Matt Levy ducksoupdev

How to make faster scroll effects?

Avoid too many reflows (the browser to recalculate everything)
Use advanced CSS3 for graphic card rendering
Precalculate sizes and positions

Beware of reflows

The reflow appens as many times as there are frames per seconds. It recalculate all positions that change in order to diplay them. Basically, when you scroll you execute a function where you move things between two reflows. But there are functions that triggers reflows such as jQuery offset, scroll... So there are two things to take care about when you dynamically change objects in javascript to avoid too many reflows:

	const books = [
	{ name: "x", author: "y" },
	{ name: "a", author: "b" },
	{ name: "x", author: "y" }
	]

	const filteredBooks = [...new Set(books.map(b => JSON.stringify(b)))].map(b => JSON.parse(b))

	console.log(filteredBooks)

	const jsdom = require('jsdom')
	const { JSDOM } = jsdom

	function allDescendants (html, node) {
	for (let i = 0; i < node.children.length; i++) {
	const child = node.children[i]
	let s = '+('
	if (i === 0) {
	s = '>'
	}

	'use strict';

	class HTMLElementPlus extends HTMLElement {

	static defaultAttributeValue() {
	/* the name of the attribute is parsed in as a parameter */
	return;
	}

	static parseAttributeValue(name, value) {

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>webcomponents test</title>
	<style>
	body {
	margin: 0;

	(function() {
	var lastScrollY = 0;
	var ticking = false;

	var update = function() {
	// do your stuff
	ticking = false;
	};

	var requestTick = function() {

	['/css/font-awesome.css', '/css/font-populaire.css'].forEach(function (f) {
	var gf = document.createElement('link')
	gf.rel = 'stylesheet'
	gf.href = f
	gf.type = 'text/css'
	var gd = document.getElementsByTagName('link')[0]
	gd.parentNode.insertBefore(gf, gd)
	})

	(function (window, document) {
	// do stuff
	})(window, document)

	function includeCSSfile(href) {
	var head_node = document.getElementsByTagName('head')[0];
	var link_tag = document.createElement('link');
	link_tag.setAttribute('rel', 'stylesheet');
	link_tag.setAttribute('type', 'text/css');
	link_tag.setAttribute('href', href);
	head_node.appendChild(link_tag);
	}

	function includeJavascript(src) {

	#!/bin/bash
	#
	# Public-Key Encryption and Decryption
	# * http://www.openssl.org/
	# * http://barelyenough.org/blog/2008/04/fun-with-public-keys/
	#
	# Mac OS X 10.6.4
	# OpenSSL 0.9.8l 5 Nov 2009

	# Generate keys