pinafore/routes/_components/timeline/Timeline.html
Nolan Lawson b7f5d04b4c
fix(scrolling): use body as scrolling container (#656)
* fix(scrolling): use body as scrolling container

Fixes #526

* fixup tests and focus
2018-11-17 18:06:49 -08:00

298 lines
10 KiB
HTML

<h1 class="sr-only">{label}</h1>
<!-- for debugging
<div style="padding:5px;position:fixed;left:0;top:0;z-index:999999999;font-size:0.9em;width: 75vw;background:rgba(0, 0, 0, 0.8);color:white;pointer-events:none;">
<p>$timelineItemIds: {JSON.stringify(($timelineItemIds || []).map(_ => '...' + _.slice(-6)), null, ' ')}</p>
<p>$itemIdsToAdd: {JSON.stringify(($itemIdsToAdd || []).map(_ => '...' + _.slice(-6)), null, ' ')}</p>
<p>$runningUpdate: {$runningUpdate}</p>
</div>
-->
<div class="timeline"
role="feed"
on:focusWithCapture="saveFocus(event)"
on:blurWithCapture="clearFocus(event)"
>
{#await componentsPromise}
<!-- awaiting promise -->
{:then result}
<svelte:component this={result.listComponent}
component={result.listItemComponent}
realm="{$currentInstance + '/' + timeline}"
{makeProps}
items={$timelineItemIds}
showFooter={true}
footerComponent={LoadingFooter}
showHeader={$showHeader}
headerComponent={MoreHeaderVirtualWrapper}
{headerProps}
{scrollToItem}
on:scrollToBottom="onScrollToBottom()"
on:scrollToTop="onScrollToTop()"
on:scrollTopChanged="onScrollTopChanged(event)"
on:initialized="initialize()"
on:noNeedToScroll="onNoNeedToScroll()"
/>
{:catch error}
<div>Error: component failed to load! Try reloading. {error}</div>
{/await}
</div>
<script>
import { store } from '../../_store/store'
import Status from '../status/Status.html'
import LoadingFooter from './LoadingFooter.html'
import MoreHeaderVirtualWrapper from './MoreHeaderVirtualWrapper.html'
import {
importVirtualList,
importList,
importStatusVirtualListItem,
importNotificationVirtualListItem
} from '../../_utils/asyncModules'
import { timelines } from '../../_static/timelines'
import {
fetchTimelineItemsOnScrollToBottom,
setupTimeline,
showMoreItemsForTimeline,
showMoreItemsForThread,
showMoreItemsForCurrentTimeline
} from '../../_actions/timeline'
import { focusWithCapture, blurWithCapture } from '../../_utils/events'
import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
import { mark, stop } from '../../_utils/marks'
import isEqual from 'lodash-es/isEqual'
import { doubleRAF } from '../../_utils/doubleRAF'
import { observe } from 'svelte-extras'
import { createMakeProps } from '../../_actions/createMakeProps'
export default {
oncreate () {
console.log('timeline oncreate()')
this.setupFocus()
setupTimeline()
this.restoreFocus()
this.setupStreaming()
},
ondestroy () {
console.log('ondestroy')
this.teardownFocus()
},
data: () => ({
LoadingFooter,
MoreHeaderVirtualWrapper,
Status,
scrollTop: 0
}),
computed: {
// For threads, it's simpler to just render all items as a pseudo-virtual list
// due to need to scroll to the right item and thus calculate all item heights up-front.
// Here we lazy-load both the virtual list component itself as well as the component
// it renders.
componentsPromise: ({ timelineType }) => {
return Promise.all([
timelineType === 'status'
? importList()
: importVirtualList(),
timelineType === 'notifications'
? importNotificationVirtualListItem()
: importStatusVirtualListItem()
]).then(results => ({
listComponent: results[0],
listItemComponent: results[1]
}))
},
makeProps: ({ $currentInstance, timelineType, timelineValue }) => (
createMakeProps($currentInstance, timelineType, timelineValue)
),
label: ({ timeline, $currentInstance, timelineType, timelineValue }) => {
if (timelines[timeline]) {
return `Statuses: ${timelines[timeline].label} timeline on ${$currentInstance}`
}
switch (timelineType) {
case 'tag':
return `Statuses: #${timelineValue} hashtag`
case 'status':
return `Statuses: thread`
case 'account':
return `Statuses: account timeline`
case 'list':
return `Statuses: list`
case 'notifications':
return `Notifications on ${$currentInstance}`
}
},
timelineType: ({ timeline }) => {
return timeline.split('/')[0]
},
timelineValue: ({ timeline }) => {
return timeline.split('/').slice(-1)[0]
},
// Scroll to the first item if this is a "status in own thread" timeline.
// Don't scroll to the first item because it obscures the "back" button.
scrollToItem: ({ timelineType, timelineValue, $firstTimelineItemId }) => (
timelineType === 'status' && $firstTimelineItemId &&
timelineValue !== $firstTimelineItemId && timelineValue
),
itemIdsToAdd: ({ $itemIdsToAdd }) => $itemIdsToAdd,
headerProps: ({ itemIdsToAdd }) => {
return {
count: itemIdsToAdd ? itemIdsToAdd.length : 0,
onClick: showMoreItemsForCurrentTimeline
}
}
},
store: () => store,
events: {
focusWithCapture,
blurWithCapture
},
methods: {
observe,
initialize () {
let { initializeStarted } = this.get()
if (initializeStarted) {
return
}
this.set({ initializeStarted: true })
mark('initializeTimeline')
doubleRAF(() => {
console.log('timeline initialized')
this.store.set({ timelineInitialized: true })
stop('initializeTimeline')
})
},
onScrollTopChanged (scrollTop) {
this.set({ scrollTop: scrollTop })
},
onScrollToBottom () {
let { timelineType } = this.get()
let { timelineInitialized, runningUpdate } = this.store.get()
if (!timelineInitialized ||
runningUpdate ||
timelineType === 'status') { // for status contexts, we've already fetched the whole thread
return
}
let { currentInstance } = this.store.get()
let { timeline } = this.get()
fetchTimelineItemsOnScrollToBottom(
currentInstance,
timeline
)
},
onScrollToTop () {
let { shouldShowHeader } = this.store.get()
if (shouldShowHeader) {
this.store.setForCurrentTimeline({
showHeader: true,
shouldShowHeader: false
})
}
},
setupStreaming () {
let { currentInstance } = this.store.get()
let { timeline, timelineType } = this.get()
let handleItemIdsToAdd = () => {
let { itemIdsToAdd } = this.get()
if (!itemIdsToAdd || !itemIdsToAdd.length) {
return
}
mark('handleItemIdsToAdd')
let { scrollTop } = this.get()
let {
shouldShowHeader,
showHeader
} = this.store.get()
if (timelineType === 'status') {
// this is a thread, just insert the statuses already
showMoreItemsForThread(currentInstance, timeline)
} else if (scrollTop === 0 && !shouldShowHeader && !showHeader) {
// if the user is scrolled to the top and we're not showing the header, then
// just insert the statuses. this is "chat room mode"
showMoreItemsForTimeline(currentInstance, timeline)
} else {
// user hasn't scrolled to the top, show a header instead
this.store.setForTimeline(currentInstance, timeline, { shouldShowHeader: true })
}
stop('handleItemIdsToAdd')
}
this.observe('itemIdsToAdd', (newItemIdsToAdd, oldItemIdsToAdd) => {
if (!newItemIdsToAdd ||
!newItemIdsToAdd.length ||
isEqual(newItemIdsToAdd, oldItemIdsToAdd)) {
return
}
scheduleIdleTask(handleItemIdsToAdd)
})
},
setupFocus () {
this.onPushState = this.onPushState.bind(this)
this.store.setForCurrentTimeline({
ignoreBlurEvents: false
})
window.addEventListener('pushState', this.onPushState)
},
teardownFocus () {
window.removeEventListener('pushState', this.onPushState)
},
onPushState () {
this.store.setForCurrentTimeline({ ignoreBlurEvents: true })
},
saveFocus (e) {
try {
let { currentInstance } = this.store.get()
let { timeline } = this.get()
let lastFocusedElementSelector
let activeElement = e.target
if (activeElement) {
let focusKey = activeElement.getAttribute('focus-key')
if (focusKey) {
lastFocusedElementSelector = `[focus-key=${JSON.stringify(focusKey)}]`
}
}
console.log('saving focus to ', lastFocusedElementSelector)
this.store.setForTimeline(currentInstance, timeline, {
lastFocusedElementSelector
})
} catch (err) {
console.error('unable to save focus', err)
}
},
clearFocus () {
try {
let { ignoreBlurEvents } = this.store.get()
if (ignoreBlurEvents) {
return
}
console.log('clearing focus')
let { currentInstance } = this.store.get()
let { timeline } = this.get()
this.store.setForTimeline(currentInstance, timeline, {
lastFocusedElementSelector: null
})
} catch (err) {
console.error('unable to clear focus', err)
}
},
restoreFocus () {
let { lastFocusedElementSelector } = this.store.get()
if (!lastFocusedElementSelector) {
return
}
console.log('restoreFocus', lastFocusedElementSelector)
requestAnimationFrame(() => {
requestAnimationFrame(() => {
let element = document.querySelector(lastFocusedElementSelector)
if (element) {
element.focus()
}
})
})
},
onNoNeedToScroll () {
// If the timeline doesn't need to scroll, then we can safely "preinitialize,"
// i.e. render anything above the fold of the timeline. This avoids the affect
// where the scrollable content appears to jump around if we need to scroll it.
console.log('timeline preinitialized')
this.store.set({ timelinePreinitialized: true })
}
}
}
</script>