react-calendar-mobile/src/util/draggable.js

A calendar component for mobile device

var isDragging = false;
const supportTouch = 'ontouchstart' in window;
export default function (element, options) {

	const moveFn = function (event) {
		if (options.drag) {
			options.drag(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
		}
	};

	const endFn = function (event) {
		if (!supportTouch) {
			document.removeEventListener('mousemove', moveFn);
			document.removeEventListener('mouseup', endFn);
		}
		document.onselectstart = null;
		document.ondragstart = null;

		isDragging = false;

		if (options.end) {
			options.end(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
		}
	};

	element.addEventListener(supportTouch ? 'touchstart' : 'mousedown', function (event) {
		if (isDragging) return;
		document.onselectstart = function () {
			return false;
		};
		document.ondragstart = function () {
			return false;
		};

		if (!supportTouch) {
			document.addEventListener('mousemove', moveFn);
			document.addEventListener('mouseup', endFn);
		}
		isDragging = true;

		if (options.start) {
			event.preventDefault();
			options.start(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
		}
	});

	if (supportTouch) {
		element.addEventListener('touchmove', moveFn);
		element.addEventListener('touchend', endFn);
		element.addEventListener('touchcancel', endFn);
	}
};