0
0
mirror of https://github.com/twbs/bootstrap.git synced 2024-11-29 11:24:18 +01:00
Bootstrap/js/src/scrollspy.js
2017-10-04 09:55:32 +02:00

341 lines
9.0 KiB
JavaScript

import $ from 'jquery'
import Util from './util'
/**
* --------------------------------------------------------------------------
* Bootstrap (v4.0.0-beta): scrollspy.js
* Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
* --------------------------------------------------------------------------
*/
const ScrollSpy = (() => {
/**
* ------------------------------------------------------------------------
* Constants
* ------------------------------------------------------------------------
*/
const NAME = 'scrollspy'
const VERSION = '4.0.0-beta'
const DATA_KEY = 'bs.scrollspy'
const EVENT_KEY = `.${DATA_KEY}`
const DATA_API_KEY = '.data-api'
const JQUERY_NO_CONFLICT = $.fn[NAME]
const Default = {
offset : 10,
method : 'auto',
target : ''
}
const DefaultType = {
offset : 'number',
method : 'string',
target : '(string|element)'
}
const Event = {
ACTIVATE : `activate${EVENT_KEY}`,
SCROLL : `scroll${EVENT_KEY}`,
LOAD_DATA_API : `load${EVENT_KEY}${DATA_API_KEY}`
}
const ClassName = {
DROPDOWN_ITEM : 'dropdown-item',
DROPDOWN_MENU : 'dropdown-menu',
ACTIVE : 'active'
}
const Selector = {
DATA_SPY : '[data-spy="scroll"]',
ACTIVE : '.active',
NAV_LIST_GROUP : '.nav, .list-group',
NAV_LINKS : '.nav-link',
NAV_ITEMS : '.nav-item',
LIST_ITEMS : '.list-group-item',
DROPDOWN : '.dropdown',
DROPDOWN_ITEMS : '.dropdown-item',
DROPDOWN_TOGGLE : '.dropdown-toggle'
}
const OffsetMethod = {
OFFSET : 'offset',
POSITION : 'position'
}
/**
* ------------------------------------------------------------------------
* Class Definition
* ------------------------------------------------------------------------
*/
class ScrollSpy {
constructor(element, config) {
this._element = element
this._scrollElement = element.tagName === 'BODY' ? window : element
this._config = this._getConfig(config)
this._selector = `${this._config.target} ${Selector.NAV_LINKS},`
+ `${this._config.target} ${Selector.LIST_ITEMS},`
+ `${this._config.target} ${Selector.DROPDOWN_ITEMS}`
this._offsets = []
this._targets = []
this._activeTarget = null
this._scrollHeight = 0
$(this._scrollElement).on(Event.SCROLL, (event) => this._process(event))
this.refresh()
this._process()
}
// getters
static get VERSION() {
return VERSION
}
static get Default() {
return Default
}
// public
refresh() {
const autoMethod = this._scrollElement !== this._scrollElement.window ?
OffsetMethod.POSITION : OffsetMethod.OFFSET
const offsetMethod = this._config.method === 'auto' ?
autoMethod : this._config.method
const offsetBase = offsetMethod === OffsetMethod.POSITION ?
this._getScrollTop() : 0
this._offsets = []
this._targets = []
this._scrollHeight = this._getScrollHeight()
const targets = $.makeArray($(this._selector))
targets
.map((element) => {
let target
const targetSelector = Util.getSelectorFromElement(element)
if (targetSelector) {
target = $(targetSelector)[0]
}
if (target) {
const targetBCR = target.getBoundingClientRect()
if (targetBCR.width || targetBCR.height) {
// todo (fat): remove sketch reliance on jQuery position/offset
return [
$(target)[offsetMethod]().top + offsetBase,
targetSelector
]
}
}
return null
})
.filter((item) => item)
.sort((a, b) => a[0] - b[0])
.forEach((item) => {
this._offsets.push(item[0])
this._targets.push(item[1])
})
}
dispose() {
$.removeData(this._element, DATA_KEY)
$(this._scrollElement).off(EVENT_KEY)
this._element = null
this._scrollElement = null
this._config = null
this._selector = null
this._offsets = null
this._targets = null
this._activeTarget = null
this._scrollHeight = null
}
// private
_getConfig(config) {
config = $.extend({}, Default, config)
if (typeof config.target !== 'string') {
let id = $(config.target).attr('id')
if (!id) {
id = Util.getUID(NAME)
$(config.target).attr('id', id)
}
config.target = `#${id}`
}
Util.typeCheckConfig(NAME, config, DefaultType)
return config
}
_getScrollTop() {
return this._scrollElement === window ?
this._scrollElement.pageYOffset : this._scrollElement.scrollTop
}
_getScrollHeight() {
return this._scrollElement.scrollHeight || Math.max(
document.body.scrollHeight,
document.documentElement.scrollHeight
)
}
_getOffsetHeight() {
return this._scrollElement === window ?
window.innerHeight : this._scrollElement.getBoundingClientRect().height
}
_process() {
const scrollTop = this._getScrollTop() + this._config.offset
const scrollHeight = this._getScrollHeight()
const maxScroll = this._config.offset
+ scrollHeight
- this._getOffsetHeight()
if (this._scrollHeight !== scrollHeight) {
this.refresh()
}
if (scrollTop >= maxScroll) {
const target = this._targets[this._targets.length - 1]
if (this._activeTarget !== target) {
this._activate(target)
}
return
}
if (this._activeTarget && scrollTop < this._offsets[0] && this._offsets[0] > 0) {
this._activeTarget = null
this._clear()
return
}
for (let i = this._offsets.length; i--;) {
const isActiveTarget = this._activeTarget !== this._targets[i]
&& scrollTop >= this._offsets[i]
&& (typeof this._offsets[i + 1] === 'undefined' ||
scrollTop < this._offsets[i + 1])
if (isActiveTarget) {
this._activate(this._targets[i])
}
}
}
_activate(target) {
this._activeTarget = target
this._clear()
let queries = this._selector.split(',')
// eslint-disable-next-line arrow-body-style
queries = queries.map((selector) => {
return `${selector}[data-target="${target}"],` +
`${selector}[href="${target}"]`
})
const $link = $(queries.join(','))
if ($link.hasClass(ClassName.DROPDOWN_ITEM)) {
$link.closest(Selector.DROPDOWN).find(Selector.DROPDOWN_TOGGLE).addClass(ClassName.ACTIVE)
$link.addClass(ClassName.ACTIVE)
} else {
// Set triggered link as active
$link.addClass(ClassName.ACTIVE)
// Set triggered links parents as active
// With both <ul> and <nav> markup a parent is the previous sibling of any nav ancestor
$link.parents(Selector.NAV_LIST_GROUP).prev(`${Selector.NAV_LINKS}, ${Selector.LIST_ITEMS}`).addClass(ClassName.ACTIVE)
// Handle special case when .nav-link is inside .nav-item
$link.parents(Selector.NAV_LIST_GROUP).prev(Selector.NAV_ITEMS).children(Selector.NAV_LINKS).addClass(ClassName.ACTIVE)
}
$(this._scrollElement).trigger(Event.ACTIVATE, {
relatedTarget: target
})
}
_clear() {
$(this._selector).filter(Selector.ACTIVE).removeClass(ClassName.ACTIVE)
}
// static
static _jQueryInterface(config) {
return this.each(function () {
let data = $(this).data(DATA_KEY)
const _config = typeof config === 'object' && config
if (!data) {
data = new ScrollSpy(this, _config)
$(this).data(DATA_KEY, data)
}
if (typeof config === 'string') {
if (typeof data[config] === 'undefined') {
throw new Error(`No method named "${config}"`)
}
data[config]()
}
})
}
}
/**
* ------------------------------------------------------------------------
* Data Api implementation
* ------------------------------------------------------------------------
*/
$(window).on(Event.LOAD_DATA_API, () => {
const scrollSpys = $.makeArray($(Selector.DATA_SPY))
for (let i = scrollSpys.length; i--;) {
const $spy = $(scrollSpys[i])
ScrollSpy._jQueryInterface.call($spy, $spy.data())
}
})
/**
* ------------------------------------------------------------------------
* jQuery
* ------------------------------------------------------------------------
*/
$.fn[NAME] = ScrollSpy._jQueryInterface
$.fn[NAME].Constructor = ScrollSpy
$.fn[NAME].noConflict = function () {
$.fn[NAME] = JQUERY_NO_CONFLICT
return ScrollSpy._jQueryInterface
}
return ScrollSpy
})($)
export default ScrollSpy