export function buffer(fn, ms) {
let timer;
function clear() {
if (timer) {
clearTimeout(timer);
timer = null;
}
function bufferFn() {
clear();
timer = setTimeout(fn, ms);
bufferFn.clear = clear;
return bufferFn;
export function isSamePoint(prev, next) {
if (prev === next) return true;
if (!prev || !next) return false;
if ('pageX' in next && 'pageY' in next) {
return prev.pageX === next.pageX && prev.pageY === next.pageY;
if ('clientX' in next && 'clientY' in next) {
return prev.clientX === next.clientX && prev.clientY === next.clientY;
return false;
export function isWindow(obj) {
return obj && typeof obj === 'object' && obj.window === obj;