/
keen-slider.js
744 lines (663 loc) · 19.5 KB
/
keen-slider.js
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import './polyfills'
function KeenSlider(initialContainer, initialOptions = {}) {
const attributeMoving = 'data-keen-slider-moves'
const attributeVertical = 'data-keen-slider-v'
let container
let events = []
let touchControls
let length
let origin
let slides
let width
let slidesPerView
let spacing
let resizeLastWidth
let breakpointCurrent = null
let optionsChanged = false
let sliderCreated = false
let trackCurrentIdx
let trackPosition = 0
let trackMeasurePoints = []
let trackDirection
let trackMeasureTimeout
let trackSpeed
let trackSlidePositions
let trackProgress
let options
// touch/swipe helper
let touchIndexStart
let touchActive
let touchIdentifier
let touchLastX
let touchLastClientX
let touchLastClientY
let touchMultiplicator
let touchJustStarted
// animation
let reqId
let startTime
let moveDistance
let moveDuration
let moveEasing
let moved
let moveForceFinish
let moveCallBack
function eventAdd(element, event, handler, options = {}) {
element.addEventListener(event, handler, options)
events.push([element, event, handler, options])
}
function eventDrag(e) {
if (
!touchActive ||
touchIdentifier !== eventGetIdentifier(e) ||
!isTouchable()
)
return
const x = eventGetX(e).x
if (!eventIsSlide(e) && touchJustStarted) {
return eventDragStop(e)
}
if (touchJustStarted) {
trackMeasureReset()
touchLastX = x
container.setAttribute(attributeMoving, true)
touchJustStarted = false
}
if (e.cancelable) e.preventDefault()
const touchDistance = touchLastX - x
trackAdd(touchMultiplicator(touchDistance, pubfuncs), e.timeStamp)
touchLastX = x
}
function eventDragStart(e) {
if (touchActive || !isTouchable() || eventIsIgnoreTarget(e.target)) return
touchActive = true
touchJustStarted = true
touchIdentifier = eventGetIdentifier(e)
eventIsSlide(e)
moveAnimateAbort()
touchIndexStart = trackCurrentIdx
touchLastX = eventGetX(e).x
trackAdd(0, e.timeStamp)
hook('dragStart')
}
function eventDragStop(e) {
if (
!touchActive ||
touchIdentifier !== eventGetIdentifier(e, true) ||
!isTouchable()
)
return
container.removeAttribute(attributeMoving)
touchActive = false
moveWithSpeed()
hook('dragEnd')
}
function eventGetChangedTouches(e) {
return e.changedTouches
}
function eventGetIdentifier(e, changedTouches = false) {
const touches = changedTouches
? eventGetChangedTouches(e)
: eventGetTargetTouches(e)
return !touches ? 'default' : touches[0] ? touches[0].identifier : 'error'
}
function eventGetTargetTouches(e) {
return e.targetTouches
}
function eventGetX(e) {
const touches = eventGetTargetTouches(e)
return {
x: isVertialSlider()
? !touches
? e.pageY
: touches[0].screenY
: !touches
? e.pageX
: touches[0].screenX,
timestamp: e.timeStamp,
}
}
function eventIsIgnoreTarget(target) {
return target.hasAttribute(options.preventEvent)
}
function eventIsSlide(e) {
const touches = eventGetTargetTouches(e)
if (!touches) return true
const touch = touches[0]
const x = isVertialSlider() ? touch.clientY : touch.clientX
const y = isVertialSlider() ? touch.clientX : touch.clientY
const isSlide =
touchLastClientX !== undefined &&
touchLastClientY !== undefined &&
Math.abs(touchLastClientY - y) <= Math.abs(touchLastClientX - x)
touchLastClientX = x
touchLastClientY = y
return isSlide
}
function eventWheel(e) {
if (!isTouchable()) return
if (touchActive) e.preventDefault()
}
function eventsAdd() {
eventAdd(window, 'orientationchange', sliderResizeFix)
eventAdd(window, 'resize', () => sliderResize())
eventAdd(container, 'dragstart', function (e) {
if (!isTouchable()) return
e.preventDefault()
})
eventAdd(container, 'mousedown', eventDragStart)
eventAdd(container, 'mousemove', eventDrag)
eventAdd(container, 'mouseleave', eventDragStop)
eventAdd(container, 'mouseup', eventDragStop)
eventAdd(container, 'touchstart', eventDragStart)
eventAdd(container, 'touchmove', eventDrag)
eventAdd(container, 'touchend', eventDragStop)
eventAdd(container, 'touchcancel', eventDragStop)
eventAdd(window, 'wheel', eventWheel, {
passive: !1,
})
}
function eventsRemove() {
events.forEach(event => {
event[0].removeEventListener(event[1], event[2], event[3])
})
events = []
}
function hook(hook) {
if (options[hook]) options[hook](pubfuncs)
}
function isCenterMode() {
return options.centered
}
function isTouchable() {
return touchControls !== undefined ? touchControls : options.controls
}
function isLoop() {
return options.loop
}
function isRubberband() {
return !options.loop && options.rubberband
}
function isVertialSlider() {
return !!options.vertical
}
function moveAnimate() {
reqId = window.requestAnimationFrame(moveAnimateUpdate)
}
function moveAnimateAbort() {
if (reqId) {
window.cancelAnimationFrame(reqId)
reqId = null
}
startTime = null
}
function moveAnimateUpdate(timestamp) {
if (!startTime) startTime = timestamp
const duration = timestamp - startTime
let add = moveCalcValue(duration)
if (duration >= moveDuration) {
trackAdd(moveDistance - moved, false)
if (moveCallBack) return moveCallBack()
hook('afterChange')
return
}
const offset = trackCalculateOffset(add)
if (offset !== 0 && !isLoop() && !isRubberband() && !moveForceFinish) {
trackAdd(add - offset, false)
return
}
if (offset !== 0 && isRubberband() && !moveForceFinish) {
return moveRubberband(Math.sign(offset))
}
moved += add
trackAdd(add, false)
moveAnimate()
}
function moveCalcValue(progress) {
const value = moveDistance * moveEasing(progress / moveDuration) - moved
return value
}
function moveWithSpeed() {
hook('beforeChange')
switch (options.mode) {
case 'free':
moveFree()
break
case 'free-snap':
moveSnapFree()
break
case 'snap':
default:
moveSnapOne()
break
}
}
function moveSnapOne() {
const startIndex =
slidesPerView === 1 && trackDirection !== 0
? touchIndexStart
: trackCurrentIdx
moveToIdx(startIndex + Math.sign(trackDirection))
}
function moveToIdx(
idx,
forceFinish,
duration = options.duration,
relative = false,
nearest = false
) {
// forceFinish is used to ignore boundaries when rubberband movement is active
idx = trackGetIdx(idx, relative, nearest)
const easing = t => 1 + --t * t * t * t * t
moveTo(trackGetIdxDistance(idx), duration, easing, forceFinish)
}
function moveFree() {
// todo: refactor!
if (trackSpeed === 0)
return trackCalculateOffset(0) && !isLoop()
? moveToIdx(trackCurrentIdx)
: false
const friction = options.friction / Math.pow(Math.abs(trackSpeed), -0.5)
const distance =
(Math.pow(trackSpeed, 2) / friction) * Math.sign(trackSpeed)
const duration = Math.abs(trackSpeed / friction) * 6
const easing = function (t) {
return 1 - Math.pow(1 - t, 5)
}
moveTo(distance, duration, easing)
}
function moveSnapFree() {
// todo: refactor!
if (trackSpeed === 0) return moveToIdx(trackCurrentIdx)
const friction = options.friction / Math.pow(Math.abs(trackSpeed), -0.5)
const distance =
(Math.pow(trackSpeed, 2) / friction) * Math.sign(trackSpeed)
const duration = Math.abs(trackSpeed / friction) * 6
const easing = function (t) {
return 1 - Math.pow(1 - t, 5)
}
const idx_trend = (trackPosition + distance) / (width / slidesPerView)
const idx =
trackDirection === -1 ? Math.floor(idx_trend) : Math.ceil(idx_trend)
moveTo(idx * (width / slidesPerView) - trackPosition, duration, easing)
}
function moveRubberband() {
moveAnimateAbort()
// todo: refactor!
if (trackSpeed === 0) return moveToIdx(trackCurrentIdx, true)
const friction = 0.04 / Math.pow(Math.abs(trackSpeed), -0.5)
const distance =
(Math.pow(trackSpeed, 2) / friction) * Math.sign(trackSpeed)
const easing = function (t) {
return --t * t * t + 1
}
const speed = trackSpeed
const cb = () => {
moveTo(
trackGetIdxDistance(trackGetIdx(trackCurrentIdx)),
500,
easing,
true
)
}
moveTo(distance, Math.abs(speed / friction) * 3, easing, true, cb)
}
function moveTo(distance, duration, easing, forceFinish, cb) {
moveAnimateAbort()
moveDistance = distance
moved = 0
moveDuration = duration
moveEasing = easing
moveForceFinish = forceFinish
moveCallBack = cb
startTime = null
moveAnimate()
}
function sliderBind(force_resize) {
let _container = getElements(initialContainer)
if (!_container.length) return
container = _container[0]
sliderResize(force_resize)
eventsAdd()
hook('mounted')
}
function sliderCheckBreakpoint() {
const breakpoints = initialOptions.breakpoints || []
let lastValid
for (let value in breakpoints) {
if (window.matchMedia(value).matches) lastValid = value
}
if (lastValid === breakpointCurrent) return true
breakpointCurrent = lastValid
const _options = breakpointCurrent
? breakpoints[breakpointCurrent]
: initialOptions
if (_options.breakpoints && breakpointCurrent) delete _options.breakpoints
options = { ...defaultOptions, ...initialOptions, ..._options }
optionsChanged = true
resizeLastWidth = null
sliderRebind()
}
function sliderGetSlidesPerView(option) {
return typeof option === 'function'
? option()
: clampValue(option, 1, Math.max(isLoop() ? length - 1 : length, 1))
}
function sliderInit() {
sliderCheckBreakpoint()
sliderCreated = true
hook('created')
}
function sliderRebind(new_options, force_resize) {
if (new_options) initialOptions = new_options
if (force_resize) breakpointCurrent = null
sliderUnbind()
sliderBind(force_resize)
}
function sliderResize(force) {
const windowWidth = window.innerWidth
if (!sliderCheckBreakpoint() || (windowWidth === resizeLastWidth && !force))
return
resizeLastWidth = windowWidth
const optionSlides = options.slides
if (typeof optionSlides === 'number') {
slides = null
length = optionSlides
} else {
slides = getElements(optionSlides, container)
length = slides ? slides.length : 0
}
const dragSpeed = options.dragSpeed
touchMultiplicator =
typeof dragSpeed === 'function' ? dragSpeed : val => val * dragSpeed
width = isVertialSlider() ? container.offsetHeight : container.offsetWidth
slidesPerView = sliderGetSlidesPerView(options.slidesPerView)
spacing = clampValue(options.spacing, 0, width / (slidesPerView - 1) - 1)
width += spacing
origin = isCenterMode()
? (width / 2 - width / slidesPerView / 2) / width
: 0
slidesSetWidths()
const currentIdx =
!sliderCreated || (optionsChanged && options.resetSlide)
? options.initial
: trackCurrentIdx
trackSetPositionByIdx(isLoop() ? currentIdx : trackClampIndex(currentIdx))
if (isVertialSlider()) {
container.setAttribute(attributeVertical, true)
}
optionsChanged = false
}
function sliderResizeFix(force) {
sliderResize()
setTimeout(sliderResize, 500)
setTimeout(sliderResize, 2000)
}
function sliderUnbind() {
eventsRemove()
slidesRemoveStyles()
if (container && container.hasAttribute(attributeVertical))
container.removeAttribute(attributeVertical)
hook('destroyed')
}
function slidesSetPositions() {
if (!slides) return
slides.forEach((slide, idx) => {
const absoluteDistance = trackSlidePositions[idx].distance * width
const pos =
absoluteDistance -
idx *
(width / slidesPerView -
spacing / slidesPerView -
(spacing / slidesPerView) * (slidesPerView - 1))
const x = isVertialSlider() ? 0 : pos
const y = isVertialSlider() ? pos : 0
const transformString = `translate3d(${x}px, ${y}px, 0)`
slide.style.transform = transformString
slide.style['-webkit-transform'] = transformString
})
}
function slidesSetWidths() {
if (!slides) return
slides.forEach(slide => {
const style = `calc(${100 / slidesPerView}% - ${
(spacing / slidesPerView) * (slidesPerView - 1)
}px)`
if (isVertialSlider()) {
slide.style['min-height'] = style
slide.style['max-height'] = style
} else {
slide.style['min-width'] = style
slide.style['max-width'] = style
}
})
}
function slidesRemoveStyles() {
if (!slides) return
let styles = ['transform', '-webkit-transform']
styles = isVertialSlider
? [...styles, 'min-height', 'max-height']
: [...styles, 'min-width', 'max-width']
slides.forEach(slide => {
styles.forEach(style => {
slide.style.removeProperty(style)
})
})
}
function trackAdd(val, drag = true, timestamp = Date.now()) {
trackMeasure(val, timestamp)
if (drag) val = trackrubberband(val)
trackPosition += val
trackMove()
}
function trackCalculateOffset(add) {
const trackLength =
(width * (length - 1 * (isCenterMode() ? 1 : slidesPerView))) /
slidesPerView
const position = trackPosition + add
return position > trackLength
? position - trackLength
: position < 0
? position
: 0
}
function trackClampIndex(idx) {
return clampValue(
idx,
0,
length - 1 - (isCenterMode() ? 0 : slidesPerView - 1)
)
}
function trackGetDetails() {
const trackProgressAbs = Math.abs(trackProgress)
const progress = trackPosition < 0 ? 1 - trackProgressAbs : trackProgressAbs
return {
direction: trackDirection,
progressTrack: progress,
progressSlides: (progress * length) / (length - 1),
positions: trackSlidePositions,
position: trackPosition,
speed: trackSpeed,
relativeSlide: ((trackCurrentIdx % length) + length) % length,
absoluteSlide: trackCurrentIdx,
size: length,
slidesPerView,
widthOrHeight: width,
}
}
function trackGetIdx(idx, relative = false, nearest = false) {
return !isLoop()
? trackClampIndex(idx)
: !relative
? idx
: trackGetRelativeIdx(idx, nearest)
}
function trackGetIdxDistance(idx) {
return -(-((width / slidesPerView) * idx) + trackPosition)
}
function trackGetRelativeIdx(idx, nearest) {
idx = ((idx % length) + length) % length
const current = ((trackCurrentIdx % length) + length) % length
const left = current < idx ? -current - length + idx : -(current - idx)
const right = current > idx ? length - current + idx : idx - current
const add = nearest
? Math.abs(left) <= right
? left
: right
: idx < current
? left
: right
return trackCurrentIdx + add
}
function trackMeasure(val, timestamp) {
// todo - improve measurement - it could be better for ios
clearTimeout(trackMeasureTimeout)
const direction = Math.sign(val)
if (direction !== trackDirection) trackMeasureReset()
trackDirection = direction
trackMeasurePoints.push({
distance: val,
time: timestamp,
})
trackMeasureTimeout = setTimeout(() => {
trackMeasurePoints = []
trackSpeed = 0
}, 50)
trackMeasurePoints = trackMeasurePoints.slice(-6)
if (trackMeasurePoints.length <= 1 || trackDirection === 0)
return (trackSpeed = 0)
const distance = trackMeasurePoints
.slice(0, -1)
.reduce((acc, next) => acc + next.distance, 0)
const end = trackMeasurePoints[trackMeasurePoints.length - 1].time
const start = trackMeasurePoints[0].time
trackSpeed = clampValue(distance / (end - start), -10, 10)
}
function trackMeasureReset() {
trackMeasurePoints = []
}
// todo - option for not calculating slides that are not in sight
function trackMove() {
trackProgress = isLoop()
? (trackPosition % ((width * length) / slidesPerView)) /
((width * length) / slidesPerView)
: trackPosition / ((width * length) / slidesPerView)
trackSetCurrentIdx()
const slidePositions = []
for (let idx = 0; idx < length; idx++) {
let distance =
(((1 / length) * idx -
(trackProgress < 0 && isLoop() ? trackProgress + 1 : trackProgress)) *
length) /
slidesPerView +
origin
if (isLoop())
distance +=
distance > (length - 1) / slidesPerView
? -(length / slidesPerView)
: distance < -(length / slidesPerView) + 1
? length / slidesPerView
: 0
const slideWidth = 1 / slidesPerView
const left = distance + slideWidth
const portion =
left < slideWidth
? left / slideWidth
: left > 1
? 1 - ((left - 1) * slidesPerView) / 1
: 1
slidePositions.push({
portion: portion < 0 || portion > 1 ? 0 : portion,
distance,
})
}
trackSlidePositions = slidePositions
slidesSetPositions()
hook('move')
}
function trackrubberband(add) {
if (isLoop()) return add
const offset = trackCalculateOffset(add)
if (!isRubberband()) return add - offset
if (offset === 0) return add
const easing = t => (1 - Math.abs(t)) * (1 - Math.abs(t))
return add * easing(offset / width)
}
function trackSetCurrentIdx() {
const new_idx = Math.round(trackPosition / (width / slidesPerView))
if (new_idx === trackCurrentIdx) return
trackCurrentIdx = new_idx
hook('slideChanged')
}
function trackSetPositionByIdx(idx) {
hook('beforeChange')
trackAdd(trackGetIdxDistance(idx), false)
hook('afterChange')
}
const defaultOptions = {
centered: false,
breakpoints: null,
controls: true,
dragSpeed: 1,
friction: 0.0025,
loop: false,
initial: 0,
duration: 500,
preventEvent: 'data-keen-slider-pe',
slides: '.keen-slider__slide',
vertical: false,
resetSlide: false,
slidesPerView: 1,
spacing: 0,
mode: 'snap',
rubberband: true,
}
const pubfuncs = {
controls: active => {
touchControls = active
},
destroy: sliderUnbind,
refresh(options) {
sliderRebind(options, true)
},
next() {
moveToIdx(trackCurrentIdx + 1, true)
},
prev() {
moveToIdx(trackCurrentIdx - 1, true)
},
moveToSlide(idx, duration) {
moveToIdx(idx, true, duration)
},
moveToSlideRelative(idx, nearest = false, duration) {
moveToIdx(idx, true, duration, true, nearest)
},
resize() {
sliderResize(true)
},
details() {
return trackGetDetails()
},
}
sliderInit()
return pubfuncs
}
export default KeenSlider
// helper functions
function convertToArray(nodeList) {
return Array.prototype.slice.call(nodeList)
}
function getElements(element, wrapper = document) {
return typeof element === 'function'
? convertToArray(element())
: typeof element === 'string'
? convertToArray(wrapper.querySelectorAll(element))
: element instanceof HTMLElement !== false
? [element]
: element instanceof NodeList !== false
? element
: []
}
function clampValue(value, min, max) {
return Math.min(Math.max(value, min), max)
}