From 25b7093302879b9a2c237569e0cfe507e9d5faec Mon Sep 17 00:00:00 2001 From: Ajay Bura Date: Sat, 4 Dec 2021 15:25:14 +0530 Subject: [PATCH] Added local timeline pagination Signed-off-by: Ajay Bura --- src/app/hooks/useForceUpdate.js | 4 +- src/app/organisms/room/RoomViewContent.jsx | 107 +++++++++++++++++---- src/client/state/RoomTimeline.js | 6 +- 3 files changed, 92 insertions(+), 25 deletions(-) diff --git a/src/app/hooks/useForceUpdate.js b/src/app/hooks/useForceUpdate.js index 2eb5c3c..5ab2d94 100644 --- a/src/app/hooks/useForceUpdate.js +++ b/src/app/hooks/useForceUpdate.js @@ -2,7 +2,7 @@ import { useState } from 'react'; export function useForceUpdate() { - const [, setData] = useState(null); + const [data, setData] = useState(null); - return () => setData({}); + return [data, () => setData({})]; } diff --git a/src/app/organisms/room/RoomViewContent.jsx b/src/app/organisms/room/RoomViewContent.jsx index 65861dd..eba91f1 100644 --- a/src/app/organisms/room/RoomViewContent.jsx +++ b/src/app/organisms/room/RoomViewContent.jsx @@ -25,8 +25,11 @@ import RoomIntro from '../../molecules/room-intro/RoomIntro'; import TimelineChange from '../../molecules/message/TimelineChange'; import { useStore } from '../../hooks/useStore'; +import { useForceUpdate } from '../../hooks/useForceUpdate'; import { parseTimelineChange } from './common'; +const DEFAULT_MAX_EVENTS = 50; +const PAG_LIMIT = 30; const MAX_MSG_DIFF_MINUTES = 5; const PLACEHOLDER_COUNT = 2; const PLACEHOLDERS_HEIGHT = 96 * PLACEHOLDER_COUNT; @@ -118,7 +121,7 @@ class TimelineScroll extends EventEmitter { this.backwards = false; this.inTopHalf = false; - this.maxEvents = 50; + this.maxEvents = DEFAULT_MAX_EVENTS; this.isScrollable = false; this.top = 0; @@ -253,11 +256,44 @@ class TimelineScroll extends EventEmitter { let timelineScroll = null; let focusEventIndex = null; const throttle = new Throttle(); +const limit = { + from: 0, + getMaxEvents() { + return timelineScroll?.maxEvents ?? DEFAULT_MAX_EVENTS; + }, + getEndIndex() { + return this.from + this.getMaxEvents(); + }, + calcNextFrom(backwards, tLength) { + let newFrom = backwards ? this.from - PAG_LIMIT : this.from + PAG_LIMIT; + if (!backwards && newFrom + this.getMaxEvents() > tLength) { + newFrom = tLength - this.getMaxEvents(); + } + if (newFrom < 0) newFrom = 0; + return newFrom; + }, + setFrom(from) { + if (from < 0) { + this.from = 0; + return; + } + this.from = from; + }, +}; function useTimeline(roomTimeline, eventId) { const [timelineInfo, setTimelineInfo] = useState(null); + // TODO: + // open specific event. + // 1. readUpTo event is in specific timeline + // 2. readUpTo event isn't in specific timeline + // 3. readUpTo event is specific event + // open live timeline. + // 1. readUpTo event is in live timeline + // 2. readUpTo event isn't in live timeline const initTimeline = (eId) => { + limit.setFrom(roomTimeline.timeline.length - limit.getMaxEvents()); setTimelineInfo({ focusEventId: eId, }); @@ -279,17 +315,20 @@ function useTimeline(roomTimeline, eventId) { return () => { roomTimeline.removeListener(cons.events.roomTimeline.READY, initTimeline); roomTimeline.removeInternalListeners(); + limit.setFrom(0); }; }, [roomTimeline, eventId]); return timelineInfo; } -function useOnPaginate(roomTimeline) { +function usePaginate(roomTimeline, forceUpdateLimit) { const [info, setInfo] = useState(null); useEffect(() => { const handleOnPagination = (backwards, loaded, canLoadMore) => { + if (loaded === 0) return; + limit.setFrom(limit.calcNextFrom(backwards, roomTimeline.timeline.length)); setInfo({ backwards, loaded, @@ -302,28 +341,45 @@ function useOnPaginate(roomTimeline) { }; }, [roomTimeline]); - return info; -} - -function useAutoPaginate(roomTimeline) { - return useCallback(() => { + const autoPaginate = useCallback(() => { if (roomTimeline.isOngoingPagination) return; + const tLength = roomTimeline.timeline.length; - if (timelineScroll.bottom < SCROLL_TRIGGER_POS && roomTimeline.canPaginateForward()) { - roomTimeline.paginateTimeline(false); - return; + if (timelineScroll.bottom < SCROLL_TRIGGER_POS) { + if (limit.getEndIndex() < tLength) { + // paginate from memory + limit.setFrom(limit.calcNextFrom(false, tLength)); + forceUpdateLimit(); + } else if (roomTimeline.canPaginateForward()) { + // paginate from server. + roomTimeline.paginateTimeline(false, PAG_LIMIT); + return; + } } - if (timelineScroll.top < SCROLL_TRIGGER_POS && roomTimeline.canPaginateBackward()) { - roomTimeline.paginateTimeline(true); + if (timelineScroll.top < SCROLL_TRIGGER_POS) { + if (limit.from > 0) { + // paginate from memory + limit.setFrom(limit.calcNextFrom(true, tLength)); + forceUpdateLimit(); + } else if (roomTimeline.canPaginateBackward()) { + // paginate from server. + roomTimeline.paginateTimeline(true, PAG_LIMIT); + } } }, [roomTimeline]); + + return [info, autoPaginate]; } function useHandleScroll(roomTimeline, autoPaginate, viewEvent) { return useCallback(() => { requestAnimationFrame(() => { // emit event to toggle scrollToBottom button visibility - const isAtBottom = timelineScroll.bottom < 16 && !roomTimeline.canPaginateForward(); + const isAtBottom = ( + timelineScroll.bottom < 16 + && !roomTimeline.canPaginateForward() + && limit.getEndIndex() === roomTimeline.length + ); viewEvent.emit('at-bottom', isAtBottom); }); autoPaginate(); @@ -334,6 +390,10 @@ function useEventArrive(roomTimeline) { const [newEvent, setEvent] = useState(null); useEffect(() => { const handleEvent = (event) => { + const tLength = roomTimeline.timeline.length; + if (roomTimeline.isServingLiveTimeline() && tLength - 1 === limit.getEndIndex()) { + limit.setFrom(tLength - limit.getMaxEvents()); + } setEvent(event); }; roomTimeline.on(cons.events.roomTimeline.EVENT, handleEvent); @@ -354,10 +414,10 @@ function RoomViewContent({ eventId, roomTimeline, viewEvent, }) { const timelineSVRef = useRef(null); - const timelineInfo = useTimeline(roomTimeline, eventId); const readEventStore = useStore(roomTimeline); - const paginateInfo = useOnPaginate(roomTimeline); - const autoPaginate = useAutoPaginate(roomTimeline); + const [onLimitUpdate, forceUpdateLimit] = useForceUpdate(); + const timelineInfo = useTimeline(roomTimeline, eventId); + const [paginateInfo, autoPaginate] = usePaginate(roomTimeline, forceUpdateLimit); const handleScroll = useHandleScroll(roomTimeline, autoPaginate, viewEvent); useEventArrive(roomTimeline); const { timeline } = roomTimeline; @@ -394,15 +454,19 @@ function RoomViewContent({ useLayoutEffect(() => { if (!roomTimeline.initialized) return; - // TODO: decide is restore scroll timelineScroll.tryRestoringScroll(); autoPaginate(); }, [paginateInfo]); + useLayoutEffect(() => { + if (!roomTimeline.initialized) return; + timelineScroll.tryRestoringScroll(); + }, [onLimitUpdate]); + const handleTimelineScroll = (event) => { const { target } = event; if (!target) return; - throttle._(() => timelineScroll?.calcScroll(), 200)(target); + throttle._(() => timelineScroll?.calcScroll(), 400)(target); }; const getReadEvent = () => { @@ -425,11 +489,12 @@ function RoomViewContent({ let extraItemCount = 0; focusEventIndex = null; - if (roomTimeline.canPaginateBackward()) { + if (roomTimeline.canPaginateBackward() || limit.from > 0) { tl.push(loadingMsgPlaceholders(1, PLACEHOLDER_COUNT)); extraItemCount += PLACEHOLDER_COUNT; } - for (let i = 0; i < timeline.length; i += 1) { + for (let i = limit.from; i < limit.getEndIndex(); i += 1) { + if (i >= timeline.length) break; const mEvent = timeline[i]; const prevMEvent = timeline[i - 1] ?? null; @@ -461,7 +526,7 @@ function RoomViewContent({ tl.push(renderEvent(roomTimeline, mEvent, prevMEvent, isFocus)); } - if (roomTimeline.canPaginateForward()) { + if (roomTimeline.canPaginateForward() || limit.getEndIndex() < timeline.length) { tl.push(loadingMsgPlaceholders(2, PLACEHOLDER_COUNT)); } diff --git a/src/client/state/RoomTimeline.js b/src/client/state/RoomTimeline.js index b9b0c91..57beac7 100644 --- a/src/client/state/RoomTimeline.js +++ b/src/client/state/RoomTimeline.js @@ -91,8 +91,10 @@ class RoomTimeline extends EventEmitter { clearLocalTimelines() { this.timeline = []; - this.reactionTimeline.clear(); - this.editedTimeline.clear(); + + // TODO: don't clear these timeline cause there data can be used in other timeline + // this.reactionTimeline.clear(); + // this.editedTimeline.clear(); } addToTimeline(mEvent) {