Class ScrollTrigger

src/ScrollTrigger.js:597–1484

export class ScrollTrigger {

	constructor(vars, animation) {
		_coreInitted || ScrollTrigger.register(gsap) || console.warn("Please gsap.registerPlugin(ScrollTrigger)");
		_context(this);
		this.init(vars, animation);
	}

	init(vars, animation) {
		this.progress = this.start = 0;
		this.vars && this.kill(true, true); // in case it's being initted again
		if (!_enabled) {
			this.update = this.refresh = this.kill = _passThrough;
			return;
		}
		vars = _setDefaults((_isString(vars) || _isNumber(vars) || vars.nodeType) ? {trigger: vars} : vars, _defaults);
		let {onUpdate, toggleClass, id, onToggle, onRefresh, scrub, trigger, pin, pinSpacing, invalidateOnRefresh, anticipatePin, onScrubComplete, onSnapComplete, once, snap, pinReparent, pinSpacer, containerAnimation, fastScrollEnd, preventOverlaps} = vars,
			direction = vars.horizontal || (vars.containerAnimation && vars.horizontal !== false) ? _horizontal : _vertical,
			isToggle = !scrub && scrub !== 0,
			scroller = _getTarget(vars.scroller || _win),
			scrollerCache = gsap.core.getCache(scroller),
			isViewport = _isViewport(scroller),
			useFixedPosition = ("pinType" in vars ? vars.pinType : _getProxyProp(scroller, "pinType") || (isViewport && "fixed")) === "fixed",
			callbacks = [vars.onEnter, vars.onLeave, vars.onEnterBack, vars.onLeaveBack],
			toggleActions = isToggle && vars.toggleActions.split(" "),
			markers = "markers" in vars ? vars.markers : _defaults.markers,
			borderWidth = isViewport ? 0 : parseFloat(_getComputedStyle(scroller)["border" + direction.p2 + _Width]) || 0,
			self = this,
			onRefreshInit = vars.onRefreshInit && (() => vars.onRefreshInit(self)),
			getScrollerSize = _getSizeFunc(scroller, isViewport, direction),
			getScrollerOffsets = _getOffsetsFunc(scroller, isViewport),
			lastSnap = 0,
			lastRefresh = 0,
			prevProgress = 0,
			scrollFunc = _getScrollFunc(scroller, direction),
			tweenTo, pinCache, snapFunc, scroll1, scroll2, start, end, markerStart, markerEnd, markerStartTrigger, markerEndTrigger, markerVars, executingOnRefresh,
			change, pinOriginalState, pinActiveState, pinState, spacer, offset, pinGetter, pinSetter, pinStart, pinChange, spacingStart, spacerState, markerStartSetter, pinMoves,
			markerEndSetter, cs, snap1, snap2, scrubTween, scrubSmooth, snapDurClamp, snapDelayedCall, prevScroll, prevAnimProgress, caMarkerSetter, customRevertReturn;

		// for the sake of efficiency, _startClamp/_endClamp serve like a truthy value indicating that clamping was enabled on the start/end, and ALSO store the actual pre-clamped numeric value. We tap into that in ScrollSmoother for speed effects. So for example, if start="clamp(top bottom)" results in a start of -100 naturally, it would get clamped to 0 but -100 would be stored in _startClamp.
		self._startClamp = self._endClamp = false;
		self._dir = direction;
		anticipatePin *= 45;
		self.scroller = scroller;
		self.scroll = containerAnimation ? containerAnimation.time.bind(containerAnimation) : scrollFunc;
		scroll1 = scrollFunc();
		self.vars = vars;
		animation = animation || vars.animation;
		if ("refreshPriority" in vars) {
			_sort = 1;
			vars.refreshPriority === -9999 && (_primary = self); // used by ScrollSmoother
		}
		scrollerCache.tweenScroll = scrollerCache.tweenScroll || {
			top: _getTweenCreator(scroller, _vertical),
			left: _getTweenCreator(scroller, _horizontal)
		};
		self.tweenTo = tweenTo = scrollerCache.tweenScroll[direction.p];
		self.scrubDuration = value => {