├── .gitignore
├── README.md
├── index.js
├── package-lock.json
├── package.json
└── test.js


/.gitignore:
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1 | .DS_Store
2 | *.map
3 | node_modules/
4 | dist
5 | 


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/README.md:
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 1 | # srraf
 2 | Monitor scrolling and resizing without event listeners. **300 bytes gzipped.**
 3 | 
 4 | ## Install 
 5 | ```bash
 6 | npm i srraf --save
 7 | ```
 8 | 
 9 | # Usage
10 | ```javascript
11 | import srraf from 'srraf'
12 | 
13 | const scroller = srraf(({ x, px, y, py, vh, pvh, vw, pvw }, timestamp) => {
14 |   // ...
15 | })
16 | 
17 | scroller.update() // check position
18 | scroller.destroy() // destroy listener
19 | ```
20 | 
21 | Note: values prefixed with `p` denote *previous* values.
22 | 
23 | ## License
24 | MIT License © [Eric Bailey](https://estrattonbailey.com)
25 | 


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/index.js:
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 1 | let frame
 2 | 
 3 | let x
 4 | let px
 5 | let y
 6 | let py
 7 | let vh
 8 | let pvh
 9 | let vw
10 | let pvw
11 | 
12 | const fns = []
13 | 
14 | function raf (t, force) {
15 |   x = window.pageXOffset
16 |   y = window.pageYOffset
17 |   vh = window.innerHeight
18 |   vw = window.innerWidth
19 | 
20 |   if (px === undefined) px = x
21 |   if (py === undefined) py = y
22 |   if (pvw === undefined) pvw = vw
23 |   if (pvh === undefined) pvh = vh
24 | 
25 |   if (
26 |     force ||
27 |     y !== py ||
28 |     x !== px ||
29 |     vh !== pvh ||
30 |     vw !== pvw
31 |   ) {
32 |     run(t)
33 | 
34 |     px = x
35 |     py = y
36 |     pvh = vh
37 |     pvw = vw
38 |   }
39 | 
40 |   return requestAnimationFrame(raf)
41 | }
42 | 
43 | function run (t) {
44 |   for (let i = 0; i < fns.length; i++) {
45 |     fns[i]({ x, y, px, py, vh, pvh, vw, pvw }, t)
46 |   }
47 | }
48 | 
49 | export default function srraf (fn) {
50 |   fns.indexOf(fn) < 0 && fns.push(fn)
51 |   frame = frame || raf(performance.now())
52 |   return {
53 |     update () {
54 |       raf(performance.now(), true)
55 |       return this
56 |     },
57 |     destroy () {
58 |       fns.splice(fns.indexOf(fn), 1)
59 |     }
60 |   }
61 | }
62 | 


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/package.json:
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 1 | {
 2 |   "name": "srraf",
 3 |   "version": "3.2.0",
 4 |   "description": "Better scroll and resize handling",
 5 |   "source": "index.js",
 6 |   "module": "dist/srraf.es.js",
 7 |   "main": "dist/srraf.js",
 8 |   "umd:main": "dist/srraf.umd.js",
 9 |   "files": [
10 |     "dist"
11 |   ],
12 |   "scripts": {
13 |     "build": "microbundle build",
14 |     "watch": "microbundle watch --compress false",
15 |     "test": "ava",
16 |     "postbuild": "npm run test"
17 |   },
18 |   "repository": {
19 |     "type": "git",
20 |     "url": "git+ssh://git@github.com/estrattonbailey/srraf.git"
21 |   },
22 |   "author": "estrattonbailey",
23 |   "license": "MIT",
24 |   "bugs": {
25 |     "url": "https://github.com/estrattonbailey/srraf/issues"
26 |   },
27 |   "homepage": "https://github.com/estrattonbailey/srraf#readme",
28 |   "devDependencies": {
29 |     "ava": "^1.4.1",
30 |     "microbundle": "^0.9.0"
31 |   }
32 | }
33 | 


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/test.js:
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 1 | import test from 'ava'
 2 | import srraf from './dist/srraf.js'
 3 | 
 4 | global.performance = {
 5 |   now () {}
 6 | }
 7 | global.requestAnimationFrame = () => {}
 8 | global.window = {}
 9 | 
10 | test('init', t => {
11 |   t.plan(2)
12 | 
13 |   // calls update AND returns this
14 |   const scroller = srraf(() => {
15 |     t.pass()
16 |   }).update()
17 | 
18 |   scroller.update() // fires again
19 |   scroller.destroy() // kill it
20 |   scroller.update() // shouldn't fire
21 | })
22 | 


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