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- import browser from 'webextension-polyfill'
- import throttle from 'lodash/throttle'
-
- import { onEnabledChange, isEnabled } from './perOrigin'
-
-
- function hideBanners() {
- const revertSteps = []
-
- /* Hide all elements with position:fixed */
- const fixedElements = Array.from(document.querySelectorAll('*'))
- .filter(el => (
- getComputedStyle(el).position === 'fixed'
- && el.style.opacity !== '0' // ignore if we already hid this one
- ))
-
- fixedElements.forEach(el => {
- const originalVisibility = el.style.visibility
- const originalOpacity = el.style.opacity
- const originalTransition = el.style.transition
- el.style.transition = 'opacity 1s'
- el.style.opacity = '0'
-
- const hiderTimeoutId = window.setTimeout(() => {
- el.style.visibility = 'hidden'
- }, 1000)
-
- revertSteps.push(() => {
- window.clearTimeout(hiderTimeoutId)
- const reverterTimeoutId = window.setTimeout(() => {
- el.style.transition = originalTransition
- }, 1000)
- el.style.visibility = originalVisibility
- el.style.opacity = originalOpacity
- })
- })
-
- /* Stop position:sticky elements from sticking. */
- const stickyElements = Array.from(document.querySelectorAll('*'))
- .filter(el => getComputedStyle(el).position === 'sticky')
-
- stickyElements.forEach(el => {
- const originalPosition = el.style.position
- el.style.position = 'relative'
- revertSteps.push(() => {
- el.style.position = originalPosition
- })
- })
-
- return revertSteps
- }
-
- async function main() {
- let revertSteps = []
-
- // XXX We read the location only once, but it may be changed by page scripts.
- // Fortunately we only need the origin, which should remain the same.
- const url = window.location.href
-
- function run() {
- if (enabled && scrolledDown) {
- // Hide everything that looks annoying. Remember the steps to revert this.
- revertSteps = hideBanners().concat(revertSteps)
- } else {
- // Unhide everything we have hidden.
- if (revertSteps.length > 0) {
- revertSteps.forEach(step => step())
- revertSteps = []
- }
- }
- }
-
- // Run whenever the extension is enabled/disabled for this domain.
- let enabled = await isEnabled(url)
- onEnabledChange(url, newValue => { enabled = newValue; run() })
-
- // Run whenever crossing the scroll threshold.
- let scrolledDown = window.scrollY > 20
- window.addEventListener('scroll', () => {
- // We add a hysteresis of 20px.
- if (window.scrollY > 20 && !scrolledDown) {
- scrolledDown = true
- run()
- } else if (window.scrollY <= 0 && scrolledDown) {
- scrolledDown = false
- run()
- }
- })
-
- // Run on any page mutation, but at most once per second.
- const observer = new MutationObserver(throttle(() => run(), 1000))
- observer.observe(document, {
- subtree: true,
- childList: true,
- attributes: true,
- })
-
- // Run once now.
- run()
- }
-
- main()
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