Dan dlindenkreuz

Analysis of Apple’s rubber band scrolling

January 6, 2013

I recently saw a post on Twitter from @chpwn that described the alogorithm that Apple uses for its “rubber band” or “bungee” scrolling.

b = (1.0 – (1.0 / ((x * c / d) + 1.0))) * d

	/**
	* Fetchr middleware for koa
	*
	* Translate Fetchr.middleware() from express.js to koa
	* This is pretty rough and might be buggy but it does the job nicely for me at the moment.
	*
	* Tested with fetchr v0.5.14
	*/
	export default function () {
	return function * (next) {

	// one-liner version
	// retains latin-1 supplement chars as well as latin extended-a and latin extended-b

	Shopify.handleize = function (str) {
	return str.toLowerCase().replace(/[^\w\u00C0-\u024f]+/g, "-").replace(/^-+\|-+$/g, "");
	};

	import { RouteThunk } from "redux-first-router"
	import * as compose from "koa-compose"
	import { Middleware } from "koa-compose"
	import { Dispatch } from "redux"

	interface ThunkContext<S> {
	dispatch: Dispatch<S>
	getState: () => S
	}