109 lines
3.1 KiB
JavaScript
109 lines
3.1 KiB
JavaScript
/**
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* Muuri AutoScroller
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* Copyright (c) 2019-present, Niklas Rämö <inramo@gmail.com>
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* Released under the MIT license
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* https://github.com/haltu/muuri/blob/master/src/AutoScroller/LICENSE.md
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*/
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import isFunction from '../utils/isFunction';
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import { AXIS_X, FORWARD } from './constants';
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import { getScrollLeft, getScrollTop, getItemAutoScrollSettings } from './utils';
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export default function ScrollRequest() {
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this.reset();
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}
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ScrollRequest.prototype.reset = function () {
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if (this.isActive) this.onStop();
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this.item = null;
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this.element = null;
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this.isActive = false;
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this.isEnding = false;
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this.direction = null;
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this.value = null;
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this.maxValue = 0;
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this.threshold = 0;
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this.distance = 0;
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this.speed = 0;
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this.duration = 0;
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this.action = null;
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};
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ScrollRequest.prototype.hasReachedEnd = function () {
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return FORWARD & this.direction ? this.value >= this.maxValue : this.value <= 0;
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};
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ScrollRequest.prototype.computeCurrentScrollValue = function () {
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if (this.value === null) {
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return AXIS_X & this.direction ? getScrollLeft(this.element) : getScrollTop(this.element);
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}
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return Math.max(0, Math.min(this.value, this.maxValue));
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};
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ScrollRequest.prototype.computeNextScrollValue = function (deltaTime) {
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var delta = this.speed * (deltaTime / 1000);
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var nextValue = FORWARD & this.direction ? this.value + delta : this.value - delta;
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return Math.max(0, Math.min(nextValue, this.maxValue));
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};
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ScrollRequest.prototype.computeSpeed = (function () {
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var data = {
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direction: null,
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threshold: 0,
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distance: 0,
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value: 0,
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maxValue: 0,
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deltaTime: 0,
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duration: 0,
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isEnding: false,
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};
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return function (deltaTime) {
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var item = this.item;
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var speed = getItemAutoScrollSettings(item).speed;
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if (isFunction(speed)) {
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data.direction = this.direction;
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data.threshold = this.threshold;
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data.distance = this.distance;
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data.value = this.value;
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data.maxValue = this.maxValue;
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data.duration = this.duration;
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data.speed = this.speed;
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data.deltaTime = deltaTime;
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data.isEnding = this.isEnding;
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return speed(item, this.element, data);
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} else {
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return speed;
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}
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};
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})();
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ScrollRequest.prototype.tick = function (deltaTime) {
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if (!this.isActive) {
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this.isActive = true;
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this.onStart();
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}
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this.value = this.computeCurrentScrollValue();
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this.speed = this.computeSpeed(deltaTime);
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this.value = this.computeNextScrollValue(deltaTime);
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this.duration += deltaTime;
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return this.value;
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};
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ScrollRequest.prototype.onStart = function () {
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var item = this.item;
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var onStart = getItemAutoScrollSettings(item).onStart;
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if (isFunction(onStart)) onStart(item, this.element, this.direction);
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};
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ScrollRequest.prototype.onStop = function () {
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var item = this.item;
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var onStop = getItemAutoScrollSettings(item).onStop;
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if (isFunction(onStop)) onStop(item, this.element, this.direction);
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// Manually nudge sort to happen. There's a good chance that the item is still
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// after the scroll stops which means that the next sort will be triggered
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// only after the item is moved or it's parent scrolled.
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if (item._drag) item._drag.sort();
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};
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