webkit and IE support at least "mousewheel"
'DOMMouseScroll', // let's assume that remaining browsers are older Firefox,
animationEventName: [
'webkitAnimationEnd',
'mozAnimationEnd',
'MSAnimationEnd',
'oanimationend',
'animationend'
].join(ScrollLock.ANIMATION_NAMESPACE + ' ') + ScrollLock.ANIMATION_NAMESPACE,
unblockHandler: function (event) {
event.__currentTarget = event.currentTarget
},
handler: function (event) {
// allow zooming
if (this.enabled && !event.ctrlKey) {
var $this = $(event.currentTarget)
if (this.options.strict !== true || this.options.strictFn($this)) {
// Support for nested scrollable blocks (see https://github.com/MohammadYounes/jquery-scrollLock/issues/4)
event.stopPropagation()
var result = $.proxy(processScrollEvent, this)(event, $this)
if (event.__currentTarget)
result.prevent &= $.proxy(processScrollEvent, this)(event, $(event.__currentTarget)).prevent
if (result.prevent) {
event.preventDefault()
if (result.deltaY) {
$this.scrollTop(result.scrollTop + result.deltaY)
}
var key = result.top ? 'top' : 'bottom'
if (this.options.animation) {
setTimeout(ScrollLock.CORE.animationHandler.bind(this, $this, key), 0)
}
$this.trigger($.Event(key + ScrollLock.NAMESPACE))
}
}
}
},
touchHandler: function (event) {
this.startClientY = event.originalEvent.touches[0].clientY
},
animationHandler: function ($element, key) {
var css = this.options.animation[key],
all = this.options.animation.top + ' ' + this.options.animation.bottom
$element.off(ScrollLock.ANIMATION_NAMESPACE)
.removeClass(all)
.addClass(css)
.one(ScrollLock.CORE.animationEventName,
function () {
$element.removeClass(css)
})
},
keyboardHandler: function (event) {
var $this = $(event.currentTarget),
scrollTop = $this.scrollTop(),
result = processKeyboardEvent(event, $this)
if (event.__currentTarget) {
var result2 = processKeyboardEvent(event, $(event.__currentTarget))
result.top &= result2.top
result.bottom &= result2.bottom
}
if (result.top) {
$this.trigger($.Event('top' + ScrollLock.NAMESPACE))
if (this.options.animation) {
setTimeout(ScrollLock.CORE.animationHandler.bind(this, $this, 'top'), 0)
}
return false
} else if (result.bottom) {
$this.trigger($.Event('bottom' + ScrollLock.NAMESPACE))
if (this.options.animation) {
setTimeout(ScrollLock.CORE.animationHandler.bind(this, $this, 'bottom'), 0)
}
return false
}
}
}
ScrollLock.prototype.toggleStrict = function () {
this.options.strict = !this.options.strict
}
ScrollLock.prototype.enable = function () {
this.enabled = true
}
ScrollLock.prototype.disable = function () {
this.enabled = false
}
ScrollLock.prototype.destroy = function () {
this.disable()
this.$element.off(ScrollLock.NAMESPACE)
this.$element = null
this.options = null
}
// plugin defintion.
var old = $.fn.scrollLock
$.fn.scrollLock = function (option) {
return this.each(function () {
var $this = $(this)
var options = typeof option == 'object' && option
var data = $this.data(ScrollLock.NAME)
if (!data && 'destroy' === option) return
if (!data) $this.data(ScrollLock.NAME, (data = new ScrollLock($this, options)))
if (typeof option == 'string') data[option]()
})
}
$.fn.scrollLock.defaults = ScrollLock.DEFAULTS
// no conflict
$.fn.scrollLock.noConflict = function () {
$.fn.scrollLock = old
return this
}
}));